fix: Credential error message (#1738)

fixes #1737

.clang-tidy

@@ -142,7 +142,7 @@ 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@v3.7.2
         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>
 

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/2.3.0-rc2',
+        '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/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 +70,14 @@
         "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
     },
     // 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 +1,9 @@
 add_subdirectory(util)
 add_subdirectory(data)
 add_subdirectory(etl)
+add_subdirectory(etlng)
 add_subdirectory(feed)
 add_subdirectory(rpc)
 add_subdirectory(web)
+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)
+
+target_link_libraries(clio_app PUBLIC clio_etl clio_etlng clio_feed clio_web clio_rpc)

src/app/CliArgs.cpp

@@ -0,0 +1,70 @@
+//------------------------------------------------------------------------------
+/*
+    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 "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")
+    ;
+    // 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>();
+    return Action{Action::Run{std::move(configPath)}};
+}
+
+}  // namespace app

src/app/CliArgs.hpp

@@ -0,0 +1,96 @@
+//------------------------------------------------------------------------------
+/*
+    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/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 {
+            /** @brief Configuration file path. */
+            std::string configPath;
+        };
+
+        /** @brief Exit action. */
+        struct Exit {
+            /** @brief Exit code. */
+            int exitCode;
+        };
+
+        /**
+         * @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>
+        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> 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 +1,142 @@
+//------------------------------------------------------------------------------
+/*
+    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 "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/config/Config.hpp"
+#include "util/log/Logger.hpp"
+#include "util/prometheus/Prometheus.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 <boost/asio/io_context.hpp>
+
+#include <cstdint>
+#include <cstdlib>
+#include <memory>
+#include <thread>
+#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 const& config) : config_(config), signalsHandler_{config_}
+{
+    LOG(util::LogService::info()) << "Clio version: " << util::build::getClioFullVersionString();
+    PrometheusService::init(config);
+}
+
+int
+ClioApplication::run()
+{
+    auto const threads = config_.valueOr("io_threads", 2);
+    if (threads <= 0) {
+        LOG(util::LogService::fatal()) << "io_threads is less than 1";
+        return EXIT_FAILURE;
+    }
+    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);
+
+    // 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 +1,51 @@
+//------------------------------------------------------------------------------
+/*
+    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/config//Config.hpp"
+
+namespace app {
+
+/**
+ * @brief The main application class
+ */
+class ClioApplication {
+    util::Config const& config_;
+    util::SignalsHandler signalsHandler_;
+
+public:
+    /**
+     * @brief Construct a new ClioApplication object
+     *
+     * @param config The configuration of the application
+     */
+    ClioApplication(util::Config const& config);
+
+    /**
+     * @brief Run the application
+     *
+     * @return exit code
+     */
+    int
+    run();
+};
+
+}  // 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

@@ -51,8 +51,7 @@ make_Backend(util::Config const& config)
     auto const type = config.value<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")) {
+    if (boost::iequals(type, "cassandra")) {
         auto cfg = config.section("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,

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.
      *
@@ -592,6 +636,14 @@ 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.
      *

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>
@@ -94,7 +93,7 @@ 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 databse: " + res.error());
 
         if (not readOnly) {
             if (auto const res = handle_.execute(schema_.createKeyspace); not res) {
@@ -336,8 +335,8 @@ 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 +345,7 @@ 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";
 
@@ -548,6 +547,45 @@ 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 +605,25 @@ 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 +697,7 @@ 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 +817,7 @@ 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);
@@ -848,7 +905,7 @@ 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 +944,17 @@ 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
     {

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>

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/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/Schema.hpp

@@ -257,6 +257,19 @@ 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")
+        ));
+
         return statements;
     }();
 
@@ -393,6 +406,17 @@ 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"(
@@ -687,6 +711,20 @@ 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"(

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.
@@ -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");
@@ -141,7 +139,7 @@ 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/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

@@ -30,8 +30,8 @@
 #include "util/log/Logger.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>

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>;
 

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/LoadBalancer.cpp

@@ -24,8 +24,10 @@
 #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 <boost/asio/io_context.hpp>
@@ -33,12 +35,14 @@
 #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>
@@ -77,7 +81,10 @@ LoadBalancer::LoadBalancer(
 {
     auto const forwardingCacheTimeout = config.valueOr<float>("forwarding.cache_timeout", 0.f);
     if (forwardingCacheTimeout > 0.f) {
-        forwardingCache_ = impl::ForwardingCache{Config::toMilliseconds(forwardingCacheTimeout)};
+        forwardingCache_ = util::ResponseExpirationCache{
+            Config::toMilliseconds(forwardingCacheTimeout),
+            {"server_info", "server_state", "server_definitions", "fee", "ledger_closed"}
+        };
     }
 
     static constexpr std::uint32_t MAX_DOWNLOAD = 256;
@@ -109,10 +116,13 @@ LoadBalancer::LoadBalancer(
             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 +221,7 @@ 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 +229,13 @@ 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 +247,26 @@ 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 +334,13 @@ 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

@@ -23,8 +23,10 @@
 #include "etl/ETLState.hpp"
 #include "etl/NetworkValidatedLedgersInterface.hpp"
 #include "etl/Source.hpp"
-#include "etl/impl/ForwardingCache.hpp"
 #include "feed/SubscriptionManagerInterface.hpp"
+#include "rpc/Errors.hpp"
+#include "util/Mutex.hpp"
+#include "util/ResponseExpirationCache.hpp"
 #include "util/config/Config.hpp"
 #include "util/log/Logger.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:
     /**
@@ -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 +1,83 @@
+//------------------------------------------------------------------------------
+/*
+    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/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
+ */
+static 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{newMPT[ripple::sfMPTokenIssuanceID], 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{mptIssuanceID, 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>
@@ -116,8 +116,8 @@ getNFTokenMintData(ripple::TxMeta const& txMeta, ripple::STTx const& sttx)
         }
     }
 
