I enabled the InnoDB Lock Monitor in my MariaDB 5.5 instance (using XtraDB+ as the InnoDB – which is the default in MariaDB) and noticed that while the SHOW ENGINE INNODB STATUS was being logged to the error log, it wasn’t logging the “additional” lock information – it just looked like the plain ‘ole INNODB STATUS.
Long story short, Percona added a new variable so one has better control over what gets logged:
If off (default), then the InnoDB Lock Monitor logs the normal INNODB STATUS, and if enabled, then it logs it with the extended lock information.
They also created another variable that goes along with this one (and the InnoDB Lock Monitor), which is:
This variable indicates the number of locks to print that are held for each InnoDB transaction (the default is 10, max is 1000).
For reference, these 2 options are discussed further in Percona’s manual.
Hope this helps. 🙂