chore: Commits from develop for 2.4.0-b2 (#1811)

Additional fixes for #1627

.clang-tidy

@@ -8,6 +8,7 @@ Checks: '-*,
   bugprone-chained-comparison,
   bugprone-compare-pointer-to-member-virtual-function,
   bugprone-copy-constructor-init,
+  bugprone-crtp-constructor-accessibility,
   bugprone-dangling-handle,
   bugprone-dynamic-static-initializers,
   bugprone-empty-catch,
@@ -33,9 +34,11 @@ Checks: '-*,
   bugprone-non-zero-enum-to-bool-conversion,
   bugprone-optional-value-conversion,
   bugprone-parent-virtual-call,
+  bugprone-pointer-arithmetic-on-polymorphic-object,
   bugprone-posix-return,
   bugprone-redundant-branch-condition,
   bugprone-reserved-identifier,
+  bugprone-return-const-ref-from-parameter,
   bugprone-shared-ptr-array-mismatch,
   bugprone-signal-handler,
   bugprone-signed-char-misuse,
@@ -55,6 +58,7 @@ Checks: '-*,
   bugprone-suspicious-realloc-usage,
   bugprone-suspicious-semicolon,
   bugprone-suspicious-string-compare,
+  bugprone-suspicious-stringview-data-usage,
   bugprone-swapped-arguments,
   bugprone-switch-missing-default-case,
   bugprone-terminating-continue,
@@ -97,10 +101,12 @@ Checks: '-*,
   modernize-make-unique,
   modernize-pass-by-value,
   modernize-type-traits,
+  modernize-use-designated-initializers,
   modernize-use-emplace,
   modernize-use-equals-default,
   modernize-use-equals-delete,
   modernize-use-override,
+  modernize-use-ranges,
   modernize-use-starts-ends-with,
   modernize-use-std-numbers,
   modernize-use-using,
@@ -121,9 +127,12 @@ Checks: '-*,
   readability-convert-member-functions-to-static,
   readability-duplicate-include,
   readability-else-after-return,
+  readability-enum-initial-value,
   readability-implicit-bool-conversion,
   readability-inconsistent-declaration-parameter-name,
+  readability-identifier-naming,
   readability-make-member-function-const,
+  readability-math-missing-parentheses,
   readability-misleading-indentation,
   readability-non-const-parameter,
   readability-redundant-casting,
@@ -135,14 +144,48 @@ Checks: '-*,
   readability-simplify-boolean-expr,
   readability-static-accessed-through-instance,
   readability-static-definition-in-anonymous-namespace,
-  readability-suspicious-call-argument
+  readability-suspicious-call-argument,
+  readability-use-std-min-max
   '
 
 CheckOptions:
   readability-braces-around-statements.ShortStatementLines: 2
+  readability-identifier-naming.MacroDefinitionCase: UPPER_CASE
+  readability-identifier-naming.ClassCase: CamelCase
+  readability-identifier-naming.StructCase: CamelCase
+  readability-identifier-naming.UnionCase: CamelCase
+  readability-identifier-naming.EnumCase: CamelCase
+  readability-identifier-naming.EnumConstantCase: CamelCase
+  readability-identifier-naming.ScopedEnumConstantCase: CamelCase
+  readability-identifier-naming.GlobalConstantCase: UPPER_CASE
+  readability-identifier-naming.GlobalConstantPrefix: 'k'
+  readability-identifier-naming.GlobalVariableCase: CamelCase
+  readability-identifier-naming.GlobalVariablePrefix: 'g'
+  readability-identifier-naming.ConstexprFunctionCase: camelBack
+  readability-identifier-naming.ConstexprMethodCase: camelBack
+  readability-identifier-naming.ClassMethodCase: camelBack
+  readability-identifier-naming.ClassMemberCase: camelBack
+  readability-identifier-naming.ClassConstantCase: UPPER_CASE
+  readability-identifier-naming.ClassConstantPrefix: 'k'
+  readability-identifier-naming.StaticConstantCase: UPPER_CASE
+  readability-identifier-naming.StaticConstantPrefix: 'k'
+  readability-identifier-naming.StaticVariableCase: UPPER_CASE
+  readability-identifier-naming.StaticVariablePrefix: 'k'
+  readability-identifier-naming.ConstexprVariableCase: UPPER_CASE
+  readability-identifier-naming.ConstexprVariablePrefix: 'k'
+  readability-identifier-naming.LocalConstantCase: camelBack
+  readability-identifier-naming.LocalVariableCase: camelBack
+  readability-identifier-naming.TemplateParameterCase: CamelCase
+  readability-identifier-naming.ParameterCase: camelBack
+  readability-identifier-naming.FunctionCase: camelBack
+  readability-identifier-naming.MemberCase: camelBack
+  readability-identifier-naming.PrivateMemberSuffix: _
+  readability-identifier-naming.ProtectedMemberSuffix: _
+  readability-identifier-naming.PublicMemberSuffix: ''
+  readability-identifier-naming.FunctionIgnoredRegexp: '.*tag_invoke.*'
   bugprone-unsafe-functions.ReportMoreUnsafeFunctions: true
   bugprone-unused-return-value.CheckedReturnTypes: ::std::error_code;::std::error_condition;::std::errc
-  misc-include-cleaner.IgnoreHeaders: '.*/(detail|impl)/.*;.*(expected|unexpected).*'
+  misc-include-cleaner.IgnoreHeaders: '.*/(detail|impl)/.*;.*(expected|unexpected).*;.*ranges_lower_bound\.h;time.h;stdlib.h'
 
 HeaderFilterRegex: '^.*/(src|tests)/.*\.(h|hpp)$'
 WarningsAsErrors: '*'

.clangd

@@ -5,4 +5,9 @@ Diagnostics:
   UnusedIncludes: Strict
   MissingIncludes: Strict
   Includes:
-    IgnoreHeader: ".*/(detail|impl)/.*"
+    IgnoreHeader:
+      - ".*/(detail|impl)/.*"
+      - ".*expected.*"
+      - ".*ranges_lower_bound.h"
+      - "time.h"
+      - "stdlib.h"

.githooks/check-docs

@@ -13,6 +13,7 @@ TMPDIR=${ROOT}/.cache/doxygen
 TMPFILE=${TMPDIR}/docs.log
 DOCDIR=${TMPDIR}/out
 
+# Check doxygen is at all installed
 if [ -z "$DOXYGEN" ]; then
     # No hard error if doxygen is not installed yet
     cat <<EOF
@@ -20,7 +21,28 @@ if [ -z "$DOXYGEN" ]; then
                                    WARNING
 -----------------------------------------------------------------------------
         'doxygen' is required to check documentation. 
-        Please install it for next time. For the time being it's on CI.
+        Please install it for next time.
+
+        Your changes may fail to pass CI once pushed.
+-----------------------------------------------------------------------------
+
+EOF
+    exit 0
+fi
+
+# Check version of doxygen is at least 1.12
+version=$($DOXYGEN --version | grep -o '[0-9\.]*')
+
+if [[ "1.12.0" > "$version" ]]; then
+    # No hard error if doxygen version is not the one we want - let CI deal with it
+    cat <<EOF
+
+                                    ERROR
+-----------------------------------------------------------------------------
+        A minimum of version 1.12 of `which doxygen` is required.
+        Your version is $version. Please upgrade it for next time.
+
+        Your changes may fail to pass CI once pushed.
 -----------------------------------------------------------------------------
 
 EOF

.githooks/check-format

@@ -5,6 +5,20 @@
 # This script checks the format of the code and cmake files.
 # In many cases it will automatically fix the issues and abort the commit.
 
+no_formatted_directories_staged() {
+    staged_directories=$(git diff-index --cached --name-only HEAD | awk -F/ '{print $1}')
+    for sd in $staged_directories; do
+        if [[ "$sd" =~ ^(benchmark|cmake|src|tests)$ ]]; then
+            return 1
+        fi
+    done
+    return 0
+}
+
+if no_formatted_directories_staged ; then
+    exit 0
+fi
+
 echo "+ Checking code format..."
 
 # paths to check and re-format
@@ -12,12 +26,12 @@ sources="src tests"
 formatter="clang-format -i"
 version=$($formatter --version | grep -o '[0-9\.]*')
 
-if [[ "18.0.0" > "$version" ]]; then
+if [[ "19.0.0" > "$version" ]]; then
     cat <<EOF
 
                                     ERROR
 -----------------------------------------------------------------------------
-            A minimum of version 18 of `which clang-format` is required.
+            A minimum of version 19 of `which clang-format` is required.
             Your version is $version.
             Please fix paths and run again.
 -----------------------------------------------------------------------------

.githooks/pre-commit

@@ -4,3 +4,4 @@
 
 source .githooks/check-format
 source .githooks/check-docs
+

.githooks/pre-push

@@ -1,3 +1,58 @@
 #!/bin/sh
+
+
+# git for-each-ref refs/tags  # see which tags are annotated and which are lightweight. Annotated tags are "tag" objects.
+# # Set these so your commits and tags are always signed
+# git config commit.gpgsign true
+# git config tag.gpgsign true
+
+verify_commit_signed() {
+    if git verify-commit HEAD &> /dev/null; then
+        :
+        # echo "HEAD commit seems signed..."
+    else
+        echo "HEAD commit isn't signed!"
+        exit 1
+    fi
+}
+
+verify_tag() {
+    if git describe --exact-match --tags HEAD &> /dev/null; then
+        : # You might be ok to push
+        # echo "Tag is annotated."
+        return 0
+    else
+        echo "Tag for [$version] not an annotated tag."
+        exit 1
+    fi
+}
+
+verify_tag_signed() {
+    if git verify-tag "$version" &> /dev/null ; then
+        : # ok, I guess we'll let you push
+        # echo "Tag appears signed"
+        return 0
+    else
+        echo "$version tag isn't signed"
+        echo "Sign it with [git tag -ams\"$version\" $version]"
+        exit 1
+    fi
+}
+
+while read local_ref local_oid remote_ref remote_oid; do
+    # Check some things if we're pushing a branch called "release/"
+    if echo "$remote_ref" | grep ^refs\/heads\/release\/ &> /dev/null ; then
+        version=$(git tag --points-at HEAD)
+        echo "Looks like you're trying to push a $version release..."
+        echo "Making sure you've signed and tagged it."
+        if verify_commit_signed && verify_tag && verify_tag_signed ; then
+            : # Ok, I guess you can push
+        else
+            exit 1
+        fi
+    fi
+done
+
 command -v git-lfs >/dev/null 2>&1 || { echo >&2 "\nThis repository is configured for Git LFS but 'git-lfs' was not found on your path. If you no longer wish to use Git LFS, remove this hook by deleting the 'pre-push' file in the hooks directory (set by 'core.hookspath'; usually '.git/hooks').\n"; exit 2; }
+
 git lfs pre-push "$@"

.github/actions/build_docker_image/action.yml

@@ -0,0 +1,66 @@
+name: Build and push Docker image
+description: Build and push Docker image to DockerHub and GitHub Container Registry
+inputs:
+  image_name:
+    description: Name of the image to build
+    required: true
+  push_image:
+    description: Whether to push the image to the registry (true/false)
+    required: true
+  directory:
+    description: The directory containing the Dockerfile
+    required: true
+  tags:
+    description: Comma separated tags to apply to the image
+    required: true
+  platforms:
+    description: Platforms to build the image for (e.g. linux/amd64,linux/arm64)
+    required: true
+  description:
+    description: Short description of the image
+    required: true
+runs:
+  using: composite
+  steps:
+      - name: Login to DockerHub
+        if: ${{ inputs.push_image == 'true' }}
+        uses: docker/login-action@v3
+        with:
+          username: ${{ env.DOCKERHUB_USER }}
+          password: ${{ env.DOCKERHUB_PW }}
+
+      - name: Login to GitHub Container Registry
+        if: ${{ inputs.push_image == 'true' }}
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ env.GITHUB_TOKEN }}
+
+      - uses: docker/setup-qemu-action@v3
+      - uses: docker/setup-buildx-action@v3
+
+      - uses: docker/metadata-action@v5
+        id: meta
+        with:
+          images: ${{ inputs.image_name }}
+          tags: ${{ inputs.tags }}
+
+      - name: Build and push
+        uses: docker/build-push-action@v5
+        with:
+          context: ${{ inputs.directory }}
+          platforms: ${{ inputs.platforms }}
+          push: ${{ inputs.push_image == 'true' }}
+          tags: ${{ steps.meta.outputs.tags }}
+
+      - name: Update DockerHub description
+        if: ${{ inputs.push_image == 'true' }}
+        uses: peter-evans/dockerhub-description@v4
+        with:
+          username: ${{ env.DOCKERHUB_USER }}
+          password: ${{ env.DOCKERHUB_PW }}
+          repository: ${{ inputs.image_name }}
+          short-description: ${{ inputs.description }}
+          readme-filepath: ${{ inputs.directory }}/README.md
+

.github/actions/create_issue/action.yml

@@ -7,6 +7,14 @@ inputs:
   body:
     description: Issue body
     required: true
+  labels:
+    description: Comma-separated list of labels
+    required: true
+    default: 'bug'
+  assignees:
+    description: Comma-separated list of assignees
+    required: true
+    default: 'cindyyan317,godexsoft,kuznetsss'
 outputs:
   created_issue_id:
     description: Created issue id
@@ -19,7 +27,7 @@ runs:
         shell: bash
         run: |
           echo -e '${{ inputs.body }}' > issue.md
-          gh issue create --assignee 'cindyyan317,godexsoft,kuznetsss' --label bug --title '${{ inputs.title }}' --body-file ./issue.md > create_issue.log
+          gh issue create --assignee '${{ inputs.assignees }}' --label '${{ inputs.labels }}' --title '${{ inputs.title }}' --body-file ./issue.md > create_issue.log
           created_issue=$(cat create_issue.log | sed 's|.*/||')
           echo "created_issue=$created_issue" >> $GITHUB_OUTPUT
           rm create_issue.log issue.md

.github/actions/prepare_runner/action.yml

@@ -11,7 +11,7 @@ runs:
       if: ${{ runner.os == 'macOS' }}
       shell: bash
       run: |
-          brew install llvm@14 pkg-config ninja bison cmake ccache jq gh conan@1
+          brew install llvm@14 pkg-config ninja bison cmake ccache jq gh conan@1 ca-certificates
           echo "/opt/homebrew/opt/conan@1/bin" >> $GITHUB_PATH
 
     - name: Fix git permissions on Linux

.github/actions/setup_conan/action.yml

@@ -15,10 +15,10 @@ runs:
       if: ${{ runner.os == 'macOS' }}
       shell: bash
       env:
-        CONAN_PROFILE: apple_clang_15
+        CONAN_PROFILE: apple_clang_16
       id: conan_setup_mac
       run: |
-        echo "Creating $CONAN_PROFILE conan profile";
+        echo "Creating $CONAN_PROFILE conan profile"
         conan profile new $CONAN_PROFILE --detect --force
         conan profile update settings.compiler.libcxx=libc++ $CONAN_PROFILE
         conan profile update settings.compiler.cppstd=20 $CONAN_PROFILE

.github/dependabot.yml

@@ -0,0 +1,16 @@
+version: 2
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+      day: "monday"
+      time: "04:00"
+      timezone: "Etc/GMT"
+    reviewers:
+      - "cindyyan317"
+      - "godexsoft"
+      - "kuznetsss"
+    commit-message:
+      prefix: "[CI] "
+    target-branch: "develop"

.github/scripts/update-libxrpl-version

@@ -0,0 +1,28 @@
+#!/bin/bash
+
+# Note: This script is intended to be run from the root of the repository.
+#
+# This script modifies conanfile.py such that the specified version of libXRPL is used.
+
+if [[ -z "$1" ]]; then
+    cat <<EOF
+
+                                    ERROR
+-----------------------------------------------------------------------------
+            Version should be passed as first argument to the script.
+-----------------------------------------------------------------------------
+
+EOF
+    exit 1
+fi
+
+VERSION=$1
+GNU_SED=$(sed --version 2>&1 | grep -q 'GNU' && echo true || echo false)
+
+echo "+ Updating required libXRPL version to $VERSION"
+
+if [[ "$GNU_SED" == "false" ]]; then
+    sed -i '' -E "s|'xrpl/[a-zA-Z0-9\\.\\-]+'|'xrpl/$VERSION'|g" conanfile.py
+else
+    sed -i -E "s|'xrpl/[a-zA-Z0-9\\.\\-]+'|'xrpl/$VERSION'|g" conanfile.py
+fi

.github/workflows/build.yml

@@ -74,7 +74,7 @@ jobs:
             conan_profile: clang
             code_coverage: false
             static: true
-          - os: macos14
+          - os: macos15
             build_type: Release
             code_coverage: false
             static: false
@@ -197,8 +197,8 @@ jobs:
               image: rippleci/clio_ci:latest
             conan_profile: clang
             build_type: Debug
-          - os: macos14
-            conan_profile: apple_clang_15
+          - os: macos15
+            conan_profile: apple_clang_16
             build_type: Release
     runs-on: [self-hosted, "${{ matrix.os }}"]
     container: ${{ matrix.container }}
@@ -211,6 +211,7 @@ jobs:
       - uses: actions/download-artifact@v4
         with:
           name: clio_tests_${{ runner.os }}_${{ matrix.build_type }}_${{ matrix.conan_profile }}
+
       - name: Run clio_tests
         run: |
           chmod +x ./clio_tests

.github/workflows/build_clio_docker_image.yml

@@ -0,0 +1,95 @@
+name: Build and publish Clio docker image
+on:
+  workflow_call:
+    inputs:
+      tags:
+        required: true
+        type: string
+        description: Comma separated tags for docker image
+      artifact_name:
+        type: string
+        description: Name of Github artifact to put into docker image
+      strip_binary:
+        type: boolean
+        description: Whether to strip clio binary
+        default: true
+      publish_image:
+        type: boolean
+        description: Whether to publish docker image
+        required: true
+
+  workflow_dispatch:
+    inputs:
+      tags:
+        required: true
+        type: string
+        description: Comma separated tags for docker image
+      clio_server_binary_url:
+        required: true
+        type: string
+        description: Url to download clio_server binary from
+      binary_sha256:
+        required: true
+        type: string
+        description: sha256 hash of the binary
+      strip_binary:
+        type: boolean
+        description: Whether to strip clio binary
+        default: true
+
+jobs:
+  build_and_publish_image:
+    name: Build and publish image
+    runs-on: ubuntu-20.04
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Download Clio binary from artifact
+        if: ${{ inputs.artifact_name != null }}
+        uses: actions/download-artifact@v4
+        with:
+          name: ${{ inputs.artifact_name }}
+          path: ./docker/clio/artifact/
+
+      - name: Download Clio binary from url
+        if: ${{ inputs.clio_server_binary_url != null }}
+        shell: bash
+        run: |
+          wget ${{inputs.clio_server_binary_url}} -P ./docker/clio/artifact/
+          if [ "$(sha256sum ./docker/clio/clio_server | awk '{print $1}')" != "${{inputs.binary_sha256}}" ]; then
+            echo "Binary sha256 sum doesn't match"
+            exit 1
+          fi
+      - name: Unpack binary
+        shell: bash
+        run: |
+          sudo apt update && sudo apt install -y tar unzip
+          cd docker/clio/artifact
+          artifact=$(find . -type f)
+          if [[ $artifact == *.zip ]]; then
+            unzip $artifact
+          elif [[ $artifact == *.tar.gz ]]; then
+            tar -xvf $artifact
+          fi
+          mv clio_server ../
+          cd ../
+          rm -rf ./artifact
+
+      - name: Strip binary
+        if: ${{ inputs.strip_binary }}
+        shell: bash
+        run: strip ./docker/clio/clio_server
+
+      - name: Build Docker image
+        uses: ./.github/actions/build_docker_image
+        env:
+          DOCKERHUB_USER: ${{ secrets.DOCKERHUB_USER }}
+          DOCKERHUB_PW: ${{ secrets.DOCKERHUB_PW }}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          image_name: rippleci/clio
+          push_image: ${{ inputs.publish_image }}
+          directory: docker/clio
+          tags: ${{ inputs.tags }}
+          platforms: linux/amd64
+          description: Clio is an XRP Ledger API server.

.github/workflows/check_libxrpl.yml

@@ -0,0 +1,91 @@
+name: Check new libXRPL
+on:
+  repository_dispatch:
+    types: [check_libxrpl]
+
+jobs:
+  build:
+    name: Build Clio / `libXRPL ${{ github.event.client_payload.version }}`
+    runs-on: [self-hosted, heavy]
+    container:
+      image: rippleci/clio_ci:latest
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+            fetch-depth: 0
+
+      - name: Update libXRPL version requirement
+        shell: bash
+        run: |
+          ./.github/scripts/update-libxrpl-version ${{ github.event.client_payload.version }}
+
+      - name: Prepare runner
+        uses: ./.github/actions/prepare_runner
+        with:
+            disable_ccache: true
+
+      - name: Setup conan
+        uses: ./.github/actions/setup_conan
+        id: conan
+        with:
+          conan_profile: gcc
+
+      - name: Run conan and cmake
+        uses: ./.github/actions/generate
+        with:
+          conan_profile: ${{ steps.conan.outputs.conan_profile }}
+          conan_cache_hit: ${{ steps.restore_cache.outputs.conan_cache_hit }}
+          build_type: Release
+
+      - name: Build Clio
+        uses: ./.github/actions/build_clio
+
+      - name: Strip tests
+        run: strip build/clio_tests
+
+      - name: Upload clio_tests
+        uses: actions/upload-artifact@v4
+        with:
+          name: clio_tests_check_libxrpl
+          path: build/clio_tests
+
+  run_tests:
+    name: Run tests
+    needs: build
+    runs-on: [self-hosted, heavy]
+    container:
+      image: rippleci/clio_ci:latest
+
+    steps:
+      - uses: actions/download-artifact@v4
+        with:
+          name: clio_tests_check_libxrpl
+
+      - name: Run clio_tests
+        run: |
+          chmod +x ./clio_tests
+          ./clio_tests
+
+  create_issue_on_failure:
+    name: Create an issue on failure
+    needs: [build, run_tests]
+    if: ${{ always() && contains(needs.*.result, 'failure') }}
+    runs-on: ubuntu-20.04
+    permissions:
+      contents: write
+      issues: write
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Create an issue
+        uses: ./.github/actions/create_issue
+        env:
+          GH_TOKEN: ${{ github.token }}
+        with:
+          labels: 'compatibility,bug'
+          title: 'Proposed libXRPL check failed'
+          body: >
+            Clio build or tests failed against `libXRPL ${{ github.event.client_payload.version }}`.
+
+            Workflow: ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}/

.github/workflows/check_pr_title.yml

@@ -0,0 +1,18 @@
+name: Check PR title
+on:
+  pull_request:
+    types: [opened, edited, reopened, synchronize]
+    branches: [develop]
+
+jobs:
+  check_title:
+    runs-on: ubuntu-20.04
+    # permissions:
+    #   pull-requests: write
+    steps:
+      - uses: ytanikin/PRConventionalCommits@1.3.0
+        with:
+          task_types: '["build","feat","fix","docs","test","ci","style","refactor","perf","chore"]'
+          add_label: false
+          # Turned off labelling because it leads to an error, see https://github.com/ytanikin/PRConventionalCommits/issues/19
+          # custom_labels: '{"build":"build", "feat":"enhancement", "fix":"bug", "docs":"documentation", "test":"testability", "ci":"ci", "style":"refactoring", "refactor":"refactoring", "perf":"performance", "chore":"tooling"}'

.github/workflows/clang-tidy.yml

@@ -60,7 +60,7 @@ jobs:
         shell: bash
         id: run_clang_tidy
         run: |
-          run-clang-tidy-18 -p build -j ${{ steps.number_of_threads.outputs.threads_number }} -fix -quiet 1>output.txt
+          run-clang-tidy-19 -p build -j ${{ steps.number_of_threads.outputs.threads_number }} -fix -quiet 1>output.txt
 
       - name: Check format
         if: ${{ steps.run_clang_tidy.outcome != 'success' }}
@@ -89,7 +89,7 @@ jobs:
 
             List of the issues found: ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}/
 
-      - uses: crazy-max/ghaction-import-gpg@v5
+      - uses: crazy-max/ghaction-import-gpg@v6
         if: ${{ steps.run_clang_tidy.outcome != 'success' }}
         with:
           gpg_private_key: ${{ secrets.ACTIONS_GPG_PRIVATE_KEY }}
@@ -99,7 +99,7 @@ jobs:
 
       - name: Create PR with fixes
         if: ${{ steps.run_clang_tidy.outcome != 'success' }}
-        uses: peter-evans/create-pull-request@v5
+        uses: peter-evans/create-pull-request@v7
         env:
           GH_REPO: ${{ github.repository }}
           GH_TOKEN: ${{ github.token }}
@@ -109,7 +109,7 @@ jobs:
           branch: "clang_tidy/autofix"
           branch-suffix: timestamp
           delete-branch: true
-          title: "[CI] clang-tidy auto fixes"
+          title: "style: clang-tidy auto fixes"
           body: "Fixes #${{ steps.create_issue.outputs.created_issue_id }}. Please review and commit clang-tidy fixes."
           reviewers: "cindyyan317,godexsoft,kuznetsss"
 

