ensure static mysql libs are added to build engine

Builds/CMake/FindMySQL.cmake

@@ -0,0 +1,48 @@
+# - Find MySQL
+find_path(MYSQL_INCLUDE_DIR
+    NAMES mysql.h
+    PATHS
+        /usr/include/mysql
+        /usr/local/include/mysql
+        /opt/mysql/mysql/include
+    DOC "MySQL include directory"
+)
+
+find_library(MYSQL_LIBRARY
+    NAMES mysqlclient
+    PATHS
+        /usr/lib
+        /usr/lib/x86_64-linux-gnu
+        /usr/lib/mysql
+        /usr/local/lib/mysql
+        /opt/mysql/mysql/lib
+    DOC "MySQL client library"
+)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(MySQL
+    REQUIRED_VARS
+        MYSQL_LIBRARY
+        MYSQL_INCLUDE_DIR
+)
+
+if(MYSQL_FOUND)
+    set(MYSQL_INCLUDE_DIRS ${MYSQL_INCLUDE_DIR})
+    set(MYSQL_LIBRARIES ${MYSQL_LIBRARY})
+    
+    # Create an imported target
+    if(NOT TARGET MySQL::MySQL)
+        add_library(MySQL::MySQL UNKNOWN IMPORTED)
+        set_target_properties(MySQL::MySQL PROPERTIES
+            IMPORTED_LOCATION "${MYSQL_LIBRARY}"
+            INTERFACE_INCLUDE_DIRECTORIES "${MYSQL_INCLUDE_DIR}"
+        )
+    endif()
+    
+    mark_as_advanced(MYSQL_INCLUDE_DIR MYSQL_LIBRARY)
+else()
+    message(FATAL_ERROR "Could not find MySQL development files")
+endif()
+
+message(STATUS "Using MySQL include dir: ${MYSQL_INCLUDE_DIR}")
+message(STATUS "Using MySQL library: ${MYSQL_LIBRARY}")

Builds/CMake/RippledCore.cmake

@@ -540,6 +540,7 @@ target_sources (rippled PRIVATE
   #]===============================]
   src/ripple/nodestore/backend/CassandraFactory.cpp
   src/ripple/nodestore/backend/RWDBFactory.cpp
+  src/ripple/nodestore/backend/MySQLFactory.cpp
   src/ripple/nodestore/backend/MemoryFactory.cpp
   src/ripple/nodestore/backend/FlatmapFactory.cpp
   src/ripple/nodestore/backend/NuDBFactory.cpp

Builds/CMake/deps/MySQL.cmake

@@ -0,0 +1,56 @@
+#[===================================================================[
+   dep: MySQL
+   MySQL client library integration for rippled (static linking)
+#]===================================================================]
+# Create an IMPORTED target for MySQL
+add_library(mysql_client UNKNOWN IMPORTED)
+
+# Find MySQL client library and headers
+find_path(MYSQL_INCLUDE_DIR
+    NAMES mysql.h
+    PATHS
+        /usr/include/mysql
+        /usr/local/include/mysql
+        /opt/mysql/mysql/include
+    DOC "MySQL include directory"
+)
+
+# Modified to specifically look for static library
+find_library(MYSQL_LIBRARY
+    NAMES libmysqlclient.a mysqlclient.a    # Look for static libraries first
+    PATHS
+        /usr/lib
+        /usr/lib/x86_64-linux-gnu
+        /usr/lib/mysql
+        /usr/local/lib/mysql
+        /opt/mysql/mysql/lib
+    DOC "MySQL client static library"
+    NO_DEFAULT_PATH    # Prevents finding dynamic library first
+)
+
+# Set properties on the imported target
+if(MYSQL_INCLUDE_DIR AND MYSQL_LIBRARY)
+    set_target_properties(mysql_client PROPERTIES
+        IMPORTED_LOCATION "${MYSQL_LIBRARY}"
+        INTERFACE_INCLUDE_DIRECTORIES "${MYSQL_INCLUDE_DIR}"
+        IMPORTED_LINK_INTERFACE_LANGUAGES "CXX"    # Added for static linking
+        IMPORTED_LINK_INTERFACE_MULTIPLICITY "1"    # Added for static linking
+    )
+    message(STATUS "Found MySQL include dir: ${MYSQL_INCLUDE_DIR}")
+    message(STATUS "Found MySQL library: ${MYSQL_LIBRARY}")
+else()
+    message(FATAL_ERROR "Could not find MySQL static development files. Please install libmysqlclient-dev")
+endif()
+
+# Add MySQL backend source to rippled sources
+list(APPEND rippled_src
+    src/ripple/nodestore/backend/MySQLBackend.cpp)
+
+# Link MySQL to rippled
+target_link_libraries(ripple_libs
+    INTERFACE
+        mysql_client
+)
+
+# Create an alias target for consistency with other deps
+add_library(deps::mysql ALIAS mysql_client)

CMakeLists.txt

@@ -75,6 +75,7 @@ include(deps/gRPC)
 include(deps/cassandra)
 include(deps/Postgres)
 include(deps/WasmEdge)
+include(deps/MySQL)
 