-    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.
@@ -294,14 +294,12 @@ 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;
+        return a.tokenID == b.tokenID;
     });
     txs.erase(last, txs.end());
     return {txs, {}};
@@ -358,4 +356,21 @@ 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 = std::unique(results.begin(), results.end(), [](NFTsData const& a, NFTsData const& b) {
+        return a.tokenID == b.tokenID;
+    });
+    results.erase(last, results.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.hpp

@@ -22,6 +22,7 @@
 #include "data/BackendInterface.hpp"
 #include "etl/NetworkValidatedLedgersInterface.hpp"
 #include "feed/SubscriptionManagerInterface.hpp"
+#include "rpc/Errors.hpp"
 #include "util/config/Config.hpp"
 #include "util/log/Logger.hpp"
 
@@ -34,6 +35,7 @@
 
 #include <chrono>
 #include <cstdint>
+#include <expected>
 #include <functional>
 #include <memory>
 #include <optional>
@@ -51,7 +53,7 @@ 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 +133,9 @@ 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,

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>

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>

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>

src/etl/impl/LedgerLoader.hpp

@@ -22,6 +22,7 @@
 #include "data/BackendInterface.hpp"
 #include "data/DBHelpers.hpp"
 #include "data/Types.hpp"
+#include "etl/MPTHelpers.hpp"
 #include "etl/NFTHelpers.hpp"
 #include "etl/SystemState.hpp"
 #include "etl/impl/LedgerFetcher.hpp"
@@ -30,13 +31,13 @@
 #include "util/Profiler.hpp"
 #include "util/log/Logger.hpp"
 
-#include <ripple/basics/base_uint.h>
-#include <ripple/basics/strHex.h>
-#include <ripple/beast/core/CurrentThreadName.h>
-#include <ripple/protocol/LedgerHeader.h>
-#include <ripple/protocol/STTx.h>
-#include <ripple/protocol/Serializer.h>
-#include <ripple/protocol/TxMeta.h>
+#include <xrpl/basics/base_uint.h>
+#include <xrpl/basics/strHex.h>
+#include <xrpl/beast/core/CurrentThreadName.h>
+#include <xrpl/protocol/LedgerHeader.h>
+#include <xrpl/protocol/STTx.h>
+#include <xrpl/protocol/Serializer.h>
+#include <xrpl/protocol/TxMeta.h>
 
 #include <chrono>
 #include <cstddef>
@@ -55,6 +56,7 @@ struct FormattedTransactionsData {
     std::vector<AccountTransactionsData> accountTxData;
     std::vector<NFTTransactionsData> nfTokenTxData;
     std::vector<NFTsData> nfTokensData;
+    std::vector<MPTHolderData> mptHoldersData;
 };
 
 namespace etl::impl {
@@ -124,6 +126,10 @@ public:
             if (maybeNFT)
                 result.nfTokensData.push_back(*maybeNFT);
 
+            auto const maybeMPTHolder = getMPTHolderFromTx(txMeta, sttx);
+            if (maybeMPTHolder)
+                result.mptHoldersData.push_back(*maybeMPTHolder);
+
             result.accountTxData.emplace_back(txMeta, sttx.getTransactionID());
             static constexpr std::size_t KEY_SIZE = 32;
             std::string keyStr{reinterpret_cast<char const*>(sttx.getTransactionID().data()), KEY_SIZE};
@@ -136,20 +142,7 @@ public:
             );
         }
 
-        // Remove all but the last NFTsData for each id. unique removes all but the first of a group, so we want to
-        // reverse sort by transaction index
-        std::sort(result.nfTokensData.begin(), result.nfTokensData.end(), [](NFTsData const& a, NFTsData const& b) {
-            return a.tokenID > b.tokenID && a.transactionIndex > b.transactionIndex;
-        });
-
-        // Now we can unique the NFTs by tokenID.
-        auto last = std::unique(
-            result.nfTokensData.begin(),
-            result.nfTokensData.end(),
-            [](NFTsData const& a, NFTsData const& b) { return a.tokenID == b.tokenID; }
-        );
-        result.nfTokensData.erase(last, result.nfTokensData.end());
-
+        result.nfTokensData = getUniqueNFTsDatas(result.nfTokensData);
         return result;
     }
 
@@ -253,6 +246,7 @@ public:
                 backend_->writeAccountTransactions(std::move(insertTxResult.accountTxData));
                 backend_->writeNFTs(insertTxResult.nfTokensData);
                 backend_->writeNFTTransactions(insertTxResult.nfTokenTxData);
+                backend_->writeMPTHolders(insertTxResult.mptHoldersData);
             }
 
             backend_->finishWrites(sequence);

src/etl/impl/LedgerPublisher.hpp

@@ -31,12 +31,12 @@
 
 #include <boost/asio/io_context.hpp>
 #include <boost/asio/strand.hpp>
-#include <ripple/basics/chrono.h>
-#include <ripple/protocol/Fees.h>
-#include <ripple/protocol/LedgerHeader.h>
-#include <ripple/protocol/SField.h>
-#include <ripple/protocol/STObject.h>
-#include <ripple/protocol/Serializer.h>
+#include <xrpl/basics/chrono.h>
+#include <xrpl/protocol/Fees.h>
+#include <xrpl/protocol/LedgerHeader.h>
+#include <xrpl/protocol/SField.h>
+#include <xrpl/protocol/STObject.h>
+#include <xrpl/protocol/Serializer.h>
 
 #include <chrono>
 #include <cstddef>
@@ -166,13 +166,16 @@ public:
             LOG(log_.info()) << "Publishing ledger " << std::to_string(lgrInfo.seq);
 
             if (!state_.get().isWriting) {
-                LOG(log_.info()) << "Updating cache";
+                LOG(log_.info()) << "Updating ledger range for read node.";
 