.github/workflows/clang-tidy_on_fix_merged.yml

@@ -17,7 +17,7 @@ jobs:
         id: check
         shell: bash
         run: |
-          passed=$(if [[ $(git log -1 --pretty=format:%s | grep '\[CI\] clang-tidy auto fixes') ]]; then echo 'true' ; else echo 'false' ; fi)
+          passed=$(if [[ $(git log -1 --pretty=format:%s | grep 'style: clang-tidy auto fixes') ]]; then echo 'true' ; else echo 'false' ; fi)
           echo "passed=$passed" >> $GITHUB_OUTPUT
 
       - name: Run clang-tidy workflow

.github/workflows/docs.yml

@@ -34,7 +34,7 @@ jobs:
           cmake ../docs && cmake --build . --target docs
       
       - name: Setup Pages
-        uses: actions/configure-pages@v4
+        uses: actions/configure-pages@v5
 
       - name: Upload artifact
         uses: actions/upload-pages-artifact@v3

.github/workflows/nightly.yml

@@ -3,6 +3,10 @@ on:
   schedule:
     - cron:  '0 5 * * 1-5'
   workflow_dispatch:
+  pull_request:
+    paths:
+      - '.github/workflows/nightly.yml'
+      - '.github/workflows/build_clio_docker_image.yml'
 
 jobs:
   build:
@@ -11,14 +15,17 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - os: macos14
+          - os: macos15
             build_type: Release
+            static: false
           - os: heavy
             build_type: Release
+            static: true
             container:
               image: rippleci/clio_ci:latest
           - os: heavy
             build_type: Debug
+            static: true
             container:
               image: rippleci/clio_ci:latest
     runs-on: [self-hosted, "${{ matrix.os }}"]
@@ -50,6 +57,7 @@ jobs:
           conan_profile: ${{ steps.conan.outputs.conan_profile }}
           conan_cache_hit: ${{ steps.restore_cache.outputs.conan_cache_hit }}
           build_type: ${{ matrix.build_type }}
+          static: ${{ matrix.static }}
 
       - name: Build Clio
         uses: ./.github/actions/build_clio
@@ -82,7 +90,7 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - os: macos14
+          - os: macos15
             build_type: Release
             integration_tests: false
           - os: heavy
@@ -130,6 +138,7 @@ jobs:
           ./clio_integration_tests --backend_host=scylladb
 
   nightly_release:
+    if: ${{ github.event_name != 'pull_request' }}
     needs: run_tests
     runs-on: ubuntu-20.04
     env:
@@ -143,13 +152,13 @@ jobs:
       - uses: actions/download-artifact@v4
         with:
           path: nightly_release
+          pattern: clio_server_*
 
       - name: Prepare files
         shell: bash
         run: |
           cp ${{ github.workspace }}/.github/workflows/nightly_notes.md "${RUNNER_TEMP}/nightly_notes.md"
           cd nightly_release
-          rm -r clio_*tests*
           for d in $(ls); do
             archive_name=$(ls $d)
             mv ${d}/${archive_name} ./
@@ -172,9 +181,21 @@ jobs:
             --target $GITHUB_SHA --notes-file "${RUNNER_TEMP}/nightly_notes.md" \
             ./nightly_release/clio_server*
 
+  build_and_publish_docker_image:
+    uses: ./.github/workflows/build_clio_docker_image.yml
+    needs: run_tests
+    secrets: inherit
+    with:
+      tags: |
+          type=raw,value=nightly
+          type=raw,value=${{ github.sha }}
+      artifact_name: clio_server_Linux_Release
+      strip_binary: true
+      publish_image: ${{ github.event_name != 'pull_request' }}
+
   create_issue_on_failure:
-    needs: [build, run_tests, nightly_release]
-    if: ${{ always() && contains(needs.*.result, 'failure') }}
+    needs: [build, run_tests, nightly_release, build_and_publish_docker_image]
+    if: ${{ always() && contains(needs.*.result, 'failure') && github.event_name != 'pull_request' }}
     runs-on: ubuntu-20.04
     permissions:
       contents: write

.github/workflows/update_docker_ci.yml

@@ -18,30 +18,19 @@ jobs:
     name: Build and push docker image
     runs-on: [self-hosted, heavy]
     steps:
-      - name: Login to DockerHub
-        if: ${{ github.event_name != 'pull_request' }}
-        uses: docker/login-action@v3
-        with:
-          username: ${{ secrets.DOCKERHUB_USER }}
-          password: ${{ secrets.DOCKERHUB_PW }}
-
       - uses: actions/checkout@v4
-      - uses: docker/setup-qemu-action@v3
-      - uses: docker/setup-buildx-action@v3
-      - uses: docker/metadata-action@v5
-        id: meta
+      - uses: ./.github/actions/build_docker_image
+        env:
+          DOCKERHUB_USER: ${{ secrets.DOCKERHUB_USER }}
+          DOCKERHUB_PW: ${{ secrets.DOCKERHUB_PW }}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         with:
-          images: rippleci/clio_ci
+          image_name: rippleci/clio_ci
+          push_image: ${{ github.event_name != 'pull_request' }}
+          directory: docker/ci
           tags: |
             type=raw,value=latest
             type=raw,value=gcc_12_clang_16
-            type=raw,value=${{ env.GITHUB_SHA }}
-
-      - name: Build and push
-        uses: docker/build-push-action@v5
-        with:
-          context: ${{ github.workspace }}/docker/ci
+            type=raw,value=${{ github.sha }}
           platforms: linux/amd64,linux/arm64
-          push: ${{ github.event_name != 'pull_request' }}
-          tags: ${{ steps.meta.outputs.tags }}
-
+          description: CI image for XRPLF/clio.

.github/workflows/upload_coverage_report.yml

@@ -23,7 +23,7 @@ jobs:
 
       - name: Upload coverage report
         if: ${{ hashFiles('build/coverage_report.xml') != '' }}
-        uses: wandalen/wretry.action@v1.4.10
+        uses: wandalen/wretry.action@v3.7.3
         with:
           action: codecov/codecov-action@v4
           with: |

.gitignore

@@ -8,4 +8,4 @@
 .DS_Store
 CMakeUserPresets.json
 config.json
-src/main/impl/Build.cpp
+src/util/build/Build.cpp

CONTRIBUTING.md

@@ -21,7 +21,7 @@ git config --local core.hooksPath .githooks
 ```
 
 ## Git hooks dependencies
-The pre-commit hook requires `clang-format >= 18.0.0` and `cmake-format` to be installed on your machine.
+The pre-commit hook requires `clang-format >= 19.0.0` and `cmake-format` to be installed on your machine.
 `clang-format` can be installed using `brew` on macOS and default package manager on Linux.
 `cmake-format` can be installed using `pip`.
 The hook will also attempt to automatically use `doxygen` to verify that everything public in the codebase is covered by doc comments. If `doxygen` is not installed, the hook will raise a warning suggesting to install `doxygen` for future commits.
@@ -72,6 +72,9 @@ git push --force
 Clio uses `ccache` to speed up compilation. If you want to use it, please make sure it is installed on your machine.
 CMake will automatically detect it and use it if it is available.
 
+## Opening a pull request
+When a pull request is open CI will perform checks on the new code.
+Title of the pull request and squashed commit should follow [conventional commits specification](https://www.conventionalcommits.org/en/v1.0.0/).
 
 ## Fixing issues found during code review
 While your code is in review, it's possible that some changes will be requested by reviewer(s).
@@ -102,7 +105,7 @@ The button for that is near the bottom of the PR's page on GitHub.
 This is a non-exhaustive list of recommended style guidelines. These are not always strictly enforced and serve as a way to keep the codebase coherent.
 
 ## Formatting
-Code must conform to `clang-format` version 18, unless the result would be unreasonably difficult to read or maintain.
+Code must conform to `clang-format` version 19, unless the result would be unreasonably difficult to read or maintain.
 In most cases the pre-commit hook will take care of formatting and will fix any issues automatically.
 To manually format your code, use `clang-format -i <your changed files>` for C++ files and `cmake-format -i <your changed files>` for CMake files.
 

README.md

@@ -36,6 +36,7 @@ Below are some useful docs to learn more about Clio.
 - [How to configure Clio and rippled](./docs/configure-clio.md)
 - [How to run Clio](./docs/run-clio.md)
 - [Logging](./docs/logging.md)
+- [Troubleshooting guide](./docs/trouble_shooting.md)
 
 **General reference material:**
 

benchmarks/CMakeLists.txt

@@ -12,5 +12,5 @@ target_sources(
 include(deps/gbench)
 
 target_include_directories(clio_benchmark PRIVATE .)
-target_link_libraries(clio_benchmark PUBLIC clio benchmark::benchmark_main)
+target_link_libraries(clio_benchmark PUBLIC clio_etl benchmark::benchmark_main)
 set_target_properties(clio_benchmark PROPERTIES RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR})

benchmarks/util/async/ExecutionContextBenchmarks.cpp

@@ -31,7 +31,6 @@
 #include <cstdint>
 #include <latch>
 #include <optional>
-#include <stdexcept>
 #include <thread>
 #include <vector>
 
@@ -189,10 +188,10 @@ public:
 static auto
 generateData()
 {
-    constexpr auto TOTAL = 10'000;
+    constexpr auto kTOTAL = 10'000;
     std::vector<uint64_t> data;
-    data.reserve(TOTAL);
-    for (auto i = 0; i < TOTAL; ++i)
+    data.reserve(kTOTAL);
+    for (auto i = 0; i < kTOTAL; ++i)
         data.push_back(util::Random::uniform(1, 100'000'000));
 
     return data;
@@ -209,7 +208,7 @@ benchmarkThreads(benchmark::State& state)
 }
 
 template <typename CtxType>
-void
+static void
 benchmarkExecutionContextBatched(benchmark::State& state)
 {
     auto data = generateData();
@@ -220,7 +219,7 @@ benchmarkExecutionContextBatched(benchmark::State& state)
 }
 
 template <typename CtxType>
-void
+static void
 benchmarkAnyExecutionContextBatched(benchmark::State& state)
 {
     auto data = generateData();

cmake/Build.cpp.in

@@ -17,25 +17,26 @@
 */
 //==============================================================================
 
-#include "main/Build.hpp"
+#include "util/build/Build.hpp"
 
 #include <string>
 
-namespace Build {
-static constexpr char versionString[] = "@CLIO_VERSION@";
+namespace util::build {
+
+static constexpr char versionString[] = "@CLIO_VERSION@"; // NOLINT(readability-identifier-naming)
 
 std::string const&
 getClioVersionString()
 {
-    static std::string const value = versionString;
+    static std::string const value = versionString; // NOLINT(readability-identifier-naming)
     return value;
 }
 
 std::string const&
 getClioFullVersionString()
 {
-    static std::string const value = "clio-" + getClioVersionString();
+    static std::string const value = "clio-" + getClioVersionString(); // NOLINT(readability-identifier-naming)
     return value;
 }
 
-}  // namespace Build
+}  // namespace util::build

cmake/ClangTidy.cmake

@@ -8,7 +8,7 @@ if (lint)
     endif ()
     message(STATUS "Using clang-tidy from CLIO_CLANG_TIDY_BIN")
   else ()
-    find_program(_CLANG_TIDY_BIN NAMES "clang-tidy-18" "clang-tidy" REQUIRED)
+    find_program(_CLANG_TIDY_BIN NAMES "clang-tidy-19" "clang-tidy" REQUIRED)
   endif ()
 
   if (NOT _CLANG_TIDY_BIN)

cmake/ClioVersion.cmake

@@ -45,4 +45,4 @@ endif ()
 
 message(STATUS "Build version: ${CLIO_VERSION}")
 
-configure_file(${CMAKE_CURRENT_LIST_DIR}/Build.cpp.in ${CMAKE_CURRENT_LIST_DIR}/../src/main/impl/Build.cpp)
+configure_file(${CMAKE_CURRENT_LIST_DIR}/Build.cpp.in ${CMAKE_CURRENT_LIST_DIR}/../src/util/build/Build.cpp)

conanfile.py

@@ -28,7 +28,8 @@ class Clio(ConanFile):
         'protobuf/3.21.9',
         'grpc/1.50.1',
         'openssl/1.1.1u',
-        'xrpl/2.2.0-rc3',
+        'xrpl/2.4.0-b1',
+        'zlib/1.3.1',
         'libbacktrace/cci.20210118'
     ]
 

docker/ci/README.md

@@ -0,0 +1,15 @@
+# CI image for XRPLF/clio
+
+This image contains an environment to build [Clio](https://github.com/XRPLF/clio), check code and documentation.
+It is used in [Clio Github Actions](https://github.com/XRPLF/clio/actions) but can also be used to compile Clio locally.
+
+The image is based on Ubuntu 20.04 and contains:
+- clang 16
+- gcc 12.3
+- doxygen 1.10
+- gh 2.40
+- ccache 4.8.3
+- conan
+- and some other useful tools
+
+Conan is set up to build Clio without any additional steps. There are two preset conan profiles: `clang` and `gcc` to use corresponding compiler.

docker/ci/dockerfile

@@ -6,10 +6,10 @@ SHELL ["/bin/bash", "-c"]
 USER root
 WORKDIR /root
 
-ENV CCACHE_VERSION=4.8.3 \
-    LLVM_TOOLS_VERSION=18 \
+ENV CCACHE_VERSION=4.10.2 \
+    LLVM_TOOLS_VERSION=19 \
     GH_VERSION=2.40.0 \
-    DOXYGEN_VERSION=1.10.0
+    DOXYGEN_VERSION=1.12.0
  
 # Add repositories
 RUN apt-get -qq update \

docker/clio/README.md

@@ -0,0 +1,23 @@
+# Clio official docker image
+
+[Clio](https://github.com/XRPLF/clio) is an XRP Ledger API server optimized for RPC calls over WebSocket or JSON-RPC.
+It stores validated historical ledger and transaction data in a space efficient format.
+
+This image contains `clio_server` binary allowing users to run Clio easily.
+
+## Clio configuration file
+
+Please note that while Clio requires a configuration file, this image doesn't include any default config.
+Your configuration file should be mounted under the path `/opt/clio/etc/config.json`.
+Clio repository provides an [example](https://github.com/XRPLF/clio/blob/develop/docs/examples/config/example-config.json) of the configuration file.
+
+Config file recommendations:
+- Set `log_to_console` to `false` if you want to avoid logs being written to `stdout`.
+- Set `log_directory` to `/opt/clio/log` to store logs in a volume.
+
+## Usage
+
+The following command can be used to run Clio in docker (assuming server's port is `51233` in your config):
+```bash
+docker run -d -v <path to your config.json>:/opt/clio/etc/config.json -v <path to store logs>:/opt/clio/log -p 51233:51233 rippleci/clio
+```

docker/clio/dockerfile

@@ -0,0 +1,16 @@
+FROM ubuntu:22.04
+
+COPY ./clio_server /opt/clio/bin/clio_server
+
+RUN ln -s /opt/clio/bin/clio_server /usr/local/bin/clio_server && \
+    mkdir -p /opt/clio/etc/ && \
+    mkdir -p /opt/clio/log/ && \
+    groupadd -g 10001 clio && \
+    useradd -u 10000 -g 10001 -s /bin/bash clio && \
+    chown clio:clio /opt/clio/log && \
+    apt update && \
+    apt install -y libatomic1
+
+USER clio
+ENTRYPOINT ["/opt/clio/bin/clio_server"]
+CMD ["--conf", "/opt/clio/etc/config.json"]

docker/develop/compose.yaml

@@ -1,4 +1,3 @@
-version: '3.7'
 services:
   clio_develop:
     image: rippleci/clio_ci:latest

docs/build-clio.md

@@ -36,6 +36,8 @@ compiler.version=15
 compiler.libcxx=libc++
 build_type=Release
 compiler.cppstd=20
+[conf]
+tools.build:cxxflags+=["-DBOOST_ASIO_DISABLE_CONCEPTS"]
 ```
 
 > Linux example:
@@ -91,6 +93,9 @@ If successful, `conan install` will find the required packages and `cmake` will
 > [!TIP]
 > To generate a Code Coverage report, include `-o coverage=True` in the `conan install` command above, along with `-o tests=True` to enable tests. After running the `cmake` commands, execute `make clio_tests-ccov`. The coverage report will be found at `clio_tests-llvm-cov/index.html`.
 
+> [!NOTE]
+> If you've built Clio before and the build is now failing, it's likely due to updated dependencies. Try deleting the build folder and then rerunning the Conan and CMake commands mentioned above.
+
 ### Generating API docs for Clio
 
 The API documentation for Clio is generated by [Doxygen](https://www.doxygen.nl/index.html). If you want to generate the API documentation when building Clio, make sure to install Doxygen on your system.
@@ -136,3 +141,43 @@ If you wish to develop against a `rippled` instance running in standalone mode t
 
 1. Advance the `rippled` ledger to at least ledger 256.
 2. Wait 10 minutes before first starting Clio against this standalone node.
+
+## Building with a Custom `libxrpl`
+
+Sometimes, during development, you need to build against a custom version of `libxrpl`. (For example, you may be developing compatibility for a proposed amendment that is not yet merged to the main `rippled` codebase.) To build Clio with compatibility for a custom fork or branch of `rippled`, follow these steps:
+
+1. First, pull/clone the appropriate `rippled` fork and switch to the branch you want to build. For example, the following example uses an in-development build with [XLS-33d Multi-Purpose Tokens](https://github.com/XRPLF/XRPL-Standards/tree/master/XLS-0033d-multi-purpose-tokens):
+
+    ```sh
+    git clone https://github.com/shawnxie999/rippled/
+    cd rippled
+    git switch mpt-1.1
+    ```
+
+2. Export a custom package to your local Conan store using a user/channel:
+
+    ```sh
+    conan export . my/feature
+    ```
+
+3. Patch your local Clio build to use the right package.
+
+    Edit `conanfile.py` (from the Clio repository root). Replace the `xrpl` requirement with the custom package version from the previous step. This must also include the current version number from your `rippled` branch. For example:
+
+    ```py
+    # ... (excerpt from conanfile.py)
+        requires = [
+        'boost/1.82.0',
+        'cassandra-cpp-driver/2.17.0',
+        'fmt/10.1.1',
+        'protobuf/3.21.9',
+        'grpc/1.50.1',
+        'openssl/1.1.1u',
+        'xrpl/2.3.0-b1@my/feature', # Update this line
+        'libbacktrace/cci.20210118'
+    ]
+    ```
+
+4. Build Clio as you would have before.
+
+    See [Building Clio](#building-clio) for details.

docs/configure-clio.md

@@ -27,7 +27,7 @@ If you're running Clio and `rippled` on separate machines, in addition to uncomm
 
 2. Open a public, unencrypted WebSocket port on your `rippled` server.
 
-3. In the `rippled` config, change the IP specified for `secure_gateway`, under the `port_grpc` section, to the IP of your Clio server. This entry can take the form of a comma-separated list if you are running multiple Clio nodes.
+3. In the `rippled` config, change the IP specified for `secure_gateway`, under the `port_grpc` and websocket server sections, to the IP of your Clio server. This entry can take the form of a comma-separated list if you are running multiple Clio nodes.
 
 ## Ledger sequence
 

docs/examples/config/cloud-example-config.json

@@ -1,43 +0,0 @@
-/*
- * This is an example configuration file. Please do not use without modifying to suit your needs.
- */
-{
-    "database": {
-        "type": "cassandra",
-        "cassandra": {
-            // This option can be used to setup a secure connect bundle connection
-            "secure_connect_bundle": "[path/to/zip. ignore if using contact_points]",
-            // The following options are used only if using contact_points
-            "contact_points": "[ip. ignore if using secure_connect_bundle]",
-            "port": "[port. ignore if using_secure_connect_bundle]",
-            // Authentication settings
-            "username": "[username, if any]",
-            "password": "[password, if any]",
-            // Other common settings
-            "keyspace": "clio",
-            "max_write_requests_outstanding": 25000,
-            "max_read_requests_outstanding": 30000,
-            "threads": 8
-        }
-    },
-    "etl_sources": [
-        {
-            "ip": "[rippled ip]",
-            "ws_port": "6006",
-            "grpc_port": "50051"
-        }
-    ],
-    "dos_guard": {
-        "whitelist": [
-            "127.0.0.1"
-        ]
-    },
-    "server": {
-        "ip": "0.0.0.0",
-        "port": 8080
-    },
-    "log_level": "debug",
-    "log_file": "./clio.log",
-    "extractor_threads": 8,
-    "read_only": false
-}

docs/examples/config/example-config.json

@@ -31,11 +31,17 @@
     "etl_sources": [
         {
             "ip": "127.0.0.1",
-            "ws_port": "6006",
+            "ws_port": "6005",
             "grpc_port": "50051"
         }
     ],
-    "forwarding_cache_timeout": 0.250, // in seconds, could be 0, which means no cache
+    "forwarding": {
+        "cache_timeout": 0.250, // in seconds, could be 0, which means no cache
+        "request_timeout": 10.0 // time for Clio to wait for rippled to reply on a forwarded request (default is 10 seconds)
+    },
+    "rpc": {
+        "cache_timeout": 0.5 // in seconds, could be 0, which means no cache for rpc
+    },
     "dos_guard": {
         // Comma-separated list of IPs to exclude from rate limiting
         "whitelist": [
@@ -64,10 +70,18 @@
         "admin_password": "xrp",
         // If local_admin is true, Clio will consider requests come from 127.0.0.1 as admin requests
         // It's true by default unless admin_password is set,'local_admin' : true and 'admin_password' can not be set at the same time
-        "local_amdin": false
+        "local_admin": false,
+        "processing_policy": "parallel", // Could be "sequent" or "parallel".
+        // For sequent policy request from one client connection will be processed one by one and the next one will not be read before
+        // the previous one is processed. For parallel policy Clio will take all requests and process them in parallel and
+        // send a reply for each request whenever it is ready.
+        "parallel_requests_limit": 10, // Optional parameter, used only if "processing_strategy" is "parallel". It limits the number of requests for one client connection processed in parallel. Infinite if not specified.
+        // Max number of responses to queue up before sent successfully. If a client's waiting queue is too long, the server will close the connection.
+        "ws_max_sending_queue_size": 1500,
+        "__ng_web_server": false // Use ng web server. This is a temporary setting which will be deleted after switching to ng web server
     },
     // Time in seconds for graceful shutdown. Defaults to 10 seconds. Not fully implemented yet.
-    "graceful_period": 10.,
+    "graceful_period": 10.0,
     // Overrides log level on a per logging channel.
     // Defaults to global "log_level" for each unspecified channel.
     "log_channels": [

docs/metrics-and-static-analysis.md

@@ -14,7 +14,7 @@ You can find an example docker-compose file, with Prometheus and Grafana configs
 
 ## Using `clang-tidy` for static analysis
 
-The minimum [clang-tidy](https://clang.llvm.org/extra/clang-tidy/) version required is 17.0.
+The minimum [clang-tidy](https://clang.llvm.org/extra/clang-tidy/) version required is 19.0.
 
