[Pgpool-general] Unable to accept new connection after terminating pgpool backend process

[Kelly Burkhart]

On Tue, Dec 28, 2010 at 7:58 PM, Tatsuo Ishii <ishii at sraoss.co.jp> wrote:
>> Hi,
>>
>> I have a question regarding terminating pgpool backend processes. We are
>> running one Postgres 8.4.4 node (with 2 databases on it) and using pgpool-II
>> 2.3.3 (max_pool = 2) as a connection pool.
>>
>>>From this e-mail thread (
>> http://www.mail-archive.com/pgpool-general@pgfoundry.org/msg01941.html), I
>> understand that when a backend process is killed (kill the Postgres process
>> manually, or using pg_terminate_backend), pgpool gets the same error code as
>> database down, so it initiates the failover process. However, in our
>> environment, we do not have a failover node. Database is unlikely to go
>> offline, and it is more likely that we need to manually kill a long running
>> query.
>>
>> What we like to have is the ability to:
>> - Treat the error code got back from pg_terminate_backend (or the kill
>> command) as a regular disconnect
>
> It isn't possible without changing PostgreSQL itself.

Can you please explain why?  If we kill -INT a backend postgres
process, it doesn't take the whole database cluster down, it shouldn't
take the whole pool down either.  The fact that it does is a bug in
pg_pool IMO.

-K