[pgpool-hackers: 1283] Re: Fw: [pgpool-II 0000162]: To start watchdog pgpool nodes simultaneously is not safe

[Yugo Nagata]

On Tue, 29 Dec 2015 03:35:34 +0500
Muhammad Usama <m.usama at gmail.com> wrote:

> On Mon, Dec 28, 2015 at 7:22 AM, Yugo Nagata <nagata at sraoss.co.jp> wrote:
> 
> > Hi Usama,
> >
> > I have add a description about the problem into the documents of
> > 3.2, 3.3. and 3.4.
> >
> >
> > http://git.postgresql.org/gitweb?p=pgpool2.git;a=commitdiff;h=68cbdd88477f8294cab0324d627f8cff213df958
> >
> > Do you know whether this problem occurs in watchdog of 3.5? If so,
> > I'll commit the same to master.
> >
> 
> The new watchdog takes care of this situation when multiple pgpool-II nodes
> are started simultaneously, So I think we are good and do not need to
> commit this message in the master branch

Sure, Thanks!

> 
> Thanks
> Best regards
> Muhammad Usama
> 
> 
> >
> > Begin forwarded message:
> >
> > Date: Fri, 25 Dec 2015 13:13:43 +0900
> > From: pgpool Bug Tracker <bugtracker at pgpool.net>
> > To: nagata at sraoss.co.jp
> > Subject: [pgpool-II 0000162]: To start watchdog pgpool nodes
> > simultaneously is not safe
> >
> >
> >
> > The following issue has been ASSIGNED.
> > ======================================================================
> > http://www.pgpool.net/mantisbt/view.php?id=162
> > ======================================================================
> > Reported By:                harukat
> > Assigned To:                nagata
> > ======================================================================
> > Project:                    pgpool-II
> > Issue ID:                   162
> > Category:                   Bug
> > Reproducibility:            always
> > Severity:                   minor
> > Priority:                   normal
> > Status:                     assigned
> > ======================================================================
> > Date Submitted:             2015-12-20 20:28 JST
> > Last Modified:              2015-12-25 13:13 JST
> > ======================================================================
> > Summary:                    To start watchdog pgpool nodes simultaneously
> > is not
> > safe
> > Description:
> > To start watchdog pgpool nodes simultaneously is not safe.
> > There is the case that the following happens.
> >
> > - "FATAL: failed to initialize watchdog, delegate_IP "x.x.x.x" already
> > exists"
> > - Master nodes more than two are born
> > - The recognitions of the invalid node are not consistent.
> >
> > There are not robust initial coordination logic.
> > So I think that we describe clearly "must start it one by one" to the
> > manual.
> >
> >
> > Steps to Reproduce:
> > Tested version: pgpool2-V3_4_STABLE-3d2093e (snapshot at 2015-12-20) + patch
> >
> > The patch file improves 'DETAIL:  connect() reports failure "Success"',
> > but it isn't related to this main issue.
> >
> > I set up the following watchdog cluster and started 4 pgpools
> > simultaneously.
> > (pg1, pg2 ... are hostname in my test environment)
> >
> >  [pg1 (pgpool)] ---------+- [pg3 (PostgreSQL)]
> >  [pg2 (pgpool)] ---------+
> >  [pgpool1 (pgpool)] -----+
> >  [pgpool2 (pgpool)] -----+
> >
> > ======================================================================
> >
> > Issue History
> > Date Modified    Username       Field                    Change
> > ======================================================================
> > 2015-12-20 20:28 harukat        New Issue
> > 2015-12-20 20:28 harukat        File Added: pgpool_conf_and_patch.zip
> >
> > 2015-12-25 13:13 t-ishii        Assigned To               => nagata
> > 2015-12-25 13:13 t-ishii        Status                   new => assigned
> > 2015-12-25 13:13 t-ishii        Description Updated
> > 2015-12-25 13:13 t-ishii        Steps to Reproduce Updated
> > ======================================================================
> >
> >
> >
> > --
> > 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>