-                std::vector<data::LedgerObject> const diff = data::synchronousAndRetryOnTimeout([&](auto yield) {
-                    return backend_->fetchLedgerDiff(lgrInfo.seq, yield);
-                });
+                if (!cache_.get().isDisabled()) {
+                    std::vector<data::LedgerObject> const diff = data::synchronousAndRetryOnTimeout([&](auto yield) {
+                        return backend_->fetchLedgerDiff(lgrInfo.seq, yield);
+                    });
+
+                    cache_.get().update(diff, lgrInfo.seq);
+                }
 
-                cache_.get().update(diff, lgrInfo.seq);
                 backend_->updateRange(lgrInfo.seq);
             }
 

src/etl/impl/SourceImpl.hpp

@@ -23,6 +23,7 @@
 #include "etl/impl/ForwardingSource.hpp"
 #include "etl/impl/GrpcSource.hpp"
 #include "etl/impl/SubscriptionSource.hpp"
+#include "rpc/Errors.hpp"
 
 #include <boost/asio/spawn.hpp>
 #include <boost/json/object.hpp>
@@ -31,12 +32,14 @@
 
 #include <chrono>
 #include <cstdint>
+#include <expected>
 #include <memory>
 #include <optional>
 #include <string>
 #include <string_view>
 #include <utility>
 #include <vector>
+
 namespace etl::impl {
 
 /**
@@ -205,9 +208,9 @@ public:
      * @param forwardToRippledClientIp IP of the client forwarding this request if known
      * @param xUserValue Optional value of the X-User header
      * @param yield The coroutine context
-     * @return Response wrapped in an optional on success; nullopt otherwise
+     * @return Response or ClioError
      */
-    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/SubscriptionSource.cpp

@@ -24,6 +24,8 @@
 #include "rpc/JS.hpp"
 #include "util/Retry.hpp"
 #include "util/log/Logger.hpp"
+#include "util/prometheus/Label.hpp"
+#include "util/prometheus/Prometheus.hpp"
 #include "util/requests/Types.hpp"
 
 #include <boost/algorithm/string/classification.hpp>
@@ -40,7 +42,7 @@
 #include <boost/json/serialize.hpp>
 #include <boost/json/value_to.hpp>
 #include <fmt/core.h>
-#include <ripple/protocol/jss.h>
+#include <xrpl/protocol/jss.h>
 
 #include <algorithm>
 #include <chrono>
@@ -66,22 +68,28 @@ SubscriptionSource::SubscriptionSource(
     OnConnectHook onConnect,
     OnDisconnectHook onDisconnect,
     OnLedgerClosedHook onLedgerClosed,
-    std::chrono::steady_clock::duration const connectionTimeout,
+    std::chrono::steady_clock::duration const wsTimeout,
     std::chrono::steady_clock::duration const retryDelay
 )
-    : log_(fmt::format("GrpcSource[{}:{}]", ip, wsPort))
+    : log_(fmt::format("SubscriptionSource[{}:{}]", ip, wsPort))
     , wsConnectionBuilder_(ip, wsPort)
     , validatedLedgers_(std::move(validatedLedgers))
     , subscriptions_(std::move(subscriptions))
     , strand_(boost::asio::make_strand(ioContext))
+    , wsTimeout_(wsTimeout)
     , retry_(util::makeRetryExponentialBackoff(retryDelay, RETRY_MAX_DELAY, strand_))
     , onConnect_(std::move(onConnect))
     , onDisconnect_(std::move(onDisconnect))
     , onLedgerClosed_(std::move(onLedgerClosed))
+    , lastMessageTimeSecondsSinceEpoch_(PrometheusService::gaugeInt(
+          "subscription_source_last_message_time",
+          util::prometheus::Labels({{"source", fmt::format("{}:{}", ip, wsPort)}}),
+          "Seconds since epoch of the last message received from rippled subscription streams"
+      ))
 {
     wsConnectionBuilder_.addHeader({boost::beast::http::field::user_agent, "clio-client"})
         .addHeader({"X-User", "clio-client"})
-        .setConnectionTimeout(connectionTimeout);
+        .setConnectionTimeout(wsTimeout_);
 }
 
 SubscriptionSource::~SubscriptionSource()
@@ -133,6 +141,7 @@ void
 SubscriptionSource::setForwarding(bool isForwarding)
 {
     isForwarding_ = isForwarding;
+    LOG(log_.info()) << "Forwarding set to " << isForwarding_;
 }
 
 std::chrono::steady_clock::time_point
@@ -166,20 +175,22 @@ SubscriptionSource::subscribe()
             }
 
             wsConnection_ = std::move(connection).value();
-            isConnected_ = true;
-            onConnect_();
 
             auto const& subscribeCommand = getSubscribeCommandJson();
-            auto const writeErrorOpt = wsConnection_->write(subscribeCommand, yield);
+            auto const writeErrorOpt = wsConnection_->write(subscribeCommand, yield, wsTimeout_);
             if (writeErrorOpt) {
                 handleError(writeErrorOpt.value(), yield);
                 return;
             }
 
+            isConnected_ = true;
+            LOG(log_.info()) << "Connected";
+            onConnect_();
+
             retry_.reset();
 
             while (!stop_) {
-                auto const message = wsConnection_->read(yield);
+                auto const message = wsConnection_->read(yield, wsTimeout_);
                 if (not message) {
                     handleError(message.error(), yield);
                     return;
@@ -224,10 +235,11 @@ SubscriptionSource::handleMessage(std::string const& message)
                 auto validatedLedgers = boost::json::value_to<std::string>(result.at(JS(validated_ledgers)));
                 setValidatedRange(std::move(validatedLedgers));
             }
-            LOG(log_.info()) << "Received a message on ledger subscription stream. Message : " << object;
+            LOG(log_.debug()) << "Received a message on ledger subscription stream. Message: " << object;
 
