MySQL server memory usage troubleshooting tips

If I may, one additional thing that I found which helps a lot with memory issues as relate to MySQL: Use jemalloc or similar. Essentially I brought a system which killed off the MySQL service every few weeks in OOM, to running faster than ever and never having memory issues.

That isn't to say it's a substitute for full troubleshooting, but as a first step, using a different malloc routine can sometimes help quite a bit!

I usually use this tool: http://www.mysqlcalculator.com/ It's not perfect by any means but gives you a pretty good idea

Yeah, the MySQL 5.6 defaults are quite different to the ones mentioned here. Also:

- the query cache is now off by default (but 1M)

- innodb_additional_mem_pool_size no longer applies.

- some of the per-session variables can actually allocate more than once (or not at all).

- There is fixed memory allocated for performance_schema per thread.

wget mysqltuner.pl