 Clang-tidy can be run by Cmake when building the project. To achieve this, you just need to provide the option `-o lint=True` for the `conan install` command:
 
@@ -26,5 +26,5 @@ By default Cmake will try to find `clang-tidy` automatically in your system.
 To force Cmake to use your desired binary, set the `CLIO_CLANG_TIDY_BIN` environment variable to the path of the `clang-tidy` binary. For example:
 
 ```sh
-export CLIO_CLANG_TIDY_BIN=/opt/homebrew/opt/llvm@17/bin/clang-tidy
+export CLIO_CLANG_TIDY_BIN=/opt/homebrew/opt/llvm@19/bin/clang-tidy
 ```

docs/trouble_shooting.md

@@ -0,0 +1,47 @@
+# Troubleshooting Guide
+This guide will help you troubleshoot common issues of Clio.
+
+## Can't connect to DB
+If you see the error log message `Could not connect to Cassandra: No hosts available`, this means that Clio can't connect to the database. Check the following:
+- Make sure the database is running at the specified address and port.
+- Make sure the database is accessible from the machine where Clio is running.
+You can use [cqlsh](https://pypi.org/project/cqlsh/) to check the connection to the database.
+If you would like to run a local ScyllaDB, you can call:
+```sh
+docker run --rm -p 9042:9042 --name clio-scylla -d scylladb/scylla 
+```
+
+## Check the server status of Clio
+To check if Clio is syncing with rippled:
+```sh
+curl -v -d '{"method":"server_info", "params":[{}]}' 127.0.0.1:51233|python3 -m json.tool|grep seq
+```
+If Clio is syncing with rippled, the `seq` value will be increasing.
+
+## Clio fails to start
+If you see the error log message `Failed to fetch ETL state from...`, this means the configured rippled node is not reachable. Check the following:
+- Make sure the rippled node is running at the specified address and port.
+- Make sure the rippled node is accessible from the machine where Clio is running.
+
+If you would like to run Clio without an avaliable rippled node, you can add below setting to Clio's configuration file:
+```
+"allow_no_etl": true
+```
+
+## Clio is not added to secure_gateway in rippled's config
+If you see the warning message `AsyncCallData is_unlimited is false.`, this means that Clio is not added to the `secure_gateway` of `port_grpc` session in the rippled configuration file. It will slow down the sync process. Please add Clio's IP to the `secure_gateway` in the rippled configuration file for both grpc and ws port.
+
+## Clio is slow
+To speed up the response time, Clio has a cache inside. However, cache can take time to warm up. If you see slow response time, you can firstly check if cache is still loading.
+You can check the cache status by calling:
+```sh
+curl -v -d '{"method":"server_info", "params":[{}]}' 127.0.0.1:51233|python3 -m json.tool|grep is_full
+curl -v -d '{"method":"server_info", "params":[{}]}' 127.0.0.1:51233|python3 -m json.tool|grep is_enabled
+```
+If `is_full` is false, it means the cache is still loading. Normally, the Clio can respond quicker if cache finishs loading. If `is_enabled` is false, it means the cache is disabled in the configuration file or there is data corruption in the database. 
+
+## Receive error message `Too many requests`
+If client sees the error message `Too many requests`, this means that the client is blocked by Clio's DosGuard protection. You may want to add the client's IP to the whitelist in the configuration file, Or update other your DosGuard settings.
+
+
+

src/CMakeLists.txt

@@ -1,7 +1,10 @@
 add_subdirectory(util)
 add_subdirectory(data)
 add_subdirectory(etl)
+add_subdirectory(etlng)
 add_subdirectory(feed)
 add_subdirectory(rpc)
 add_subdirectory(web)
+add_subdirectory(migration)
+add_subdirectory(app)
 add_subdirectory(main)

src/app/CMakeLists.txt

@@ -0,0 +1,4 @@
+add_library(clio_app)
+target_sources(clio_app PRIVATE CliArgs.cpp ClioApplication.cpp WebHandlers.cpp)
+
+target_link_libraries(clio_app PUBLIC clio_etl clio_etlng clio_feed clio_web clio_rpc clio_migration)

src/app/CliArgs.cpp

@@ -0,0 +1,82 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of clio: https://github.com/XRPLF/clio
+    Copyright (c) 2024, the clio developers.
+
+    Permission to use, copy, modify, and distribute this software for any
+    purpose with or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL,  DIRECT,  INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include "app/CliArgs.hpp"
+
+#include "migration/MigrationApplication.hpp"
+#include "util/build/Build.hpp"
+
+#include <boost/program_options/options_description.hpp>
+#include <boost/program_options/parsers.hpp>
+#include <boost/program_options/positional_options.hpp>
+#include <boost/program_options/value_semantic.hpp>
+#include <boost/program_options/variables_map.hpp>
+
+#include <cstdlib>
+#include <iostream>
+#include <string>
+#include <utility>
+
+namespace app {
+
+CliArgs::Action
+CliArgs::parse(int argc, char const* argv[])
+{
+    namespace po = boost::program_options;
+    // clang-format off
+    po::options_description description("Options");
+    description.add_options()
+        ("help,h", "print help message and exit")
+        ("version,v", "print version and exit")
+        ("conf,c", po::value<std::string>()->default_value(kDEFAULT_CONFIG_PATH), "configuration file")
+        ("ng-web-server,w", "Use ng-web-server")
+        ("migrate", po::value<std::string>(), "start migration helper")
+    ;
+    // clang-format on
+    po::positional_options_description positional;
+    positional.add("conf", 1);
+
+    po::variables_map parsed;
+    po::store(po::command_line_parser(argc, argv).options(description).positional(positional).run(), parsed);
+    po::notify(parsed);
+
+    if (parsed.count("help") != 0u) {
+        std::cout << "Clio server " << util::build::getClioFullVersionString() << "\n\n" << description;
+        return Action{Action::Exit{EXIT_SUCCESS}};
+    }
+
+    if (parsed.count("version") != 0u) {
+        std::cout << util::build::getClioFullVersionString() << '\n';
+        return Action{Action::Exit{EXIT_SUCCESS}};
+    }
+
+    auto configPath = parsed["conf"].as<std::string>();
+
+    if (parsed.count("migrate") != 0u) {
+        auto const opt = parsed["migrate"].as<std::string>();
+        if (opt == "status")
+            return Action{Action::Migrate{.configPath = std::move(configPath), .subCmd = MigrateSubCmd::status()}};
+        return Action{Action::Migrate{.configPath = std::move(configPath), .subCmd = MigrateSubCmd::migration(opt)}};
+    }
+
+    return Action{Action::Run{.configPath = std::move(configPath), .useNgWebServer = parsed.count("ng-web-server") != 0}
+    };
+}
+
+}  // namespace app

src/app/CliArgs.hpp

@@ -0,0 +1,103 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of clio: https://github.com/XRPLF/clio
+    Copyright (c) 2024, the clio developers.
+
+    Permission to use, copy, modify, and distribute this software for any
+    purpose with or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL,  DIRECT,  INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#pragma once
+
+#include "migration/MigrationApplication.hpp"
+#include "util/OverloadSet.hpp"
+
+#include <string>
+#include <variant>
+
+namespace app {
+
+/**
+ * @brief Parsed command line arguments representation.
+ */
+class CliArgs {
+public:
+    /**
+     * @brief Default configuration path.
+     */
+    static constexpr char kDEFAULT_CONFIG_PATH[] = "/etc/opt/clio/config.json";
+
+    /**
+     * @brief An action parsed from the command line.
+     */
+    class Action {
+    public:
+        /** @brief Run action. */
+        struct Run {
+            std::string configPath;  ///< Configuration file path.
+            bool useNgWebServer;     ///< Whether to use a ng web server
+        };
+
+        /** @brief Exit action. */
+        struct Exit {
+            int exitCode;  ///< Exit code.
+        };
+
+        /** @brief Migration action. */
+        struct Migrate {
+            std::string configPath;
+            MigrateSubCmd subCmd;
+        };
+
+        /**
+         * @brief Construct an action from a Run.
+         *
+         * @param action Run action.
+         */
+        template <typename ActionType>
+            requires std::is_same_v<ActionType, Run> or std::is_same_v<ActionType, Exit> or
+            std::is_same_v<ActionType, Migrate>
+        explicit Action(ActionType&& action) : action_(std::forward<ActionType>(action))
+        {
+        }
+
+        /**
+         * @brief Apply a function to the action.
+         *
+         * @tparam Processors Action processors types. Must be callable with the action type and return int.
+         * @param processors Action processors.
+         * @return Exit code.
+         */
+        template <typename... Processors>
+        int
+        apply(Processors&&... processors) const
+        {
+            return std::visit(util::OverloadSet{std::forward<Processors>(processors)...}, action_);
+        }
+
+    private:
+        std::variant<Run, Exit, Migrate> action_;
+    };
+
+    /**
+     * @brief Parse command line arguments.
+     *
+     * @param argc Number of arguments.
+     * @param argv Array of arguments.
+     * @return Parsed command line arguments.
+     */
+    static Action
+    parse(int argc, char const* argv[]);
+};
+
+}  // namespace app

src/app/ClioApplication.cpp

@@ -0,0 +1,183 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of clio: https://github.com/XRPLF/clio
+    Copyright (c) 2024, the clio developers.
+
+    Permission to use, copy, modify, and distribute this software for any
+    purpose with or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL,  DIRECT,  INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include "app/ClioApplication.hpp"
+
+#include "app/WebHandlers.hpp"
+#include "data/AmendmentCenter.hpp"
+#include "data/BackendFactory.hpp"
+#include "etl/ETLService.hpp"
+#include "etl/LoadBalancer.hpp"
+#include "etl/NetworkValidatedLedgers.hpp"
+#include "feed/SubscriptionManager.hpp"
+#include "rpc/Counters.hpp"
+#include "rpc/RPCEngine.hpp"
+#include "rpc/WorkQueue.hpp"
+#include "rpc/common/impl/HandlerProvider.hpp"
+#include "util/build/Build.hpp"
+#include "util/log/Logger.hpp"
+#include "util/newconfig/ConfigDefinition.hpp"
+#include "util/prometheus/Prometheus.hpp"
+#include "web/AdminVerificationStrategy.hpp"
+#include "web/RPCServerHandler.hpp"
+#include "web/Server.hpp"
+#include "web/dosguard/DOSGuard.hpp"
+#include "web/dosguard/IntervalSweepHandler.hpp"
+#include "web/dosguard/WhitelistHandler.hpp"
+#include "web/ng/RPCServerHandler.hpp"
+#include "web/ng/Server.hpp"
+
+#include <boost/asio/io_context.hpp>
+
+#include <cstdint>
+#include <cstdlib>
+#include <memory>
+#include <optional>
+#include <thread>
+#include <utility>
+#include <vector>
+
+namespace app {
+
+namespace {
+
+/**
+ * @brief Start context threads
+ *
+ * @param ioc Context
+ * @param numThreads Number of worker threads to start
+ */
+void
+start(boost::asio::io_context& ioc, std::uint32_t numThreads)
+{
+    std::vector<std::thread> v;
+    v.reserve(numThreads - 1);
+    for (auto i = numThreads - 1; i > 0; --i)
+        v.emplace_back([&ioc] { ioc.run(); });
+
+    ioc.run();
+    for (auto& t : v)
+        t.join();
+}
+
+}  // namespace
+
+ClioApplication::ClioApplication(util::config::ClioConfigDefinition const& config)
+    : config_(config), signalsHandler_{config_}
+{
+    LOG(util::LogService::info()) << "Clio version: " << util::build::getClioFullVersionString();
+    PrometheusService::init(config);
+}
+
+int
+ClioApplication::run(bool const useNgWebServer)
+{
+    auto const threads = config_.get<uint16_t>("io_threads");
+    LOG(util::LogService::info()) << "Number of io threads = " << threads;
+
+    // IO context to handle all incoming requests, as well as other things.
+    // This is not the only io context in the application.
+    boost::asio::io_context ioc{threads};
+
+    // Rate limiter, to prevent abuse
+    auto whitelistHandler = web::dosguard::WhitelistHandler{config_};
+    auto dosGuard = web::dosguard::DOSGuard{config_, whitelistHandler};
+    auto sweepHandler = web::dosguard::IntervalSweepHandler{config_, ioc, dosGuard};
+
+    // Interface to the database
+    auto backend = data::makeBackend(config_);
+
+    // Manages clients subscribed to streams
+    auto subscriptions = feed::SubscriptionManager::makeSubscriptionManager(config_, backend);
+
+    // Tracks which ledgers have been validated by the network
+    auto ledgers = etl::NetworkValidatedLedgers::makeValidatedLedgers();
+
+    // Handles the connection to one or more rippled nodes.
+    // ETL uses the balancer to extract data.
+    // The server uses the balancer to forward RPCs to a rippled node.
+    // The balancer itself publishes to streams (transactions_proposed and accounts_proposed)
+    auto balancer = etl::LoadBalancer::makeLoadBalancer(config_, ioc, backend, subscriptions, ledgers);
+
+    // ETL is responsible for writing and publishing to streams. In read-only mode, ETL only publishes
+    auto etl = etl::ETLService::makeETLService(config_, ioc, backend, subscriptions, balancer, ledgers);
+
+    auto workQueue = rpc::WorkQueue::makeWorkQueue(config_);
+    auto counters = rpc::Counters::makeCounters(workQueue);
+    auto const amendmentCenter = std::make_shared<data::AmendmentCenter const>(backend);
+    auto const handlerProvider = std::make_shared<rpc::impl::ProductionHandlerProvider const>(
+        config_, backend, subscriptions, balancer, etl, amendmentCenter, counters
+    );
+
+    using RPCEngineType = rpc::RPCEngine<etl::LoadBalancer, rpc::Counters>;
+    auto const rpcEngine =
+        RPCEngineType::makeRPCEngine(config_, backend, balancer, dosGuard, workQueue, counters, handlerProvider);
+
+    if (useNgWebServer or config_.get<bool>("server.__ng_web_server")) {
+        web::ng::RPCServerHandler<RPCEngineType, etl::ETLService> handler{config_, backend, rpcEngine, etl};
+
+        auto expectedAdminVerifier = web::makeAdminVerificationStrategy(config_);
+        if (not expectedAdminVerifier.has_value()) {
+            LOG(util::LogService::error()) << "Error creating admin verifier: " << expectedAdminVerifier.error();
+            return EXIT_FAILURE;
+        }
+        auto const adminVerifier = std::move(expectedAdminVerifier).value();
+
+        auto httpServer = web::ng::makeServer(config_, OnConnectCheck{dosGuard}, DisconnectHook{dosGuard}, ioc);
+
+        if (not httpServer.has_value()) {
+            LOG(util::LogService::error()) << "Error creating web server: " << httpServer.error();
+            return EXIT_FAILURE;
+        }
+
+        httpServer->onGet("/metrics", MetricsHandler{adminVerifier});
+        httpServer->onGet("/health", HealthCheckHandler{});
+        auto requestHandler = RequestHandler{adminVerifier, handler, dosGuard};
+        httpServer->onPost("/", requestHandler);
+        httpServer->onWs(std::move(requestHandler));
+
+        auto const maybeError = httpServer->run();
+        if (maybeError.has_value()) {
+            LOG(util::LogService::error()) << "Error starting web server: " << *maybeError;
+            return EXIT_FAILURE;
+        }
+
+        // Blocks until stopped.
+        // When stopped, shared_ptrs fall out of scope
+        // Calls destructors on all resources, and destructs in order
+        start(ioc, threads);
+
+        return EXIT_SUCCESS;
+    }
+
+    // Init the web server
+    auto handler =
+        std::make_shared<web::RPCServerHandler<RPCEngineType, etl::ETLService>>(config_, backend, rpcEngine, etl);
+
+    auto const httpServer = web::makeHttpServer(config_, ioc, dosGuard, handler);
+
+    // Blocks until stopped.
+    // When stopped, shared_ptrs fall out of scope
+    // Calls destructors on all resources, and destructs in order
+    start(ioc, threads);
+
+    return EXIT_SUCCESS;
+}
+
+}  // namespace app

src/app/ClioApplication.hpp

@@ -0,0 +1,53 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of clio: https://github.com/XRPLF/clio
+    Copyright (c) 2024, the clio developers.
+
+    Permission to use, copy, modify, and distribute this software for any
+    purpose with or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL,  DIRECT,  INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#pragma once
+
+#include "util/SignalsHandler.hpp"
+#include "util/newconfig/ConfigDefinition.hpp"
+
+namespace app {
+
+/**
+ * @brief The main application class
+ */
+class ClioApplication {
+    util::config::ClioConfigDefinition const& config_;
+    util::SignalsHandler signalsHandler_;
+
+public:
+    /**
+     * @brief Construct a new ClioApplication object
+     *
+     * @param config The configuration of the application
+     */
+    ClioApplication(util::config::ClioConfigDefinition const& config);
+
+    /**
+     * @brief Run the application
+     *
+     * @param useNgWebServer Whether to use the new web server
+     *
+     * @return exit code
+     */
+    int
+    run(bool useNgWebServer);
+};
+
+}  // namespace app

src/app/WebHandlers.cpp

@@ -0,0 +1,111 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of clio: https://github.com/XRPLF/clio
+    Copyright (c) 2024, the clio developers.
+
+    Permission to use, copy, modify, and distribute this software for any
+    purpose with or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL,  DIRECT,  INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include "app/WebHandlers.hpp"
+
+#include "util/Assert.hpp"
+#include "util/prometheus/Http.hpp"
+#include "web/AdminVerificationStrategy.hpp"
+#include "web/SubscriptionContextInterface.hpp"
+#include "web/dosguard/DOSGuardInterface.hpp"
+#include "web/ng/Connection.hpp"
+#include "web/ng/Request.hpp"
+#include "web/ng/Response.hpp"
+
+#include <boost/asio/spawn.hpp>
+#include <boost/beast/http/status.hpp>
+
+#include <memory>
+#include <optional>
+#include <utility>
+
+namespace app {
+
+OnConnectCheck::OnConnectCheck(web::dosguard::DOSGuardInterface& dosguard) : dosguard_{dosguard}
+{
+}
+
+std::expected<void, web::ng::Response>
+OnConnectCheck::operator()(web::ng::Connection const& connection)
+{
+    dosguard_.get().increment(connection.ip());
+    if (not dosguard_.get().isOk(connection.ip())) {
+        return std::unexpected{
+            web::ng::Response{boost::beast::http::status::too_many_requests, "Too many requests", connection}
+        };
+    }
+
+    return {};
+}
+
+DisconnectHook::DisconnectHook(web::dosguard::DOSGuardInterface& dosguard) : dosguard_{dosguard}
+{
+}
+
+void
+DisconnectHook::operator()(web::ng::Connection const& connection)
+{
+    dosguard_.get().decrement(connection.ip());
+}
+
+MetricsHandler::MetricsHandler(std::shared_ptr<web::AdminVerificationStrategy> adminVerifier)
+    : adminVerifier_{std::move(adminVerifier)}
+{
+}
+
+web::ng::Response
+MetricsHandler::operator()(
+    web::ng::Request const& request,
+    web::ng::ConnectionMetadata& connectionMetadata,
+    web::SubscriptionContextPtr,
+    boost::asio::yield_context
+)
+{
+    auto const maybeHttpRequest = request.asHttpRequest();
+    ASSERT(maybeHttpRequest.has_value(), "Got not a http request in Get");
+    auto const& httpRequest = maybeHttpRequest->get();
+
+    // FIXME(#1702): Using veb server thread to handle prometheus request. Better to post on work queue.
+    auto maybeResponse = util::prometheus::handlePrometheusRequest(
+        httpRequest, adminVerifier_->isAdmin(httpRequest, connectionMetadata.ip())
+    );
+    ASSERT(maybeResponse.has_value(), "Got unexpected request for Prometheus");
+    return web::ng::Response{std::move(maybeResponse).value(), request};
+}
+
+web::ng::Response
+HealthCheckHandler::operator()(
+    web::ng::Request const& request,
+    web::ng::ConnectionMetadata&,
+    web::SubscriptionContextPtr,
+    boost::asio::yield_context
+)
+{
+    static auto constexpr kHEALTH_CHECK_HTML = R"html(
+    <!DOCTYPE html>
+    <html>
+        <head><title>Test page for Clio</title></head>
+        <body><h1>Clio Test</h1><p>This page shows Clio http(s) connectivity is working.</p></body>
+    </html>
+)html";
+
+    return web::ng::Response{boost::beast::http::status::ok, kHEALTH_CHECK_HTML, request};
+}
+
+}  // namespace app

src/app/WebHandlers.hpp

@@ -0,0 +1,234 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of clio: https://github.com/XRPLF/clio
+    Copyright (c) 2024, the clio developers.
+
+    Permission to use, copy, modify, and distribute this software for any
+    purpose with or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL,  DIRECT,  INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#pragma once
+
+#include "rpc/Errors.hpp"
+#include "util/log/Logger.hpp"
+#include "web/AdminVerificationStrategy.hpp"
+#include "web/SubscriptionContextInterface.hpp"
+#include "web/dosguard/DOSGuardInterface.hpp"
+#include "web/ng/Connection.hpp"
+#include "web/ng/Request.hpp"
+#include "web/ng/Response.hpp"
+
+#include <boost/asio/spawn.hpp>
+#include <boost/beast/http/status.hpp>
+#include <boost/json/array.hpp>
+#include <boost/json/parse.hpp>
+
+#include <exception>
+#include <functional>
+#include <memory>
+#include <utility>
+
+namespace app {
+
+/**
+ * @brief A function object that checks if the connection is allowed to proceed.
+ */
+class OnConnectCheck {
+    std::reference_wrapper<web::dosguard::DOSGuardInterface> dosguard_;
+
+public:
+    /**
+     * @brief Construct a new OnConnectCheck object
+     *
+     * @param dosguard The DOSGuardInterface to use for checking the connection.
+     */
+    OnConnectCheck(web::dosguard::DOSGuardInterface& dosguard);
+
+    /**
+     * @brief Check if the connection is allowed to proceed.
+     *
+     * @param connection The connection to check.
+     * @return A response if the connection is not allowed to proceed or void otherwise.
+     */
+    std::expected<void, web::ng::Response>
+    operator()(web::ng::Connection const& connection);
+};
+
+/**
+ * @brief A function object to be called when a connection is disconnected.
+ */
+class DisconnectHook {
+    std::reference_wrapper<web::dosguard::DOSGuardInterface> dosguard_;
+
+public:
+    /**
+     * @brief Construct a new DisconnectHook object
+     *
+     * @param dosguard The DOSGuardInterface to use for disconnecting the connection.
+     */
+    DisconnectHook(web::dosguard::DOSGuardInterface& dosguard);
+
+    /**
+     * @brief The call of the function object.
+     *
+     * @param connection The connection which has disconnected.
+     */
+    void
+    operator()(web::ng::Connection const& connection);
+};
+
+/**
+ * @brief A function object that handles the metrics endpoint.
+ */
+class MetricsHandler {
+    std::shared_ptr<web::AdminVerificationStrategy> adminVerifier_;
+
+public:
+    /**
+     * @brief Construct a new MetricsHandler object
+     *
+     * @param adminVerifier The AdminVerificationStrategy to use for verifying the connection for admin access.
+     */
+    MetricsHandler(std::shared_ptr<web::AdminVerificationStrategy> adminVerifier);
+
+    /**
+     * @brief The call of the function object.
+     *
+     * @param request The request to handle.
+     * @param connectionMetadata The connection metadata.
+     * @return The response to the request.
+     */
+    web::ng::Response
+    operator()(
+        web::ng::Request const& request,
+        web::ng::ConnectionMetadata& connectionMetadata,
+        web::SubscriptionContextPtr,
+        boost::asio::yield_context
+    );
+};
+
+/**
+ * @brief A function object that handles the health check endpoint.
+ */
+class HealthCheckHandler {
+public:
+    /**
+     * @brief The call of the function object.
+     *
+     * @param request The request to handle.
+     * @return The response to the request
+     */
+    web::ng::Response
+    operator()(
+        web::ng::Request const& request,
+        web::ng::ConnectionMetadata&,
+        web::SubscriptionContextPtr,
+        boost::asio::yield_context
+    );
+};
+
+/**
+ * @brief A function object that handles the websocket endpoint.
+ *
+ * @tparam RpcHandlerType The type of the RPC handler.
+ */
+template <typename RpcHandlerType>
+class RequestHandler {
+    util::Logger webServerLog_{"WebServer"};
+    std::shared_ptr<web::AdminVerificationStrategy> adminVerifier_;
+    std::reference_wrapper<RpcHandlerType> rpcHandler_;
+    std::reference_wrapper<web::dosguard::DOSGuardInterface> dosguard_;
+
+public:
+    /**
+     * @brief Construct a new RequestHandler object
+     *
+     * @param adminVerifier The AdminVerificationStrategy to use for verifying the connection for admin access.
+     * @param rpcHandler The RPC handler to use for handling the request.
+     * @param dosguard The DOSGuardInterface to use for checking the connection.
+     */
+    RequestHandler(
+        std::shared_ptr<web::AdminVerificationStrategy> adminVerifier,
+        RpcHandlerType& rpcHandler,
+        web::dosguard::DOSGuardInterface& dosguard
+    )
+        : adminVerifier_(std::move(adminVerifier)), rpcHandler_(rpcHandler), dosguard_(dosguard)
+    {
+    }
+
+    /**
+     * @brief The call of the function object.
+     *
+     * @param request The request to handle.
+     * @param connectionMetadata The connection metadata.
+     * @param subscriptionContext The subscription context.
+     * @param yield The yield context.
+     * @return The response to the request.
+     */
+    web::ng::Response
+    operator()(
+        web::ng::Request const& request,
+        web::ng::ConnectionMetadata& connectionMetadata,
+        web::SubscriptionContextPtr subscriptionContext,
+        boost::asio::yield_context yield
+    )
+    {
+        if (not dosguard_.get().request(connectionMetadata.ip())) {
+            auto error = rpc::makeError(rpc::RippledError::rpcSLOW_DOWN);
+
+            if (not request.isHttp()) {
+                try {
+                    auto requestJson = boost::json::parse(request.message());
+                    if (requestJson.is_object() && requestJson.as_object().contains("id"))
+                        error["id"] = requestJson.as_object().at("id");
+                    error["request"] = request.message();
+                } catch (std::exception const&) {
+                    error["request"] = request.message();
+                }
+            }
+            return web::ng::Response{boost::beast::http::status::service_unavailable, error, request};
+        }
+        LOG(webServerLog_.info()) << connectionMetadata.tag()
+                                  << "Received request from ip = " << connectionMetadata.ip()
+                                  << " - posting to WorkQueue";
+
+        connectionMetadata.setIsAdmin([this, &request, &connectionMetadata]() {
+            return adminVerifier_->isAdmin(request.httpHeaders(), connectionMetadata.ip());
+        });
+
+        try {
+            auto response = rpcHandler_(request, connectionMetadata, std::move(subscriptionContext), yield);
+
+            if (not dosguard_.get().add(connectionMetadata.ip(), response.message().size())) {
+                auto jsonResponse = boost::json::parse(response.message()).as_object();
+                jsonResponse["warning"] = "load";
+                if (jsonResponse.contains("warnings") && jsonResponse["warnings"].is_array()) {
+                    jsonResponse["warnings"].as_array().push_back(rpc::makeWarning(rpc::WarnRpcRateLimit));
+                } else {
+                    jsonResponse["warnings"] = boost::json::array{rpc::makeWarning(rpc::WarnRpcRateLimit)};
+                }
+                response.setMessage(jsonResponse);
+            }
+
+            return response;
+        } catch (std::exception const&) {
+            return web::ng::Response{
+                boost::beast::http::status::internal_server_error,
+                rpc::makeError(rpc::RippledError::rpcINTERNAL),
+                request
+            };
+        }
+    }
+};
+
+}  // namespace app