         } else if (object.contains(JS(type)) && object.at(JS(type)) == JS_LedgerClosed) {
-            LOG(log_.info()) << "Received a message on ledger subscription stream. Message : " << object;
+            LOG(log_.debug()) << "Received a message of type 'ledgerClosed' on ledger subscription stream. Message: "
+                              << object;
             if (object.contains(JS(ledger_index))) {
                 ledgerIndex = object.at(JS(ledger_index)).as_int64();
             }
@@ -245,10 +257,13 @@ SubscriptionSource::handleMessage(std::string const& message)
                 // 2 - Validated transaction
                 // Only forward proposed transaction, validated transactions are sent by Clio itself
                 if (object.contains(JS(transaction)) and !object.contains(JS(meta))) {
+                    LOG(log_.debug()) << "Forwarding proposed transaction: " << object;
                     subscriptions_->forwardProposedTransaction(object);
                 } else if (object.contains(JS(type)) && object.at(JS(type)) == JS_ValidationReceived) {
+                    LOG(log_.debug()) << "Forwarding validation: " << object;
                     subscriptions_->forwardValidation(object);
                 } else if (object.contains(JS(type)) && object.at(JS(type)) == JS_ManifestReceived) {
+                    LOG(log_.debug()) << "Forwarding manifest: " << object;
                     subscriptions_->forwardManifest(object);
                 }
             }
@@ -261,7 +276,7 @@ SubscriptionSource::handleMessage(std::string const& message)
 
         return std::nullopt;
     } catch (std::exception const& e) {
-        LOG(log_.error()) << "Exception in handleMessage : " << e.what();
+        LOG(log_.error()) << "Exception in handleMessage: " << e.what();
         return util::requests::RequestError{fmt::format("Error handling message: {}", e.what())};
     }
 }
@@ -270,16 +285,14 @@ void
 SubscriptionSource::handleError(util::requests::RequestError const& error, boost::asio::yield_context yield)
 {
     isConnected_ = false;
-    isForwarding_ = false;
+    bool const wasForwarding = isForwarding_.exchange(false);
     if (not stop_) {
-        onDisconnect_();
+        LOG(log_.info()) << "Disconnected";
+        onDisconnect_(wasForwarding);
     }
 
     if (wsConnection_ != nullptr) {
-        auto const err = wsConnection_->close(yield);
-        if (err) {
-            LOG(log_.error()) << "Error closing websocket connection: " << err->message();
-        }
+        wsConnection_->close(yield);
         wsConnection_.reset();
     }
 
@@ -306,7 +319,11 @@ SubscriptionSource::logError(util::requests::RequestError const& error) const
 void
 SubscriptionSource::setLastMessageTime()
 {
-    lastMessageTime_.lock().get() = std::chrono::steady_clock::now();
+    lastMessageTimeSecondsSinceEpoch_.get().set(
+        std::chrono::duration_cast<std::chrono::seconds>(std::chrono::system_clock::now().time_since_epoch()).count()
+    );
+    auto lock = lastMessageTime_.lock();
+    lock.get() = std::chrono::steady_clock::now();
 }
 
 void

src/etl/impl/SubscriptionSource.hpp

@@ -19,12 +19,13 @@
 
 #pragma once
 
-#include "etl/ETLHelpers.hpp"
+#include "etl/NetworkValidatedLedgersInterface.hpp"
 #include "etl/Source.hpp"
 #include "feed/SubscriptionManagerInterface.hpp"
 #include "util/Mutex.hpp"
 #include "util/Retry.hpp"
 #include "util/log/Logger.hpp"
+#include "util/prometheus/Gauge.hpp"
 #include "util/requests/Types.hpp"
 #include "util/requests/WsConnection.hpp"
 
@@ -37,6 +38,7 @@
 #include <atomic>
 #include <chrono>
 #include <cstdint>
+#include <functional>
 #include <future>
 #include <memory>
 #include <optional>
@@ -71,6 +73,8 @@ private:
 
     boost::asio::strand<boost::asio::io_context::executor_type> strand_;
 
+    std::chrono::steady_clock::duration wsTimeout_;
+
     util::Retry retry_;
 
     OnConnectHook onConnect_;
@@ -83,9 +87,11 @@ private:
 
     util::Mutex<std::chrono::steady_clock::time_point> lastMessageTime_;
 
+    std::reference_wrapper<util::prometheus::GaugeInt> lastMessageTimeSecondsSinceEpoch_;
+
     std::future<void> runFuture_;
 
-    static constexpr std::chrono::seconds CONNECTION_TIMEOUT{30};
+    static constexpr std::chrono::seconds WS_TIMEOUT{30};
     static constexpr std::chrono::seconds RETRY_MAX_DELAY{30};
     static constexpr std::chrono::seconds RETRY_DELAY{1};
 
@@ -99,11 +105,11 @@ public:
      * @param wsPort The port of the source
      * @param validatedLedgers The network validated ledgers object
      * @param subscriptions The subscription manager object
+     * @param onConnect The onConnect hook. Called when the connection is established
      * @param onDisconnect The onDisconnect hook. Called when the connection is lost
-     * @param onNewLedger The onNewLedger hook. Called when a new ledger is received
      * @param onLedgerClosed The onLedgerClosed hook. Called when the ledger is closed but only if the source is
      * forwarding
-     * @param connectionTimeout The connection timeout. Defaults to 30 seconds
+     * @param wsTimeout A timeout for websocket operations. Defaults to 30 seconds
      * @param retryDelay The retry delay. Defaults to 1 second
      */
     SubscriptionSource(
@@ -115,7 +121,7 @@ public:
         OnConnectHook onConnect,
         OnDisconnectHook onDisconnect,
         OnLedgerClosedHook onLedgerClosed,
-        std::chrono::steady_clock::duration const connectionTimeout = CONNECTION_TIMEOUT,
+        std::chrono::steady_clock::duration const wsTimeout = WS_TIMEOUT,
         std::chrono::steady_clock::duration const retryDelay = RETRY_DELAY
     );
 

src/etl/impl/Transformer.hpp

@@ -23,7 +23,7 @@
 #include "data/DBHelpers.hpp"
 #include "data/Types.hpp"
 #include "etl/SystemState.hpp"
-#include "etl/impl/AmendmentBlock.hpp"
+#include "etl/impl/AmendmentBlockHandler.hpp"
 #include "etl/impl/LedgerLoader.hpp"
 #include "util/Assert.hpp"
 #include "util/LedgerUtils.hpp"
@@ -31,11 +31,11 @@
 #include "util/log/Logger.hpp"
 
