Hi, Just following up with some more information...
I've been seeing a bit better behaviour by going from LinuxThreads to FreeBSD native threads. My hunch is also that this is somehow related to qmail; something of a contention issue between qmail and mysql. As I said, system load remains low. BUT, there are processes blocking, and vmstat shows that context switching is where I'm getting hit. Does that information help at all? Interactive performance is good, qmail is happy, but it seems like mysql gets "the short end of the stick" in this situation. Thanks, Charles On Thu, 1 Jul 2004, Charles Sprickman wrote: > Hi, > > I have (what I thought) was a fairly small mysql setup. It's backing a > vpopmail installation, and basically just handling alot of SELECTs. > > In the process of delivering mail, the db gets hit a few times: > > -initial check that the user exists during smtp conversation > -lookup for homedir during delivery > -optional lookup again if doing spam filtering > > Additionally, everytime someone authenticates via smtp-auth, pop or imap, > there's a SELECT to grab the password. > > So I haven't really done much to optimize things, as this seems like a > fairly light load. I'm running 4.0.20 on FreeBSD 4.8 (port build w/Linux > Threads). > > However, I'm starting to have problems. The various vpopmail programs > that perform all these lookups are timing out, which leads to login > failures (and worse). I see a number of simple things like "PINGs" from a > local cronjob that graphs queries/sec timing out. > > Server load can swing from .30 during a calm period to brief spikes of > 10.0-15.0 (generally during a spam run). > > I'm not sure what exactly to look at. I've bumped my max connections up > to 1000, and based my my.cnf on the "my-large.cnf" file and I'm still > seeing plenty of slow queries. I'm not swapping to disk at all, I'm not > really taxing the CPU, and iostat shows that the raid array isn't > struggling. > > It's been at least 4 years since I had to get very in-depth with MySQL, > and it seems plenty has changed (for the better). If anyone can give me a > push in the right direction, it would be much appreciated. > > Thanks, > > Charles > -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
