feat: Repeating operations for util::async (#1776)

Async framework needed a way to do repeating operations (think simplest
cases like AmendmentBlockHandler).
This PR implements the **absolute minimum**, barebones repeating
operations that
- Can't return any values (void)
- Do not take any arguments in the user-provided function
- Can't be scheduled (i.e. a delay before starting repeating)
- Can't be stopped from inside the user block of code (i.e. does not
have stop token or anything like that)
- Can be stopped through the RepeatedOperation's `abort()` function (but
not from the user-provided repeating function)

.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 +127,11 @@ 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-make-member-function-const,
+  readability-math-missing-parentheses,
   readability-misleading-indentation,
   readability-non-const-parameter,
   readability-redundant-casting,
@@ -135,14 +143,15 @@ 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
   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

@@ -8,3 +8,6 @@ Diagnostics:
     IgnoreHeader:
       - ".*/(detail|impl)/.*"
       - ".*expected.*"
+      - ".*ranges_lower_bound.h"
+      - "time.h"
+      - "stdlib.h"

.githooks/check-docs

@@ -13,14 +13,36 @@ 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
 
                                    WARNING
 -----------------------------------------------------------------------------
-        'doxygen' is required to check documentation.
-        Please install it for next time. For the time being it's on CI.
+        'doxygen' is required to check documentation. 
+        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

@@ -3,6 +3,5 @@
 # This script is intended to be run from the root of the repository.
 
 source .githooks/check-format
-#source .githooks/check-docs
+source .githooks/check-docs
 
-# TODO: Fix Doxygen issue with reference links. See https://github.com/XRPLF/clio/issues/1431

.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/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/workflows/build.yml

@@ -23,7 +23,7 @@ jobs:
         run: |
           ./.githooks/check-format --diff
         shell: bash
-  
+ 
   check_docs:
     name: Check documentation
     runs-on: ubuntu-20.04
@@ -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

@@ -47,7 +47,7 @@ jobs:
       - name: Upload clio_tests
         uses: actions/upload-artifact@v4
         with:
-          name: clio_tests_libxrpl-${{ github.event.client_payload.version }}
+          name: clio_tests_check_libxrpl
           path: build/clio_tests
 
   run_tests:
@@ -60,7 +60,7 @@ jobs:
     steps:
       - uses: actions/download-artifact@v4
         with:
-          name: clio_tests_libxrpl-${{ github.event.client_payload.version }}
+          name: clio_tests_check_libxrpl
 
       - name: Run clio_tests
         run: |

.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:
@@ -13,12 +17,15 @@ jobs:
         include:
           - os: macos14
             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
@@ -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.
 

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>
 
@@ -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

@@ -17,11 +17,12 @@
 */
 //==============================================================================
 
-#include "main/Build.hpp"
+#include "util/build/Build.hpp"
 
 #include <string>
 
-namespace Build {
+namespace util::build {
+
 static constexpr char versionString[] = "@CLIO_VERSION@";
 
 std::string const&
@@ -38,4 +39,4 @@ getClioFullVersionString()
     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',
+        '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

@@ -141,3 +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/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

@@ -31,7 +31,7 @@
     "etl_sources": [
         {
             "ip": "127.0.0.1",
-            "ws_port": "6006",
+            "ws_port": "6005",
             "grpc_port": "50051"
         }
     ],
@@ -39,6 +39,9 @@
         "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": [
@@ -67,7 +70,15 @@
         "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_admin": 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": 10.0,