src/data/AmendmentCenter.cpp

@@ -0,0 +1,203 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of clio: https://github.com/XRPLF/clio
+    Copyright (c) 2024, the clio developers.
+
+    Permission to use, copy, modify, and distribute this software for any
+    purpose with or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL,  DIRECT,  INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include "data/AmendmentCenter.hpp"
+
+#include "data/BackendInterface.hpp"
+#include "data/Types.hpp"
+#include "util/Assert.hpp"
+
+#include <boost/asio/spawn.hpp>
+#include <xrpl/basics/Slice.h>
+#include <xrpl/basics/base_uint.h>
+#include <xrpl/protocol/Feature.h>
+#include <xrpl/protocol/Indexes.h>
+#include <xrpl/protocol/SField.h>
+#include <xrpl/protocol/STLedgerEntry.h>
+#include <xrpl/protocol/Serializer.h>
+#include <xrpl/protocol/digest.h>
+
+#include <algorithm>
+#include <cstdint>
+#include <iterator>
+#include <map>
+#include <memory>
+#include <optional>
+#include <ranges>
+#include <stdexcept>
+#include <string>
+#include <string_view>
+#include <unordered_set>
+#include <utility>
+#include <vector>
+
+namespace {
+
+std::unordered_set<std::string>&
+supportedAmendments()
+{
+    static std::unordered_set<std::string> kAMENDMENTS = {};
+    return kAMENDMENTS;
+}
+
+bool
+lookupAmendment(auto const& allAmendments, std::vector<ripple::uint256> const& ledgerAmendments, std::string_view name)
+{
+    namespace rg = std::ranges;
+    if (auto const am = rg::find(allAmendments, name, &data::Amendment::name); am != rg::end(allAmendments))
+        return rg::find(ledgerAmendments, am->feature) != rg::end(ledgerAmendments);
+    return false;
+}
+
+}  // namespace
+
+namespace data {
+namespace impl {
+
+WritingAmendmentKey::WritingAmendmentKey(std::string amendmentName) : AmendmentKey{std::move(amendmentName)}
+{
+    ASSERT(not supportedAmendments().contains(name), "Attempt to register the same amendment twice");
+    supportedAmendments().insert(name);
+}
+
+}  // namespace impl
+
+AmendmentKey::operator std::string const&() const
+{
+    return name;
+}
+
+AmendmentKey::operator std::string_view() const
+{
+    return name;
+}
+
+AmendmentKey::operator ripple::uint256() const
+{
+    return Amendment::getAmendmentId(name);
+}
+
+AmendmentCenter::AmendmentCenter(std::shared_ptr<data::BackendInterface> const& backend) : backend_{backend}
+{
+    namespace rg = std::ranges;
+    namespace vs = std::views;
+
+    rg::copy(
+        ripple::allAmendments() | vs::transform([&](auto const& p) {
+            auto const& [name, support] = p;
+            return Amendment{
+                .name = name,
+                .feature = Amendment::getAmendmentId(name),
+                .isSupportedByXRPL = support != ripple::AmendmentSupport::Unsupported,
+                .isSupportedByClio = rg::find(supportedAmendments(), name) != rg::end(supportedAmendments()),
+                .isRetired = support == ripple::AmendmentSupport::Retired
+            };
+        }),
+        std::back_inserter(all_)
+    );
+
+    for (auto const& am : all_ | vs::filter([](auto const& am) { return am.isSupportedByClio; }))
+        supported_.insert_or_assign(am.name, am);
+}
+
+bool
+AmendmentCenter::isSupported(AmendmentKey const& key) const
+{
+    return supported_.contains(key);
+}
+
+std::map<std::string, Amendment> const&
+AmendmentCenter::getSupported() const
+{
+    return supported_;
+}
+
+std::vector<Amendment> const&
+AmendmentCenter::getAll() const
+{
+    return all_;
+}
+
+bool
+AmendmentCenter::isEnabled(AmendmentKey const& key, uint32_t seq) const
+{
+    return data::synchronous([this, &key, seq](auto yield) { return isEnabled(yield, key, seq); });
+}
+
+bool
+AmendmentCenter::isEnabled(boost::asio::yield_context yield, AmendmentKey const& key, uint32_t seq) const
+{
+    if (auto const listAmendments = fetchAmendmentsList(yield, seq); listAmendments)
+        return lookupAmendment(all_, *listAmendments, key);
+
+    return false;
+}
+
+std::vector<bool>
+AmendmentCenter::isEnabled(boost::asio::yield_context yield, std::vector<AmendmentKey> const& keys, uint32_t seq) const
+{
+    namespace rg = std::ranges;
+
+    if (auto const listAmendments = fetchAmendmentsList(yield, seq); listAmendments) {
+        std::vector<bool> out;
+        rg::transform(keys, std::back_inserter(out), [this, &listAmendments](auto const& key) {
+            return lookupAmendment(all_, *listAmendments, key);
+        });
+
+        return out;
+    }
+
+    return std::vector<bool>(keys.size(), false);
+}
+
+Amendment const&
+AmendmentCenter::getAmendment(AmendmentKey const& key) const
+{
+    ASSERT(supported_.contains(key), "The amendment '{}' must be present in supported amendments list", key.name);
+    return supported_.at(key);
+}
+
+Amendment const&
+AmendmentCenter::operator[](AmendmentKey const& key) const
+{
+    return getAmendment(key);
+}
+
+ripple::uint256
+Amendment::getAmendmentId(std::string_view name)
+{
+    return ripple::sha512Half(ripple::Slice(name.data(), name.size()));
+}
+
+std::optional<std::vector<ripple::uint256>>
+AmendmentCenter::fetchAmendmentsList(boost::asio::yield_context yield, uint32_t seq) const
+{
+    // the amendments should always be present on the ledger
+    auto const amendments = backend_->fetchLedgerObject(ripple::keylet::amendments().key, seq, yield);
+    if (not amendments.has_value())
+        throw std::runtime_error("Amendments ledger object must be present in the database");
+
+    ripple::SLE const amendmentsSLE{
+        ripple::SerialIter{amendments->data(), amendments->size()}, ripple::keylet::amendments().key
+    };
+
+    return amendmentsSLE[~ripple::sfAmendments];
+}
+
+}  // namespace data

src/data/AmendmentCenter.hpp

@@ -0,0 +1,261 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of clio: https://github.com/XRPLF/clio
+    Copyright (c) 2024, the clio developers.
+
+    Permission to use, copy, modify, and distribute this software for any
+    purpose with or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL,  DIRECT,  INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#pragma once
+
+#include "data/AmendmentCenterInterface.hpp"
+#include "data/BackendInterface.hpp"
+#include "data/Types.hpp"
+
+#include <boost/asio/spawn.hpp>
+#include <boost/preprocessor.hpp>
+#include <boost/preprocessor/seq/for_each.hpp>
+#include <boost/preprocessor/stringize.hpp>
+#include <boost/preprocessor/variadic/to_seq.hpp>
+#include <xrpl/basics/Slice.h>
+#include <xrpl/basics/base_uint.h>
+#include <xrpl/protocol/Feature.h>
+#include <xrpl/protocol/Indexes.h>
+#include <xrpl/protocol/SField.h>
+#include <xrpl/protocol/STLedgerEntry.h>
+#include <xrpl/protocol/Serializer.h>
+#include <xrpl/protocol/digest.h>
+
+#include <cstdint>
+#include <map>
+#include <memory>
+#include <optional>
+#include <string>
+#include <vector>
+
+#define REGISTER(name)                                   \
+    inline static impl::WritingAmendmentKey const name = \
+        impl::WritingAmendmentKey(std::string(BOOST_PP_STRINGIZE(name)))
+
+namespace data {
+namespace impl {
+
+struct WritingAmendmentKey : AmendmentKey {
+    explicit WritingAmendmentKey(std::string amendmentName);
+};
+
+}  // namespace impl
+
+/**
+ * @brief List of supported amendments
+ */
+struct Amendments {
+    // NOTE: if Clio wants to report it supports an Amendment it should be listed here.
+    // Whether an amendment is obsolete and/or supported by libxrpl is extracted directly from libxrpl.
+    // If an amendment is in the list below it just means Clio did whatever changes needed to support it.
+    // Most of the time it's going to be no changes at all.
+
+    /** @cond */
+    // NOLINTBEGIN(readability-identifier-naming)
+    REGISTER(OwnerPaysFee);
+    REGISTER(Flow);
+    REGISTER(FlowCross);
+    REGISTER(fix1513);
+    REGISTER(DepositAuth);
+    REGISTER(Checks);
+    REGISTER(fix1571);
+    REGISTER(fix1543);
+    REGISTER(fix1623);
+    REGISTER(DepositPreauth);
+    REGISTER(fix1515);
+    REGISTER(fix1578);
+    REGISTER(MultiSignReserve);
+    REGISTER(fixTakerDryOfferRemoval);
+    REGISTER(fixMasterKeyAsRegularKey);
+    REGISTER(fixCheckThreading);
+    REGISTER(fixPayChanRecipientOwnerDir);
+    REGISTER(DeletableAccounts);
+    REGISTER(fixQualityUpperBound);
+    REGISTER(RequireFullyCanonicalSig);
+    REGISTER(fix1781);
+    REGISTER(HardenedValidations);
+    REGISTER(fixAmendmentMajorityCalc);
+    REGISTER(NegativeUNL);
+    REGISTER(TicketBatch);
+    REGISTER(FlowSortStrands);
+    REGISTER(fixSTAmountCanonicalize);
+    REGISTER(fixRmSmallIncreasedQOffers);
+    REGISTER(CheckCashMakesTrustLine);
+    REGISTER(ExpandedSignerList);
+    REGISTER(NonFungibleTokensV1_1);
+    REGISTER(fixTrustLinesToSelf);
+    REGISTER(fixRemoveNFTokenAutoTrustLine);
+    REGISTER(ImmediateOfferKilled);
+    REGISTER(DisallowIncoming);
+    REGISTER(XRPFees);
+    REGISTER(fixUniversalNumber);
+    REGISTER(fixNonFungibleTokensV1_2);
+    REGISTER(fixNFTokenRemint);
+    REGISTER(fixReducedOffersV1);
+    REGISTER(Clawback);
+    REGISTER(AMM);
+    REGISTER(XChainBridge);
+    REGISTER(fixDisallowIncomingV1);
+    REGISTER(DID);
+    REGISTER(fixFillOrKill);
+    REGISTER(fixNFTokenReserve);
+    REGISTER(fixInnerObjTemplate);
+    REGISTER(fixAMMOverflowOffer);
+    REGISTER(PriceOracle);
+    REGISTER(fixEmptyDID);
+    REGISTER(fixXChainRewardRounding);
+    REGISTER(fixPreviousTxnID);
+    REGISTER(fixAMMv1_1);
+    REGISTER(NFTokenMintOffer);
+    REGISTER(fixReducedOffersV2);
+    REGISTER(fixEnforceNFTokenTrustline);
+    REGISTER(fixInnerObjTemplate2);
+    REGISTER(fixNFTokenPageLinks);
+    REGISTER(InvariantsV1_1);
+    REGISTER(MPTokensV1);
+    REGISTER(fixAMMv1_2);
+    REGISTER(AMMClawback);
+    REGISTER(Credentials);
+
+    // Obsolete but supported by libxrpl
+    REGISTER(CryptoConditionsSuite);
+    REGISTER(NonFungibleTokensV1);
+    REGISTER(fixNFTokenDirV1);
+    REGISTER(fixNFTokenNegOffer);
+
+    // Retired amendments
+    REGISTER(MultiSign);
+    REGISTER(TrustSetAuth);
+    REGISTER(FeeEscalation);
+    REGISTER(PayChan);
+    REGISTER(fix1368);
+    REGISTER(CryptoConditions);
+    REGISTER(Escrow);
+    REGISTER(TickSize);
+    REGISTER(fix1373);
+    REGISTER(EnforceInvariants);
+    REGISTER(SortedDirectories);
+    REGISTER(fix1201);
+    REGISTER(fix1512);
+    REGISTER(fix1523);
+    REGISTER(fix1528);
+    // NOLINTEND(readability-identifier-naming)
+    /** @endcond */
+};
+
+#undef REGISTER
+
+/**
+ * @brief Knowledge center for amendments within XRPL
+ */
+class AmendmentCenter : public AmendmentCenterInterface {
+    std::shared_ptr<data::BackendInterface> backend_;
+
+    std::map<std::string, Amendment> supported_;
+    std::vector<Amendment> all_;
+
+public:
+    /**
+     * @brief Construct a new AmendmentCenter instance
+     *
+     * @param backend The backend
+     */
+    explicit AmendmentCenter(std::shared_ptr<data::BackendInterface> const& backend);
+
+    /**
+     * @brief Check whether an amendment is supported by Clio
+     *
+     * @param key The key of the amendment to check
+     * @return true if supported; false otherwise
+     */
+    [[nodiscard]] bool
+    isSupported(AmendmentKey const& key) const final;
+
+    /**
+     * @brief Get all supported amendments as a map
+     *
+     * @return The amendments supported by Clio
+     */
+    [[nodiscard]] std::map<std::string, Amendment> const&
+    getSupported() const final;
+
+    /**
+     * @brief Get all known amendments
+     *
+     * @return All known amendments as a vector
+     */
+    [[nodiscard]] std::vector<Amendment> const&
+    getAll() const final;
+
+    /**
+     * @brief Check whether an amendment was/is enabled for a given sequence
+     *
+     * @param key The key of the amendment to check
+     * @param seq The sequence to check for
+     * @return true if enabled; false otherwise
+     */
+    [[nodiscard]] bool
+    isEnabled(AmendmentKey const& key, uint32_t seq) const final;
+
+    /**
+     * @brief Check whether an amendment was/is enabled for a given sequence
+     *
+     * @param yield The coroutine context to use
+     * @param key The key of the amendment to check
+     * @param seq The sequence to check for
+     * @return true if enabled; false otherwise
+     */
+    [[nodiscard]] bool
+    isEnabled(boost::asio::yield_context yield, AmendmentKey const& key, uint32_t seq) const final;
+
+    /**
+     * @brief Check whether an amendment was/is enabled for a given sequence
+     *
+     * @param yield The coroutine context to use
+     * @param keys The keys of the amendments to check
+     * @param seq The sequence to check for
+     * @return A vector of bools representing enabled state for each of the given keys
+     */
+    [[nodiscard]] std::vector<bool>
+    isEnabled(boost::asio::yield_context yield, std::vector<AmendmentKey> const& keys, uint32_t seq) const final;
+
+    /**
+     * @brief Get an amendment
+     *
+     * @param key The key of the amendment to get
+     * @return The amendment as a const ref; asserts if the amendment is unknown
+     */
+    [[nodiscard]] Amendment const&
+    getAmendment(AmendmentKey const& key) const final;
+
+    /**
+     * @brief Get an amendment by its key
+
+     * @param key The amendment key from @see Amendments
+     * @return The amendment as a const ref; asserts if the amendment is unknown
+     */
+    [[nodiscard]] Amendment const&
+    operator[](AmendmentKey const& key) const final;
+
+private:
+    [[nodiscard]] std::optional<std::vector<ripple::uint256>>
+    fetchAmendmentsList(boost::asio::yield_context yield, uint32_t seq) const;
+};
+
+}  // namespace data

src/data/AmendmentCenterInterface.hpp

@@ -0,0 +1,116 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of clio: https://github.com/XRPLF/clio
+    Copyright (c) 2024, the clio developers.
+
+    Permission to use, copy, modify, and distribute this software for any
+    purpose with or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL,  DIRECT,  INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#pragma once
+
+#include "data/Types.hpp"
+
+#include <boost/asio/spawn.hpp>
+
+#include <cstdint>
+#include <map>
+#include <string>
+#include <vector>
+
+namespace data {
+
+/**
+ * @brief The interface of an amendment center
+ */
+class AmendmentCenterInterface {
+public:
+    virtual ~AmendmentCenterInterface() = default;
+
+    /**
+     * @brief Check whether an amendment is supported by Clio
+     *
+     * @param key The key of the amendment to check
+     * @return true if supported; false otherwise
+     */
+    [[nodiscard]] virtual bool
+    isSupported(AmendmentKey const& key) const = 0;
+
+    /**
+     * @brief Get all supported amendments as a map
+     *
+     * @return The amendments supported by Clio
+     */
+    [[nodiscard]] virtual std::map<std::string, Amendment> const&
+    getSupported() const = 0;
+
+    /**
+     * @brief Get all known amendments
+     *
+     * @return All known amendments as a vector
+     */
+    [[nodiscard]] virtual std::vector<Amendment> const&
+    getAll() const = 0;
+
+    /**
+     * @brief Check whether an amendment was/is enabled for a given sequence
+     *
+     * @param key The key of the amendment to check
+     * @param seq The sequence to check for
+     * @return true if enabled; false otherwise
+     */
+    [[nodiscard]] virtual bool
+    isEnabled(AmendmentKey const& key, uint32_t seq) const = 0;
+
+    /**
+     * @brief Check whether an amendment was/is enabled for a given sequence
+     *
+     * @param yield The coroutine context to use
+     * @param key The key of the amendment to check
+     * @param seq The sequence to check for
+     * @return true if enabled; false otherwise
+     */
+    [[nodiscard]] virtual bool
+    isEnabled(boost::asio::yield_context yield, AmendmentKey const& key, uint32_t seq) const = 0;
+
+    /**
+     * @brief Check whether an amendment was/is enabled for a given sequence
+     *
+     * @param yield The coroutine context to use
+     * @param keys The keys of the amendments to check
+     * @param seq The sequence to check for
+     * @return A vector of bools representing enabled state for each of the given keys
+     */
+    [[nodiscard]] virtual std::vector<bool>
+    isEnabled(boost::asio::yield_context yield, std::vector<AmendmentKey> const& keys, uint32_t seq) const = 0;
+
+    /**
+     * @brief Get an amendment
+     *
+     * @param key The key of the amendment to get
+     * @return The amendment as a const ref; asserts if the amendment is unknown
+     */
+    [[nodiscard]] virtual Amendment const&
+    getAmendment(AmendmentKey const& key) const = 0;
+
+    /**
+     * @brief Get an amendment by its key
+     *
+     * @param key The amendment key from @see Amendments
+     * @return The amendment as a const ref; asserts if the amendment is unknown
+     */
+    [[nodiscard]] virtual Amendment const&
+    operator[](AmendmentKey const& key) const = 0;
+};
+
+}  // namespace data

src/data/BackendCounters.cpp

@@ -36,7 +36,7 @@ namespace data {
 
 namespace {
 
-std::vector<std::int64_t> const histogramBuckets{1, 2, 5, 10, 20, 50, 100, 200, 500, 700, 1000};
+std::vector<std::int64_t> const kHISTOGRAM_BUCKETS{1, 2, 5, 10, 20, 50, 100, 200, 500, 700, 1000};
 
 std::int64_t
 durationInMillisecondsSince(std::chrono::steady_clock::time_point const startTime)
@@ -69,13 +69,13 @@ BackendCounters::BackendCounters()
     , readDurationHistogram_(PrometheusService::histogramInt(
           "backend_duration_milliseconds_histogram",
           Labels({Label{"operation", "read"}}),
-          histogramBuckets,
+          kHISTOGRAM_BUCKETS,
           "The duration of backend read operations including retries"
       ))
     , writeDurationHistogram_(PrometheusService::histogramInt(
           "backend_duration_milliseconds_histogram",
           Labels({Label{"operation", "write"}}),
-          histogramBuckets,
+          kHISTOGRAM_BUCKETS,
           "The duration of backend write operations including retries"
       ))
 {

src/data/BackendFactory.hpp

@@ -22,8 +22,8 @@
 #include "data/BackendInterface.hpp"
 #include "data/CassandraBackend.hpp"
 #include "data/cassandra/SettingsProvider.hpp"
-#include "util/config/Config.hpp"
 #include "util/log/Logger.hpp"
+#include "util/newconfig/ConfigDefinition.hpp"
 
 #include <boost/algorithm/string.hpp>
 #include <boost/algorithm/string/predicate.hpp>
@@ -41,19 +41,18 @@ namespace data {
  * @return A shared_ptr<BackendInterface> with the selected implementation
  */
 inline std::shared_ptr<BackendInterface>
-make_Backend(util::Config const& config)
+makeBackend(util::config::ClioConfigDefinition const& config)
 {
-    static util::Logger const log{"Backend"};
+    static util::Logger const log{"Backend"};  // NOLINT(readability-identifier-naming)
     LOG(log.info()) << "Constructing BackendInterface";
 
-    auto const readOnly = config.valueOr("read_only", false);
+    auto const readOnly = config.get<bool>("read_only");
 
-    auto const type = config.value<std::string>("database.type");
+    auto const type = config.get<std::string>("database.type");
     std::shared_ptr<BackendInterface> backend = nullptr;
 
-    // TODO: retire `cassandra-new` by next release after 2.0
-    if (boost::iequals(type, "cassandra") or boost::iequals(type, "cassandra-new")) {
-        auto cfg = config.section("database." + type);
+    if (boost::iequals(type, "cassandra")) {
+        auto const cfg = config.getObject("database." + type);
         backend = std::make_shared<data::cassandra::CassandraBackend>(data::cassandra::SettingsProvider{cfg}, readOnly);
     }
 

src/data/BackendInterface.cpp

@@ -24,13 +24,13 @@
 #include "util/log/Logger.hpp"
 
 #include <boost/asio/spawn.hpp>
-#include <ripple/basics/base_uint.h>
-#include <ripple/basics/strHex.h>
-#include <ripple/protocol/Fees.h>
-#include <ripple/protocol/Indexes.h>
-#include <ripple/protocol/SField.h>
-#include <ripple/protocol/STLedgerEntry.h>
-#include <ripple/protocol/Serializer.h>
+#include <xrpl/basics/base_uint.h>
+#include <xrpl/basics/strHex.h>
+#include <xrpl/protocol/Fees.h>
+#include <xrpl/protocol/Indexes.h>
+#include <xrpl/protocol/SField.h>
+#include <xrpl/protocol/STLedgerEntry.h>
+#include <xrpl/protocol/Serializer.h>
 
 #include <chrono>
 #include <cstddef>
@@ -93,7 +93,6 @@ BackendInterface::fetchLedgerObject(
         return obj;
     }
 
-    LOG(gLog.trace()) << "Cache miss - " << ripple::strHex(key);
     auto dbObj = doFetchLedgerObject(key, sequence, yield);
     if (!dbObj) {
         LOG(gLog.trace()) << "Missed cache and missed in db";
@@ -103,6 +102,19 @@ BackendInterface::fetchLedgerObject(
     return dbObj;
 }
 
+std::optional<std::uint32_t>
+BackendInterface::fetchLedgerObjectSeq(
+    ripple::uint256 const& key,
+    std::uint32_t const sequence,
+    boost::asio::yield_context yield
+) const
+{
+    auto seq = doFetchLedgerObjectSeq(key, sequence, yield);
+    if (!seq)
+        LOG(gLog.trace()) << "Missed in db";
+    return seq;
+}
+
 std::vector<Blob>
 BackendInterface::fetchLedgerObjects(
     std::vector<ripple::uint256> const& keys,
@@ -164,9 +176,9 @@ BackendInterface::fetchSuccessorObject(
     if (succ) {
         auto obj = fetchLedgerObject(*succ, ledgerSequence, yield);
         if (!obj)
-            return {{*succ, {}}};
+            return {{.key = *succ, .blob = {}}};
 
-        return {{*succ, *obj}};
+        return {{.key = *succ, .blob = *obj}};
     }
     return {};
 }
@@ -255,7 +267,7 @@ std::optional<LedgerRange>
 BackendInterface::fetchLedgerRange() const
 {
     std::shared_lock const lck(rngMtx_);
-    return range;
+    return range_;
 }
 
 void
@@ -264,16 +276,16 @@ BackendInterface::updateRange(uint32_t newMax)
     std::scoped_lock const lck(rngMtx_);
 
     ASSERT(
-        !range || newMax >= range->maxSequence,
+        !range_ || newMax >= range_->maxSequence,
         "Range shouldn't exist yet or newMax should be greater. newMax = {}, range->maxSequence = {}",
         newMax,
-        range->maxSequence
+        range_->maxSequence
     );
 
-    if (!range) {
-        range = {newMax, newMax};
+    if (!range_) {
+        range_ = {.minSequence = newMax, .maxSequence = newMax};
     } else {
-        range->maxSequence = newMax;
+        range_->maxSequence = newMax;
     }
 }
 
@@ -284,10 +296,10 @@ BackendInterface::setRange(uint32_t min, uint32_t max, bool force)
 
     if (!force) {
         ASSERT(min <= max, "Range min must be less than or equal to max");
-        ASSERT(not range.has_value(), "Range was already set");
+        ASSERT(not range_.has_value(), "Range was already set");
     }
 
-    range = {min, max};
+    range_ = {.minSequence = min, .maxSequence = max};
 }
 