 ###
 

build-full.sh

@@ -69,7 +69,14 @@ fi
 mkdir .nih_c;
 mkdir .nih_toolchain;
 cd .nih_toolchain &&
-yum install -y wget lz4 lz4-devel git llvm13-static.x86_64 llvm13-devel.x86_64 devtoolset-10-binutils zlib-static ncurses-static -y \
+(cat > /etc/yum.repos.d/MariaDB.repo << EOF
+[mariadb]
+name = MariaDB
+baseurl = http://yum.mariadb.org/10.5/centos7-amd64
+gpgkey=https://yum.mariadb.org/RPM-GPG-KEY-MariaDB
+gpgcheck=1
+EOF ) &&
+yum install -y wget lz4 lz4-devel git llvm13-static.x86_64 llvm13-devel.x86_64 devtoolset-10-binutils zlib-static ncurses-static MariaDB-devel MariaDB-shared -y \
   devtoolset-7-gcc-c++ \
   devtoolset-9-gcc-c++ \
   devtoolset-10-gcc-c++ \

src/ripple/app/rdb/impl/RelationalDatabase.cpp

@@ -20,6 +20,7 @@
 #include <ripple/app/main/Application.h>
 #include <ripple/app/rdb/RelationalDatabase.h>
 #include <ripple/app/rdb/backend/FlatmapDatabase.h>
+#include <ripple/app/rdb/backend/MySQLDatabase.h>
 #include <ripple/app/rdb/backend/RWDBDatabase.h>
 #include <ripple/core/ConfigSections.h>
 #include <ripple/nodestore/DatabaseShard.h>
@@ -42,6 +43,7 @@ RelationalDatabase::init(
     bool use_postgres = false;
     bool use_rwdb = false;
     bool use_flatmap = false;
+    bool use_mysql = false;
 
     if (config.reporting())
     {
@@ -64,6 +66,10 @@ RelationalDatabase::init(
             {
                 use_flatmap = true;
             }
+            else if (boost::iequals(get(rdb_section, "backend"), "mysql"))
+            {
+                use_mysql = true;
+            }
             else
             {
                 Throw<std::runtime_error>(
@@ -93,6 +99,10 @@ RelationalDatabase::init(
     {
         return getFlatmapDatabase(app, config, jobQueue);
     }
+    else if (use_mysql)
+    {
+        return getMySQLDatabase(app, config, jobQueue);
+    }
 
     return std::unique_ptr<RelationalDatabase>();
 }

src/ripple/basics/BasicConfig.h

@@ -36,6 +36,8 @@ using IniFileSections = std::map<std::string, std::vector<std::string>>;
 
 //------------------------------------------------------------------------------
 
+class Config;
+
 /** Holds a collection of configuration values.
     A configuration file contains zero or more sections.
 */
@@ -48,11 +50,22 @@ private:
     std::vector<std::string> values_;
     bool had_trailing_comments_ = false;
 
+    Config const* parent_;
+
     using const_iterator = decltype(lookup_)::const_iterator;
 
 public:
+    // throws if no parent for this section
+    Config const&
+    getParent() const
+    {
+        if (!parent_)
+            Throw<std::runtime_error>("No parent_ for config section");
+        return *parent_;
+    }
+
     /** Create an empty section. */
-    explicit Section(std::string const& name = "");
+    explicit Section(std::string const& name = "", Config* parent = nullptr);
 
     /** Returns the name of this section. */
     std::string const&
@@ -218,6 +231,8 @@ private:
     std::map<std::string, Section, boost::beast::iless> map_;
 
 public:
+    virtual ~BasicConfig() = default;
+
     /** Returns `true` if a section with the given name exists. */
     bool
     exists(std::string const& name) const;

src/ripple/basics/impl/BasicConfig.cpp

@@ -24,7 +24,10 @@
 
 namespace ripple {
 
-Section::Section(std::string const& name) : name_(name)
+class Config;
+
+Section::Section(std::string const& name, Config* parent)
+    : name_(name), parent_(parent)
 {
 }
 
@@ -175,12 +178,14 @@ BasicConfig::legacy(std::string const& sectionName) const
 void
 BasicConfig::build(IniFileSections const& ifs)
 {
+    Config* config_this = dynamic_cast<Config*>(this);
     for (auto const& entry : ifs)
     {
         auto const result = map_.emplace(
             std::piecewise_construct,
             std::make_tuple(entry.first),
-            std::make_tuple(entry.first));
+            std::make_tuple(
+                entry.first, config_this));  // Will be nullptr if cast failed
         result.first->second.append(entry.second);
     }
 }

src/ripple/core/Config.h

@@ -175,6 +175,17 @@ public:
     // Network parameters
     uint32_t NETWORK_ID = 0;
 
+    struct MysqlSettings
+    {
+        std::string host;
+        std::string user;
+        std::string pass;
+        std::string name;
+        uint16_t port;
+    };
+
+    std::optional<MysqlSettings> mysql;
+
     // DEPRECATED - Fee units for a reference transction.
     // Only provided for backwards compatibility in a couple of places
     static constexpr std::uint32_t FEE_UNITS_DEPRECATED = 10;

src/ripple/core/ConfigSections.h

@@ -102,6 +102,7 @@ struct ConfigSection
 #define SECTION_NETWORK_ID "network_id"
 #define SECTION_IMPORT_VL_KEYS "import_vl_keys"
 #define SECTION_DATAGRAM_MONITOR "datagram_monitor"
+#define SECTION_MYSQL_SETTINGS "mysql_settings"
 