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
 ```

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(defaultConfigPath), "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 defaultConfigPath[] = "/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::make_Backend(config_);
+
+    // Manages clients subscribed to streams
+    auto subscriptions = feed::SubscriptionManager::make_SubscriptionManager(config_, backend);
+
+    // Tracks which ledgers have been validated by the network
+    auto ledgers = etl::NetworkValidatedLedgers::make_ValidatedLedgers();
+
+    // 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::make_LoadBalancer(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::make_ETLService(config_, ioc, backend, subscriptions, balancer, ledgers);
+
+    auto workQueue = rpc::WorkQueue::make_WorkQueue(config_);
+    auto counters = rpc::Counters::make_Counters(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::make_RPCEngine(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::make_AdminVerificationStrategy(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::make_Server(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::make_HttpServer(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 +1,52 @@
+//------------------------------------------------------------------------------
+/*
+    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 HealthCheckHTML = 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, HealthCheckHTML, 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::warnRPC_RATE_LIMIT));
+                } else {
+                    jsonResponse["warnings"] = boost::json::array{rpc::makeWarning(rpc::warnRPC_RATE_LIMIT)};
+                }
+                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>&
+SUPPORTED_AMENDMENTS()
+{
+    static std::unordered_set<std::string> amendments = {};
+    return amendments;
+}
+
+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 SUPPORTED_AMENDMENTS().contains(name), "Attempt to register the same amendment twice");
+    SUPPORTED_AMENDMENTS().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(SUPPORTED_AMENDMENTS(), name) != rg::end(SUPPORTED_AMENDMENTS()),
+                .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 +1,259 @@
+//------------------------------------------------------------------------------
+/*
+    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 */
+    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);
+    /** @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/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)
+make_Backend(util::config::ClioConfigDefinition const& config)
 {
     static util::Logger const log{"Backend"};
     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 {};
 }
@@ -271,7 +283,7 @@ BackendInterface::updateRange(uint32_t newMax)
     );
 
     if (!range) {
-        range = {newMax, newMax};
+        range = {.minSequence = newMax, .maxSequence = newMax};
     } else {
         range->maxSequence = newMax;
     }
@@ -287,7 +299,7 @@ BackendInterface::setRange(uint32_t min, uint32_t max, bool force)
         ASSERT(not range.has_value(), "Range was already set");
     }
 
-    range = {min, max};
+    range = {.minSequence = min, .maxSequence = max};
 }
 
 LedgerPage

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>
@@ -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

@@ -22,7 +22,6 @@
 #include "data/BackendInterface.hpp"
 #include "data/DBHelpers.hpp"
 #include "data/Types.hpp"
-#include "data/cassandra/Concepts.hpp"
 #include "data/cassandra/Handle.hpp"
 #include "data/cassandra/Schema.hpp"
 #include "data/cassandra/SettingsProvider.hpp"
@@ -36,13 +35,13 @@
 #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 +72,15 @@ 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 +95,7 @@ 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 +130,7 @@ public:
     {
         auto rng = fetchLedgerRange();
         if (!rng)
-            return {{}, {}};
+            return {.txns = {}, .cursor = {}};
 