 #include <grpcpp/grpcpp.h>
-#include <ripple/basics/base_uint.h>
-#include <ripple/basics/strHex.h>
-#include <ripple/beast/core/CurrentThreadName.h>
-#include <ripple/proto/org/xrpl/rpc/v1/xrp_ledger.grpc.pb.h>
-#include <ripple/protocol/LedgerHeader.h>
+#include <xrpl/basics/base_uint.h>
+#include <xrpl/basics/strHex.h>
+#include <xrpl/beast/core/CurrentThreadName.h>
+#include <xrpl/proto/org/xrpl/rpc/v1/xrp_ledger.grpc.pb.h>
+#include <xrpl/protocol/LedgerHeader.h>
 
 #include <chrono>
 #include <cstdint>
@@ -213,6 +213,7 @@ private:
         backend_->writeAccountTransactions(std::move(insertTxResultOp->accountTxData));
         backend_->writeNFTs(insertTxResultOp->nfTokensData);
         backend_->writeNFTTransactions(insertTxResultOp->nfTokenTxData);
+        backend_->writeMPTHolders(insertTxResultOp->mptHoldersData);
 
         auto [success, duration] =
             ::util::timed<std::chrono::duration<double>>([&]() { return backend_->finishWrites(lgrInfo.seq); });

src/etlng/CMakeLists.txt

@@ -0,0 +1,5 @@
+add_library(clio_etlng INTERFACE)
+
+# target_sources(clio_etlng PRIVATE )
+
+target_link_libraries(clio_etlng INTERFACE clio_data)

src/etlng/Models.hpp

@@ -0,0 +1,129 @@
+//------------------------------------------------------------------------------
+/*
+    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/Concepts.hpp"
+
+#include <boost/json/object.hpp>
+#include <fmt/core.h>
+#include <xrpl/basics/Blob.h>
+#include <xrpl/basics/base_uint.h>
+#include <xrpl/proto/org/xrpl/rpc/v1/get_ledger.pb.h>
+#include <xrpl/proto/org/xrpl/rpc/v1/ledger.pb.h>
+#include <xrpl/protocol/LedgerHeader.h>
+#include <xrpl/protocol/STTx.h>
+#include <xrpl/protocol/TxFormats.h>
+#include <xrpl/protocol/TxMeta.h>
+
+#include <cstdint>
+#include <optional>
+#include <string>
+#include <vector>
+
+namespace etlng::model {
+
+/**
+ * @brief A specification for the Registry.
+ *
+ * This specification simply defines the transaction types that are to be filtered out from the incoming transactions by
+ * the Registry for its `onTransaction` and `onInitialTransaction` hooks.
+ * It's a compilation error to list the same transaction type more than once.
+ */
+template <ripple::TxType... Types>
+    requires(util::hasNoDuplicates(Types...))
+struct Spec {
+    static constexpr bool SpecTag = true;
+
+    /**
+     * @brief Checks if the transaction type was requested.
+     *
+     * @param type The transaction type
+     * @return true if the transaction was requested; false otherwise
+     */
+    [[nodiscard]] constexpr static bool
+    wants(ripple::TxType type) noexcept
+    {
+        return ((Types == type) || ...);
+    }
+};
+
+/**
+ * @brief Represents a single transaction on the ledger.
+ */
+struct Transaction {
+    std::string raw;  // raw binary blob
+    std::string metaRaw;
+
+    // unpacked blob and meta
+    ripple::STTx sttx;
+    ripple::TxMeta meta;
+
+    // commonly used stuff
+    ripple::uint256 id;
+    std::string key;  // key is the above id as a string of 32 characters
+    ripple::TxType type;
+};
+
+/**
+ * @brief Represents a single object on the ledger.
+ */
+struct Object {
+    /**
+     * @brief Modification type for the object.
+     */
+    enum class ModType : int {
+        Unspecified = 0,
+        Created = 1,
+        Modified = 2,
+        Deleted = 3,
+    };
+
+    ripple::uint256 key;
+    std::string keyRaw;
+    ripple::Blob data;
+    std::string dataRaw;
+    std::string successor;
+    std::string predecessor;
+
+    ModType type;
+};
+
+/**
+ * @brief Represents a book successor.
+ */
+struct BookSuccessor {
+    std::string firstBook;
+    std::string bookBase;
+};
+
+/**
+ * @brief Represents an entire ledger diff worth of transactions and objects.
+ */
+struct LedgerData {
+    std::vector<Transaction> transactions;
+    std::vector<Object> objects;
+    std::optional<std::vector<BookSuccessor>> successors;
+
+    ripple::LedgerHeader header;
+    std::string rawHeader;
+    uint32_t seq;
+};
+
+}  // namespace etlng::model