 LedgerPage
@@ -308,10 +320,10 @@ BackendInterface::fetchLedgerPage(
         ripple::uint256 const& curCursor = [&]() {
             if (!keys.empty())
                 return keys.back();
-            return (cursor ? *cursor : firstKey);
+            return (cursor ? *cursor : kFIRST_KEY);
         }();
 
-        std::uint32_t const seq = outOfOrder ? range->maxSequence : ledgerSequence;
+        std::uint32_t const seq = outOfOrder ? range_->maxSequence : ledgerSequence;
         auto succ = fetchSuccessorKey(curCursor, seq, yield);
 
         if (!succ) {

src/data/BackendInterface.hpp

@@ -31,10 +31,10 @@
 #include <boost/json.hpp>
 #include <boost/json/object.hpp>
 #include <boost/utility/result_of.hpp>
-#include <ripple/basics/base_uint.h>
-#include <ripple/protocol/AccountID.h>
-#include <ripple/protocol/Fees.h>
-#include <ripple/protocol/LedgerHeader.h>
+#include <xrpl/basics/base_uint.h>
+#include <xrpl/protocol/AccountID.h>
+#include <xrpl/protocol/Fees.h>
+#include <xrpl/protocol/LedgerHeader.h>
 
 #include <chrono>
 #include <cstddef>
@@ -65,7 +65,7 @@ public:
     }
 };
 
-static constexpr std::size_t DEFAULT_WAIT_BETWEEN_RETRY = 500;
+static constexpr std::size_t kDEFAULT_WAIT_BETWEEN_RETRY = 500;
 /**
  * @brief A helper function that catches DatabaseTimout exceptions and retries indefinitely.
  *
@@ -76,9 +76,9 @@ static constexpr std::size_t DEFAULT_WAIT_BETWEEN_RETRY = 500;
  */
 template <typename FnType>
 auto
-retryOnTimeout(FnType func, size_t waitMs = DEFAULT_WAIT_BETWEEN_RETRY)
+retryOnTimeout(FnType func, size_t waitMs = kDEFAULT_WAIT_BETWEEN_RETRY)
 {
-    static util::Logger const log{"Backend"};
+    static util::Logger const log{"Backend"};  // NOLINT(readability-identifier-naming)
 
     while (true) {
         try {
@@ -138,7 +138,7 @@ synchronousAndRetryOnTimeout(FnType&& func)
 class BackendInterface {
 protected:
     mutable std::shared_mutex rngMtx_;
-    std::optional<LedgerRange> range;
+    std::optional<LedgerRange> range_;
     LedgerCache cache_;
     std::optional<etl::CorruptionDetector<LedgerCache>> corruptionDetector_;
 
@@ -364,6 +364,25 @@ public:
         boost::asio::yield_context yield
     ) const = 0;
 
+    /**
+     * @brief Fetches all holders' balances for a MPTIssuanceID
+     *
+     * @param mptID MPTIssuanceID you wish you query.
+     * @param limit Paging limit.
+     * @param cursorIn Optional cursor to allow us to pick up from where we last left off.
+     * @param ledgerSequence The ledger sequence to fetch for
+     * @param yield Currently executing coroutine.
+     * @return std::vector<Blob> of MPToken balances and an optional marker
+     */
+    virtual MPTHoldersAndCursor
+    fetchMPTHolders(
+        ripple::uint192 const& mptID,
+        std::uint32_t const limit,
+        std::optional<ripple::AccountID> const& cursorIn,
+        std::uint32_t const ledgerSequence,
+        boost::asio::yield_context yield
+    ) const = 0;
+
     /**
      * @brief Fetches a specific ledger object.
      *
@@ -378,6 +397,19 @@ public:
     std::optional<Blob>
     fetchLedgerObject(ripple::uint256 const& key, std::uint32_t sequence, boost::asio::yield_context yield) const;
 
+    /**
+     * @brief Fetches a specific ledger object sequence.
+     *
+     * Currently the real fetch happens in doFetchLedgerObjectSeq
+     *
+     * @param key The key of the object
+     * @param sequence The ledger sequence to fetch for
+     * @param yield The coroutine context
+     * @return The sequence in unit32_t on success; nullopt otherwise
+     */
+    std::optional<std::uint32_t>
+    fetchLedgerObjectSeq(ripple::uint256 const& key, std::uint32_t sequence, boost::asio::yield_context yield) const;
+
     /**
      * @brief Fetches all ledger objects by their keys.
      *
@@ -407,6 +439,18 @@ public:
     virtual std::optional<Blob>
     doFetchLedgerObject(ripple::uint256 const& key, std::uint32_t sequence, boost::asio::yield_context yield) const = 0;
 
+    /**
+     * @brief The database-specific implementation for fetching a ledger object sequence.
+     *
+     * @param key The key to fetch for
+     * @param sequence The ledger sequence to fetch for
+     * @param yield The coroutine context
+     * @return The sequence in unit32_t on success; nullopt otherwise
+     */
+    virtual std::optional<std::uint32_t>
+    doFetchLedgerObjectSeq(ripple::uint256 const& key, std::uint32_t sequence, boost::asio::yield_context yield)
+        const = 0;
+
     /**
      * @brief The database-specific implementation for fetching ledger objects.
      *
@@ -504,6 +548,16 @@ public:
         boost::asio::yield_context yield
     ) const;
 
+    /**
+     * @brief Fetches the status of migrator by name.
+     *
+     * @param migratorName The name of the migrator
+     * @param yield The coroutine context
+     * @return The status of the migrator if found; nullopt otherwise
+     */
+    virtual std::optional<std::string>
+    fetchMigratorStatus(std::string const& migratorName, boost::asio::yield_context yield) const = 0;
+
     /**
      * @brief Synchronously fetches the ledger range from DB.
      *
@@ -592,6 +646,14 @@ public:
     virtual void
     writeNFTTransactions(std::vector<NFTTransactionsData> const& data) = 0;
 
+    /**
+     * @brief Write accounts that started holding onto a MPT.
+     *
+     * @param data A vector of MPT ID and account pairs
+     */
+    virtual void
+    writeMPTHolders(std::vector<MPTHolderData> const& data) = 0;
+
     /**
      * @brief Write a new successor.
      *
@@ -621,6 +683,15 @@ public:
     bool
     finishWrites(std::uint32_t ledgerSequence);
 
+    /**
+     * @brief Mark the migration status of a migrator as Migrated in the database
+     *
+     * @param migratorName The name of the migrator
+     * @param status The status to set
+     */
+    virtual void
+    writeMigratorStatus(std::string const& migratorName, std::string const& status) = 0;
+
     /**
      * @return true if database is overwhelmed; false otherwise
      */

src/data/CMakeLists.txt

@@ -1,7 +1,8 @@
 add_library(clio_data)
 target_sources(
   clio_data
-  PRIVATE BackendCounters.cpp
+  PRIVATE AmendmentCenter.cpp
+          BackendCounters.cpp
           BackendInterface.cpp
           LedgerCache.cpp
           cassandra/impl/Future.cpp

src/data/CassandraBackend.hpp

@@ -36,13 +36,13 @@
 #include <boost/asio/spawn.hpp>
 #include <boost/json/object.hpp>
 #include <cassandra.h>
-#include <ripple/basics/Blob.h>
-#include <ripple/basics/base_uint.h>
-#include <ripple/basics/strHex.h>
-#include <ripple/protocol/AccountID.h>
-#include <ripple/protocol/Indexes.h>
-#include <ripple/protocol/LedgerHeader.h>
-#include <ripple/protocol/nft.h>
+#include <xrpl/basics/Blob.h>
+#include <xrpl/basics/base_uint.h>
+#include <xrpl/basics/strHex.h>
+#include <xrpl/protocol/AccountID.h>
+#include <xrpl/protocol/Indexes.h>
+#include <xrpl/protocol/LedgerHeader.h>
+#include <xrpl/protocol/nft.h>
 
 #include <atomic>
 #include <chrono>
@@ -73,13 +73,15 @@ class BasicCassandraBackend : public BackendInterface {
 
     SettingsProviderType settingsProvider_;
     Schema<SettingsProviderType> schema_;
+
+    std::atomic_uint32_t ledgerSequence_ = 0u;
+
+protected:
     Handle handle_;
 
     // have to be mutable because BackendInterface constness :(
     mutable ExecutionStrategyType executor_;
 
-    std::atomic_uint32_t ledgerSequence_ = 0u;
-
 public:
     /**
      * @brief Create a new cassandra/scylla backend instance.
@@ -94,7 +96,7 @@ public:
         , executor_{settingsProvider_.getSettings(), handle_}
     {
         if (auto const res = handle_.connect(); not res)
-            throw std::runtime_error("Could not connect to Cassandra: " + res.error());
+            throw std::runtime_error("Could not connect to database: " + res.error());
 
         if (not readOnly) {
             if (auto const res = handle_.execute(schema_.createKeyspace); not res) {
@@ -129,7 +131,7 @@ public:
     {
         auto rng = fetchLedgerRange();
         if (!rng)
-            return {{}, {}};
+            return {.txns = {}, .cursor = {}};
 
         Statement const statement = [this, forward, &account]() {
             if (forward)
@@ -192,7 +194,7 @@ public:
         // wait for other threads to finish their writes
         executor_.sync();
 
-        if (!range) {
+        if (!range_) {
             executor_.writeSync(schema_->updateLedgerRange, ledgerSequence_, false, ledgerSequence_);
         }
 
@@ -206,13 +208,13 @@ public:
     }
 
     void
-    writeLedger(ripple::LedgerHeader const& ledgerInfo, std::string&& blob) override
+    writeLedger(ripple::LedgerHeader const& ledgerHeader, std::string&& blob) override
     {
-        executor_.write(schema_->insertLedgerHeader, ledgerInfo.seq, std::move(blob));
+        executor_.write(schema_->insertLedgerHeader, ledgerHeader.seq, std::move(blob));
 
-        executor_.write(schema_->insertLedgerHash, ledgerInfo.hash, ledgerInfo.seq);
+        executor_.write(schema_->insertLedgerHash, ledgerHeader.hash, ledgerHeader.seq);
 
-        ledgerSequence_ = ledgerInfo.seq;
+        ledgerSequence_ = ledgerHeader.seq;
     }
 
     std::optional<std::uint32_t>
@@ -336,8 +338,8 @@ public:
 
         auto const& result = res.value();
         if (not result.hasRows()) {
-            LOG(log_.error()) << "Could not fetch all transaction hashes - no rows; ledger = "
-                              << std::to_string(ledgerSequence);
+            LOG(log_.warn()) << "Could not fetch all transaction hashes - no rows; ledger = "
+                             << std::to_string(ledgerSequence);
             return {};
         }
 
@@ -346,7 +348,7 @@ public:
             hashes.push_back(std::move(hash));
 
         auto end = std::chrono::system_clock::now();
-        LOG(log_.debug()) << "Fetched " << hashes.size() << " transaction hashes from Cassandra in "
+        LOG(log_.debug()) << "Fetched " << hashes.size() << " transaction hashes from database in "
                           << std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count()
                           << " milliseconds";
 
@@ -400,7 +402,7 @@ public:
     {
         auto rng = fetchLedgerRange();
         if (!rng)
-            return {{}, {}};
+            return {.txns = {}, .cursor = {}};
 
         Statement const statement = [this, forward, &tokenID]() {
             if (forward)
@@ -548,6 +550,45 @@ public:
         return ret;
     }
 
+    MPTHoldersAndCursor
+    fetchMPTHolders(
+        ripple::uint192 const& mptID,
+        std::uint32_t const limit,
+        std::optional<ripple::AccountID> const& cursorIn,
+        std::uint32_t const ledgerSequence,
+        boost::asio::yield_context yield
+    ) const override
+    {
+        auto const holderEntries = executor_.read(
+            yield, schema_->selectMPTHolders, mptID, cursorIn.value_or(ripple::AccountID(0)), Limit{limit}
+        );
+
+        auto const& holderResults = holderEntries.value();
+        if (not holderResults.hasRows()) {
+            LOG(log_.debug()) << "No rows returned";
+            return {};
+        }
+
+        std::vector<ripple::uint256> mptKeys;
+        std::optional<ripple::AccountID> cursor;
+        for (auto const [holder] : extract<ripple::AccountID>(holderResults)) {
+            mptKeys.push_back(ripple::keylet::mptoken(mptID, holder).key);
+            cursor = holder;
+        }
+
+        auto mptObjects = doFetchLedgerObjects(mptKeys, ledgerSequence, yield);
+
+        auto it = std::remove_if(mptObjects.begin(), mptObjects.end(), [](Blob const& mpt) { return mpt.empty(); });
+
+        mptObjects.erase(it, mptObjects.end());
+
+        ASSERT(mptKeys.size() <= limit, "Number of keys can't exceed the limit");
+        if (mptKeys.size() == limit)
+            return {mptObjects, cursor};
+
+        return {mptObjects, {}};
+    }
+
     std::optional<Blob>
     doFetchLedgerObject(ripple::uint256 const& key, std::uint32_t const sequence, boost::asio::yield_context yield)
         const override
@@ -567,6 +608,25 @@ public:
         return std::nullopt;
     }
 
+    std::optional<std::uint32_t>
+    doFetchLedgerObjectSeq(ripple::uint256 const& key, std::uint32_t const sequence, boost::asio::yield_context yield)
+        const override
+    {
+        LOG(log_.debug()) << "Fetching ledger object for seq " << sequence << ", key = " << ripple::to_string(key);
+        if (auto const res = executor_.read(yield, schema_->selectObject, key, sequence); res) {
+            if (auto const result = res->template get<Blob, std::uint32_t>(); result) {
+                auto [_, seq] = result.value();
+                return seq;
+            }
+            LOG(log_.debug()) << "Could not fetch ledger object sequence - no rows";
+
+        } else {
+            LOG(log_.error()) << "Could not fetch ledger object sequence: " << res.error();
+        }
+
+        return std::nullopt;
+    }
+
     std::optional<TransactionAndMetadata>
     fetchTransaction(ripple::uint256 const& hash, boost::asio::yield_context yield) const override
     {
@@ -590,7 +650,7 @@ public:
     {
         if (auto const res = executor_.read(yield, schema_->selectSuccessor, key, ledgerSequence); res) {
             if (auto const result = res->template get<ripple::uint256>(); result) {
-                if (*result == lastKey)
+                if (*result == kLAST_KEY)
                     return std::nullopt;
                 return result;
             }
@@ -640,7 +700,7 @@ public:
         });
 
         ASSERT(numHashes == results.size(), "Number of hashes and results must match");
-        LOG(log_.debug()) << "Fetched " << numHashes << " transactions from Cassandra in " << timeDiff
+        LOG(log_.debug()) << "Fetched " << numHashes << " transactions from database in " << timeDiff
                           << " milliseconds";
         return results;
     }
@@ -760,7 +820,7 @@ public:
         if (keys.empty())
             return {};
 
-        LOG(log_.debug()) << "Fetched " << keys.size() << " diff hashes from Cassandra in " << timeDiff
+        LOG(log_.debug()) << "Fetched " << keys.size() << " diff hashes from database in " << timeDiff
                           << " milliseconds";
 
         auto const objs = fetchLedgerObjects(keys, ledgerSequence, yield);
@@ -778,12 +838,32 @@ public:
         return results;
     }
 
+    std::optional<std::string>
+    fetchMigratorStatus(std::string const& migratorName, boost::asio::yield_context yield) const override
+    {
+        auto const res = executor_.read(yield, schema_->selectMigratorStatus, Text(migratorName));
+        if (not res) {
+            LOG(log_.error()) << "Could not fetch migrator status: " << res.error();
+            return {};
+        }
+
+        auto const& results = res.value();
+        if (not results) {
+            return {};
+        }
+
+        for (auto [statusString] : extract<std::string>(results))
+            return statusString;
+
+        return {};
+    }
+
     void
     doWriteLedgerObject(std::string&& key, std::uint32_t const seq, std::string&& blob) override
     {
         LOG(log_.trace()) << " Writing ledger object " << key.size() << ":" << seq << " [" << blob.size() << " bytes]";
 
-        if (range)
+        if (range_)
             executor_.write(schema_->insertDiff, seq, key);
 
         executor_.write(schema_->insertObject, std::move(key), seq, std::move(blob));
@@ -848,7 +928,7 @@ public:
         std::string&& metadata
     ) override
     {
-        LOG(log_.trace()) << "Writing txn to cassandra";
+        LOG(log_.trace()) << "Writing txn to database";
 
         executor_.write(schema_->insertLedgerTransaction, seq, hash);
         executor_.write(
@@ -887,6 +967,17 @@ public:
         executor_.write(std::move(statements));
     }
 
+    void
+    writeMPTHolders(std::vector<MPTHolderData> const& data) override
+    {
+        std::vector<Statement> statements;
+        statements.reserve(data.size());
+        for (auto [mptId, holder] : data)
+            statements.push_back(schema_->insertMPTHolder.bind(std::move(mptId), std::move(holder)));
+
+        executor_.write(std::move(statements));
+    }
+
     void
     startWrites() const override
     {
@@ -894,6 +985,14 @@ public:
         // probably was used in PG to start a transaction or smth.
     }
 
+    void
+    writeMigratorStatus(std::string const& migratorName, std::string const& status) override
+    {
+        executor_.writeSync(
+            schema_->insertMigratorStatus, data::cassandra::Text{migratorName}, data::cassandra::Text(status)
+        );
+    }
+
     bool
     isTooBusy() const override
     {

src/data/DBHelpers.hpp

@@ -23,16 +23,16 @@
 #include "util/Assert.hpp"
 
 #include <boost/container/flat_set.hpp>
-#include <ripple/basics/Blob.h>
-#include <ripple/basics/Log.h>
-#include <ripple/basics/StringUtilities.h>
-#include <ripple/basics/base_uint.h>
-#include <ripple/protocol/AccountID.h>
-#include <ripple/protocol/SField.h>
-#include <ripple/protocol/STAccount.h>
-#include <ripple/protocol/STLedgerEntry.h>
-#include <ripple/protocol/Serializer.h>
-#include <ripple/protocol/TxMeta.h>
+#include <xrpl/basics/Blob.h>
+#include <xrpl/basics/Log.h>
+#include <xrpl/basics/StringUtilities.h>
+#include <xrpl/basics/base_uint.h>
+#include <xrpl/protocol/AccountID.h>
+#include <xrpl/protocol/SField.h>
+#include <xrpl/protocol/STAccount.h>
+#include <xrpl/protocol/STLedgerEntry.h>
+#include <xrpl/protocol/Serializer.h>
+#include <xrpl/protocol/TxMeta.h>
 
 #include <cstddef>
 #include <cstdint>
@@ -172,6 +172,14 @@ struct NFTsData {
     }
 };
 
+/**
+ * @brief Represents an MPT and holder pair
+ */
+struct MPTHolderData {
+    ripple::uint192 mptID;
+    ripple::AccountID holder;
+};
+
 /**
  * @brief Check whether the supplied object is an offer.
  *
@@ -182,11 +190,11 @@ template <typename T>
 inline bool
 isOffer(T const& object)
 {
-    static constexpr short OFFER_OFFSET = 0x006f;
-    static constexpr short SHIFT = 8;
+    static constexpr short kOFFER_OFFSET = 0x006f;
+    static constexpr short kSHIFT = 8;
 
-    short offer_bytes = (object[1] << SHIFT) | object[2];
-    return offer_bytes == OFFER_OFFSET;
+    short offerBytes = (object[1] << kSHIFT) | object[2];
+    return offerBytes == kOFFER_OFFSET;
 }
 
 /**
@@ -215,9 +223,9 @@ template <typename T>
 inline bool
 isDirNode(T const& object)
 {
-    static constexpr short DIR_NODE_SPACE_KEY = 0x0064;
+    static constexpr short kDIR_NODE_SPACE_KEY = 0x0064;
     short const spaceKey = (object.data()[1] << 8) | object.data()[2];
-    return spaceKey == DIR_NODE_SPACE_KEY;
+    return spaceKey == kDIR_NODE_SPACE_KEY;
 }
 
 /**
@@ -265,12 +273,12 @@ template <typename T>
 inline ripple::uint256
 getBookBase(T const& key)
 {
-    static constexpr size_t KEY_SIZE = 24;
+    static constexpr size_t kEY_SIZE = 24;
 
     ASSERT(key.size() == ripple::uint256::size(), "Invalid key size {}", key.size());
 
     ripple::uint256 ret;
-    for (size_t i = 0; i < KEY_SIZE; ++i)
+    for (size_t i = 0; i < kEY_SIZE; ++i)
         ret.data()[i] = key.data()[i];
 
     return ret;
@@ -289,4 +297,4 @@ uint256ToString(ripple::uint256 const& input)
 }
 
 /** @brief The ripple epoch start timestamp. Midnight on 1st January 2000. */
-static constexpr std::uint32_t rippleEpochStart = 946684800;
+static constexpr std::uint32_t kRIPPLE_EPOCH_START = 946684800;

src/data/LedgerCache.cpp

@@ -22,7 +22,7 @@
 #include "data/Types.hpp"
 #include "util/Assert.hpp"
 
-#include <ripple/basics/base_uint.h>
+#include <xrpl/basics/base_uint.h>
 
 #include <cstddef>
 #include <cstdint>
@@ -75,7 +75,7 @@ LedgerCache::update(std::vector<LedgerObject> const& objs, uint32_t seq, bool is
 
                 auto& e = map_[obj.key];
                 if (seq > e.seq) {
-                    e = {seq, obj.blob};
+                    e = {.seq = seq, .blob = obj.blob};
                 }
             } else {
                 map_.erase(obj.key);
@@ -101,7 +101,7 @@ LedgerCache::getSuccessor(ripple::uint256 const& key, uint32_t seq) const
     if (e == map_.end())
         return {};
     ++successorHitCounter_.get();
-    return {{e->first, e->second.blob}};
+    return {{.key = e->first, .blob = e->second.blob}};
 }
 
 std::optional<LedgerObject>
@@ -117,7 +117,7 @@ LedgerCache::getPredecessor(ripple::uint256 const& key, uint32_t seq) const
     if (e == map_.begin())
         return {};
     --e;
-    return {{e->first, e->second.blob}};
+    return {{.key = e->first, .blob = e->second.blob}};
 }
 
 std::optional<Blob>

src/data/LedgerCache.hpp

@@ -24,8 +24,8 @@
 #include "util/prometheus/Label.hpp"
 #include "util/prometheus/Prometheus.hpp"
 
-#include <ripple/basics/base_uint.h>
-#include <ripple/basics/hardened_hash.h>
+#include <xrpl/basics/base_uint.h>
+#include <xrpl/basics/hardened_hash.h>
 
