[pgpool-general: 9184] Re: Pgpool-II 4.4.4 Split-brain situation

[Tatsuo Ishii]

Isn't it the same inquiry as:
https://github.com/pgpool/pgpool2/issues/64

I guess why you send the same inquiry to the mailing list is, I did
not respond earlier. Sorry for that but can you please do not send
identical inquiry to multiple channels? That's confusing to Pgpool-II
developers.

Best reagards,
--
Tatsuo Ishii
SRA OSS K.K.
English: http://www.sraoss.co.jp/index_en/
Japanese:http://www.sraoss.co.jp

> Yes , I am using watchdog.
>  Please refer the issue which I described in my previous email and guide.
> Why the node 1 pgpool uses his outdated information to became primary again.
> 
> Regards,
> Pradeep Prajapati
> 
> On Fri, 16 Aug, 2024, 3:02 pm Bo Peng, <pengbo at sraoss.co.jp> wrote:
> 
>> Hi,
>>
>> > Hello Team,
>> >
>> > I Need help or suggestions on the issue below pgpool-II.
>> >
>> > Example:-
>> > Node1 -- Primary (Postgres & pgpool installed)
>> > Node2 -- Standby (Postgres & pgpool installed)
>> > Node3 -- Witness  (Pgpool installed)
>> >
>> > Incident:-
>> >
>> > 1. In the pgpool cluster we have node1 is primary, node2 is secondary,
>> and
>> > node3 is witness.
>> > 2. node1 becomes unresponsive then failover is triggered and then node2
>> > becomes the new primary.
>> > 3. After 15 minutes node1 became responsive again and node1 is in primary
>> > state and we have node 2 also in primary so a split brain situation
>> > happened.
>> > 4. Node 1 itself is decided as leader/coordinator based on the node 1
>> > pgpool record and more number of connected standby nodes (based on old
>> > state of information) , now i am the true leader, it is decided as the
>> true
>> > leader and asks node 2 to step down.
>> > 5. In this case for 15 minutes data written to node 2 new primary after
>> > node 1 responsive data gets started to return on node 1 again so here
>> data
>> > gets inconsistent.
>> >
>> > Please provide a suggestion in this case.
>> >
>> > NOTE:- We are using only for auto-failover not for auto-failback so
>> > auto-failback is disabled.
>>
>> To avoid Split-brain, you can use watchdog by setting "use_watchdog = on".
>> Are you using watchdog?
>>
>> --
>> Bo Peng <pengbo at sraoss.co.jp>
>> SRA OSS K.K.
>> TEL: 03-5979-2701 FAX: 03-5979-2702
>> URL: https://www.sraoss.co.jp/
>>