src/etlng/RegistryInterface.hpp

@@ -0,0 +1,108 @@
+//------------------------------------------------------------------------------
+/*
+    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 "etlng/Models.hpp"
+
+#include <cstdint>
+#include <string>
+#include <vector>
+
+namespace etlng {
+
+/**
+ * @brief The interface for a registry that can dispatch transactions and objects to extensions.
+ *
+ * This class defines the interface for dispatching data through to extensions.
+ *
+ * @note
+ * The registry itself consists of Extensions.
+ * Each extension must define at least one valid hook:
+ * - for ongoing ETL dispatch:
+ *   - void onLedgerData(etlng::model::LedgerData const&)
+ *   - void onTransaction(uint32_t, etlng::model::Transaction const&)
+ *   - void onObject(uint32_t, etlng::model::Object const&)
+ * - for initial ledger load
+ *   - void onInitialData(etlng::model::LedgerData const&)
+ *   - void onInitialTransaction(uint32_t, etlng::model::Transaction const&)
+ * - for initial objects (called for each downloaded batch)
+ *   - void onInitialObjects(uint32_t, std::vector<etlng::model::Object> const&, std::string)
+ *   - void onInitialObject(uint32_t, etlng::model::Object const&)
+ *
+ * When the registry dispatches (initial)data or objects, each of the above hooks will be called in order on each
+ * registered extension.
+ * This means that the order of execution is from left to right (hooks) and top to bottom (registered extensions).
+ *
+ * If either `onTransaction` or `onInitialTransaction` are defined, the extension will have to additionally define a
+ * Specification. The specification lists transaction types to filter from the incoming data such that `onTransaction`
+ * and `onInitialTransaction` are only called for the transactions that are of interest for the given extension.
+ *
+ * The specification is setup like so:
+ * @code{.cpp}
+ * struct Ext {
+ *   using spec = etlng::model::Spec<
+ *     ripple::TxType::ttNFTOKEN_BURN,
+ *     ripple::TxType::ttNFTOKEN_ACCEPT_OFFER,
+ *     ripple::TxType::ttNFTOKEN_CREATE_OFFER,
+ *     ripple::TxType::ttNFTOKEN_CANCEL_OFFER,
+ *     ripple::TxType::ttNFTOKEN_MINT>;
+ *
+ *   static void
+ *   onInitialTransaction(uint32_t, etlng::model::Transaction const&);
+ * };
+ * @endcode
+ */
+struct RegistryInterface {
+    virtual ~RegistryInterface() = default;
+
+    /**
+     * @brief Dispatch initial objects.
+     *
+     * These objects are received during initial ledger load.
+     *
+     * @param seq The sequence
+     * @param data The objects to dispatch
+     * @param lastKey The predcessor of the first object in data if known; an empty string otherwise
+     */
+    virtual void
+    dispatchInitialObjects(uint32_t seq, std::vector<model::Object> const& data, std::string lastKey) = 0;
+
+    /**
+     * @brief Dispatch initial ledger data.
+     *
+     * The transactions, header and edge keys are received during initial ledger load.
+     *
+     * @param data The data to dispatch
+     */
+    virtual void
+    dispatchInitialData(model::LedgerData const& data) = 0;
+
+    /**
+     * @brief Dispatch an entire ledger diff.
+     *
+     * This is used to dispatch incoming diffs through the extensions.
+     *
+     * @param data The data to dispatch
+     */
+    virtual void
+    dispatch(model::LedgerData const& data) = 0;
+};
+
+}  // namespace etlng

