Re: Invalid data read from synchronously replicated hot standby

Adrian Klaver <adrian(dot)klaver(at)aklaver(dot)com> wrote on 04/21/2016 16:03:55:

> From: Adrian Klaver <adrian(dot)klaver(at)aklaver(dot)com>
> To: Martin Kamp Jensen/DK/Schneider(at)Europe, pgsql-general(at)postgresql(dot)org
> Date: 04/21/2016 16:09
> Subject: Re: [GENERAL] Invalid data read from synchronously
> replicated hot standby
>
> On 04/21/2016 01:05 AM, martin(dot)kamp(dot)jensen(at)schneider-electric(dot)com wrote:
> > Hi,
> >
> > We are getting invalid data when reading from a synchronously
replicated
> > hot standby node in a 2-node setup. To better understand the
situation,
> > we have created a document that provides an overview. We are hoping
that
> > someone might be able to confirm whether or not the setup makes sense,
> > i.e., whether we are using PostgreSQL correctly and experiencing a
bug,
> > or if we are using PostgreSQL incorrectly.
> >
> > Link to document that contains a step-by-step description of the
> > situation:
> > https://docs.google.com/document/d/1MuX8rq1gKw_WZ-
> HVflqxFslvXNTRGKa77A4NHto4ue0/edit?usp=sharing
> >
> >
> > If the setup is sane (and expected to work), we will work on setting
up
> > a minimal reproduce that avoids our complete system. We are thinking
> > that a scripted Ansible/Vagrant setup makes sense.
>
> Questions:
>
> What is wal_level set to?

wal_level = hot_standby

>
> Why on Node A do you have in recovery.conf?:
> primary_conninfo = 'host=<Node A IP address>'
>
> What exactly are you trying to do?
>
> Looks to me you are trying to have multi-master, is that the case?

Eh, that's a mistake in the document. Probably because of a leftover
recovery.done file. We only have Node A as master. I have updated the
document.

I have been trying to reproduce the issue with a simple setup but so far
without any luck.

>
> >
> > Best regards,
> > Martin
>
>
> --
> Adrian Klaver
> adrian(dot)klaver(at)aklaver(dot)com
>
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