 }  // namespace ripple
 

src/ripple/core/impl/Config.cpp

@@ -756,6 +756,30 @@ Config::loadFromString(std::string const& fileContents)
         SERVER_DOMAIN = strTemp;
     }
 
+    if (exists(SECTION_MYSQL_SETTINGS))
+    {
+        auto const sec = section(SECTION_MYSQL_SETTINGS);
+        if (!sec.exists("host") || !sec.exists("user") || !sec.exists("pass") ||
+            !sec.exists("port") || !sec.exists("name"))
+        {
+            Throw<std::runtime_error>(
+                "[mysql_settings] requires host=, user=, pass=, name= and "
+                "port= keys.");
+        }
+
+        MysqlSettings my;
+
+        my.host = *sec.get("host");
+        my.user = *sec.get("user");
+        my.pass = *sec.get("pass");
+        my.name = *sec.get("name");
+
+        std::string portStr = *sec.get("port");
+        my.port = beast::lexicalCastThrow<int>(portStr);
+
+        mysql = my;
+    }
+
     if (exists(SECTION_OVERLAY))
     {
         auto const sec = section(SECTION_OVERLAY);

src/ripple/nodestore/backend/MySQLFactory.cpp

@@ -0,0 +1,966 @@
+#ifndef RIPPLE_NODESTORE_MYSQLBACKEND_H_INCLUDED
+#define RIPPLE_NODESTORE_MYSQLBACKEND_H_INCLUDED
+
+#include <ripple/basics/contract.h>
+#include <ripple/nodestore/Factory.h>
+#include <ripple/nodestore/Manager.h>
+#include <ripple/nodestore/impl/DecodedBlob.h>
+#include <ripple/nodestore/impl/EncodedBlob.h>
+#include <ripple/nodestore/impl/codec.h>
+#include <boost/beast/core/string.hpp>
+#include <chrono>
+#include <cstdint>
+#include <map>
+#include <memory>
+#include <mutex>
+#include <mysql/mysql.h>
+#include <queue>
+#include <sstream>
+#include <thread>
+
+namespace ripple {
+namespace NodeStore {
+
+// SQL statements as constants
+static constexpr auto CREATE_DATABASE = R"SQL(
+    CREATE DATABASE IF NOT EXISTS `%s` 
+    CHARACTER SET utf8mb4 
+    COLLATE utf8mb4_unicode_ci
+)SQL";
+
+static constexpr auto CREATE_TABLE = R"SQL(
+    CREATE TABLE IF NOT EXISTS `%s` (
+        hash BINARY(32) PRIMARY KEY,
+        data MEDIUMBLOB NOT NULL,
+        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+        INDEX idx_created_at (created_at)
+    ) ENGINE=InnoDB
+)SQL";
+
+static constexpr auto INSERT_NODE = R"SQL(
+    INSERT INTO %s (hash, data) 
+    VALUES (?, ?) 
+    ON DUPLICATE KEY UPDATE data = VALUES(data)
+)SQL";
+
+static constexpr auto SET_ISOLATION_LEVEL = R"SQL(
+    SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED
+)SQL";
+
+class MySQLConnection
+{
+private:
+    std::unique_ptr<MYSQL, decltype(&mysql_close)> mysql_;
+    Config const& config_;
+    beast::Journal journal_;
+    static constexpr int MAX_RETRY_ATTEMPTS = 3;
+    static constexpr auto RETRY_DELAY_MS = 1000;
+
+    bool
+    connect()
+    {
+        mysql_.reset(mysql_init(nullptr));
+        if (!mysql_)
+            return false;
+
+        // Set connection options
+        unsigned int timeout = 5;
+        mysql_options(mysql_.get(), MYSQL_OPT_CONNECT_TIMEOUT, &timeout);
+        uint8_t const reconnect = 1;
+        mysql_options(mysql_.get(), MYSQL_OPT_RECONNECT, &reconnect);
+
+        // Connect without database first
+        auto* conn = mysql_real_connect(
+            mysql_.get(),
+            config_.mysql->host.c_str(),
+            config_.mysql->user.c_str(),
+            config_.mysql->pass.c_str(),
+            nullptr,  // No database selected yet
+            config_.mysql->port,
+            nullptr,
+            CLIENT_MULTI_STATEMENTS);
+
+        if (!conn)
+            return false;
+
+        // Set isolation level for dirty reads
+        if (mysql_query(mysql_.get(), SET_ISOLATION_LEVEL))
+        {
+            JLOG(journal_.warn()) << "Failed to set isolation level: "
+                                  << mysql_error(mysql_.get());
+            return false;
+        }
+
+        // Create database (unconditionally)
+        std::string query(1024, '\0');
+        int length = snprintf(
+            &query[0],
+            query.size(),
+            CREATE_DATABASE,
+            config_.mysql->name.c_str());
+        query.resize(length);
+
+        if (mysql_query(mysql_.get(), query.c_str()))
+        {
+            JLOG(journal_.error())
+                << "Failed to create database: " << mysql_error(mysql_.get());
+            return false;
+        }
+
+        // Now select the database
+        if (mysql_select_db(mysql_.get(), config_.mysql->name.c_str()))
+        {
+            JLOG(journal_.error())
+                << "Failed to select database: " << mysql_error(mysql_.get());
+            return false;
+        }
+
+        return true;
+    }
+
+public:
+    MySQLConnection(Config const& config, beast::Journal journal)
+        : mysql_(nullptr, mysql_close), config_(config), journal_(journal)
+    {
+        if (!config_.mysql.has_value())
+            throw std::runtime_error(
+                "[mysql_settings] stanza missing from config!");
+
+        if (config_.mysql->name.empty())
+            throw std::runtime_error(
+                "Database name missing from mysql_settings!");
