[pgpool-general: 7616] Re: Pgpool - ERROR: Sorry, too many clients already

[Tatsuo Ishii]

Looking into the pgppol.conf, I noticed num_init_children is 200,
rather than 120. Also it seems you have 2 Pgpool servers: db1 and db2.
Does your application servers accesses both db1 and db2? If so, the
required max_connections for PostgreSQL would be at least 400 because
2 Pgpool servers connect to PostgreSQL with up to num_init_children =
200 each, thus up to 400 connections will be made.

> Hi,
> 
> Pgpool-II version: pgpool-II version 4.2.2 (chichiriboshi)
> pgpool.conf attached. Kindly check.
> 
> Thanks!
> 
> 
> On Thu, Jul 1, 2021 at 1:46 PM Tatsuo Ishii <ishii at sraoss.co.jp> wrote:
> 
>> > Hi,
>> >
>> > After integrating pgpool with the app server, we tested by running load
>> > tests with 25 concurrent users.
>> > The following error comes multiple times while test running:
>> >
>> >> ERROR:  Sorry, too many clients already
>> >> LOG:  backend [1]: WARNING: there is already a transaction in progress
>> >
>> >
>> > Set the following in pgpool:
>> > connection_cache=off
>> > child_life_time = 5min
>> > num_init_children=120
>> > max_pool=1
>> >
>> > There are master-slave postgre DB servers with max_connections=250.
>> > There are 2 appservers with XADatasource max pool size 60, pointing to
>> the
>> > Pgpool server.
>> > The application connects to 4 databases but only one database is used
>> 90%.
>> >
>> > When we point directly to the master DB server, all works fine. But when
>> > connected via the Pgpool server, these errors come intermittently.
>> >
>> > Is it because Pgpool connections are not getting released and are all in
>> > active state?
>> > Is there any way the excess connection requests in the queue instead
>> > of throwing errors so that it will be processed once existing connections
>> > are released?
>> > Anyone please help me identify the bottleneck.
>>
>> Can you share the exact Pgpool-II version and pgpool.conf?
>>
>> Best regards,
>> --
>> Tatsuo Ishii
>> SRA OSS, Inc. Japan
>> English: http://www.sraoss.co.jp/index_en.php
>> Japanese:http://www.sraoss.co.jp
>>
> 
> 
> -- 
> Life is like this: "Just when we get all the answers of life.... God
> changes the question paper....
> 
> Valsaraj Viswanathan