[pgpool-general: 2435] Re: pgpool connections: FATAL: sorry, too many clients already
ishii at postgresql.org
Thu Jan 16 15:42:50 JST 2014
> 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.
SRA OSS, Inc. Japan
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