+
+        if (!connect())
+        {
+            Throw<std::runtime_error>(
+                std::string("Failed to connect to MySQL: ") +
+                (mysql_ ? mysql_error(mysql_.get()) : "initialization failed"));
+        }
+    }
+
+    MYSQL*
+    get()
+    {
+        return mysql_.get();
+    }
+
+    bool
+    ensureConnection()
+    {
+        for (int attempt = 0; attempt < MAX_RETRY_ATTEMPTS; ++attempt)
+        {
+            if (!mysql_ || mysql_ping(mysql_.get()) != 0)
+            {
+                JLOG(journal_.warn())
+                    << "MySQL connection lost, attempting reconnect (attempt "
+                    << (attempt + 1) << "/" << MAX_RETRY_ATTEMPTS << ")";
+
+                if (connect())
+                    return true;
+
+                if (attempt < MAX_RETRY_ATTEMPTS - 1)
+                {
+                    std::this_thread::sleep_for(
+                        std::chrono::milliseconds(RETRY_DELAY_MS));
+                }
+            }
+            else
+            {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    // Helper method to execute a query with retry logic
+    bool
+    executeQuery(std::string const& query)
+    {
+        for (int attempt = 0; attempt < MAX_RETRY_ATTEMPTS; ++attempt)
+        {
+            if (ensureConnection() && !mysql_query(mysql_.get(), query.c_str()))
+                return true;
+
+            if (attempt < MAX_RETRY_ATTEMPTS - 1)
+            {
+                std::this_thread::sleep_for(
+                    std::chrono::milliseconds(RETRY_DELAY_MS));
+            }
+        }
+        return false;
+    }
+};
+
+static thread_local std::unique_ptr<MySQLConnection> threadConnection_;
+
+class MySQLBackend : public Backend
+{
+private:
+    std::string name_;
+    beast::Journal journal_;
+    bool isOpen_{false};
+    Config const& config_;
+    static constexpr std::size_t BATCH_SIZE = 1000;
+    static constexpr std::size_t MAX_CACHE_SIZE =
+        100000;  // Maximum number of entries
+    static constexpr std::size_t CACHE_CLEANUP_THRESHOLD =
+        120000;  // When to trigger cleanup
+
+    using DataStore = std::map<uint256, std::vector<std::uint8_t>>;
+    DataStore cache_;
+    std::mutex cacheMutex_;
+
+    // LRU tracking for cache management
+    struct CacheEntry
+    {
+        std::chrono::steady_clock::time_point last_access;
+        size_t size;
+        bool pending{false};
+    };
+
+    std::map<uint256, CacheEntry> cacheMetadata_;
+    std::mutex metadataMutex_;
+    std::atomic<size_t> currentCacheSize_{0};
+
+    // Background write queue
+    struct WriteOp
+    {
+        uint256 hash;
+        std::vector<std::uint8_t> data;
+    };
+    std::queue<WriteOp> writeQueue_;
+    std::mutex queueMutex_;
+    std::condition_variable queueCV_;
+    std::atomic<bool> shouldStop_{false};
+    std::thread writeThread_;
+
+    MySQLConnection*
+    getConnection()
+    {
+        if (!threadConnection_)
+        {
+            threadConnection_ =
+                std::make_unique<MySQLConnection>(config_, journal_);
+        }
+        return threadConnection_.get();
+    }
+
+    std::string
+    sanitizeTableName(std::string name)
+    {
+        name.erase(
+            std::unique(
+                name.begin(),
+                std::transform(
+                    name.begin(),
+                    name.end(),
+                    name.begin(),
+                    [](char c) { return std::isalnum(c) ? c : '_'; })),
+            name.end());
+        return "nodes_" + name;
+    }
+
+    void
+    cleanupCache()
+    {
+        if (currentCacheSize_.load() < CACHE_CLEANUP_THRESHOLD)
+            return;
+
+        // Collect entries sorted by last access time
+        std::vector<std::pair<uint256, std::chrono::steady_clock::time_point>>
+            entries;
+        {
+            std::lock_guard<std::mutex> metadataLock(metadataMutex_);
+            for (const auto& [hash, metadata] : cacheMetadata_)
+            {
+                if (!metadata.pending)
+                    entries.emplace_back(hash, metadata.last_access);
+            }
+        }
+
+        // Sort by access time, oldest first
+        std::sort(
+            entries.begin(), entries.end(), [](const auto& a, const auto& b) {
+                return a.second < b.second;
+            });
+
+        // Remove oldest entries until we're below target size
+        size_t removedSize = 0;
+        for (const auto& entry : entries)
+        {
+            if (currentCacheSize_.load() <= MAX_CACHE_SIZE)
+                break;
+
+            {
+                std::lock_guard<std::mutex> metadataLock(metadataMutex_);
+                auto metaIt = cacheMetadata_.find(entry.first);
+                if (metaIt != cacheMetadata_.end())
+                {
+                    removedSize += metaIt->second.size;
+                    cacheMetadata_.erase(metaIt);
+                }
+            }
+            {
+                std::lock_guard<std::mutex> cacheLock(cacheMutex_);
