InnoDB Redo Log Sizing: Stop Guessing, Start Measuring

Introduction Many MySQL configurations inherit redo log sizing from defaults, aging blog posts, or configuration folklore. innodb_redo_log_capacity gets set once… and then quietly fades into the background. But redo log capacity directly shapes how efficiently MySQL absorbs writes, manages checkpoint pressure, and handles burst-heavy workloads. Set it too low, and aggressive flushing can throttle throughput. Set it too high, and crash recovery can become painfully long. Redo logs are more than crash insurance.