[pgpool-hackers: 2512] Re: wd_authkey bug (bug tracker #333)

[Yugo Nagata]

On Fri, 25 Aug 2017 16:30:35 +0500
Muhammad Usama <m.usama at gmail.com> wrote:

> Hi Yugo,
> 
> Do you want me to take care of this patch or will you be committing it
> yourself ?

I'll do this.

> 
> Thanks
> Best Regards
> Muhammad Usama
> 
> 
> On Thu, Aug 24, 2017 at 4:53 PM, Muhammad Usama <m.usama at gmail.com> wrote:
> 
> >
> >
> > 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
> >> >>
> >> >>
> >>
> >
> >


-- 
Yugo Nagata <nagata at sraoss.co.jp>