src/etlng/impl/Registry.hpp

@@ -0,0 +1,219 @@
+//------------------------------------------------------------------------------
+/*
+    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 "etlng/Models.hpp"
+#include "etlng/RegistryInterface.hpp"
+
+#include <xrpl/protocol/TxFormats.h>
+
+#include <concepts>
+#include <cstdint>
+#include <string>
+#include <tuple>
+#include <type_traits>
+#include <utility>
+#include <vector>
+
+namespace etlng::impl {
+
+template <typename T>
+concept HasLedgerDataHook = requires(T p) {
+    { p.onLedgerData(std::declval<etlng::model::LedgerData>()) } -> std::same_as<void>;
+};
+
+template <typename T>
+concept HasInitialDataHook = requires(T p) {
+    { p.onInitialData(std::declval<etlng::model::LedgerData>()) } -> std::same_as<void>;
+};
+
+template <typename T>
+concept HasTransactionHook = requires(T p) {
+    { p.onTransaction(uint32_t{}, std::declval<etlng::model::Transaction>()) } -> std::same_as<void>;
+};
+
+template <typename T>
+concept HasObjectHook = requires(T p) {
+    { p.onObject(uint32_t{}, std::declval<etlng::model::Object>()) } -> std::same_as<void>;
+};
+
+template <typename T>
+concept HasInitialTransactionHook = requires(T p) {
+    { p.onInitialTransaction(uint32_t{}, std::declval<etlng::model::Transaction>()) } -> std::same_as<void>;
+};
+
+template <typename T>
+concept HasInitialObjectsHook = requires(T p) {
+    {
+        p.onInitialObjects(uint32_t{}, std::declval<std::vector<etlng::model::Object>>(), std::string{})
+    } -> std::same_as<void>;
+};
+
+template <typename T>
+concept HasInitialObjectHook = requires(T p) {
+    { p.onInitialObject(uint32_t{}, std::declval<etlng::model::Object>()) } -> std::same_as<void>;
+};
+
+template <typename T>
+concept ContainsSpec = std::decay_t<T>::spec::SpecTag;
+
+template <typename T>
+concept ContainsValidHook = HasLedgerDataHook<T> or HasInitialDataHook<T> or
+    (HasTransactionHook<T> and ContainsSpec<T>) or (HasInitialTransactionHook<T> and ContainsSpec<T>) or
+    HasObjectHook<T> or HasInitialObjectsHook<T> or HasInitialObjectHook<T>;
+
+template <typename T>
+concept NoTwoOfKind = not(HasLedgerDataHook<T> and HasTransactionHook<T>) and
+    not(HasInitialDataHook<T> and HasInitialTransactionHook<T>) and not(HasInitialDataHook<T> and HasObjectHook<T>) and
+    not(HasInitialObjectsHook<T> and HasInitialObjectHook<T>);
+
+template <typename T>
+concept SomeExtension = NoTwoOfKind<T> and ContainsValidHook<T>;
+
+template <SomeExtension... Ps>
+class Registry : public RegistryInterface {
+    std::tuple<Ps...> store_;
+
+    static_assert(
+        (((not HasTransactionHook<std::decay_t<Ps>>) or ContainsSpec<std::decay_t<Ps>>) and ...),
+        "Spec must be specified when 'onTransaction' function exists."
+    );
+
+    static_assert(
+        (((not HasInitialTransactionHook<std::decay_t<Ps>>) or ContainsSpec<std::decay_t<Ps>>) and ...),
+        "Spec must be specified when 'onInitialTransaction' function exists."
+    );
+
+public:
+    explicit constexpr Registry(SomeExtension auto&&... exts)
+        requires(std::is_same_v<std::decay_t<decltype(exts)>, std::decay_t<Ps>> and ...)
+        : store_(std::forward<Ps>(exts)...)
+    {
+    }
+
+    ~Registry() override = default;
+    Registry(Registry const&) = delete;
+    Registry(Registry&&) = default;
+    Registry&
+    operator=(Registry const&) = delete;
+    Registry&
+    operator=(Registry&&) = default;
+
+    constexpr void
+    dispatch(model::LedgerData const& data) override
+    {
+        // send entire batch of data at once
+        {
+            auto const expand = [&](auto& p) {
+                if constexpr (requires { p.onLedgerData(data); }) {
+                    p.onLedgerData(data);
+                }
+            };
+
+            std::apply([&expand](auto&&... xs) { (expand(xs), ...); }, store_);
+        }
+
+        // send filtered transactions
+        {
+            auto const expand = [&]<typename P>(P& p, model::Transaction const& t) {
+                if constexpr (requires { p.onTransaction(data.seq, t); }) {
+                    if (std::decay_t<P>::spec::wants(t.type))
+                        p.onTransaction(data.seq, t);
+                }
+            };
+
+            for (auto const& t : data.transactions) {
+                std::apply([&expand, &t](auto&&... xs) { (expand(xs, t), ...); }, store_);
+            }
+        }
+
+        // send per object path
+        {
+            auto const expand = [&]<typename P>(P&& p, model::Object const& o) {
+                if constexpr (requires { p.onObject(data.seq, o); }) {
+                    p.onObject(data.seq, o);
+                }
+            };
+
+            for (auto const& obj : data.objects) {
+                std::apply([&expand, &obj](auto&&... xs) { (expand(xs, obj), ...); }, store_);
+            }
+        }
+    }
+
+    constexpr void
+    dispatchInitialObjects(uint32_t seq, std::vector<model::Object> const& data, std::string lastKey) override
+    {
+        // send entire vector path
+        {
+            auto const expand = [&](auto&& p) {
+                if constexpr (requires { p.onInitialObjects(seq, data, lastKey); }) {
+                    p.onInitialObjects(seq, data, lastKey);
+                }
+            };
+
+            std::apply([&expand](auto&&... xs) { (expand(xs), ...); }, store_);
+        }
+
+        // send per object path
+        {
+            auto const expand = [&]<typename P>(P&& p, model::Object const& o) {
+                if constexpr (requires { p.onInitialObject(seq, o); }) {
+                    p.onInitialObject(seq, o);
+                }
+            };
+
+            for (auto const& obj : data) {
+                std::apply([&expand, &obj](auto&&... xs) { (expand(xs, obj), ...); }, store_);
+            }
+        }
+    }
+
+    constexpr void
+    dispatchInitialData(model::LedgerData const& data) override
+    {
+        // send entire batch path
+        {
+            auto const expand = [&](auto&& p) {
+                if constexpr (requires { p.onInitialData(data); }) {
+                    p.onInitialData(data);
+                }
+            };
+
+            std::apply([&expand](auto&&... xs) { (expand(xs), ...); }, store_);
+        }
+
+        // send per tx path
+        {
+            auto const expand = [&]<typename P>(P&& p, model::Transaction const& tx) {
+                if constexpr (requires { p.onInitialTransaction(data.seq, tx); }) {
+                    if (std::decay_t<P>::spec::wants(tx.type))
+                        p.onInitialTransaction(data.seq, tx);
+                }
+            };
+
+            for (auto const& tx : data.transactions) {
+                std::apply([&expand, &tx](auto&&... xs) { (expand(xs, tx), ...); }, store_);
+            }
+        }
+    }
+};
+
+}  // namespace etlng::impl

src/feed/SubscriptionManager.cpp

@@ -24,10 +24,10 @@
 
 #include <boost/asio/spawn.hpp>
 #include <boost/json/object.hpp>
-#include <ripple/protocol/AccountID.h>
-#include <ripple/protocol/Book.h>
-#include <ripple/protocol/Fees.h>
-#include <ripple/protocol/LedgerHeader.h>
+#include <xrpl/protocol/AccountID.h>
+#include <xrpl/protocol/Book.h>
+#include <xrpl/protocol/Fees.h>
+#include <xrpl/protocol/LedgerHeader.h>
 
 #include <cstdint>
 #include <string>

src/feed/SubscriptionManager.hpp

@@ -28,22 +28,24 @@
 #include "feed/impl/LedgerFeed.hpp"
 #include "feed/impl/ProposedTransactionFeed.hpp"
 #include "feed/impl/TransactionFeed.hpp"
+#include "util/async/AnyExecutionContext.hpp"
+#include "util/async/context/BasicExecutionContext.hpp"
+#include "util/config/Config.hpp"
 #include "util/log/Logger.hpp"
 
 #include <boost/asio/executor_work_guard.hpp>
 #include <boost/asio/io_context.hpp>
 #include <boost/asio/spawn.hpp>
 #include <boost/json/object.hpp>
-#include <ripple/protocol/AccountID.h>
-#include <ripple/protocol/Book.h>
-#include <ripple/protocol/Fees.h>
-#include <ripple/protocol/LedgerHeader.h>
+#include <xrpl/protocol/AccountID.h>
+#include <xrpl/protocol/Book.h>
+#include <xrpl/protocol/Fees.h>
+#include <xrpl/protocol/LedgerHeader.h>
 