 #include <atomic>
 #include <condition_variable>

src/data/README.md

@@ -262,3 +262,15 @@ CREATE TABLE clio.nf_token_transactions (
 ```
 
 The `nf_token_transactions` table serves as the NFT counterpart to `account_tx`, inspired by the same motivations and fulfilling a similar role within this context. It drives the `nft_history` API.
+
+### migrator_status
+
+```
+CREATE TABLE clio.migrator_status (
+    migrator_name TEXT,     # The name of the migrator
+    status TEXT,            # The status of the migrator
+    PRIMARY KEY (migrator_name)
+) 
+```
+
+The `migrator_status` table stores the status of the migratior in this database. If a migrator's status is `migrated`, it means this database has finished data migration for this migrator.

src/data/Types.hpp

@@ -19,11 +19,13 @@
 
 #pragma once
 
-#include <ripple/basics/base_uint.h>
-#include <ripple/protocol/AccountID.h>
+#include <xrpl/basics/base_uint.h>
+#include <xrpl/protocol/AccountID.h>
 
+#include <concepts>
 #include <cstdint>
 #include <optional>
+#include <string>
 #include <string_view>
 #include <tuple>
 #include <utility>
@@ -231,6 +233,14 @@ struct NFTsAndCursor {
     std::optional<ripple::uint256> cursor;
 };
 
+/**
+ * @brief Represents an array of MPTokens
+ */
+struct MPTHoldersAndCursor {
+    std::vector<Blob> mptokens;
+    std::optional<ripple::AccountID> cursor;
+};
+
 /**
  * @brief Stores a range of sequences as a min and max pair.
  */
@@ -239,8 +249,71 @@ struct LedgerRange {
     std::uint32_t maxSequence = 0;
 };
 
-constexpr ripple::uint256 firstKey{"0000000000000000000000000000000000000000000000000000000000000000"};
-constexpr ripple::uint256 lastKey{"FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF"};
-constexpr ripple::uint256 hi192{"0000000000000000000000000000000000000000000000001111111111111111"};
+/**
+ * @brief Represents an amendment in the XRPL
+ */
+struct Amendment {
+    std::string name;
+    ripple::uint256 feature;
+    bool isSupportedByXRPL = false;
+    bool isSupportedByClio = false;
+    bool isRetired = false;
+
+    /**
+     * @brief Get the amendment Id from its name
+     *
+     * @param name The name of the amendment
+     * @return The amendment Id as uint256
+     */
+    static ripple::uint256
+    getAmendmentId(std::string_view const name);
+
+    /**
+     * @brief Equality comparison operator
+     * @param other The object to compare to
+     * @return Whether the objects are equal
+     */
+    bool
+    operator==(Amendment const& other) const
+    {
+        return name == other.name;
+    }
+};
+
+/**
+ * @brief A helper for amendment name to feature conversions
+ */
+struct AmendmentKey {
+    std::string name;
+
+    /**
+     * @brief Construct a new AmendmentKey
+     * @param val Anything convertible to a string
+     */
+    AmendmentKey(std::convertible_to<std::string> auto&& val) : name{std::forward<decltype(val)>(val)}
+    {
+    }
+
+    /** @brief Conversion to string */
+    operator std::string const&() const;
+
+    /** @brief Conversion to string_view */
+    operator std::string_view() const;
+
+    /** @brief Conversion to uint256 */
+    operator ripple::uint256() const;
+
+    /**
+     * @brief Comparison operators
+     * @param other The object to compare to
+     * @return Whether the objects are equal, greater or less
+     */
+    auto
+    operator<=>(AmendmentKey const& other) const = default;
+};
+
+constexpr ripple::uint256 kFIRST_KEY{"0000000000000000000000000000000000000000000000000000000000000000"};
+constexpr ripple::uint256 kLAST_KEY{"FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF"};
+constexpr ripple::uint256 kHI192{"0000000000000000000000000000000000000000000000001111111111111111"};
 
 }  // namespace data

src/data/cassandra/Handle.cpp

@@ -60,7 +60,7 @@ Handle::connect() const
 Handle::FutureType
 Handle::asyncConnect(std::string_view keyspace) const
 {
-    return cass_session_connect_keyspace(session_, cluster_, keyspace.data());
+    return cass_session_connect_keyspace_n(session_, cluster_, keyspace.data(), keyspace.size());
 }
 
 Handle::MaybeErrorType
@@ -155,7 +155,7 @@ Handle::asyncExecute(std::vector<StatementType> const& statements, std::function
 Handle::PreparedStatementType
 Handle::prepare(std::string_view query) const
 {
-    Handle::FutureType const future = cass_session_prepare(session_, query.data());
+    Handle::FutureType const future = cass_session_prepare_n(session_, query.data(), query.size());
     auto const rc = future.await();
     if (rc)
         return cass_future_get_prepared(future);

src/data/cassandra/Schema.hpp

@@ -257,6 +257,31 @@ public:
             qualifiedTableName(settingsProvider_.get(), "nf_token_transactions")
         ));
 
+        statements.emplace_back(fmt::format(
+            R"(
+           CREATE TABLE IF NOT EXISTS {}
+                  ( 
+                    mpt_id blob,
+                    holder blob,
+                   PRIMARY KEY (mpt_id, holder)
+                  ) 
+             WITH CLUSTERING ORDER BY (holder ASC)
+            )",
+            qualifiedTableName(settingsProvider_.get(), "mp_token_holders")
+        ));
+
+        statements.emplace_back(fmt::format(
+            R"(
+           CREATE TABLE IF NOT EXISTS {}
+                  ( 
+                   migrator_name TEXT,
+                          status TEXT,
+                         PRIMARY KEY (migrator_name)
+                  ) 
+            )",
+            qualifiedTableName(settingsProvider_.get(), "migrator_status")
+        ));
+
         return statements;
     }();
 
@@ -393,6 +418,17 @@ public:
             ));
         }();
 
+        PreparedStatement insertMPTHolder = [this]() {
+            return handle_.get().prepare(fmt::format(
+                R"(
+                INSERT INTO {} 
+                       (mpt_id, holder)
+                VALUES (?, ?)
+                )",
+                qualifiedTableName(settingsProvider_.get(), "mp_token_holders")
+            ));
+        }();
+
         PreparedStatement insertLedgerHeader = [this]() {
             return handle_.get().prepare(fmt::format(
                 R"(
@@ -442,6 +478,17 @@ public:
             ));
         }();
 
+        PreparedStatement insertMigratorStatus = [this]() {
+            return handle_.get().prepare(fmt::format(
+                R"(
+                INSERT INTO {}
+                       (migrator_name, status)
+                VALUES (?, ?)
+                )",
+                qualifiedTableName(settingsProvider_.get(), "migrator_status")
+            ));
+        }();
+
         //
         // Select queries
         //
@@ -687,6 +734,20 @@ public:
             ));
         }();
 
+        PreparedStatement selectMPTHolders = [this]() {
+            return handle_.get().prepare(fmt::format(
+                R"(
+                SELECT holder
+                  FROM {}    
+                 WHERE mpt_id = ?
+                   AND holder > ?
+              ORDER BY holder ASC
+                 LIMIT ?
+                )",
+                qualifiedTableName(settingsProvider_.get(), "mp_token_holders")
+            ));
+        }();
+
         PreparedStatement selectLedgerByHash = [this]() {
             return handle_.get().prepare(fmt::format(
                 R"(
@@ -730,6 +791,17 @@ public:
                 qualifiedTableName(settingsProvider_.get(), "ledger_range")
             ));
         }();
+
+        PreparedStatement selectMigratorStatus = [this]() {
+            return handle_.get().prepare(fmt::format(
+                R"(
+                SELECT status
+                  FROM {}
+                 WHERE migrator_name = ?
+                )",
+                qualifiedTableName(settingsProvider_.get(), "migrator_status")
+            ));
+        }();
     };
 
     /**

src/data/cassandra/SettingsProvider.cpp

@@ -22,10 +22,7 @@
 #include "data/cassandra/Types.hpp"
 #include "data/cassandra/impl/Cluster.hpp"
 #include "util/Constants.hpp"
-#include "util/config/Config.hpp"
-
-#include <boost/json/conversion.hpp>
-#include <boost/json/value.hpp>
+#include "util/newconfig/ObjectView.hpp"
 
 #include <cerrno>
 #include <chrono>
@@ -36,43 +33,17 @@
 #include <ios>
 #include <iterator>
 #include <optional>
-#include <stdexcept>
 #include <string>
+#include <string_view>
 #include <system_error>
 
 namespace data::cassandra {
 
-namespace impl {
-inline Settings::ContactPoints
-tag_invoke(boost::json::value_to_tag<Settings::ContactPoints>, boost::json::value const& value)
-{
-    if (not value.is_object()) {
-        throw std::runtime_error("Feed entire Cassandra section to parse Settings::ContactPoints instead");
-    }
-
-    util::Config const obj{value};
-    Settings::ContactPoints out;
-
-    out.contactPoints = obj.valueOrThrow<std::string>("contact_points", "`contact_points` must be a string");
-    out.port = obj.maybeValue<uint16_t>("port");
-
-    return out;
-}
-
-inline Settings::SecureConnectionBundle
-tag_invoke(boost::json::value_to_tag<Settings::SecureConnectionBundle>, boost::json::value const& value)
-{
-    if (not value.is_string())
-        throw std::runtime_error("`secure_connect_bundle` must be a string");
-    return Settings::SecureConnectionBundle{value.as_string().data()};
-}
-}  // namespace impl
-
-SettingsProvider::SettingsProvider(util::Config const& cfg)
+SettingsProvider::SettingsProvider(util::config::ObjectView const& cfg)
     : config_{cfg}
-    , keyspace_{cfg.valueOr<std::string>("keyspace", "clio")}
+    , keyspace_{cfg.get<std::string>("keyspace")}
     , tablePrefix_{cfg.maybeValue<std::string>("table_prefix")}
-    , replicationFactor_{cfg.valueOr<uint16_t>("replication_factor", 3)}
+    , replicationFactor_{cfg.get<uint16_t>("replication_factor")}
     , settings_{parseSettings()}
 {
 }
@@ -86,8 +57,8 @@ SettingsProvider::getSettings() const
 std::optional<std::string>
 SettingsProvider::parseOptionalCertificate() const
 {
-    if (auto const certPath = config_.maybeValue<std::string>("certfile"); certPath) {
-        auto const path = std::filesystem::path(*certPath);
+    if (auto const certPath = config_.getValueView("certfile"); certPath.hasValue()) {
+        auto const path = std::filesystem::path(certPath.asString());
         std::ifstream fileStream(path.string(), std::ios::in);
         if (!fileStream) {
             throw std::system_error(errno, std::generic_category(), "Opening certificate " + path.string());
@@ -108,30 +79,34 @@ Settings
 SettingsProvider::parseSettings() const
 {
     auto settings = Settings::defaultSettings();
-    if (auto const bundle = config_.maybeValue<Settings::SecureConnectionBundle>("secure_connect_bundle"); bundle) {
-        settings.connectionInfo = *bundle;
+
+    // all config values used in settings is under "database.cassandra" prefix
+    if (config_.getValueView("secure_connect_bundle").hasValue()) {
+        auto const bundle = Settings::SecureConnectionBundle{(config_.get<std::string>("secure_connect_bundle"))};
+        settings.connectionInfo = bundle;
     } else {
-        settings.connectionInfo =
-            config_.valueOrThrow<Settings::ContactPoints>("Missing contact_points in Cassandra config");
+        Settings::ContactPoints out;
+        out.contactPoints = config_.get<std::string>("contact_points");
+        out.port = config_.maybeValue<uint32_t>("port");
+        settings.connectionInfo = out;
     }
 
-    settings.threads = config_.valueOr<uint32_t>("threads", settings.threads);
-    settings.maxWriteRequestsOutstanding =
-        config_.valueOr<uint32_t>("max_write_requests_outstanding", settings.maxWriteRequestsOutstanding);
-    settings.maxReadRequestsOutstanding =
-        config_.valueOr<uint32_t>("max_read_requests_outstanding", settings.maxReadRequestsOutstanding);
-    settings.coreConnectionsPerHost =
-        config_.valueOr<uint32_t>("core_connections_per_host", settings.coreConnectionsPerHost);
+    settings.threads = config_.get<uint32_t>("threads");
+    settings.maxWriteRequestsOutstanding = config_.get<uint32_t>("max_write_requests_outstanding");
+    settings.maxReadRequestsOutstanding = config_.get<uint32_t>("max_read_requests_outstanding");
+    settings.coreConnectionsPerHost = config_.get<uint32_t>("core_connections_per_host");
     settings.queueSizeIO = config_.maybeValue<uint32_t>("queue_size_io");
-    settings.writeBatchSize = config_.valueOr<std::size_t>("write_batch_size", settings.writeBatchSize);
+    settings.writeBatchSize = config_.get<std::size_t>("write_batch_size");
 
-    auto const connectTimeoutSecond = config_.maybeValue<uint32_t>("connect_timeout");
-    if (connectTimeoutSecond)
-        settings.connectionTimeout = std::chrono::milliseconds{*connectTimeoutSecond * util::MILLISECONDS_PER_SECOND};
+    if (config_.getValueView("connect_timeout").hasValue()) {
+        auto const connectTimeoutSecond = config_.get<uint32_t>("connect_timeout");
+        settings.connectionTimeout = std::chrono::milliseconds{connectTimeoutSecond * util::kMILLISECONDS_PER_SECOND};
+    }
 
-    auto const requestTimeoutSecond = config_.maybeValue<uint32_t>("request_timeout");
-    if (requestTimeoutSecond)
-        settings.requestTimeout = std::chrono::milliseconds{*requestTimeoutSecond * util::MILLISECONDS_PER_SECOND};
+    if (config_.getValueView("request_timeout").hasValue()) {
+        auto const requestTimeoutSecond = config_.get<uint32_t>("request_timeout");
+        settings.requestTimeout = std::chrono::milliseconds{requestTimeoutSecond * util::kMILLISECONDS_PER_SECOND};
+    }
 
     settings.certificate = parseOptionalCertificate();
     settings.username = config_.maybeValue<std::string>("username");

src/data/cassandra/SettingsProvider.hpp

@@ -19,10 +19,9 @@
 
 #pragma once
 
-#include "data/cassandra/Handle.hpp"
 #include "data/cassandra/Types.hpp"
-#include "util/config/Config.hpp"
-#include "util/log/Logger.hpp"
+#include "data/cassandra/impl/Cluster.hpp"
+#include "util/newconfig/ObjectView.hpp"
 
 #include <cstdint>
 #include <optional>
@@ -34,7 +33,7 @@ namespace data::cassandra {
  * @brief Provides settings for @ref BasicCassandraBackend.
  */
 class SettingsProvider {
-    util::Config config_;
+    util::config::ObjectView config_;
 
     std::string keyspace_;
     std::optional<std::string> tablePrefix_;
@@ -47,7 +46,7 @@ public:
      *
      * @param cfg The config of Clio to use
      */
-    explicit SettingsProvider(util::Config const& cfg);
+    explicit SettingsProvider(util::config::ObjectView const& cfg);
 
     /**
      * @return The cluster settings

src/data/cassandra/Types.hpp

@@ -21,6 +21,8 @@
 
 #include <cstdint>
 #include <expected>
+#include <string>
+#include <utility>
 
 namespace data::cassandra {
 
@@ -55,6 +57,26 @@ struct Limit {
     int32_t limit;
 };
 
+/**
+ * @brief A strong type wrapper for string
+ *
+ * This is unfortunately needed right now to support TEXT properly
+ * because clio uses string to represent BLOB
+ * If we want to bind TEXT with string, we need to use this type
+ */
+struct Text {
+    std::string text;
+
+    /**
+     * @brief Construct a new Text object from string type
+     *
+     * @param text The text to wrap
+     */
+    explicit Text(std::string text) : text{std::move(text)}
+    {
+    }
+};
+
 class Handle;
 class CassandraError;
 

src/data/cassandra/impl/Batch.cpp

@@ -31,14 +31,14 @@
 #include <vector>
 
 namespace {
-constexpr auto batchDeleter = [](CassBatch* ptr) { cass_batch_free(ptr); };
+constexpr auto kBATCH_DELETER = [](CassBatch* ptr) { cass_batch_free(ptr); };
 }  // namespace
 
 namespace data::cassandra::impl {
 
 // TODO: Use an appropriate value instead of CASS_BATCH_TYPE_LOGGED for different use cases
 Batch::Batch(std::vector<Statement> const& statements)
-    : ManagedObject{cass_batch_new(CASS_BATCH_TYPE_LOGGED), batchDeleter}
+    : ManagedObject{cass_batch_new(CASS_BATCH_TYPE_LOGGED), kBATCH_DELETER}
 {
     cass_batch_set_is_idempotent(*this, cass_true);
 

src/data/cassandra/impl/Cluster.cpp

@@ -21,6 +21,7 @@
 
 #include "data/cassandra/impl/ManagedObject.hpp"
 #include "data/cassandra/impl/SslContext.hpp"
+#include "util/OverloadSet.hpp"
 #include "util/log/Logger.hpp"
 
 #include <cassandra.h>
@@ -31,21 +32,14 @@
 #include <variant>
 
 namespace {
-constexpr auto clusterDeleter = [](CassCluster* ptr) { cass_cluster_free(ptr); };
 
-template <typename... Ts>
-struct overloadSet : Ts... {
-    using Ts::operator()...;
-};
+constexpr auto kCLUSTER_DELETER = [](CassCluster* ptr) { cass_cluster_free(ptr); };
 
-// explicit deduction guide (not needed as of C++20, but clang be clang)
-template <typename... Ts>
-overloadSet(Ts...) -> overloadSet<Ts...>;
 };  // namespace
 
 namespace data::cassandra::impl {
 
-Cluster::Cluster(Settings const& settings) : ManagedObject{cass_cluster_new(), clusterDeleter}
+Cluster::Cluster(Settings const& settings) : ManagedObject{cass_cluster_new(), kCLUSTER_DELETER}
 {
     using std::to_string;
 
@@ -90,7 +84,7 @@ void
 Cluster::setupConnection(Settings const& settings)
 {
     std::visit(
-        overloadSet{
+        util::OverloadSet{
             [this](Settings::ContactPoints const& points) { setupContactPoints(points); },
             [this](Settings::SecureConnectionBundle const& bundle) { setupSecureBundle(bundle); }
         },

src/data/cassandra/impl/Cluster.hpp

@@ -25,6 +25,8 @@
 #include <cassandra.h>
 
 #include <chrono>
+#include <cstddef>
+#include <cstdint>
 #include <optional>
 #include <string>
 #include <string_view>
@@ -39,10 +41,10 @@ namespace data::cassandra::impl {
  * @brief Bundles all cassandra settings in one place.
  */
 struct Settings {
-    static constexpr std::size_t DEFAULT_CONNECTION_TIMEOUT = 10000;
-    static constexpr uint32_t DEFAULT_MAX_WRITE_REQUESTS_OUTSTANDING = 10'000;
-    static constexpr uint32_t DEFAULT_MAX_READ_REQUESTS_OUTSTANDING = 100'000;
-    static constexpr std::size_t DEFAULT_BATCH_SIZE = 20;
+    static constexpr std::size_t kDEFAULT_CONNECTION_TIMEOUT = 10000;
+    static constexpr uint32_t kDEFAULT_MAX_WRITE_REQUESTS_OUTSTANDING = 10'000;
+    static constexpr uint32_t kDEFAULT_MAX_READ_REQUESTS_OUTSTANDING = 100'000;
+    static constexpr std::size_t kDEFAULT_BATCH_SIZE = 20;
 
     /**
      * @brief Represents the configuration of contact points for cassandra.
@@ -63,7 +65,7 @@ struct Settings {
     bool enableLog = false;
 
     /** @brief Connect timeout specified in milliseconds */
-    std::chrono::milliseconds connectionTimeout = std::chrono::milliseconds{DEFAULT_CONNECTION_TIMEOUT};
+    std::chrono::milliseconds connectionTimeout = std::chrono::milliseconds{kDEFAULT_CONNECTION_TIMEOUT};
 
     /** @brief Request timeout specified in milliseconds */
     std::chrono::milliseconds requestTimeout = std::chrono::milliseconds{0};  // no timeout at all
@@ -75,16 +77,16 @@ struct Settings {
     uint32_t threads = std::thread::hardware_concurrency();
 
     /** @brief The maximum number of outstanding write requests at any given moment */
-    uint32_t maxWriteRequestsOutstanding = DEFAULT_MAX_WRITE_REQUESTS_OUTSTANDING;
+    uint32_t maxWriteRequestsOutstanding = kDEFAULT_MAX_WRITE_REQUESTS_OUTSTANDING;
 
     /** @brief The maximum number of outstanding read requests at any given moment */
-    uint32_t maxReadRequestsOutstanding = DEFAULT_MAX_READ_REQUESTS_OUTSTANDING;
+    uint32_t maxReadRequestsOutstanding = kDEFAULT_MAX_READ_REQUESTS_OUTSTANDING;
 
     /** @brief The number of connection per host to always have active */
     uint32_t coreConnectionsPerHost = 1u;
 
     /** @brief Size of batches when writing */
-    std::size_t writeBatchSize = DEFAULT_BATCH_SIZE;
+    std::size_t writeBatchSize = kDEFAULT_BATCH_SIZE;
 
     /** @brief Size of the IO queue */
     std::optional<uint32_t> queueSizeIO = std::nullopt;  // NOLINT(readability-redundant-member-init)

src/data/cassandra/impl/Collection.hpp

@@ -22,7 +22,7 @@
 #include "data/cassandra/impl/ManagedObject.hpp"
 
 #include <cassandra.h>
-#include <ripple/basics/base_uint.h>
+#include <xrpl/basics/base_uint.h>
 
 #include <cstdint>
 #include <stdexcept>
@@ -33,7 +33,7 @@
 namespace data::cassandra::impl {
 
 class Collection : public ManagedObject<CassCollection> {
-    static constexpr auto deleter = [](CassCollection* ptr) { cass_collection_free(ptr); };
+    static constexpr auto kDELETER = [](CassCollection* ptr) { cass_collection_free(ptr); };
 
     static void
     throwErrorIfNeeded(CassError const rc, std::string_view const label)
@@ -49,7 +49,7 @@ public:
 
     template <typename Type>
     explicit Collection(std::vector<Type> const& value)
-        : ManagedObject{cass_collection_new(CASS_COLLECTION_TYPE_LIST, value.size()), deleter}
+        : ManagedObject{cass_collection_new(CASS_COLLECTION_TYPE_LIST, value.size()), kDELETER}
     {
         bind(value);
     }

src/data/cassandra/impl/Future.cpp

@@ -32,12 +32,12 @@
 #include <utility>
 
 namespace {
-constexpr auto futureDeleter = [](CassFuture* ptr) { cass_future_free(ptr); };
+constexpr auto kFUTURE_DELETER = [](CassFuture* ptr) { cass_future_free(ptr); };
 }  // namespace
 
 namespace data::cassandra::impl {
 
-/* implicit */ Future::Future(CassFuture* ptr) : ManagedObject{ptr, futureDeleter}
+/* implicit */ Future::Future(CassFuture* ptr) : ManagedObject{ptr, kFUTURE_DELETER}
 {
 }
 

src/data/cassandra/impl/ManagedObject.hpp

@@ -30,8 +30,8 @@ protected:
     std::unique_ptr<Managed, void (*)(Managed*)> ptr_;
 
 public:
-    template <typename deleterCallable>
-    ManagedObject(Managed* rawPtr, deleterCallable deleter) : ptr_{rawPtr, deleter}
+    template <typename DeleterCallable>
+    ManagedObject(Managed* rawPtr, DeleterCallable deleter) : ptr_{rawPtr, deleter}
     {
         if (rawPtr == nullptr)
             throw std::runtime_error("Could not create DB object - got nullptr");

src/data/cassandra/impl/Result.cpp

@@ -26,13 +26,13 @@
 #include <cstddef>
 
 namespace {
-constexpr auto resultDeleter = [](CassResult const* ptr) { cass_result_free(ptr); };
-constexpr auto resultIteratorDeleter = [](CassIterator* ptr) { cass_iterator_free(ptr); };
+constexpr auto kRESULT_DELETER = [](CassResult const* ptr) { cass_result_free(ptr); };
+constexpr auto kRESULT_ITERATOR_DELETER = [](CassIterator* ptr) { cass_iterator_free(ptr); };
 }  // namespace
 
 namespace data::cassandra::impl {
 
-/* implicit */ Result::Result(CassResult const* ptr) : ManagedObject{ptr, resultDeleter}
+/* implicit */ Result::Result(CassResult const* ptr) : ManagedObject{ptr, kRESULT_DELETER}
 {
 }
 
@@ -49,7 +49,7 @@ Result::hasRows() const
 }
 
 /* implicit */ ResultIterator::ResultIterator(CassIterator* ptr)
-    : ManagedObject{ptr, resultIteratorDeleter}, hasMore_{cass_iterator_next(ptr) != 0u}
+    : ManagedObject{ptr, kRESULT_ITERATOR_DELETER}, hasMore_{cass_iterator_next(ptr) != 0u}
 {
 }
 

src/data/cassandra/impl/Result.hpp

@@ -21,10 +21,11 @@
 
 #include "data/cassandra/impl/ManagedObject.hpp"
 #include "data/cassandra/impl/Tuple.hpp"
+#include "util/UnsupportedType.hpp"
 
 #include <cassandra.h>
-#include <ripple/basics/base_uint.h>
-#include <ripple/protocol/AccountID.h>
+#include <xrpl/basics/base_uint.h>
+#include <xrpl/protocol/AccountID.h>
 
 #include <cstddef>
 #include <cstdint>
@@ -41,9 +42,6 @@
 
 namespace data::cassandra::impl {
 
-template <typename>
-static constexpr bool unsupported_v = false;
-
 template <typename Type>
 inline Type
 extractColumn(CassRow const* row, std::size_t idx)
