Seen this a lot with poorly written web apps which open connections but dont close them when finished. Try setting wait_timeout and/or interactive_timeout to close unused connections.
John On 24 November 2010 11:27, Johan De Meersman <vegiv...@tuxera.be> wrote: > Hey, > > Late last night, I got a call that one of our servers was down. Turns out > the machine had all 2500 connection slots in use, but none of them appeared > to be doing anything: hardly any CPU was being used, load 0.05, and tcpdump > confirmed that pretty much no data was being sent, either. > > Disks were writeable - so not hanging write flood - and when I eventually > sent a kill, the daemon did a clean shutdown and came back up without a > hitch. > > Unfortunately I couldn't log in while this was going on because I never > configured a few extra connections for super - that's been fixed by now. > > Munin shows no discernable cause, no ramp-up on the load or whatever on > either the DB or the webservers; just a very sudden increase in open > connections and an equally sudden drop in network traffic. > > Neither slowlog nor sys/errorlog shows anything out of the ordinary. > > I can think of only two causes: bug in the app code, or bug in MySQL. This > is 5.0.32-Debian_7etch3-log (Debian package) on Debian Etch, running on > x86_64. > > Does anyone know of similar things happening ? > > -- > Bier met grenadyn > Is als mosterd by den wyn > Sy die't drinkt, is eene kwezel > Hy die't drinkt, is ras een ezel > -- John Daisley Certified MySQL 5 Database Administrator Certified MySQL 5 Developer Cognos BI Developer Telephone: +44 (0)7918 621621 Email: john.dais...@butterflysystems.co.uk