         Statement const statement = [this, forward, &account]() {
             if (forward)
@@ -336,8 +337,8 @@ 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 +347,7 @@ 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 +401,7 @@ public:
     {
         auto rng = fetchLedgerRange();
         if (!rng)
-            return {{}, {}};
+            return {.txns = {}, .cursor = {}};
 
         Statement const statement = [this, forward, &tokenID]() {
             if (forward)
@@ -548,6 +549,45 @@ 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 +607,25 @@ 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
     {
@@ -640,7 +699,7 @@ 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 +819,7 @@ 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);
@@ -778,6 +837,26 @@ 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
     {
@@ -848,7 +927,7 @@ 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 +966,17 @@ 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 +984,14 @@ 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.
  *

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.
  */
@@ -239,6 +249,69 @@ struct LedgerRange {
     std::uint32_t maxSequence = 0;
 };
 
+/**
+ * @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 firstKey{"0000000000000000000000000000000000000000000000000000000000000000"};
 constexpr ripple::uint256 lastKey{"FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF"};
 constexpr ripple::uint256 hi192{"0000000000000000000000000000000000000000000000001111111111111111"};

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::MILLISECONDS_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::MILLISECONDS_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/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>
@@ -31,16 +32,9 @@
 #include <variant>
 
 namespace {
+
 constexpr auto clusterDeleter = [](CassCluster* ptr) { cass_cluster_free(ptr); };
 
-template <typename... Ts>
-struct overloadSet : Ts... {
-    using Ts::operator()...;
-};
-
-// 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 {
@@ -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/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>

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/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>
@@ -44,9 +45,6 @@ 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;
-
 public:
     /**
      * @brief Construct a new statement with optionally provided arguments.
@@ -56,7 +54,7 @@ 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)), deleter}
     {
         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>);
         }
     }
 };

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>
@@ -38,9 +39,6 @@ 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;
-
 public:
     /* implicit */ Tuple(CassTuple* ptr);
 
@@ -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

@@ -64,7 +64,11 @@ 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)
+    CacheLoader(
+        util::config::ClioConfigDefinition const& config,
+        std::shared_ptr<BackendInterface> const& backend,
+        CacheType& cache
+    )
         : backend_{backend}, cache_{cache}, settings_{make_CacheLoaderSettings(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)
+make_CacheLoaderSettings(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);
+make_CacheLoaderSettings(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>
@@ -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,
@@ -146,7 +142,7 @@ public:
      */
     static std::shared_ptr<ETLService>
     make_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,

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

@@ -24,21 +24,28 @@
 #include "etl/NetworkValidatedLedgersInterface.hpp"
 #include "etl/Source.hpp"
 #include "feed/SubscriptionManagerInterface.hpp"
+#include "rpc/Errors.hpp"
 #include "util/Assert.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 <cstddef>
 #include <cstdint>
+#include <expected>
 #include <memory>
 #include <optional>
 #include <stdexcept>
@@ -47,13 +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,
