List:General Discussion« Previous MessageNext Message »
From:John Daisley Date:November 24 2010 12:58pm
Subject:Re: Mysql server full with idle connections
View as plain text  
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 <vegivamp@stripped> 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.daisley@stripped

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