[pgpool-hackers: 1571] Re: Pgpool Hangs connections when shutting down interface of the secondary

[Tatsuo Ishii]

So if you run psql on the node 1, can it connect to PostgreSQL (not
via pgpool) on node 2?

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
> The initial situation is that node 1 is master node for pgpool and primary
> node for postgres. Node 2 is standby node for pgpool and slave for
> postgres. If I shut down the interface on the slave/standby mode, next time
> I try to connect to postgres through pgpool, the connections just hang. I
> would think this would be pretty repeatable, but it looks like no one else
> is having this issue?
> Thanks.
> Regards
> On May 19, 2016 10:36 PM, "Tatsuo Ishii" <ishii at postgresql.org> wrote:
> 
>> 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?
>> >>
>>