+    ClioConfigDefinition const& config,
     boost::asio::io_context& ioc,
     std::shared_ptr<BackendInterface> backend,
     std::shared_ptr<feed::SubscriptionManagerInterface> subscriptions,
@@ -67,7 +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,
@@ -75,20 +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{Config::toMilliseconds(forwardingCacheTimeout)};
+        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;
@@ -99,20 +109,25 @@ LoadBalancer::LoadBalancer(
         }
     };
 
-    auto const forwardingTimeout = Config::toMilliseconds(config.valueOr<float>("forwarding.request_timeout", 10.));
-    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](bool wasForwarding) {
+                if (wasForwarding)
                     chooseForwardingSource();
             },
-            [this]() { chooseForwardingSource(); },
             [this]() {
                 if (forwardingCache_.has_value())
                     forwardingCache_->invalidate();
@@ -211,7 +226,7 @@ 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,
@@ -219,9 +234,13 @@ LoadBalancer::forwardToRippled(
     boost::asio::yield_context yield
 )
 {
+    if (not request.contains("command"))
+        return std::unexpected{rpc::ClioError::rpcCOMMAND_IS_MISSING};
+
+    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();
         }
     }
 
@@ -233,20 +252,26 @@ LoadBalancer::forwardToRippled(
     auto xUserValue = isAdmin ? ADMIN_FORWARDING_X_USER_VALUE : USER_FORWARDING_X_USER_VALUE;
 
     std::optional<boost::json::object> response;
+    rpc::ClioError error = rpc::ClioError::etlCONNECTION_ERROR;
     while (numAttempts < sources_.size()) {
-        if (auto res = sources_[sourceIdx]->forwardToRippled(request, clientIp, xUserValue, 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
@@ -314,11 +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

@@ -23,10 +23,12 @@
 #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>
@@ -36,11 +38,11 @@
 #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>
@@ -67,14 +69,17 @@ private:
 
     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};
+
+    // 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:
     /**
@@ -98,7 +103,7 @@ 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,
@@ -119,7 +124,7 @@ public:
      */
     static std::shared_ptr<LoadBalancer>
     make_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,
@@ -181,9 +186,9 @@ public:
      * @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,

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/Source.cpp

@@ -26,7 +26,7 @@
 #include "etl/impl/SourceImpl.hpp"
 #include "etl/impl/SubscriptionSource.hpp"
 #include "feed/SubscriptionManagerInterface.hpp"
-#include "util/config/Config.hpp"
+#include "util/newconfig/ObjectView.hpp"
 
 #include <boost/asio/io_context.hpp>
 
@@ -39,7 +39,7 @@ namespace etl {
 
 SourcePtr
 make_Source(
-    util::Config const& config,
+    util::config::ObjectView const& config,
     boost::asio::io_context& ioc,
     std::shared_ptr<BackendInterface> backend,
     std::shared_ptr<feed::SubscriptionManagerInterface> subscriptions,
@@ -50,9 +50,9 @@ make_Source(
     SourceBase::OnLedgerClosedHook onLedgerClosed
 )
 {
-    auto const ip = config.valueOr<std::string>("ip", {});
-    auto const wsPort = config.valueOr<std::string>("ws_port", {});
-    auto const grpcPort = config.valueOr<std::string>("grpc_port", {});
+    auto const ip = config.get<std::string>("ip");
+    auto const wsPort = config.get<std::string>("ws_port");
+    auto const grpcPort = config.get<std::string>("grpc_port");
 
     impl::ForwardingSource forwardingSource{ip, wsPort, forwardingTimeout};
     impl::GrpcSource grpcSource{ip, grpcPort, std::move(backend)};

src/etl/Source.hpp

@@ -22,8 +22,10 @@
 #include "data/BackendInterface.hpp"
 #include "etl/NetworkValidatedLedgersInterface.hpp"
 #include "feed/SubscriptionManagerInterface.hpp"
-#include "util/config/Config.hpp"
+#include "rpc/Errors.hpp"
 #include "util/log/Logger.hpp"
+#include "util/newconfig/ConfigDefinition.hpp"
+#include "util/newconfig/ObjectView.hpp"
 