+                cache_.erase(entry.first);
+            }
+            currentCacheSize_--;
+        }
+
+        JLOG(journal_.debug())
+            << "Cache cleanup removed " << removedSize
+            << " bytes, current size: " << currentCacheSize_.load();
+    }
+
+    void
+    updateCacheMetadata(const uint256& hash, size_t size)
+    {
+        CacheEntry entry{std::chrono::steady_clock::now(), size};
+        {
+            std::lock_guard<std::mutex> metadataLock(metadataMutex_);
+            cacheMetadata_[hash] = entry;
+        }
+
+        if (++currentCacheSize_ >= CACHE_CLEANUP_THRESHOLD)
+        {
+            cleanupCache();
+        }
+    }
+
+    Status
+    fetch(void const* key, std::shared_ptr<NodeObject>* pObject) override
+    {
+        if (!isOpen_)
+            return notFound;
+
+        uint256 const hash(uint256::fromVoid(key));
+
+        // Check cache first
+        {
+            std::lock_guard<std::mutex> cacheLock(cacheMutex_);
+            auto it = cache_.find(hash);
+            if (it != cache_.end())
+            {
+                // Update access time
+                {
+                    std::lock_guard<std::mutex> metadataLock(metadataMutex_);
+                    auto metaIt = cacheMetadata_.find(hash);
+                    if (metaIt != cacheMetadata_.end())
+                    {
+                        metaIt->second.last_access =
+                            std::chrono::steady_clock::now();
+                    }
+                }
+
+                nudb::detail::buffer decompressed;
+                auto const result = nodeobject_decompress(
+                    it->second.data(), it->second.size(), decompressed);
+
+                DecodedBlob decoded(hash.data(), result.first, result.second);
+                if (decoded.wasOk())
+                {
+                    *pObject = decoded.createObject();
+                    return ok;
+                }
+            }
+        }
+
+        // If not in cache, fetch from MySQL
+        return fetchFromMySQL(key, pObject);
+    }
+
+    void
+    startWriteThread()
+    {
+        writeThread_ = std::thread([this]() {
+            while (!shouldStop_)
+            {
+                std::vector<WriteOp> batch;
+                {
+                    std::unique_lock<std::mutex> lock(queueMutex_);
+                    queueCV_.wait_for(
+                        lock, std::chrono::milliseconds(100), [this]() {
+                            return !writeQueue_.empty() || shouldStop_;
+                        });
+
+                    // Grab up to BATCH_SIZE operations
+                    while (!writeQueue_.empty() && batch.size() < BATCH_SIZE)
+                    {
+                        batch.push_back(std::move(writeQueue_.front()));
+                        writeQueue_.pop();
+                    }
+                }
+
+                if (!batch.empty())
+                {
+                    auto* conn = getConnection();
+                    if (!conn->ensureConnection())
+                        continue;
+
+                    if (mysql_query(conn->get(), "START TRANSACTION"))
+                        continue;
+
+                    bool success = true;
+                    for (auto const& op : batch)
+                    {
+                        MYSQL_STMT* stmt = mysql_stmt_init(conn->get());
+                        if (!stmt)
+                        {
+                            success = false;
+                            break;
+                        }
+
+                        std::string const sql = "INSERT INTO " + name_ +
+                            " (hash, data) VALUES (?, ?) " +
+                            "ON DUPLICATE KEY UPDATE data = VALUES(data)";
+
+                        if (mysql_stmt_prepare(stmt, sql.c_str(), sql.length()))
+                        {
+                            mysql_stmt_close(stmt);
+                            success = false;
+                            break;
+                        }
+
+                        MYSQL_BIND bind[2];
+                        std::memset(bind, 0, sizeof(bind));
+
+                        bind[0].buffer_type = MYSQL_TYPE_BLOB;
+                        bind[0].buffer = const_cast<void*>(
+                            static_cast<void const*>(op.hash.data()));
+                        bind[0].buffer_length = op.hash.size();
+
+                        bind[1].buffer_type = MYSQL_TYPE_BLOB;
+                        bind[1].buffer = const_cast<uint8_t*>(op.data.data());
+                        bind[1].buffer_length = op.data.size();
+
+                        if (mysql_stmt_bind_param(stmt, bind))
+                        {
+                            mysql_stmt_close(stmt);
+                            success = false;
+                            break;
+                        }
+
+                        if (mysql_stmt_execute(stmt))
+                        {
+                            mysql_stmt_close(stmt);
+                            success = false;
