[pgpool-hackers: 3408] Re: watchdog behavior regarding VIP

[Muhammad Usama]

Hi Ishii-San,

On Tue, Sep 3, 2019 at 5:43 AM Tatsuo Ishii <ishii at sraoss.co.jp> wrote:

> Hi Usama,
>
> Can you comment on this:
> https://www.pgpool.net/mantisbt/view.php?id=541
>
> It seems VIP is not set when there's no quorum. Since there's nothing
> in the docs regarding VIP vs. quorum and I am wondering if this is
> a feature or a bug.
>

This is a feature and as per the design. The reason for doing this is to
avoid split-brain syndrome.
In the absence of a quorum, the watchdog cluster does select a master node
but waits for the quorum to perform the escalation(bringing up of VIP).

Initially, in the absence of the quorum, the cluster used to abstain from
selecting the master node but it was causing some synchronization issues so
the behaviour was modified and now the cluster goes on the elect the master
node even in the absence of the quorum but does not bring up the
VIP until it finds the quorum.

Below mentioned commit changed the said behaviour back in 2015

https://git.postgresql.org/gitweb/?p=pgpool2.git;a=commitdiff;h=6238ba9d2aaa82db415b11aca90d54981a854e09

Thanks
Best regards
Muhammad Usama



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