InnoDB waits for redolog.

The ratio of redo log contention. A good ratio value should stay below 1.

Check innodb_log_waits and if it continues to increase then it is a strong indicator that the InnoDB buffer pool is too small. It can also mean that the disks are too slow and cannot sustain the disk IO, perhaps due to peak write load.

Data is retrieved from the performance_schema or information_schema database and the global_status table.