[pgpool-general: 2436] Re: pgpool connections: FATAL: sorry, too many clients already
sergeyarl.maillist at gmail.com
Thu Jan 16 15:53:29 JST 2014
On Jan 16, 2014, at 10:42 AM, Tatsuo Ishii <ishii at postgresql.org> wrote:
>> On Jan 16, 2014, at 10:10 AM, Tatsuo Ishii <ishii at postgresql.org> wrote:
>>>> It seems I misunderstood this formula :)
>>>> I have 2 backends. Each can handle 27 connections. So I want pgpool to be able to handle 27*2 connections.
>>>> If I use
>>>> 13 * 2 <= (30 -3 )
>>>> then the total number of connections won't exceed 26. Is that correct?
>>> Yes, correct.
>> So this where this calculation comes from.
>> I mean: 25*2 <= (30-3)*2
> No. Pgpool-II connects to each backend independently. That's the
> reason why following formulas do not include the number of PostgreSQL
> max_pool*num_init_children <= (max_connections - superuser_reserved_connections) (no query canceling needed)
> max_pool*num_init_children*2 <= (max_connections - superuser_reserved_connections) (query canceling needed)
>> If I use 13*2 <= (30-3) then there will be no way to utilize the capacity of all backend servers. Is that so?
> That depends on the definition of "utilize". Pgpool-II utilizes
> standby servers as a resouce for load balance. It does not utilize
> max_connection of PostgreSQL.
So in other words even if I have 10 backends with max_connections = 30 each, I still should use
num_init_children = 13
max_pool = 2
Is that correct?
> Best regards,
> Tatsuo Ishii
> SRA OSS, Inc. Japan
> English: http://www.sraoss.co.jp/index_en.php
> Japanese: http://www.sraoss.co.jp
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