+                            break;
+                        }
+
+                        mysql_stmt_close(stmt);
+                    }
+
+                    if (success)
+                    {
+                        if (mysql_query(conn->get(), "COMMIT") == 0)
+                        {
+                            // Clear pending flag for successfully written
+                            // entries
+                            std::lock_guard<std::mutex> metadataLock(
+                                metadataMutex_);
+                            for (const auto& op : batch)
+                            {
+                                auto it = cacheMetadata_.find(op.hash);
+                                if (it != cacheMetadata_.end())
+                                    it->second.pending = false;
+                            }
+                        }
+                    }
+                    else
+                        mysql_query(conn->get(), "ROLLBACK");
+                }
+            }
+        });
+    }
+
+    void
+    queueWrite(uint256 const& hash, std::vector<std::uint8_t> const& data)
+    {
+        {
+            std::lock_guard<std::mutex> metadataLock(metadataMutex_);
+            auto& entry = cacheMetadata_[hash];
+            entry.pending = true;
+        }
+        std::lock_guard<std::mutex> lock(queueMutex_);
+        writeQueue_.push({hash, data});
+        queueCV_.notify_one();
+    }
+
+    Status
+    fetchFromMySQL(void const* key, std::shared_ptr<NodeObject>* pObject)
+    {
+        auto* conn = getConnection();
+        if (!conn->ensureConnection())
+        {
+            JLOG(journal_.warn()) << "fetch: Failed to ensure connection";
+            return dataCorrupt;
+        }
+
+        uint256 const hash(uint256::fromVoid(key));
+
+        MYSQL_STMT* stmt = mysql_stmt_init(conn->get());
+        if (!stmt)
+        {
+            JLOG(journal_.warn()) << "fetch: Failed to init stmt";
+            return dataCorrupt;
+        }
+
+        std::string const sql = "SELECT data FROM " + name_ + " WHERE hash = ?";
+
+        if (mysql_stmt_prepare(stmt, sql.c_str(), sql.length()))
+        {
+            JLOG(journal_.warn()) << "fetch: Failed to prepare stmt";
+            mysql_stmt_close(stmt);
+            return dataCorrupt;
+        }
+
+        MYSQL_BIND bindParam;
+        std::memset(&bindParam, 0, sizeof(bindParam));
+        bindParam.buffer_type = MYSQL_TYPE_BLOB;
+        bindParam.buffer =
+            const_cast<void*>(static_cast<void const*>(hash.data()));
+        bindParam.buffer_length = hash.size();
+
+        if (mysql_stmt_bind_param(stmt, &bindParam))
+        {
+            JLOG(journal_.warn()) << "fetch: Failed to bind param";
+            mysql_stmt_close(stmt);
+            return dataCorrupt;
+        }
+
+        if (mysql_stmt_execute(stmt))
+        {
+            mysql_stmt_close(stmt);
+            return notFound;
+        }
+
+        MYSQL_BIND bindResult;
+        std::memset(&bindResult, 0, sizeof(bindResult));
+        uint64_t length = 0;
+
+#if MYSQL_VERSION_ID < 80000
+        char
+#else
+        bool
+#endif
+            is_null = 0;
+        bindResult.buffer_type = MYSQL_TYPE_BLOB;
+        bindResult.length = &length;
+        bindResult.is_null = &is_null;
+
+        std::vector<uint8_t> buffer(16 * 1024 * 1024);  // 16MB buffer
+        bindResult.buffer = buffer.data();
+        bindResult.buffer_length = buffer.size();
+
+        if (mysql_stmt_bind_result(stmt, &bindResult))
+        {
+            JLOG(journal_.warn()) << "fetch: Failed to bind result";
+            mysql_stmt_close(stmt);
+            return dataCorrupt;
+        }
+
+        if (mysql_stmt_store_result(stmt))
+        {
+            JLOG(journal_.warn()) << "fetch: Failed to store result";
+            mysql_stmt_close(stmt);
+            return dataCorrupt;
+        }
+
+        if (mysql_stmt_num_rows(stmt) == 0)
+        {
+            mysql_stmt_close(stmt);
+            return notFound;
+        }
+
+        if (mysql_stmt_fetch(stmt))
+        {
+            JLOG(journal_.warn()) << "fetch: Failed to fetch stmt";
+            mysql_stmt_close(stmt);
+            return dataCorrupt;
+        }
+
+        mysql_stmt_close(stmt);
+
+        // Add to cache
+        std::vector<uint8_t> cached_data(
+            buffer.begin(), buffer.begin() + length);
+        cache_.insert_or_assign(hash, cached_data);
+        updateCacheMetadata(hash, length);
+
+        nudb::detail::buffer decompressed;
+        auto const result = nodeobject_decompress(
+            cached_data.data(), cached_data.size(), decompressed);
+
+        DecodedBlob decoded(hash.data(), result.first, result.second);
+        if (!decoded.wasOk())
+        {
+            JLOG(journal_.warn()) << "fetch: Failed to decode blob";
+            return dataCorrupt;
+        }
+
+        *pObject = decoded.createObject();
+        return ok;
+    }
+
+public:
+    MySQLBackend(
+        std::size_t keyBytes,
