Re: Big number of connections

2016-04-04 16:43 GMT+02:00 Moreno Andreo <moreno(dot)andreo(at)evolu-s(dot)it>:

> Il 04/04/2016 15:33, Pavel Stehule ha scritto:
>
>>
>>
>> PostgreSQL doesn't contain integrated pooler - so any connection to
>> Postgres enforces one PostgreSQL proces. A performance benchmarks is
>> showing maximum performance about 10x cores. With high number of
>> connections you have to use low size of work_mem, what enforces can have
>> negative impact on performance too. Too high number of active PostgreSQL
>> processes increase a risk of performance problems with spin locks, etc.
>>
>
> :-O
> I wasn't absolutely aware of this thing... is there a way to monitor
> active connections, or at least to report when they grow too much?
> (say, I have an 8-core system and want to track down if, and when, active
> connections grow over 80)
>

100 connections are probably ok, 200 is over the optimum - there is some
tolerance.

We are speaking about optimum - I had possibility to work with system where
max connections was 300, 600 - and it was working. But then the
max_connection doesn't work as safeguard against overloading. And the
system under higher load can be pretty slow.

Regards

Pavel

>
> Thanks
> Moreno.-
>
>
>
>
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