@@ -103,7 +101,7 @@ extractColumn(CassRow const* row, std::size_t idx)
         output = static_cast<DecayedType>(out);
     } else {
         // type not supported for extraction
-        static_assert(unsupported_v<DecayedType>);
+        static_assert(util::Unsupported<DecayedType>);
     }
 
     return output;

src/data/cassandra/impl/Session.hpp

@@ -26,10 +26,10 @@
 namespace data::cassandra::impl {
 
 class Session : public ManagedObject<CassSession> {
-    static constexpr auto deleter = [](CassSession* ptr) { cass_session_free(ptr); };
+    static constexpr auto kDELETER = [](CassSession* ptr) { cass_session_free(ptr); };
 
 public:
-    Session() : ManagedObject{cass_session_new(), deleter}
+    Session() : ManagedObject{cass_session_new(), kDELETER}
     {
     }
 };

src/data/cassandra/impl/SslContext.cpp

@@ -27,12 +27,12 @@
 #include <string>
 
 namespace {
-constexpr auto contextDeleter = [](CassSsl* ptr) { cass_ssl_free(ptr); };
+constexpr auto kCONTEXT_DELETER = [](CassSsl* ptr) { cass_ssl_free(ptr); };
 }  // namespace
 
 namespace data::cassandra::impl {
 
-SslContext::SslContext(std::string const& certificate) : ManagedObject{cass_ssl_new(), contextDeleter}
+SslContext::SslContext(std::string const& certificate) : ManagedObject{cass_ssl_new(), kCONTEXT_DELETER}
 {
     cass_ssl_set_verify_flags(*this, CASS_SSL_VERIFY_NONE);
     if (auto const rc = cass_ssl_add_trusted_cert(*this, certificate.c_str()); rc != CASS_OK) {

src/data/cassandra/impl/Statement.hpp

@@ -23,12 +23,13 @@
 #include "data/cassandra/impl/Collection.hpp"
 #include "data/cassandra/impl/ManagedObject.hpp"
 #include "data/cassandra/impl/Tuple.hpp"
+#include "util/UnsupportedType.hpp"
 
 #include <cassandra.h>
 #include <fmt/core.h>
-#include <ripple/basics/base_uint.h>
-#include <ripple/protocol/AccountID.h>
-#include <ripple/protocol/STAccount.h>
+#include <xrpl/basics/base_uint.h>
+#include <xrpl/protocol/AccountID.h>
+#include <xrpl/protocol/STAccount.h>
 
 #include <cstddef>
 #include <cstdint>
@@ -42,10 +43,7 @@
 namespace data::cassandra::impl {
 
 class Statement : public ManagedObject<CassStatement> {
-    static constexpr auto deleter = [](CassStatement* ptr) { cass_statement_free(ptr); };
-
-    template <typename>
-    static constexpr bool unsupported_v = false;
+    static constexpr auto kDELETER = [](CassStatement* ptr) { cass_statement_free(ptr); };
 
 public:
     /**
@@ -56,14 +54,14 @@ public:
      */
     template <typename... Args>
     explicit Statement(std::string_view query, Args&&... args)
-        : ManagedObject{cass_statement_new(query.data(), sizeof...(args)), deleter}
+        : ManagedObject{cass_statement_new_n(query.data(), query.size(), sizeof...(args)), kDELETER}
     {
         cass_statement_set_consistency(*this, CASS_CONSISTENCY_QUORUM);
         cass_statement_set_is_idempotent(*this, cass_true);
         bind<Args...>(std::forward<Args>(args)...);
     }
 
-    /* implicit */ Statement(CassStatement* ptr) : ManagedObject{ptr, deleter}
+    /* implicit */ Statement(CassStatement* ptr) : ManagedObject{ptr, kDELETER}
     {
         cass_statement_set_consistency(*this, CASS_CONSISTENCY_QUORUM);
         cass_statement_set_is_idempotent(*this, cass_true);
@@ -108,9 +106,9 @@ public:
         using UintByteTupleType = std::tuple<uint32_t, ripple::uint256>;
         using ByteVectorType = std::vector<ripple::uint256>;
 
-        if constexpr (std::is_same_v<DecayedType, ripple::uint256>) {
+        if constexpr (std::is_same_v<DecayedType, ripple::uint256> || std::is_same_v<DecayedType, ripple::uint192>) {
             auto const rc = bindBytes(value.data(), value.size());
-            throwErrorIfNeeded(rc, "Bind ripple::uint256");
+            throwErrorIfNeeded(rc, "Bind ripple::base_uint");
         } else if constexpr (std::is_same_v<DecayedType, ripple::AccountID>) {
             auto const rc = bindBytes(value.data(), value.size());
             throwErrorIfNeeded(rc, "Bind ripple::AccountID");
@@ -121,6 +119,9 @@ public:
             // reinterpret_cast is needed here :'(
             auto const rc = bindBytes(reinterpret_cast<unsigned char const*>(value.data()), value.size());
             throwErrorIfNeeded(rc, "Bind string (as bytes)");
+        } else if constexpr (std::is_convertible_v<DecayedType, Text>) {
+            auto const rc = cass_statement_bind_string_n(*this, idx, value.text.c_str(), value.text.size());
+            throwErrorIfNeeded(rc, "Bind string (as TEXT)");
         } else if constexpr (std::is_same_v<DecayedType, UintTupleType> ||
                              std::is_same_v<DecayedType, UintByteTupleType>) {
             auto const rc = cass_statement_bind_tuple(*this, idx, Tuple{std::forward<Type>(value)});
@@ -141,7 +142,7 @@ public:
             throwErrorIfNeeded(rc, "Bind int64");
         } else {
             // type not supported for binding
-            static_assert(unsupported_v<DecayedType>);
+            static_assert(util::Unsupported<DecayedType>);
         }
     }
 };
@@ -152,10 +153,10 @@ public:
  * This is used to produce Statement objects that can be executed.
  */
 class PreparedStatement : public ManagedObject<CassPrepared const> {
-    static constexpr auto deleter = [](CassPrepared const* ptr) { cass_prepared_free(ptr); };
+    static constexpr auto kDELETER = [](CassPrepared const* ptr) { cass_prepared_free(ptr); };
 
 public:
-    /* implicit */ PreparedStatement(CassPrepared const* ptr) : ManagedObject{ptr, deleter}
+    /* implicit */ PreparedStatement(CassPrepared const* ptr) : ManagedObject{ptr, kDELETER}
     {
     }
 

src/data/cassandra/impl/Tuple.cpp

@@ -24,17 +24,17 @@
 #include <cassandra.h>
 
 namespace {
-constexpr auto tupleDeleter = [](CassTuple* ptr) { cass_tuple_free(ptr); };
-constexpr auto tupleIteratorDeleter = [](CassIterator* ptr) { cass_iterator_free(ptr); };
+constexpr auto kTUPLE_DELETER = [](CassTuple* ptr) { cass_tuple_free(ptr); };
+constexpr auto kTUPLE_ITERATOR_DELETER = [](CassIterator* ptr) { cass_iterator_free(ptr); };
 }  // namespace
 
 namespace data::cassandra::impl {
 
-/* implicit */ Tuple::Tuple(CassTuple* ptr) : ManagedObject{ptr, tupleDeleter}
+/* implicit */ Tuple::Tuple(CassTuple* ptr) : ManagedObject{ptr, kTUPLE_DELETER}
 {
 }
 
-/* implicit */ TupleIterator::TupleIterator(CassIterator* ptr) : ManagedObject{ptr, tupleIteratorDeleter}
+/* implicit */ TupleIterator::TupleIterator(CassIterator* ptr) : ManagedObject{ptr, kTUPLE_ITERATOR_DELETER}
 {
 }
 

src/data/cassandra/impl/Tuple.hpp

@@ -20,9 +20,10 @@
 #pragma once
 
 #include "data/cassandra/impl/ManagedObject.hpp"
+#include "util/UnsupportedType.hpp"
 
 #include <cassandra.h>
-#include <ripple/basics/base_uint.h>
+#include <xrpl/basics/base_uint.h>
 
 #include <cstddef>
 #include <cstdint>
@@ -36,17 +37,14 @@
 namespace data::cassandra::impl {
 
 class Tuple : public ManagedObject<CassTuple> {
-    static constexpr auto deleter = [](CassTuple* ptr) { cass_tuple_free(ptr); };
-
-    template <typename>
-    static constexpr bool unsupported_v = false;
+    static constexpr auto kDELETER = [](CassTuple* ptr) { cass_tuple_free(ptr); };
 
 public:
     /* implicit */ Tuple(CassTuple* ptr);
 
     template <typename... Types>
     explicit Tuple(std::tuple<Types...>&& value)
-        : ManagedObject{cass_tuple_new(std::tuple_size<std::tuple<Types...>>{}), deleter}
+        : ManagedObject{cass_tuple_new(std::tuple_size<std::tuple<Types...>>{}), kDELETER}
     {
         std::apply(std::bind_front(&Tuple::bind<Types...>, this), std::move(value));
     }
@@ -91,15 +89,12 @@ public:
             throwErrorIfNeeded(rc, "Bind ripple::uint256");
         } else {
             // type not supported for binding
-            static_assert(unsupported_v<DecayedType>);
+            static_assert(util::Unsupported<DecayedType>);
         }
     }
 };
 
 class TupleIterator : public ManagedObject<CassIterator> {
-    template <typename>
-    static constexpr bool unsupported_v = false;
-
 public:
     /* implicit */ TupleIterator(CassIterator* ptr);
 
@@ -141,7 +136,7 @@ private:
             output = static_cast<DecayedType>(out);
         } else {
             // type not supported for extraction
-            static_assert(unsupported_v<DecayedType>);
+            static_assert(util::Unsupported<DecayedType>);
         }
 
         return output;

src/etl/CMakeLists.txt

@@ -10,7 +10,8 @@ target_sources(
           NetworkValidatedLedgers.cpp
           NFTHelpers.cpp
           Source.cpp
-          impl/ForwardingCache.cpp
+          MPTHelpers.cpp
+          impl/AmendmentBlockHandler.cpp
           impl/ForwardingSource.cpp
           impl/GrpcSource.cpp
           impl/SubscriptionSource.cpp

src/etl/CacheLoader.hpp

@@ -64,8 +64,12 @@ public:
      * @param backend The backend to use
      * @param cache The cache to load into
      */
-    CacheLoader(util::Config const& config, std::shared_ptr<BackendInterface> const& backend, CacheType& cache)
-        : backend_{backend}, cache_{cache}, settings_{make_CacheLoaderSettings(config)}, ctx_{settings_.numThreads}
+    CacheLoader(
+        util::config::ClioConfigDefinition const& config,
+        std::shared_ptr<BackendInterface> const& backend,
+        CacheType& cache
+    )
+        : backend_{backend}, cache_{cache}, settings_{makeCacheLoaderSettings(config)}, ctx_{settings_.numThreads}
     {
     }
 

src/etl/CacheLoaderSettings.cpp

@@ -19,11 +19,12 @@
 
 #include "etl/CacheLoaderSettings.hpp"
 
-#include "util/config/Config.hpp"
+#include "util/newconfig/ConfigDefinition.hpp"
 
 #include <boost/algorithm/string/predicate.hpp>
 
 #include <cstddef>
+#include <cstdint>
 #include <string>
 
 namespace etl {
@@ -47,31 +48,29 @@ CacheLoaderSettings::isDisabled() const
 }
 
 [[nodiscard]] CacheLoaderSettings
-make_CacheLoaderSettings(util::Config const& config)
+makeCacheLoaderSettings(util::config::ClioConfigDefinition const& config)
 {
     CacheLoaderSettings settings;
-    settings.numThreads = config.valueOr("io_threads", settings.numThreads);
-    if (config.contains("cache")) {
-        auto const cache = config.section("cache");
-        // Given diff number to generate cursors
-        settings.numCacheDiffs = cache.valueOr<size_t>("num_diffs", settings.numCacheDiffs);
-        // Given cursors number fetching from diff
-        settings.numCacheCursorsFromDiff = cache.valueOr<size_t>("num_cursors_from_diff", 0);
-        // Given cursors number fetching from account
-        settings.numCacheCursorsFromAccount = cache.valueOr<size_t>("num_cursors_from_account", 0);
+    settings.numThreads = config.get<uint16_t>("io_threads");
+    auto const cache = config.getObject("cache");
+    // Given diff number to generate cursors
+    settings.numCacheDiffs = cache.get<std::size_t>("num_diffs");
+    // Given cursors number fetching from diff
+    settings.numCacheCursorsFromDiff = cache.get<std::size_t>("num_cursors_from_diff");
+    // Given cursors number fetching from account
+    settings.numCacheCursorsFromAccount = cache.get<std::size_t>("num_cursors_from_account");
 
-        settings.numCacheMarkers = cache.valueOr<size_t>("num_markers", settings.numCacheMarkers);
-        settings.cachePageFetchSize = cache.valueOr<size_t>("page_fetch_size", settings.cachePageFetchSize);
+    settings.numCacheMarkers = cache.get<std::size_t>("num_markers");
+    settings.cachePageFetchSize = cache.get<std::size_t>("page_fetch_size");
+
+    auto const entry = cache.get<std::string>("load");
+    if (boost::iequals(entry, "sync"))
+        settings.loadStyle = CacheLoaderSettings::LoadStyle::SYNC;
+    if (boost::iequals(entry, "async"))
+        settings.loadStyle = CacheLoaderSettings::LoadStyle::ASYNC;
+    if (boost::iequals(entry, "none") or boost::iequals(entry, "no"))
+        settings.loadStyle = CacheLoaderSettings::LoadStyle::NONE;
 
-        if (auto entry = cache.maybeValue<std::string>("load"); entry) {
-            if (boost::iequals(*entry, "sync"))
-                settings.loadStyle = CacheLoaderSettings::LoadStyle::SYNC;
-            if (boost::iequals(*entry, "async"))
-                settings.loadStyle = CacheLoaderSettings::LoadStyle::ASYNC;
-            if (boost::iequals(*entry, "none") or boost::iequals(*entry, "no"))
-                settings.loadStyle = CacheLoaderSettings::LoadStyle::NONE;
-        }
-    }
     return settings;
 }
 

src/etl/CacheLoaderSettings.hpp

@@ -19,7 +19,7 @@
 
 #pragma once
 
-#include "util/config/Config.hpp"
+#include "util/newconfig/ConfigDefinition.hpp"
 
 #include <cstddef>
 
@@ -64,6 +64,6 @@ struct CacheLoaderSettings {
  * @returns The CacheLoaderSettings object
  */
 [[nodiscard]] CacheLoaderSettings
-make_CacheLoaderSettings(util::Config const& config);
+makeCacheLoaderSettings(util::config::ClioConfigDefinition const& config);
 
 }  // namespace etl

src/etl/ETLHelpers.cpp

@@ -21,7 +21,7 @@
 
 #include "util/Assert.hpp"
 
-#include <ripple/basics/base_uint.h>
+#include <xrpl/basics/base_uint.h>
 
 #include <cstddef>
 #include <vector>

src/etl/ETLHelpers.hpp

@@ -20,7 +20,7 @@
 /** @file */
 #pragma once
 
-#include <ripple/basics/base_uint.h>
+#include <xrpl/basics/base_uint.h>
 
 #include <condition_variable>
 #include <cstddef>

src/etl/ETLService.cpp

@@ -26,12 +26,12 @@
 #include "feed/SubscriptionManagerInterface.hpp"
 #include "util/Assert.hpp"
 #include "util/Constants.hpp"
-#include "util/config/Config.hpp"
 #include "util/log/Logger.hpp"
+#include "util/newconfig/ConfigDefinition.hpp"
 
 #include <boost/asio/io_context.hpp>
-#include <ripple/beast/core/CurrentThreadName.h>
-#include <ripple/protocol/LedgerHeader.h>
+#include <xrpl/beast/core/CurrentThreadName.h>
+#include <xrpl/protocol/LedgerHeader.h>
 
 #include <chrono>
 #include <cstddef>
@@ -88,9 +88,9 @@ ETLService::runETLPipeline(uint32_t startSequence, uint32_t numExtractors)
 
     auto const end = std::chrono::system_clock::now();
     auto const lastPublishedSeq = ledgerPublisher_.getLastPublishedSequence();
-    static constexpr auto NANOSECONDS_PER_SECOND = 1'000'000'000.0;
+    static constexpr auto kNANOSECONDS_PER_SECOND = 1'000'000'000.0;
     LOG(log_.debug()) << "Extracted and wrote " << lastPublishedSeq.value_or(startSequence) - startSequence << " in "
-                      << ((end - begin).count()) / NANOSECONDS_PER_SECOND;
+                      << ((end - begin).count()) / kNANOSECONDS_PER_SECOND;
 
     state_.isWriting = false;
 
@@ -168,7 +168,7 @@ ETLService::publishNextSequence(uint32_t nextSequence)
     if (auto rng = backend_->hardFetchLedgerRangeNoThrow(); rng && rng->maxSequence >= nextSequence) {
         ledgerPublisher_.publish(nextSequence, {});
         ++nextSequence;
-    } else if (networkValidatedLedgers_->waitUntilValidatedByNetwork(nextSequence, util::MILLISECONDS_PER_SECOND)) {
+    } else if (networkValidatedLedgers_->waitUntilValidatedByNetwork(nextSequence, util::kMILLISECONDS_PER_SECOND)) {
         LOG(log_.info()) << "Ledger with sequence = " << nextSequence << " has been validated by the network. "
                          << "Attempting to find in database and publish";
 
@@ -178,8 +178,8 @@ ETLService::publishNextSequence(uint32_t nextSequence)
         // database after the specified number of attempts. publishLedger()
         // waits one second between each attempt to read the ledger from the
         // database
-        constexpr size_t timeoutSeconds = 10;
-        bool const success = ledgerPublisher_.publish(nextSequence, timeoutSeconds);
+        constexpr size_t kTIMEOUT_SECONDS = 10;
+        bool const success = ledgerPublisher_.publish(nextSequence, kTIMEOUT_SECONDS);
 
         if (!success) {
             LOG(log_.warn()) << "Failed to publish ledger with sequence = " << nextSequence << " . Beginning ETL";
@@ -233,7 +233,7 @@ ETLService::monitorReadOnly()
             // if we can't, wait until it's validated by the network, or 1 second passes, whichever occurs
             // first. Even if we don't hear from rippled, if ledgers are being written to the db, we publish
             // them.
-            networkValidatedLedgers_->waitUntilValidatedByNetwork(latestSequence, util::MILLISECONDS_PER_SECOND);
+            networkValidatedLedgers_->waitUntilValidatedByNetwork(latestSequence, util::kMILLISECONDS_PER_SECOND);
         }
     }
 }
@@ -262,7 +262,7 @@ ETLService::doWork()
 }
 
 ETLService::ETLService(
-    util::Config const& config,
+    util::config::ClioConfigDefinition const& config,
     boost::asio::io_context& ioc,
     std::shared_ptr<BackendInterface> backend,
     std::shared_ptr<feed::SubscriptionManagerInterface> subscriptions,
@@ -280,9 +280,9 @@ ETLService::ETLService(
 {
     startSequence_ = config.maybeValue<uint32_t>("start_sequence");
     finishSequence_ = config.maybeValue<uint32_t>("finish_sequence");
-    state_.isReadOnly = config.valueOr("read_only", static_cast<bool>(state_.isReadOnly));
-    extractorThreads_ = config.valueOr<uint32_t>("extractor_threads", extractorThreads_);
-    txnThreshold_ = config.valueOr<size_t>("txn_threshold", txnThreshold_);
+    state_.isReadOnly = config.get<bool>("read_only");
+    extractorThreads_ = config.get<uint32_t>("extractor_threads");
+    txnThreshold_ = config.get<std::size_t>("txn_threshold");
 
     // This should probably be done in the backend factory but we don't have state available until here
     backend_->setCorruptionDetector(CorruptionDetector<data::LedgerCache>{state_, backend->cache()});

src/etl/ETLService.hpp

@@ -22,11 +22,11 @@
 #include "data/BackendInterface.hpp"
 #include "data/LedgerCache.hpp"
 #include "etl/CacheLoader.hpp"
-#include "etl/ETLHelpers.hpp"
 #include "etl/ETLState.hpp"
 #include "etl/LoadBalancer.hpp"
+#include "etl/NetworkValidatedLedgersInterface.hpp"
 #include "etl/SystemState.hpp"
-#include "etl/impl/AmendmentBlock.hpp"
+#include "etl/impl/AmendmentBlockHandler.hpp"
 #include "etl/impl/ExtractionDataPipe.hpp"
 #include "etl/impl/Extractor.hpp"
 #include "etl/impl/LedgerFetcher.hpp"
@@ -37,11 +37,10 @@
 #include "util/log/Logger.hpp"
 
 #include <boost/asio/io_context.hpp>
-#include <boost/asio/steady_timer.hpp>
 #include <boost/json/object.hpp>
 #include <grpcpp/grpcpp.h>
 #include <org/xrpl/rpc/v1/get_ledger.pb.h>
-#include <ripple/proto/org/xrpl/rpc/v1/xrp_ledger.grpc.pb.h>
+#include <xrpl/proto/org/xrpl/rpc/v1/xrp_ledger.grpc.pb.h>
 
 #include <cstddef>
 #include <cstdint>
@@ -53,9 +52,6 @@
 struct AccountTransactionsData;
 struct NFTTransactionsData;
 struct NFTsData;
-namespace feed {
-class SubscriptionManager;
-}  // namespace feed
 
 /**
  * @brief This namespace contains everything to do with the ETL and ETL sources.
@@ -85,7 +81,7 @@ class ETLService {
     using ExtractorType = etl::impl::Extractor<DataPipeType, LedgerFetcherType>;
     using LedgerLoaderType = etl::impl::LedgerLoader<LoadBalancerType, LedgerFetcherType>;
     using LedgerPublisherType = etl::impl::LedgerPublisher<CacheType>;
-    using AmendmentBlockHandlerType = etl::impl::AmendmentBlockHandler<>;
+    using AmendmentBlockHandlerType = etl::impl::AmendmentBlockHandler;
     using TransformerType =
         etl::impl::Transformer<DataPipeType, LedgerLoaderType, LedgerPublisherType, AmendmentBlockHandlerType>;
 
@@ -123,7 +119,7 @@ public:
      * @param ledgers The network validated ledgers datastructure
      */
     ETLService(
-        util::Config const& config,
+        util::config::ClioConfigDefinition const& config,
         boost::asio::io_context& ioc,
         std::shared_ptr<BackendInterface> backend,
         std::shared_ptr<feed::SubscriptionManagerInterface> subscriptions,
@@ -145,8 +141,8 @@ public:
      * @return A shared pointer to a new instance of ETLService
      */
     static std::shared_ptr<ETLService>
-    make_ETLService(
-        util::Config const& config,
+    makeETLService(
+        util::config::ClioConfigDefinition const& config,
         boost::asio::io_context& ioc,
         std::shared_ptr<BackendInterface> backend,
         std::shared_ptr<feed::SubscriptionManagerInterface> subscriptions,

src/etl/ETLState.cpp

@@ -24,7 +24,7 @@
 #include <boost/json/conversion.hpp>
 #include <boost/json/value.hpp>
 #include <boost/json/value_to.hpp>
-#include <ripple/protocol/jss.h>
+#include <xrpl/protocol/jss.h>
 
 #include <cstdint>
 #include <optional>

src/etl/ETLState.hpp

@@ -23,6 +23,7 @@
 
 #include <boost/json.hpp>
 #include <boost/json/conversion.hpp>
+#include <boost/json/object.hpp>
 #include <boost/json/value.hpp>
 #include <boost/json/value_to.hpp>
 
@@ -46,8 +47,11 @@ struct ETLState {
     static std::optional<ETLState>
     fetchETLStateFromSource(Forward& source) noexcept
     {
-        auto const serverInfoRippled = data::synchronous([&source](auto yield) {
-            return source.forwardToRippled({{"command", "server_info"}}, std::nullopt, yield);
+        auto const serverInfoRippled = data::synchronous([&source](auto yield) -> std::optional<boost::json::object> {
+            if (auto result = source.forwardToRippled({{"command", "server_info"}}, std::nullopt, {}, yield)) {
+                return std::move(result).value();
+            }
+            return std::nullopt;
         });
 
         if (serverInfoRippled)

src/etl/LedgerFetcherInterface.hpp

@@ -0,0 +1,65 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of clio: https://github.com/XRPLF/clio
+    Copyright (c) 2024, the clio developers.
+
+    Permission to use, copy, modify, and distribute this software for any
+    purpose with or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL,  DIRECT,  INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+/** @file */
+#pragma once
+
+#include <xrpl/proto/org/xrpl/rpc/v1/get_ledger.pb.h>
+#include <xrpl/proto/org/xrpl/rpc/v1/ledger.pb.h>
+
+#include <cstdint>
+#include <optional>
+
+namespace etl {
+
+/**
+ * @brief An interface for LedgerFetcher
+ */
+struct LedgerFetcherInterface {
+    using GetLedgerResponseType = org::xrpl::rpc::v1::GetLedgerResponse;
+    using OptionalGetLedgerResponseType = std::optional<GetLedgerResponseType>;
+
+    virtual ~LedgerFetcherInterface() = default;
+
+    /**
+     * @brief Extract data for a particular ledger from an ETL source
+     *
+     * This function continously tries to extract the specified ledger (using all available ETL sources) until the
+     * extraction succeeds, or the server shuts down.
+     *
+     * @param seq sequence of the ledger to extract
+     * @return Ledger header and transaction+metadata blobs; Empty optional if the server is shutting down
+     */
+    [[nodiscard]] virtual OptionalGetLedgerResponseType
+    fetchData(uint32_t seq) = 0;
+
+    /**
+     * @brief Extract diff data for a particular ledger from an ETL source.
+     *
+     * This function continously tries to extract the specified ledger (using all available ETL sources) until the
+     * extraction succeeds, or the server shuts down.
+     *
+     * @param seq sequence of the ledger to extract
+     * @return Ledger data diff between sequance and parent; Empty optional if the server is shutting down
+     */
+    [[nodiscard]] virtual OptionalGetLedgerResponseType
+    fetchDataAndDiff(uint32_t seq) = 0;
+};
+
+}  // namespace etl

src/etl/LoadBalancer.cpp

@@ -24,23 +24,28 @@
 #include "etl/NetworkValidatedLedgersInterface.hpp"
 #include "etl/Source.hpp"
 #include "feed/SubscriptionManagerInterface.hpp"
+#include "rpc/Errors.hpp"
 #include "util/Assert.hpp"
-#include "util/Constants.hpp"
 #include "util/Random.hpp"
