Re: MySQL Performance Tuning Help

[Rick James]

Some of the numbers I gave are on the low side -- because of only 1GB (1.7?).

table_cache (table_open_cache) -- It was recently discovered (and proven with benchmarks) that a high value can be slower. The cache is scanned linearly. Very recently, a patch was put in so that the cache is looked up via a hash. The scripts you ran assume that bigger was better. I do not have a feel for the 'right value'.

open_files_limit -- that limit comes from the OS. The only reason to worry about it is because it imposes a limit on table_cache. (No problem with 3250, regardless of the table_cache discussion.)

thread_cache_size = 8 -- fine.

Each live connection (toward max_connections) (Sleeping, or not) takes 200KB, maybe more. It becomes a tradeoff between saving memory and refusing connections. wait_timeout is a way to kick out naughty connections.

You have tuned enough. Finding and fixing slow queries is your next best target.