[pgpool-hackers: 2504] Re: wd_authkey bug (bug tracker #333)

[Muhammad Usama]

On Thu, Aug 24, 2017 at 4:29 PM, Tatsuo Ishii <ishii at sraoss.co.jp> wrote:

> I think the restriction (to use watchdog clusters, each Pgpool-II
> major/minor versions are exactly same) is not big deal for users.
>
> Yes that is correct, the restriction to use same major/minor version in
one cluster is not a problem and there may not be any use case where someone
would be inclined towards that. The only thing I was worried about is the
update procedure where a user would want to update the Pgpool-II version
while eliminating
the downtime. But that is a little grey area currently and I was thinking
of creating a lab environment and perform the tests to come up with the
strategy and a document
clearly explaining the recommended procedures to upgrade the cluster from
different versions of Pgpool-II with minimal/no-downtime.
Other than that imposing the restriction of similar versions of Pgpool-II
should not be of any concern for any type of use case.


> So I prefer to go with the change Yugo proposed.
>

Yes, exactly Yugo's patch is good and we should go with it,.

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
>
> > Hi Yugo Nagata,
> >
> > Thanks for catching this, Since most of the time we test the watchdog by
> > running multiple instances on same machine so this issue would never
> appear
> > in our test environment,
> > I believe you fix is spot on and unfortunately as far as I can think of
> > there is not much we can do for backward compatibility and have to live
> > with that to fix this issue.
> >
> >  Thanks
> > Best Regards
> > Muhammad Usama
> >
> > On Thu, Aug 24, 2017 at 12:33 PM, Yugo Nagata <nagata at sraoss.co.jp>
> wrote:
> >
> >> On Thu, 24 Aug 2017 16:31:51 +0900
> >> Yugo Nagata <nagata at sraoss.co.jp> wrote:
> >>
> >> Sorray, the previous attachment is incorrect.
> >> I attached a revised one.
> >>
> >> > Hi Usama,
> >> >
> >> > There is the recent bug report about wd_authkey.
> >> >
> >> >  0000333: watchdog fails to add node to master when wd_authkey is not
> an
> >> empty string; pgpool member shuts down
> >> >  http://www.pgpool.net/mantisbt/view.php?id=333
> >> >
> >> > We have the same issue report recently from our client. In my
> analysis,
> >> this is a bug
> >> > due to the commit [1]. This changed the definition of tv_sec that is
> >> used to check wd_authkey
> >> > so that this was affected by the clock of OS. So, if there is a lag
> >> between two nodes' clocks,
> >> > the wd_authkey check fails.
> >> >
> >> > A simple solution is not to use tv_sec in the wd_authkey check as the
> >> attached patch.
> >> > However, one concern is that this is a specification change and that
> >> this also will break
> >> > back-compatibility. Of course, we can diallow watchdog cluster to have
> >> Pgpool-II of different
> >> > minor-versions. Although this is already implicit restriction of
> >> watchdog, we can make this
> >> > explicit restriction by checking other Pgpool-II node's version when
> >> receiving watchdog
> >> > packet.
> >> >
> >> > What do you think about it?
> >> >
> >> > [1] http://www.pgpool.net/pipermail/pgpool-committers/
> >> 2017-April/003945.html
> >> >
> >> > --
> >> > Yugo Nagata <nagata at sraoss.co.jp>
> >>
> >>
> >> --
> >> Yugo Nagata <nagata at sraoss.co.jp>
> >>
> >> _______________________________________________
> >> pgpool-hackers mailing list
> >> pgpool-hackers at pgpool.net
> >> http://www.pgpool.net/mailman/listinfo/pgpool-hackers
> >>
> >>
>
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