 #include <boost/asio/io_context.hpp>
 #include <boost/asio/spawn.hpp>
@@ -34,6 +36,7 @@
 
 #include <chrono>
 #include <cstdint>
+#include <expected>
 #include <functional>
 #include <memory>
 #include <optional>
@@ -51,7 +54,7 @@ namespace etl {
 class SourceBase {
 public:
     using OnConnectHook = std::function<void()>;
-    using OnDisconnectHook = std::function<void()>;
+    using OnDisconnectHook = std::function<void(bool)>;
     using OnLedgerClosedHook = std::function<void()>;
 
     virtual ~SourceBase() = default;
@@ -131,9 +134,9 @@ public:
      * @param forwardToRippledClientIp IP of the client forwarding this request if known
      * @param xUserValue Value of the X-User header
      * @param yield The coroutine context
-     * @return Response wrapped in an optional on success; nullopt otherwise
+     * @return Response on success or error on failure
      */
-    virtual std::optional<boost::json::object>
+    virtual std::expected<boost::json::object, rpc::ClioError>
     forwardToRippled(
         boost::json::object const& request,
         std::optional<std::string> const& forwardToRippledClientIp,
@@ -145,7 +148,7 @@ public:
 using SourcePtr = std::unique_ptr<SourceBase>;
 
 using SourceFactory = std::function<SourcePtr(
-    util::Config const& config,
+    util::config::ObjectView const& config,
     boost::asio::io_context& ioc,
     std::shared_ptr<BackendInterface> backend,
     std::shared_ptr<feed::SubscriptionManagerInterface> subscriptions,
@@ -173,7 +176,7 @@ using SourceFactory = std::function<SourcePtr(
  */
 SourcePtr
 make_Source(
-    util::Config const& config,
+    util::config::ObjectView const& config,
     boost::asio::io_context& ioc,
     std::shared_ptr<BackendInterface> backend,
     std::shared_ptr<feed::SubscriptionManagerInterface> subscriptions,

src/etl/impl/AmendmentBlock.hpp

@@ -1,95 +0,0 @@
-//------------------------------------------------------------------------------
-/*
-    This file is part of clio: https://github.com/XRPLF/clio
-    Copyright (c) 2023, 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 "etl/SystemState.hpp"
-#include "util/log/Logger.hpp"
-
-#include <boost/asio/io_context.hpp>
-#include <boost/asio/post.hpp>
-#include <boost/asio/steady_timer.hpp>
-
-#include <chrono>
-#include <functional>
-
-namespace etl::impl {
-
-struct AmendmentBlockAction {
-    void
-    operator()()
-    {
-        static util::Logger const log{"ETL"};
-        LOG(log.fatal()) << "Can't process new ledgers: The current ETL source is not compatible with the version of "
-                         << "the libxrpl Clio is currently using. Please upgrade Clio to a newer version.";
-    }
-};
-
-template <typename ActionCallableType = AmendmentBlockAction>
-class AmendmentBlockHandler {
-    std::reference_wrapper<boost::asio::io_context> ctx_;
-    std::reference_wrapper<SystemState> state_;
-    boost::asio::steady_timer timer_;
-    std::chrono::milliseconds interval_;
-
-    ActionCallableType action_;
-
-public:
-    template <typename DurationType = std::chrono::seconds>
-    AmendmentBlockHandler(
-        boost::asio::io_context& ioc,
-        SystemState& state,
-        DurationType interval = DurationType{1},
-        ActionCallableType&& action = ActionCallableType()
-    )
-        : ctx_{std::ref(ioc)}
-        , state_{std::ref(state)}
-        , timer_{ioc}
-        , interval_{std::chrono::duration_cast<std::chrono::milliseconds>(interval)}
-        , action_{std::move(action)}
-    {
-    }
-
-    ~AmendmentBlockHandler()
-    {
-        boost::asio::post(ctx_.get(), [this]() { timer_.cancel(); });
-    }
-
-    void
-    onAmendmentBlock()
-    {
-        state_.get().isAmendmentBlocked = true;
-        startReportingTimer();
-    }
-
-private:
-    void
-    startReportingTimer()
-    {
-        action_();
-
-        timer_.expires_after(interval_);
-        timer_.async_wait([this](auto ec) {
-            if (!ec)
-                boost::asio::post(ctx_.get(), [this] { startReportingTimer(); });
-        });
-    }
-};
-
