[pgpool-hackers: 1570] Re: Pgpool Hangs connections when shutting down interface of the secondary

[Tatsuo Ishii]

I just want to make sure. I assume psql is running on the same machine
as pgpool is running on. Am I correct? I am asking because it sounds
ridiculous that psql can connect to the PostgreSQL server which its
network interface is down.

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

> Hey Tatsuo, thanks for the feedback, I really appreciate it. Connecting
> directly, it works.
> Thanks! Regards
> On May 19, 2016 9:24 PM, "Tatsuo Ishii" <ishii at postgresql.org> wrote:
> 
>> 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?
>>