Smooth Migration from Client-Side to Proxy-Side Sharding in Database Architecture

This article discusses the migration from client-side sharding to proxy-side sharding in database architecture, specifically using ShardingSphere and Rainbow Bridge DAL. The author explains the background of database horizontal splitting due to increasing order volumes and high traffic during promotions. Client-side sharding using Sharding-JDBC offers simplicity and high performance but lacks centralized management and requires individual project upgrades. Proxy-side sharding through Rainbow Bridge DAL provides centralized management, traffic control, shadow database support for testing, and slow SQL monitoring.

The article presents two migration approaches: directly modifying old data sources to connect to Rainbow Bridge (fast but risky) and adding new data sources with switchable configuration (more stable and rollback-friendly). The recommended approach involves adding new data sources, implementing dynamic switching through AbstractRoutingDataSource, and using configuration switches for gradual migration. Key implementation steps include configuring dual data sources, adding dynamic data source management, using @ConditionalOnProperty for old data source control, ensuring read-write separation compatibility, and rewriting sharding algorithms.

Important considerations include handling unsupported select last_insert_id() operations, implementing forced slave node queries through HintManagerHolder.clear() compatibility, and using @ForceSlave annotations for elegant query routing. The article provides code examples for SqlHintUtils class and migration steps, emphasizing the importance of backward compatibility and smooth transition strategies.