-}  // namespace etl::impl

src/etl/impl/AmendmentBlockHandler.cpp

@@ -0,0 +1,56 @@
+//------------------------------------------------------------------------------
+/*
+    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 "etl/impl/AmendmentBlockHandler.hpp"
+
+#include "etl/SystemState.hpp"
+#include "util/log/Logger.hpp"
+
+#include <boost/asio/io_context.hpp>
+
+#include <chrono>
+#include <functional>
+#include <utility>
+
+namespace etl::impl {
+
+AmendmentBlockHandler::ActionType const AmendmentBlockHandler::defaultAmendmentBlockAction = []() {
+    static util::Logger const log{"ETL"};
+    LOG(log.fatal()) << "Can't process new ledgers: The current ETL source is not compatible with the version of "
+                     << "the libxrpl Clio is currently using. Please upgrade Clio to a newer version.";
+};
+
+AmendmentBlockHandler::AmendmentBlockHandler(
+    boost::asio::io_context& ioc,
+    SystemState& state,
+    std::chrono::steady_clock::duration interval,
+    ActionType action
+)
+    : state_{std::ref(state)}, repeat_{ioc}, interval_{interval}, action_{std::move(action)}
+{
+}
+
+void
+AmendmentBlockHandler::onAmendmentBlock()
+{
+    state_.get().isAmendmentBlocked = true;
+    repeat_.start(interval_, action_);
+}
+
+}  // namespace etl::impl

src/etl/impl/AmendmentBlockHandler.hpp

@@ -0,0 +1,59 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of clio: https://github.com/XRPLF/clio
+    Copyright (c) 2023, 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 "etl/SystemState.hpp"
+#include "util/Repeat.hpp"
+
+#include <boost/asio/io_context.hpp>
+#include <boost/asio/post.hpp>
+#include <boost/asio/steady_timer.hpp>
+
+#include <chrono>
+#include <functional>
+
+namespace etl::impl {
+
+class AmendmentBlockHandler {
+public:
+    using ActionType = std::function<void()>;
+
+private:
+    std::reference_wrapper<SystemState> state_;
+    util::Repeat repeat_;
+    std::chrono::steady_clock::duration interval_;
+
+    ActionType action_;
+
+public:
+    static ActionType const defaultAmendmentBlockAction;
+
+    AmendmentBlockHandler(
+        boost::asio::io_context& ioc,
+        SystemState& state,
+        std::chrono::steady_clock::duration interval = std::chrono::seconds{1},
+        ActionType action = defaultAmendmentBlockAction
+    );
+
+    void
+    onAmendmentBlock();
+};
+
+}  // namespace etl::impl

src/etl/impl/AsyncData.hpp

@@ -22,6 +22,7 @@
 #include "data/BackendInterface.hpp"
 #include "data/Types.hpp"
 #include "etl/ETLHelpers.hpp"
+#include "etl/MPTHelpers.hpp"
 #include "etl/NFTHelpers.hpp"
 #include "util/Assert.hpp"
 #include "util/log/Logger.hpp"
@@ -30,9 +31,9 @@
 #include <grpcpp/grpcpp.h>
 #include <grpcpp/support/status.h>
 #include <org/xrpl/rpc/v1/get_ledger_data.pb.h>
-#include <ripple/basics/base_uint.h>
-#include <ripple/basics/strHex.h>
-#include <ripple/proto/org/xrpl/rpc/v1/xrp_ledger.grpc.pb.h>
+#include <xrpl/basics/base_uint.h>
+#include <xrpl/basics/strHex.h>
+#include <xrpl/proto/org/xrpl/rpc/v1/xrp_ledger.grpc.pb.h>
 
 #include <cstddef>
 #include <cstdint>
@@ -154,6 +155,11 @@ public:
                     backend.writeSuccessor(std::move(lastKey_), request_.ledger().sequence(), std::string{obj.key()});
                 lastKey_ = obj.key();
                 backend.writeNFTs(getNFTDataFromObj(request_.ledger().sequence(), obj.key(), obj.data()));
+
+                auto const maybeMPTHolder = getMPTHolderFromObj(obj.key(), obj.data());
+                if (maybeMPTHolder)
+                    backend.writeMPTHolders({*maybeMPTHolder});
+
                 backend.writeLedgerObject(
                     std::move(*obj.mutable_key()), request_.ledger().sequence(), std::move(*obj.mutable_data())
                 );

src/etl/impl/BaseCursorProvider.hpp

@@ -19,7 +19,7 @@
 
 #pragma once
 
-#include <ripple/basics/base_uint.h>
+#include <xrpl/basics/base_uint.h>
 
 #include <cstdint>
 #include <vector>

src/etl/impl/CacheLoader.hpp

@@ -28,9 +28,9 @@
 
 #include <boost/algorithm/string/predicate.hpp>
 #include <boost/context/detail/config.hpp>
-#include <ripple/basics/Blob.h>