+        Section const& keyValues,
+        beast::Journal journal)
+        : name_(sanitizeTableName(get(keyValues, "path", "nodestore")))
+        , journal_(journal)
+        , config_(keyValues.getParent())
+    {
+        startWriteThread();
+    }
+
+    ~MySQLBackend()
+    {
+        shouldStop_ = true;
+        queueCV_.notify_all();
+        if (writeThread_.joinable())
+            writeThread_.join();
+    }
+
+    std::string
+    getName() override
+    {
+        return name_;
+    }
+
+    void
+    open(bool createIfMissing) override
+    {
+        if (isOpen_)
+            Throw<std::runtime_error>("database already open");
+
+        auto* conn = getConnection();
+        if (!conn->ensureConnection())
+            Throw<std::runtime_error>("Failed to establish MySQL connection");
+
+        if (createIfMissing)
+            createTable();
+
+        isOpen_ = true;
+    }
+
+    bool
+    isOpen() override
+    {
+        return isOpen_;
+    }
+
+    void
+    close() override
+    {
+        // Wait for write queue to empty
+        {
+            std::unique_lock<std::mutex> lock(queueMutex_);
+            while (!writeQueue_.empty())
+            {
+                queueCV_.wait(lock);
+            }
+        }
+
+        threadConnection_.reset();
+        cache_.clear();
+        cacheMetadata_.clear();
+        currentCacheSize_ = 0;
+        isOpen_ = false;
+    }
+
+    std::pair<std::vector<std::shared_ptr<NodeObject>>, Status>
+    fetchBatch(std::vector<uint256 const*> const& hashes) override
+    {
+        std::vector<std::shared_ptr<NodeObject>> results;
+        results.reserve(hashes.size());
+
+        std::vector<uint256 const*> mysqlFetch;
+        mysqlFetch.reserve(hashes.size());
+
+        // First try cache
+        for (auto const& h : hashes)
+        {
+            auto it = cache_.find(*h);
+            if (it != cache_.end())
+            {
+                // Update access time
+                auto metaIt = cacheMetadata_.find(*h);
+                if (metaIt != cacheMetadata_.end())
+                {
+                    metaIt->second.last_access =
+                        std::chrono::steady_clock::now();
+                }
+
+                nudb::detail::buffer decompressed;
+                auto const result = nodeobject_decompress(
+                    it->second.data(), it->second.size(), decompressed);
+
+                DecodedBlob decoded(h->data(), result.first, result.second);
+                if (decoded.wasOk())
+                {
+                    results.push_back(decoded.createObject());
+                    continue;
+                }
+            }
+
+            mysqlFetch.push_back(h);
+            results.push_back(nullptr);  // Placeholder for MySQL fetch
+        }
+
+        // If everything was in cache, return early
+        if (mysqlFetch.empty())
+            return {results, ok};
+
+        // Fetch remaining from MySQL
+        auto* conn = getConnection();
+        if (!conn->ensureConnection())
+            return {results, dataCorrupt};
+
+        if (mysql_query(conn->get(), "START TRANSACTION"))
+            return {results, dataCorrupt};
+
+        try
+        {
+            for (size_t i = 0; i < mysqlFetch.size(); ++i)
+            {
+                std::shared_ptr<NodeObject> nObj;
+                Status status = fetchFromMySQL(mysqlFetch[i]->data(), &nObj);
+
+                // Find the original position in results
+                auto originalPos = std::distance(
+                    hashes.begin(),
+                    std::find(hashes.begin(), hashes.end(), mysqlFetch[i]));
+
+                results[originalPos] = (status == ok ? nObj : nullptr);
+            }
+
+            if (mysql_query(conn->get(), "COMMIT"))
+                return {results, dataCorrupt};
+
+            return {results, ok};
+        }
+        catch (...)
+        {
+            mysql_query(conn->get(), "ROLLBACK");
+            throw;
+        }
+    }
+
+    void
+    store(std::shared_ptr<NodeObject> const& object) override
+    {
+        if (!isOpen_ || !object)
+            return;
+
+        EncodedBlob encoded(object);
+        nudb::detail::buffer compressed;
+        auto const result = nodeobject_compress(
+            encoded.getData(), encoded.getSize(), compressed);
+
+        std::vector<std::uint8_t> data(
+            static_cast<const std::uint8_t*>(result.first),
+            static_cast<const std::uint8_t*>(result.first) + result.second);
+
+        // Update cache immediately
+        cache_.insert_or_assign(object->getHash(), data);
+        updateCacheMetadata(object->getHash(), data.size());
+
+        // Queue async write to MySQL
+        queueWrite(object->getHash(), data);
+    }
+
+    void
+    storeBatch(Batch const& batch) override
+    {
+        for (auto const& e : batch)
+        {
+            if (!e)
+                continue;
+
+            EncodedBlob encoded(e);
+            nudb::detail::buffer compressed;
+            auto const result = nodeobject_compress(
