[pgpool-hackers: 1569] Re: Pgpool Hangs connections when shutting down interface of the secondary

[Tatsuo Ishii]

If you directly connect to PostgreSQL on the server on which the
network interface was down using psql, does it fail or hang?

Best regards,
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese:http://www.sraoss.co.jp

> Hello Guys:
> i have posted this issue in pgpool-Users, but i got no answer. At this
> point i am thinking about switching solutions as i cannot make mine work,
> but i really like the idea of using pgpool, so i was wondering if i could
> get an answer here. This is the issue i am experiencing:
> 
> I am running pgpool 3.5.2 in a 2 node cluster with postgresql-9.5 in
> master-slave and streaming replication mode.
> 
> I have been testing failover and failback for a while. While doing failover
> by shutting down the processes, everything looks fine.
> 
> 
> The one test that is failing is when i shutdown the interface of one node.
> Right now i am shutting down the interface of the slave node (both pgool
> slave and postgresql slave).
> 
> The problem i am running into is that after doing this, all connections to
> my database (through pgpool) hang. i am testing it with psql, and psql just
> hangs and does not give me an output. When i bring the interface of the
> slave back up, and try to connect to psql again, it looks like pgpool never
> marked the postgresql node as disconnected.
> 
> I tried both with and without health check, and also tried with different
> values of health_check_timeout. my connect timeout value is default (10
> seconds).
> 
> Any one has encountered this issue? I just dont see pgpool attempting to do
> any failover. Pgpool is still running though, i can see the logs still
> comming. I just never see an error.
> 
> I am NOT using interface monitoring, and i would prefer not to use it.
> 
> Any pointers on how could i troubleshoot this?