-#include <ripple/basics/base_uint.h>
-#include <ripple/basics/strHex.h>
+#include <xrpl/basics/Blob.h>
+#include <xrpl/basics/base_uint.h>
+#include <xrpl/basics/strHex.h>
 
 #include <algorithm>
 #include <atomic>

src/etl/impl/CursorFromAccountProvider.hpp

@@ -23,7 +23,7 @@
 #include "data/Types.hpp"
 #include "etl/impl/BaseCursorProvider.hpp"
 
-#include <ripple/basics/base_uint.h>
+#include <xrpl/basics/base_uint.h>
 
 #include <algorithm>
 #include <cstddef>

src/etl/impl/CursorFromDiffProvider.hpp

@@ -24,7 +24,7 @@
 #include "etl/impl/BaseCursorProvider.hpp"
 #include "util/Assert.hpp"
 
-#include <ripple/basics/base_uint.h>
+#include <xrpl/basics/base_uint.h>
 
 #include <algorithm>
 #include <cstddef>

src/etl/impl/CursorFromFixDiffNumProvider.hpp

@@ -25,8 +25,8 @@
 
 #include <boost/algorithm/string/predicate.hpp>
 #include <boost/asio/io_context.hpp>
-#include <ripple/basics/base_uint.h>
-#include <ripple/basics/strHex.h>
+#include <xrpl/basics/base_uint.h>
+#include <xrpl/basics/strHex.h>
 
 #include <algorithm>
 #include <cstddef>
@@ -70,12 +70,9 @@ public:
             return a.key < b.key or (a.key == b.key and std::size(a.blob) < std::size(b.blob));
         });
 
-        diffs.erase(
-            std::unique(
-                std::begin(diffs), std::end(diffs), [](auto const& a, auto const& b) { return a.key == b.key; }
-            ),
-            std::end(diffs)
-        );
+        auto const [removalCursor, last] =
+            rg::unique(diffs, [](auto const& a, auto const& b) { return a.key == b.key; });
+        diffs.erase(removalCursor, last);
 
         std::vector<ripple::uint256> cursors{data::firstKey};
         rg::copy(

src/etl/impl/Extractor.hpp

@@ -25,7 +25,7 @@
 #include "util/Profiler.hpp"
 #include "util/log/Logger.hpp"
 
-#include <ripple/beast/core/CurrentThreadName.h>
+#include <xrpl/beast/core/CurrentThreadName.h>
 
 #include <chrono>
 #include <cstdint>
@@ -121,19 +121,19 @@ private:
         pipe_.get().finish(startSequence_);
     }
 
-    bool
+    [[nodiscard]] bool
     isStopping() const
     {
         return state_.get().isStopping;
     }
 
-    bool
+    [[nodiscard]] bool
     hasWriteConflict() const
     {
         return state_.get().writeConflict;
     }
 
-    bool
+    [[nodiscard]] bool
     shouldFinish(uint32_t seq) const
     {
         // Stopping conditions:

src/etl/impl/ForwardingSource.cpp

@@ -19,6 +19,7 @@
 
 #include "etl/impl/ForwardingSource.hpp"
 
+#include "rpc/Errors.hpp"
 #include "util/log/Logger.hpp"
 
 #include <boost/asio/spawn.hpp>
@@ -55,7 +56,7 @@ ForwardingSource::ForwardingSource(
         );
 }
 
-std::optional<boost::json::object>
+std::expected<boost::json::object, rpc::ClioError>
 ForwardingSource::forwardToRippled(
     boost::json::object const& request,
     std::optional<std::string> const& forwardToRippledClientIp,
@@ -74,18 +75,26 @@ ForwardingSource::forwardToRippled(
 
     auto expectedConnection = connectionBuilder.connect(yield);
     if (not expectedConnection) {
-        return std::nullopt;
+        LOG(log_.debug()) << "Couldn't connect to rippled to forward request.";
+        return std::unexpected{rpc::ClioError::etlCONNECTION_ERROR};
     }
     auto& connection = expectedConnection.value();
 
     auto writeError = connection->write(boost::json::serialize(request), yield, forwardingTimeout_);
     if (writeError) {
-        return std::nullopt;
+        LOG(log_.debug()) << "Error sending request to rippled to forward request.";
+        return std::unexpected{rpc::ClioError::etlREQUEST_ERROR};
     }
 
     auto response = connection->read(yield, forwardingTimeout_);
     if (not response) {
-        return std::nullopt;
+        if (auto errorCode = response.error().errorCode();
+            errorCode.has_value() and errorCode->value() == boost::system::errc::timed_out) {
+            LOG(log_.debug()) << "Request to rippled timed out";
+            return std::unexpected{rpc::ClioError::etlREQUEST_TIMEOUT};
+        }
+        LOG(log_.debug()) << "Error sending request to rippled to forward request.";