+#include "util/ResponseExpirationCache.hpp"
 #include "util/log/Logger.hpp"
+#include "util/newconfig/ArrayView.hpp"
+#include "util/newconfig/ConfigDefinition.hpp"
+#include "util/newconfig/ObjectView.hpp"
 
 #include <boost/asio/io_context.hpp>
 #include <boost/asio/spawn.hpp>
 #include <boost/json/array.hpp>
 #include <boost/json/object.hpp>
 #include <boost/json/value.hpp>
+#include <boost/json/value_to.hpp>
 #include <fmt/core.h>
 
 #include <algorithm>
 #include <chrono>
-#include <cmath>
 #include <cstddef>
 #include <cstdint>
+#include <expected>
 #include <memory>
 #include <optional>
 #include <stdexcept>
@@ -49,13 +54,13 @@
 #include <utility>
 #include <vector>
 
-using namespace util;
+using namespace util::config;
 
 namespace etl {
 
 std::shared_ptr<LoadBalancer>
-LoadBalancer::make_LoadBalancer(
-    Config const& config,
+LoadBalancer::makeLoadBalancer(
+    ClioConfigDefinition const& config,
     boost::asio::io_context& ioc,
     std::shared_ptr<BackendInterface> backend,
     std::shared_ptr<feed::SubscriptionManagerInterface> subscriptions,
@@ -69,7 +74,7 @@ LoadBalancer::make_LoadBalancer(
 }
 
 LoadBalancer::LoadBalancer(
-    Config const& config,
+    ClioConfigDefinition const& config,
     boost::asio::io_context& ioc,
     std::shared_ptr<BackendInterface> backend,
     std::shared_ptr<feed::SubscriptionManagerInterface> subscriptions,
@@ -77,22 +82,23 @@ LoadBalancer::LoadBalancer(
     SourceFactory sourceFactory
 )
 {
-    auto const forwardingCacheTimeout = config.valueOr<float>("forwarding_cache_timeout", 0.f);
+    auto const forwardingCacheTimeout = config.get<float>("forwarding.cache_timeout");
     if (forwardingCacheTimeout > 0.f) {
-        forwardingCache_ = impl::ForwardingCache{std::chrono::milliseconds{
-            std::lroundf(forwardingCacheTimeout * static_cast<float>(util::MILLISECONDS_PER_SECOND))
-        }};
+        forwardingCache_ = util::ResponseExpirationCache{
+            util::config::ClioConfigDefinition::toMilliseconds(forwardingCacheTimeout),
+            {"server_info", "server_state", "server_definitions", "fee", "ledger_closed"}
+        };
     }
 
-    static constexpr std::uint32_t MAX_DOWNLOAD = 256;
-    if (auto value = config.maybeValue<uint32_t>("num_markers"); value) {
-        ASSERT(*value > 0 and *value <= MAX_DOWNLOAD, "'num_markers' value in config must be in range 1-256");
-        downloadRanges_ = *value;
+    auto const numMarkers = config.getValueView("num_markers");
+    if (numMarkers.hasValue()) {
+        auto const value = numMarkers.asIntType<uint32_t>();
+        downloadRanges_ = value;
     } else if (backend->fetchLedgerRange()) {
         downloadRanges_ = 4;
     }
 
-    auto const allowNoEtl = config.valueOr("allow_no_etl", false);
+    auto const allowNoEtl = config.get<bool>("allow_no_etl");
 
     auto const checkOnETLFailure = [this, allowNoEtl](std::string const& log) {
         LOG(log_.warn()) << log;
@@ -103,29 +109,37 @@ LoadBalancer::LoadBalancer(
         }
     };
 
-    for (auto const& entry : config.array("etl_sources")) {
+    auto const forwardingTimeout =
+        ClioConfigDefinition::toMilliseconds(config.get<float>("forwarding.request_timeout"));
+    auto const etlArray = config.getArray("etl_sources");
+    for (auto it = etlArray.begin<ObjectView>(); it != etlArray.end<ObjectView>(); ++it) {
         auto source = sourceFactory(
-            entry,
+            *it,
             ioc,
             backend,
             subscriptions,
             validatedLedgers,
+            forwardingTimeout,
             [this]() {
-                if (not hasForwardingSource_)
+                if (not hasForwardingSource_.lock().get())
                     chooseForwardingSource();
             },
-            [this]() { chooseForwardingSource(); },
-            [this]() { forwardingCache_->invalidate(); }
+            [this](bool wasForwarding) {
+                if (wasForwarding)
+                    chooseForwardingSource();
+            },
+            [this]() {
+                if (forwardingCache_.has_value())
+                    forwardingCache_->invalidate();
+            }
         );
 
         // checking etl node validity
         auto const stateOpt = ETLState::fetchETLStateFromSource(*source);
 
         if (!stateOpt) {
-            checkOnETLFailure(fmt::format(
-                "Failed to fetch ETL state from source = {} Please check the configuration and network",
-                source->toString()
-            ));
+            LOG(log_.warn()) << "Failed to fetch ETL state from source = " << source->toString()
+                             << " Please check the configuration and network";
         } else if (etlState_ && etlState_->networkID && stateOpt->networkID &&
                    etlState_->networkID != stateOpt->networkID) {
             checkOnETLFailure(fmt::format(
@@ -141,6 +155,9 @@ LoadBalancer::LoadBalancer(
         LOG(log_.info()) << "Added etl source - " << sources_.back()->toString();
     }
 
+    if (!etlState_)
+        checkOnETLFailure("Failed to fetch ETL state from any source. Please check the configuration and network");
+
     if (sources_.empty())
         checkOnETLFailure("No ETL sources configured. Please check the configuration");
 
@@ -209,16 +226,21 @@ LoadBalancer::fetchLedger(
     return response;
 }
 
-std::optional<boost::json::object>
+std::expected<boost::json::object, rpc::ClioError>
 LoadBalancer::forwardToRippled(
     boost::json::object const& request,
     std::optional<std::string> const& clientIp,
+    bool isAdmin,
     boost::asio::yield_context yield
 )
 {
+    if (not request.contains("command"))
+        return std::unexpected{rpc::ClioError::RpcCommandIsMissing};
+
+    auto const cmd = boost::json::value_to<std::string>(request.at("command"));
     if (forwardingCache_) {
-        if (auto cachedResponse = forwardingCache_->get(request); cachedResponse) {
-            return cachedResponse;
+        if (auto cachedResponse = forwardingCache_->get(cmd); cachedResponse) {
+            return std::move(cachedResponse).value();
         }
     }
 
@@ -227,21 +249,29 @@ LoadBalancer::forwardToRippled(
 
     auto numAttempts = 0u;
 
+    auto xUserValue = isAdmin ? kADMIN_FORWARDING_X_USER_VALUE : kUSER_FORWARDING_X_USER_VALUE;
+
     std::optional<boost::json::object> response;
+    rpc::ClioError error = rpc::ClioError::EtlConnectionError;
     while (numAttempts < sources_.size()) {
-        if (auto res = sources_[sourceIdx]->forwardToRippled(request, clientIp, yield)) {
-            response = std::move(res);
+        auto res = sources_[sourceIdx]->forwardToRippled(request, clientIp, xUserValue, yield);
+        if (res) {
+            response = std::move(res).value();
             break;
         }
+        error = std::max(error, res.error());  // Choose the best result between all sources
 
         sourceIdx = (sourceIdx + 1) % sources_.size();
         ++numAttempts;
     }
 
-    if (response and forwardingCache_ and not response->contains("error"))
-        forwardingCache_->put(request, *response);
+    if (response) {
+        if (forwardingCache_ and not response->contains("error"))
+            forwardingCache_->put(cmd, *response);
+        return std::move(response).value();
+    }
 
-    return response;
+    return std::unexpected{error};
 }
 
 boost::json::value
@@ -309,11 +339,13 @@ LoadBalancer::getETLState() noexcept
 void
 LoadBalancer::chooseForwardingSource()
 {
-    hasForwardingSource_ = false;
+    LOG(log_.info()) << "Choosing a new source to forward subscriptions";
+    auto hasForwardingSourceLock = hasForwardingSource_.lock();
+    hasForwardingSourceLock.get() = false;
     for (auto& source : sources_) {
-        if (not hasForwardingSource_ and source->isConnected()) {
+        if (not hasForwardingSourceLock.get() and source->isConnected()) {
             source->setForwarding(true);
-            hasForwardingSource_ = true;
+            hasForwardingSourceLock.get() = true;
         } else {
             source->setForwarding(false);
         }

src/etl/LoadBalancer.hpp

@@ -20,13 +20,15 @@
 #pragma once
 
 #include "data/BackendInterface.hpp"
-#include "etl/ETLHelpers.hpp"
 #include "etl/ETLState.hpp"
+#include "etl/NetworkValidatedLedgersInterface.hpp"
 #include "etl/Source.hpp"
-#include "etl/impl/ForwardingCache.hpp"
 #include "feed/SubscriptionManagerInterface.hpp"
-#include "util/config/Config.hpp"
+#include "rpc/Errors.hpp"
+#include "util/Mutex.hpp"
+#include "util/ResponseExpirationCache.hpp"
 #include "util/log/Logger.hpp"
+#include "util/newconfig/ConfigDefinition.hpp"
 
 #include <boost/asio.hpp>
 #include <boost/asio/io_context.hpp>
@@ -36,15 +38,15 @@
 #include <grpcpp/grpcpp.h>
 #include <org/xrpl/rpc/v1/get_ledger.pb.h>
 #include <org/xrpl/rpc/v1/ledger.pb.h>
-#include <ripple/proto/org/xrpl/rpc/v1/xrp_ledger.grpc.pb.h>
+#include <xrpl/proto/org/xrpl/rpc/v1/xrp_ledger.grpc.pb.h>
 
-#include <atomic>
 #include <chrono>
 #include <cstdint>
+#include <expected>
 #include <memory>
 #include <optional>
 #include <string>
-#include <utility>
+#include <string_view>
 #include <vector>
 
 namespace etl {
@@ -63,18 +65,33 @@ public:
     using OptionalGetLedgerResponseType = std::optional<GetLedgerResponseType>;
 
 private:
-    static constexpr std::uint32_t DEFAULT_DOWNLOAD_RANGES = 16;
+    static constexpr std::uint32_t kDEFAULT_DOWNLOAD_RANGES = 16;
 
     util::Logger log_{"ETL"};
     // Forwarding cache must be destroyed after sources because sources have a callback to invalidate cache
-    std::optional<impl::ForwardingCache> forwardingCache_;
+    std::optional<util::ResponseExpirationCache> forwardingCache_;
+    std::optional<std::string> forwardingXUserValue_;
+
     std::vector<SourcePtr> sources_;
     std::optional<ETLState> etlState_;
     std::uint32_t downloadRanges_ =
-        DEFAULT_DOWNLOAD_RANGES; /*< The number of markers to use when downloading initial ledger */
-    std::atomic_bool hasForwardingSource_{false};
+        kDEFAULT_DOWNLOAD_RANGES; /*< The number of markers to use when downloading initial ledger */
+
+    // Using mutext instead of atomic_bool because choosing a new source to
+    // forward messages should be done with a mutual exclusion otherwise there will be a race condition
+    util::Mutex<bool> hasForwardingSource_{false};
 
 public:
+    /**
+     * @brief Value for the X-User header when forwarding admin requests
+     */
+    static constexpr std::string_view kADMIN_FORWARDING_X_USER_VALUE = "clio_admin";
+
+    /**
+     * @brief Value for the X-User header when forwarding user requests
+     */
+    static constexpr std::string_view kUSER_FORWARDING_X_USER_VALUE = "clio_user";
+
     /**
      * @brief Create an instance of the load balancer.
      *
@@ -86,12 +103,12 @@ public:
      * @param sourceFactory A factory function to create a source
      */
     LoadBalancer(
-        util::Config const& config,
+        util::config::ClioConfigDefinition const& config,
         boost::asio::io_context& ioc,
         std::shared_ptr<BackendInterface> backend,
         std::shared_ptr<feed::SubscriptionManagerInterface> subscriptions,
         std::shared_ptr<NetworkValidatedLedgersInterface> validatedLedgers,
-        SourceFactory sourceFactory = make_Source
+        SourceFactory sourceFactory = makeSource
     );
 
     /**
@@ -106,13 +123,13 @@ public:
      * @return A shared pointer to a new instance of LoadBalancer
      */
     static std::shared_ptr<LoadBalancer>
-    make_LoadBalancer(
-        util::Config const& config,
+    makeLoadBalancer(
+        util::config::ClioConfigDefinition const& config,
         boost::asio::io_context& ioc,
         std::shared_ptr<BackendInterface> backend,
         std::shared_ptr<feed::SubscriptionManagerInterface> subscriptions,
         std::shared_ptr<NetworkValidatedLedgersInterface> validatedLedgers,
-        SourceFactory sourceFactory = make_Source
+        SourceFactory sourceFactory = makeSource
     );
 
     ~LoadBalancer();
@@ -167,13 +184,15 @@ public:
      *
      * @param request JSON-RPC request to forward
      * @param clientIp The IP address of the peer, if known
+     * @param isAdmin Whether the request is from an admin
      * @param yield The coroutine context
-     * @return Response received from rippled node as JSON object on success; nullopt on failure
+     * @return Response received from rippled node as JSON object on success or error on failure
      */
-    std::optional<boost::json::object>
+    std::expected<boost::json::object, rpc::ClioError>
     forwardToRippled(
         boost::json::object const& request,
         std::optional<std::string> const& clientIp,
+        bool isAdmin,
         boost::asio::yield_context yield
     );
 

src/etl/MPTHelpers.cpp

@@ -0,0 +1,86 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of clio: https://github.com/XRPLF/clio
+    Copyright (c) 2024, the clio developers.
+
+    Permission to use, copy, modify, and distribute this software for any
+    purpose with or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL,  DIRECT,  INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include "data/DBHelpers.hpp"
+
+#include <ripple/protocol/STBase.h>
+#include <ripple/protocol/STTx.h>
+#include <ripple/protocol/TxMeta.h>
+#include <xrpl/basics/base_uint.h>
+#include <xrpl/protocol/LedgerFormats.h>
+#include <xrpl/protocol/SField.h>
+#include <xrpl/protocol/STLedgerEntry.h>
+#include <xrpl/protocol/STObject.h>
+#include <xrpl/protocol/Serializer.h>
+#include <xrpl/protocol/TER.h>
+#include <xrpl/protocol/TxFormats.h>
+
+#include <optional>
+#include <string>
+
+namespace etl {
+
+/**
+ * @brief Get the MPToken created from a transaction
+ *
+ * @param txMeta Transaction metadata
+ * @return MPT and holder account pair
+ */
+std::optional<MPTHolderData>
+getMPTokenAuthorize(ripple::TxMeta const& txMeta)
+{
+    for (ripple::STObject const& node : txMeta.getNodes()) {
+        if (node.getFieldU16(ripple::sfLedgerEntryType) != ripple::ltMPTOKEN)
+            continue;
+
+        if (node.getFName() == ripple::sfCreatedNode) {
+            auto const& newMPT = node.peekAtField(ripple::sfNewFields).downcast<ripple::STObject>();
+            return MPTHolderData{
+                .mptID = newMPT[ripple::sfMPTokenIssuanceID], .holder = newMPT.getAccountID(ripple::sfAccount)
+            };
+        }
+    }
+    return {};
+}
+
+std::optional<MPTHolderData>
+getMPTHolderFromTx(ripple::TxMeta const& txMeta, ripple::STTx const& sttx)
+{
+    if (txMeta.getResultTER() != ripple::tesSUCCESS || sttx.getTxnType() != ripple::TxType::ttMPTOKEN_AUTHORIZE)
+        return {};
+
+    return getMPTokenAuthorize(txMeta);
+}
+
+std::optional<MPTHolderData>
+getMPTHolderFromObj(std::string const& key, std::string const& blob)
+{
+    ripple::STLedgerEntry const sle =
+        ripple::STLedgerEntry(ripple::SerialIter{blob.data(), blob.size()}, ripple::uint256::fromVoid(key.data()));
+
+    if (sle.getFieldU16(ripple::sfLedgerEntryType) != ripple::ltMPTOKEN)
+        return {};
+
+    auto const mptIssuanceID = sle[ripple::sfMPTokenIssuanceID];
+    auto const holder = sle.getAccountID(ripple::sfAccount);
+
+    return MPTHolderData{.mptID = mptIssuanceID, .holder = holder};
+}
+
+}  // namespace etl

src/etl/MPTHelpers.hpp

@@ -0,0 +1,50 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of clio: https://github.com/XRPLF/clio
+    Copyright (c) 2024, the clio developers.
+
+    Permission to use, copy, modify, and distribute this software for any
+    purpose with or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL,  DIRECT,  INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+/** @file */
+#pragma once
+
+#include "data/DBHelpers.hpp"
+
+#include <ripple/protocol/STTx.h>
+#include <ripple/protocol/TxMeta.h>
+
+namespace etl {
+
+/**
+ * @brief Pull MPT data from TX via ETLService.
+ *
+ * @param txMeta Transaction metadata
+ * @param sttx The transaction
+ * @return The MPTIssuanceID and holder pair as a optional
+ */
+std::optional<MPTHolderData>
+getMPTHolderFromTx(ripple::TxMeta const& txMeta, ripple::STTx const& sttx);
+
+/**
+ * @brief Pull MPT data from ledger object via loadInitialLedger.
+ *
+ * @param key The owner key
+ * @param blob Object data as blob
+ * @return The MPTIssuanceID and holder pair as a optional
+ */
+std::optional<MPTHolderData>
+getMPTHolderFromObj(std::string const& key, std::string const& blob);
+
+}  // namespace etl

src/etl/NFTHelpers.cpp

@@ -20,20 +20,20 @@
 #include "data/DBHelpers.hpp"
 
 #include <fmt/core.h>
-#include <ripple/basics/base_uint.h>
-#include <ripple/basics/strHex.h>
-#include <ripple/protocol/AccountID.h>
-#include <ripple/protocol/LedgerFormats.h>
-#include <ripple/protocol/SField.h>
-#include <ripple/protocol/STArray.h>
-#include <ripple/protocol/STBase.h>
-#include <ripple/protocol/STLedgerEntry.h>
-#include <ripple/protocol/STObject.h>
-#include <ripple/protocol/STTx.h>
-#include <ripple/protocol/Serializer.h>
-#include <ripple/protocol/TER.h>
-#include <ripple/protocol/TxFormats.h>
-#include <ripple/protocol/TxMeta.h>
+#include <xrpl/basics/base_uint.h>
+#include <xrpl/basics/strHex.h>
+#include <xrpl/protocol/AccountID.h>
+#include <xrpl/protocol/LedgerFormats.h>
+#include <xrpl/protocol/SField.h>
+#include <xrpl/protocol/STArray.h>
+#include <xrpl/protocol/STBase.h>
+#include <xrpl/protocol/STLedgerEntry.h>
+#include <xrpl/protocol/STObject.h>
+#include <xrpl/protocol/STTx.h>
+#include <xrpl/protocol/Serializer.h>
+#include <xrpl/protocol/TER.h>
+#include <xrpl/protocol/TxFormats.h>
+#include <xrpl/protocol/TxMeta.h>
 
 #include <algorithm>
 #include <cstdint>
@@ -73,9 +73,9 @@ getNFTokenMintData(ripple::TxMeta const& txMeta, ripple::STTx const& sttx)
         if (node.getFName() == ripple::sfCreatedNode) {
             ripple::STArray const& toAddNFTs =
                 node.peekAtField(ripple::sfNewFields).downcast<ripple::STObject>().getFieldArray(ripple::sfNFTokens);
-            std::transform(
-                toAddNFTs.begin(),
-                toAddNFTs.end(),
+            std::ranges::transform(
+                toAddNFTs,
+
                 std::back_inserter(finalIDs),
                 [](ripple::STObject const& nft) { return nft.getFieldH256(ripple::sfNFTokenID); }
             );
@@ -98,29 +98,30 @@ getNFTokenMintData(ripple::TxMeta const& txMeta, ripple::STTx const& sttx)
                 continue;
 
             ripple::STArray const& toAddNFTs = previousFields.getFieldArray(ripple::sfNFTokens);
-            std::transform(
-                toAddNFTs.begin(),
-                toAddNFTs.end(),
+            std::ranges::transform(
+                toAddNFTs,
+
                 std::back_inserter(prevIDs),
                 [](ripple::STObject const& nft) { return nft.getFieldH256(ripple::sfNFTokenID); }
             );
 
             ripple::STArray const& toAddFinalNFTs =
                 node.peekAtField(ripple::sfFinalFields).downcast<ripple::STObject>().getFieldArray(ripple::sfNFTokens);
-            std::transform(
-                toAddFinalNFTs.begin(),
-                toAddFinalNFTs.end(),
+            std::ranges::transform(
+                toAddFinalNFTs,
+
                 std::back_inserter(finalIDs),
                 [](ripple::STObject const& nft) { return nft.getFieldH256(ripple::sfNFTokenID); }
             );
         }
     }
 
-    std::sort(finalIDs.begin(), finalIDs.end());
-    std::sort(prevIDs.begin(), prevIDs.end());
+    std::ranges::sort(finalIDs);
+    std::ranges::sort(prevIDs);
 
     // Find the first NFT ID that doesn't match.  We're looking for an
     // added NFT, so the one we want will be the mismatch in finalIDs.
+    // NOLINTNEXTLINE(modernize-use-ranges)
     auto const diff = std::mismatch(finalIDs.begin(), finalIDs.end(), prevIDs.begin(), prevIDs.end());
 
     // There should always be a difference so the returned finalIDs
@@ -261,7 +262,7 @@ getNFTokenAcceptOfferData(ripple::TxMeta const& txMeta, ripple::STTx const& sttx
                 .getFieldArray(ripple::sfNFTokens);
         }();
 
-        auto const nft = std::find_if(nfts.begin(), nfts.end(), [&tokenID](ripple::STObject const& candidate) {
+        auto const nft = std::ranges::find_if(nfts, [&tokenID](ripple::STObject const& candidate) {
             return candidate.getFieldH256(ripple::sfNFTokenID) == tokenID;
         });
         if (nft != nfts.end()) {
@@ -294,16 +295,14 @@ getNFTokenCancelOfferData(ripple::TxMeta const& txMeta, ripple::STTx const& sttx
         txs.emplace_back(tokenID, txMeta, sttx.getTransactionID());
     }
 
-    // Deduplicate any transactions based on tokenID/txIdx combo. Can't just
-    // use txIdx because in this case one tx can cancel offers for several
-    // NFTs.
-    std::sort(txs.begin(), txs.end(), [](NFTTransactionsData const& a, NFTTransactionsData const& b) {
-        return a.tokenID < b.tokenID && a.transactionIndex < b.transactionIndex;
+    // Deduplicate any transactions based on tokenID
+    std::ranges::sort(txs, [](NFTTransactionsData const& a, NFTTransactionsData const& b) {
+        return a.tokenID < b.tokenID;
     });
-    auto last = std::unique(txs.begin(), txs.end(), [](NFTTransactionsData const& a, NFTTransactionsData const& b) {
-        return a.tokenID == b.tokenID && a.transactionIndex == b.transactionIndex;
+    auto [last, end] = std::ranges::unique(txs, [](NFTTransactionsData const& a, NFTTransactionsData const& b) {
+        return a.tokenID == b.tokenID;
     });
-    txs.erase(last, txs.end());
+    txs.erase(last, end);
     return {txs, {}};
 }
 
@@ -358,4 +357,20 @@ getNFTDataFromObj(std::uint32_t const seq, std::string const& key, std::string c
 
     return nfts;
 }
+
+std::vector<NFTsData>
+getUniqueNFTsDatas(std::vector<NFTsData> const& nfts)
+{
+    std::vector<NFTsData> results = nfts;
+
+    std::ranges::sort(results, [](NFTsData const& a, NFTsData const& b) {
+        return a.tokenID == b.tokenID ? a.transactionIndex > b.transactionIndex : a.tokenID > b.tokenID;
+    });
+
+    auto const [last, end] =
+        std::ranges::unique(results, [](NFTsData const& a, NFTsData const& b) { return a.tokenID == b.tokenID; });
+    results.erase(last, end);
+    return results;
+}
+
 }  // namespace etl

src/etl/NFTHelpers.hpp

@@ -22,8 +22,8 @@
 
 #include "data/DBHelpers.hpp"
 
-#include <ripple/protocol/STTx.h>
-#include <ripple/protocol/TxMeta.h>
+#include <xrpl/protocol/STTx.h>
+#include <xrpl/protocol/TxMeta.h>
 
 #include <cstdint>
 #include <optional>
@@ -104,4 +104,14 @@ getNFTDataFromTx(ripple::TxMeta const& txMeta, ripple::STTx const& sttx);
 std::vector<NFTsData>
 getNFTDataFromObj(std::uint32_t seq, std::string const& key, std::string const& blob);
 
+/**
+ * @brief Get the unique NFTs data from a vector of NFTsData happening in the same ledger. For example, if a NFT has
+ * both accept offer and burn happening in the same ledger,we only keep the final state of the NFT.
+
+ * @param nfts The NFTs data to filter, happening in the same ledger
+ * @return The unique NFTs data
+ */
+std::vector<NFTsData>
+getUniqueNFTsDatas(std::vector<NFTsData> const& nfts);
+
 }  // namespace etl

src/etl/NetworkValidatedLedgers.cpp

@@ -27,7 +27,7 @@
 
 namespace etl {
 std::shared_ptr<NetworkValidatedLedgers>
-NetworkValidatedLedgers::make_ValidatedLedgers()
+NetworkValidatedLedgers::makeValidatedLedgers()
 {
     return std::make_shared<NetworkValidatedLedgers>();
 }