Re: Performance under contention - Mailing list pgsql-performance

From Ivan Voras
Subject Re: Performance under contention
Date
Msg-id ice2pd$ae8$1@dough.gmane.org
Whole thread Raw
In response to Re: Performance under contention  ("Kevin Grittner" <Kevin.Grittner@wicourts.gov>)
Responses Re: Performance under contention  (Craig Ringer <craig@postnewspapers.com.au>)
List pgsql-performance
On 11/22/10 16:26, Kevin Grittner wrote:
> Ivan Voras<ivoras@freebsd.org>  wrote:
>> On 11/22/10 02:47, Kevin Grittner wrote:
>>> Ivan Voras  wrote:
>>>
>>>> After 16 clients (which is still good since there are only 12
>>>> "real" cores in the system), the performance drops sharply
>>>
>>> Yet another data point to confirm the importance of connection
>>> pooling.  :-)
>>
>> I agree, connection pooling will get rid of the symptom. But not
>> the underlying problem. I'm not saying that having 1000s of
>> connections to the database is a particularly good design, only
>> that there shouldn't be a sharp decline in performance when it
>> does happen. Ideally, the performance should remain the same as it
>> was at its peek.
>
> Well, I suggested that we add an admission control[1] mechanism,

It looks like a hack (and one which is already implemented by connection
pool software); the underlying problem should be addressed.

But on the other hand if it's affecting so many people, maybe a warning
comment in postgresql.conf around max_connections would be helpful.

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