+        return std::unexpected{rpc::ClioError::etlREQUEST_ERROR};
     }
 
     boost::json::value parsedResponse;
@@ -94,8 +103,8 @@ ForwardingSource::forwardToRippled(
         if (not parsedResponse.is_object())
             throw std::runtime_error("response is not an object");
     } catch (std::exception const& e) {
-        LOG(log_.error()) << "Error parsing response from rippled: " << e.what() << ". Response: " << *response;
-        return std::nullopt;
+        LOG(log_.debug()) << "Error parsing response from rippled: " << e.what() << ". Response: " << *response;
+        return std::unexpected{rpc::ClioError::etlINVALID_RESPONSE};
     }
 
     auto responseObject = parsedResponse.as_object();

src/etl/impl/ForwardingSource.hpp

@@ -19,6 +19,7 @@
 
 #pragma once
 
+#include "rpc/Errors.hpp"
 #include "util/log/Logger.hpp"
 #include "util/requests/WsConnection.hpp"
 
@@ -26,6 +27,7 @@
 #include <boost/json/object.hpp>
 
 #include <chrono>
+#include <expected>
 #include <optional>
 #include <string>
 #include <string_view>
@@ -54,9 +56,9 @@ public:
      * @param forwardToRippledClientIp IP of the client forwarding this request if known
      * @param xUserValue Optional value for X-User header
      * @param yield The coroutine context
-     * @return Response wrapped in an optional on success; nullopt otherwise
+     * @return Response 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& forwardToRippledClientIp,

src/etl/impl/GrpcSource.cpp

@@ -24,7 +24,7 @@
 #include "util/Assert.hpp"
 #include "util/log/Logger.hpp"
 
-#include <boost/asio/ip/address.hpp>
+#include <boost/asio/io_context.hpp>
 #include <boost/asio/ip/tcp.hpp>
 #include <fmt/core.h>
 #include <grpcpp/client_context.h>
@@ -39,6 +39,7 @@
 #include <exception>
 #include <memory>
 #include <sstream>
+#include <stdexcept>
 #include <string>
 #include <utility>
 #include <vector>
@@ -46,12 +47,17 @@
 namespace etl::impl {
 
 GrpcSource::GrpcSource(std::string const& ip, std::string const& grpcPort, std::shared_ptr<BackendInterface> backend)
-    : log_(fmt::format("ETL_Grpc[{}:{}]", ip, grpcPort)), backend_(std::move(backend))
+    : log_(fmt::format("GrpcSource[{}:{}]", ip, grpcPort)), backend_(std::move(backend))
 {
     try {
-        boost::asio::ip::tcp::endpoint const endpoint{boost::asio::ip::make_address(ip), std::stoi(grpcPort)};
+        boost::asio::io_context ctx;
+        boost::asio::ip::tcp::resolver resolver{ctx};
+        auto const resolverResult = resolver.resolve(ip, grpcPort);
+        if (resolverResult.empty()) {
+            throw std::runtime_error("Failed to resolve " + ip + ":" + grpcPort);
+        }
         std::stringstream ss;
-        ss << endpoint;
+        ss << resolverResult.begin()->endpoint();
         grpc::ChannelArguments chArgs;
         chArgs.SetMaxReceiveMessageSize(-1);
         stub_ = org::xrpl::rpc::v1::XRPLedgerAPIService::NewStub(

src/etl/impl/GrpcSource.hpp

@@ -24,7 +24,7 @@
 
 #include <grpcpp/support/status.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 <cstdint>
 #include <memory>

src/etl/impl/LedgerFetcher.hpp

@@ -23,7 +23,7 @@
 #include "util/log/Logger.hpp"
 
 #include <grpcpp/grpcpp.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 <cstdint>
 #include <memory>
@@ -63,7 +63,7 @@ public:
      * @param sequence sequence of the ledger to extract
      * @return Ledger header and transaction+metadata blobs; Empty optional if the server is shutting down
      */
-    OptionalGetLedgerResponseType
+    [[nodiscard]] OptionalGetLedgerResponseType
     fetchData(uint32_t sequence)
     {
         LOG(log_.debug()) << "Attempting to fetch ledger with sequence = " << sequence;
@@ -83,7 +83,7 @@ public:
      * @param sequence sequence of the ledger to extract
      * @return Ledger data diff between sequance and parent; Empty optional if the server is shutting down
      */
-    OptionalGetLedgerResponseType
+    [[nodiscard]] OptionalGetLedgerResponseType
     fetchDataAndDiff(uint32_t sequence)
     {
         LOG(log_.debug()) << "Attempting to fetch ledger with sequence = " << sequence;