List:General Discussion« Previous MessageNext Message »
From:Johan De Meersman Date:November 24 2010 11:27am
Subject:Mysql server full with idle connections
View as plain text  
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

Thread
Mysql server full with idle connectionsJohan De Meersman24 Nov
  • Re: Mysql server full with idle connectionsJohn Daisley24 Nov
    • Re: Mysql server full with idle connectionsJohan De Meersman24 Nov
      • Re: Mysql server full with idle connectionsPrabhat Kumar26 Nov
        • Re: Mysql server full with idle connectionsJohan De Meersman29 Nov
  • Re: Mysql server full with idle connectionsPeter Wang29 Nov
    • Re: Mysql server full with idle connectionsJohan De Meersman29 Nov