PMM - Some Metrics (Checkpoints) are not shown with MySQL

sbstnpl · February 4, 2021, 12:43pm

Hi Everyone!

we’ve had an Mysql Health audit with an Percona Cosultant and they recommended us to use PMM - so we do now. And we find it great so far!

Unfortunately we noticed, that some important metrics do not show up in PMM. For Example almost the entire “InnoDB Checkopoint & Flushing”-Metrics. Everything else for InnoDB works good so far.

I’ve installed PMM on Ubuntu and MySQL8 according to the following instructions:

Does anyone know this issue and knows how to solve it?
or is there a Log file I could use for debugging this?

Thank you!
Sebastian

matthewb · February 4, 2021, 1:35pm

Hello @sbstnpl, there are some metrics that PMM cannot see unless you enable userstats=1 in your my.cnf file and restart MySQL. WARNING: Turning on userstats=1 can cause performance degradation because the stats generated by mysql need more CPU to compute compared to the basic stats provided by default.

sbstnpl · February 4, 2021, 1:50pm

Hi @matthewb !

thanks for your quick reply.
Unfortunately I get this error message on mysql restart:
[ERROR] [MY-000067] [Server] unknown variable ‘userstats=1’.

Should this option be available for MySQL 8 Community Server?

Thanks!

matthewb · February 4, 2021, 2:22pm

@sbstnpl Unfortunately, I believe userstats=1 is only available in Percona Server. Since you are using community, these graphs will always be empty. I suggest you look into replacing Community with Percona Server. It is a drop-in replacement.