AWS contributes a large-transaction binary log optimization to MySQL

This article announces AWS's contribution of BOLT (Binary Log Optimization for Large Transactions) to community MySQL, which removes commit latency bottlenecks for large transactions in MySQL binlog operations.

• BOLT promotes spill files directly into the binlog sequence instead of copying events, making commit latency independent of transaction size
• Reduces commit latency for 50 GiB transactions from ~7 minutes to ~2.5 seconds
• Speeds up binlog crash recovery from ~4 minutes to ~0.1 seconds for large transactions
• Improves write throughput by ~3x for large-only workloads and ~2.8x for mixed workloads
• Available in Aurora MySQL v1.22.0+ and all supported major versions (2.x, 3.x, 8.4.x) with BOLT enabled by default
• Uses Large_transaction_header_event to enable fast recovery and maintain backward compatibility with earlier consumers

BOLT significantly improves performance and availability for MySQL deployments handling large transactions while maintaining backward compatibility with existing binlog consumers.