 #include <cstdint>
-#include <functional>
 #include <memory>
 #include <string>
-#include <thread>
+#include <utility>
 #include <vector>
 
 /**
@@ -57,9 +59,8 @@ namespace feed {
  * @brief A subscription manager is responsible for managing the subscriptions and publishing the feeds
  */
 class SubscriptionManager : public SubscriptionManagerInterface {
-    std::reference_wrapper<boost::asio::io_context> ioContext_;
     std::shared_ptr<data::BackendInterface const> backend_;
-
+    util::async::AnyExecutionContext ctx_;
     impl::ForwardFeed manifestFeed_;
     impl::ForwardFeed validationsFeed_;
     impl::LedgerFeed ledgerFeed_;
@@ -68,27 +69,54 @@ class SubscriptionManager : public SubscriptionManagerInterface {
     impl::ProposedTransactionFeed proposedTransactionFeed_;
 
 public:
+    /**
+     * @brief Factory function to create a new SubscriptionManager with a PoolExecutionContext.
+     *
+     * @param config The configuration to use
+     * @param backend The backend to use
+     * @return A shared pointer to a new instance of SubscriptionManager
+     */
+    static std::shared_ptr<SubscriptionManager>
+    make_SubscriptionManager(util::Config const& config, std::shared_ptr<data::BackendInterface const> const& backend)
+    {
+        auto const workersNum = config.valueOr<std::uint64_t>("subscription_workers", 1);
+
+        util::Logger const logger{"Subscriptions"};
+        LOG(logger.info()) << "Starting subscription manager with " << workersNum << " workers";
+
+        return std::make_shared<feed::SubscriptionManager>(util::async::PoolExecutionContext(workersNum), backend);
+    }
+
     /**
      * @brief Construct a new Subscription Manager object
      *
-     * @param ioContext The io context to use
+     * @param executor The executor to use to publish the feeds
      * @param backend The backend to use
      */
     SubscriptionManager(
-        boost::asio::io_context& ioContext,
+        util::async::AnyExecutionContext&& executor,
         std::shared_ptr<data::BackendInterface const> const& backend
     )
-        : ioContext_(ioContext)
-        , backend_(backend)
-        , manifestFeed_(ioContext, "manifest")
-        , validationsFeed_(ioContext, "validations")
-        , ledgerFeed_(ioContext)
-        , bookChangesFeed_(ioContext)
-        , transactionFeed_(ioContext)
-        , proposedTransactionFeed_(ioContext)
+        : backend_(backend)
+        , ctx_(std::move(executor))
+        , manifestFeed_(ctx_, "manifest")
+        , validationsFeed_(ctx_, "validations")
+        , ledgerFeed_(ctx_)
+        , bookChangesFeed_(ctx_)
+        , transactionFeed_(ctx_)
+        , proposedTransactionFeed_(ctx_)
     {
     }
 
+    /**
+     * @brief Destructor of the SubscriptionManager object. It will block until all running jobs finished.
+     */
+    ~SubscriptionManager() override
+    {
+        ctx_.stop();
+        ctx_.join();
+    }
+
     /**
      * @brief Subscribe to the book changes feed.
      * @param subscriber
@@ -285,51 +313,4 @@ public:
     report() const final;
 };
 
-/**
- * @brief The help class to run the subscription manager. The container of io_context which is used to publish the
- * feeds.
- */
-class SubscriptionManagerRunner {
-    boost::asio::io_context ioContext_;
-    std::shared_ptr<SubscriptionManager> subscriptionManager_;
-    util::Logger logger_{"Subscriptions"};
-    boost::asio::executor_work_guard<boost::asio::io_context::executor_type> work_ =
-        boost::asio::make_work_guard(ioContext_);
-    std::vector<std::thread> workers_;
-
-public:
-    /**
-     * @brief Construct a new Subscription Manager Runner object
-     *
-     * @param config The configuration
-     * @param backend The backend to use
-     */
-    SubscriptionManagerRunner(util::Config const& config, std::shared_ptr<data::BackendInterface> const& backend)
-        : subscriptionManager_(std::make_shared<SubscriptionManager>(ioContext_, backend))
-    {
-        auto numThreads = config.valueOr<uint64_t>("subscription_workers", 1);
-        LOG(logger_.info()) << "Starting subscription manager with " << numThreads << " workers";
-        workers_.reserve(numThreads);
-        for (auto i = numThreads; i > 0; --i)
-            workers_.emplace_back([&] { ioContext_.run(); });
-    }
-
-    /**
-     * @brief Get the subscription manager
-     *
-     * @return The subscription manager
-     */
-    std::shared_ptr<SubscriptionManager>
-    getManager()
-    {
-        return subscriptionManager_;
-    }
-
-    ~SubscriptionManagerRunner()
-    {
-        work_.reset();
-        for (auto& worker : workers_)
-            worker.join();
-    }
-};
 }  // namespace feed

src/feed/SubscriptionManagerInterface.hpp

@@ -26,10 +26,10 @@
 #include <boost/asio/io_context.hpp>
 #include <boost/asio/spawn.hpp>
 #include <boost/json/object.hpp>
-#include <ripple/protocol/AccountID.h>
-#include <ripple/protocol/Book.h>
-#include <ripple/protocol/Fees.h>
-#include <ripple/protocol/LedgerHeader.h>
+#include <xrpl/protocol/AccountID.h>
+#include <xrpl/protocol/Book.h>
+#include <xrpl/protocol/Fees.h>
+#include <xrpl/protocol/LedgerHeader.h>
 
 #include <cstdint>
 #include <string>
@@ -109,6 +109,7 @@ public:
      * @brief Subscribe to the ledger feed.
      * @param yield The coroutine context
      * @param subscriber The subscriber to the ledger feed
+     *
      * @return The ledger feed
      */
     virtual boost::json::object