+                encoded.getData(), encoded.getSize(), compressed);
+
+            std::vector<std::uint8_t> data(
+                static_cast<const std::uint8_t*>(result.first),
+                static_cast<const std::uint8_t*>(result.first) + result.second);
+
+            // Update cache immediately
+            cache_.insert_or_assign(e->getHash(), data);
+            updateCacheMetadata(e->getHash(), data.size());
+
+            // Queue async write to MySQL
+            queueWrite(e->getHash(), data);
+        }
+    }
+
+    void
+    sync() override
+    {
+        // Wait for write queue to empty
+        std::unique_lock<std::mutex> lock(queueMutex_);
+        while (!writeQueue_.empty())
+        {
+            queueCV_.wait(lock);
+        }
+    }
+
+    void
+    for_each(std::function<void(std::shared_ptr<NodeObject>)> f) override
+    {
+        if (!isOpen_)
+            return;
+
+        // First, process all cached entries
+        std::vector<std::pair<uint256, std::vector<std::uint8_t>>>
+            cached_entries;
+        for (const auto& entry : cache_)
+        {
+            cached_entries.push_back(entry);
+        }
+
+        for (const auto& entry : cached_entries)
+        {
+            nudb::detail::buffer decompressed;
+            auto const result = nodeobject_decompress(
+                entry.second.data(), entry.second.size(), decompressed);
+
+            DecodedBlob decoded(
+                entry.first.data(), result.first, result.second);
+            if (decoded.wasOk())
+                f(decoded.createObject());
+        }
+
+        // Then fetch any remaining entries from MySQL
+        auto* conn = getConnection();
+        if (!conn->ensureConnection())
+            return;
+
+        if (mysql_query(
+                conn->get(),
+                ("SELECT hash, data FROM " + name_ + " ORDER BY created_at")
+                    .c_str()))
+            return;
+
+        MYSQL_RES* result = mysql_store_result(conn->get());
+        if (!result)
+            return;
+
+        MYSQL_ROW row;
+        while ((row = mysql_fetch_row(result)))
+        {
+            unsigned long* lengths = mysql_fetch_lengths(result);
+            if (!lengths)
+                continue;
+
+            uint256 hash;
+            std::memcpy(hash.data(), row[0], hash.size());
+
+            // Skip if already processed from cache
+            if (cache_.find(hash) != cache_.end())
+                continue;
+
+            nudb::detail::buffer decompressed;
+            auto const decomp_result = nodeobject_decompress(
+                row[1], static_cast<std::size_t>(lengths[1]), decompressed);
+
+            DecodedBlob decoded(
+                hash.data(), decomp_result.first, decomp_result.second);
+
+            if (decoded.wasOk())
+            {
+                auto obj = decoded.createObject();
+                f(obj);
+
+                // Add to cache for future use
+                std::vector<std::uint8_t> data(
+                    reinterpret_cast<const std::uint8_t*>(row[1]),
+                    reinterpret_cast<const std::uint8_t*>(row[1]) + lengths[1]);
+                cache_.insert_or_assign(hash, std::move(data));
+                updateCacheMetadata(hash, lengths[1]);
+            }
+        }
+
+        mysql_free_result(result);
+    }
+
+    int
+    getWriteLoad() override
+    {
+        std::lock_guard<std::mutex> lock(queueMutex_);
+        return static_cast<int>(writeQueue_.size());
+    }
+
+    void
+    setDeletePath() override
+    {
+        close();
+    }
+
+    int
+    fdRequired() const override
+    {
+        return 1;
+    }
+
+private:
+    void
+    createTable()
+    {
+        auto* conn = getConnection();
+        if (!conn->ensureConnection())
+            Throw<std::runtime_error>("Failed to connect to MySQL server");
+
+        std::string query(1024, '\0');
+        int length =
+            snprintf(&query[0], query.size(), CREATE_TABLE, name_.c_str());
+        query.resize(length);
+
+        if (!conn->executeQuery(query))
+        {
+            JLOG(journal_.error())
+                << "Failed to create table: " << mysql_error(conn->get());
+            Throw<std::runtime_error>("Failed to create table");
+        }
+    }
+};
+
+class MySQLFactory : public Factory
+{
+public:
+    MySQLFactory()
+    {
+        Manager::instance().insert(*this);
+    }
+
+    ~MySQLFactory() override
+    {
+        Manager::instance().erase(*this);
+    }
+
+    std::string
+    getName() const override
+    {
+        return "MySQL";
+    }
+
+    std::unique_ptr<Backend>
+    createInstance(
+        std::size_t keyBytes,
+        Section const& keyValues,
+        std::size_t burstSize,
+        Scheduler& scheduler,
+        beast::Journal journal) override
+    {
+        return std::make_unique<MySQLBackend>(keyBytes, keyValues, journal);
+    }
+};
+
+static MySQLFactory mysqlFactory;
+
+}  // namespace NodeStore
+}  // namespace ripple
+
+#endif  // RIPPLE_NODESTORE_MYSQLBACKEND_H_INCLUDED