SHOW INNODB STATUS: LOG


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LOG
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Log sequence number 1039 3161691821
Log flushed up to 1039 3161691821
Last checkpoint at 1039 2401802667
0 pending log writes, 0 pending chkp writes
222872631 log i/o's done, 56.99 log i/o's/second


• Log sequence number is the number of bytes written to the buffer pool.


• Log flushed up to is the number of bytes that has been flushed or unflush (sequence number - log flushed up to)
  
• Last checkpoint is a fuzzy line of what was flushed to logs ie recovery line for a crash (from my understanding).

Then there is some cool stats on log writes which should remain low.

Tuning

If you see more than 30% of log buffer size being unflushed (Log flushed up to) increase it if possible.