Re: max_connections reached in postgres 9.3.3

On Fri, Jun 20, 2014 at 12:58 AM, Erik van Zijst
<erik(dot)van(dot)zijst(at)gmail(dot)com> wrote:
> On Thu, Jun 19, 2014 at 10:10 PM, Erik van Zijst
> <erik(dot)van(dot)zijst(at)gmail(dot)com> wrote:
>> On Thu, Jun 19, 2014 at 3:57 PM, Merlin Moncure <mmoncure(at)gmail(dot)com> wrote:
>>> In your case user% is dominating system load. Along with the high cs
>>> this is really suggesting spinlock contention. A 'perf top' is
>>> essential for identifying the culprit. It's very possible that 9.4
>>> will fix your problem...see:
>>> http://postgresql.1045698.n5.nabble.com/Cpu-usage-100-on-slave-s-lock-problem-td5768655.html.
>>> There was some poorly optimized code in the wal replay.
>>
>> Did that patch go in? The mailing list thread doesn't seem conclusive.
>
> Also, that thread talks about slave databases (we're seeing these
> issues exclusively on our master). Is that RecoveryMightBeInProgress
> code applicable to masters, too?

hm -- no. However, it shows how important it is to grab a performance
profile in cases of suspected contention.

merlin