Hi all of a sudden my server has slowed to a crawl, queries that were 0.10 of a second consistently now taking 20 seconds. somewhat randomly, sometimes it snaps right back. so I have a really sudden and harsh performance problem.
I ran mysqltuner.pl and it reported one thing that might be a problem :
[!!] Table cache hit rate: 0% (400 open / 1M opened)
I am just starting to delve into this performance problem, but does anyone know if this a big immediate red flag?
I can do some DD but am pressed right now. any help much appreciated.