Aw: Re: PostgreSQL replication failover

Hi John,

I can't find any s390 packages for repmgr :-(

> Gesendet: Donnerstag, 14. Januar 2021 um 16:03 Uhr
> Von: "John Wiencek" <jwiencek3(at)comcast(dot)net>
> An: "Jan Peters" <haseningo(at)gmx(dot)de>
> Cc: "Ganesh Korde" <ganeshakorde(at)gmail(dot)com>, "Pepe TD Vo" <pepevo(at)yahoo(dot)com>, "Pgsql-admin" <pgsql-admin(at)lists(dot)postgresql(dot)org>, "Laurenz Albe" <laurenz(dot)albe(at)cybertec(dot)at>
> Betreff: Re: PostgreSQL replication failover
>
> Hi
>
> You can use repmgr, which is free, or EFM which requires a subscription.
>
> John
>
> > On Jan 14, 2021, at 2:16 AM, Jan Peters <haseningo(at)gmx(dot)de> wrote:
> >
> > Hello,
> >
> > thank you very much for the answers.
> > Can you tell me some tools, but they must be available for s390 ZLinux.
> > For our purposes in redhat linux
> >
> >
> > Gesendet: Mittwoch, 13. Januar 2021 um 19:46 Uhr
> > Von: "Ganesh Korde" <ganeshakorde(at)gmail(dot)com>
> > An: "Pepe TD Vo" <pepevo(at)yahoo(dot)com>
> > Cc: "Jan Peters" <haseningo(at)gmx(dot)de>, pgsql-admin(at)lists(dot)postgresql(dot)org, "Laurenz Albe" <laurenz(dot)albe(at)cybertec(dot)at>
> > Betreff: Re: PostgreSQL replication failover
> >
> > You can use different tools which detects if primary fails and automatically promotes standby.
> >
> > To assure all data on standby you should use synchronous replication.
> >
> > On Wed, 13 Jan 2021, 6:54 pm Pepe TD Vo, <pepevo(at)yahoo(dot)com[mailto:pepevo(at)yahoo(dot)com]> wrote:
> >
> >>> If you shut down the primary server cleanly, all changes will be replicated,so you should be good.
> >
> >>> During a failover, that is, if the primary suddenly fails, there is always
> > the possibility that you lose some transactions, unless you use synchronous
> > you said above which I don't need to run promote to make it failover as long as I set synchronous on? The last couple of weeks I have a failure on the primary server and can't run on a slave. It picks up as reading mode only.
> >
> >
> > Bach-Nga
> >
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> >
> > On Wednesday, January 13, 2021, 06:25:53 AM EST, Laurenz Albe <laurenz(dot)albe(at)cybertec(dot)at[mailto:laurenz(dot)albe(at)cybertec(dot)at]> wrote:
> >
> >
> >
> > On Wed, 2021-01-13 at 09:27 +0100, Jan Peters wrote:
> >> we are running postgresqlserver on s390 zLinux machines. The distribution
> >> is RedHat 7 and RedHat 8, so we do not have the many x86 tools available.
> >>
> >> We always run 2 instances with a replication (streaming) async mode, the replica
> >> is in hot_standby and we use it for read-only accesses. About the setup we have the following question:
> >>
> >> How is an orderly failover accomplished? Our current procedure is.
> >>
> >> 1. primary stop
> >> 2. promote replica to primary
> >> 3. create standby.signal on old primary
> >> 4. change primary_conninfo on old primary
> >> 5. start old primary as new replica
> >>
> >> Is this processing correct? Are there any other steps that simplify a failover?
> >> How can we be sure that all changes have been transferred from the old master to the replica?
> >
> > What you describe is not a failover, but a switchover.
> >
> > If you shut down the primary server cleanly, all changes will be replicated,
> > so you should be good.
> >
> > During a failover, that is, if the primary suddenly fails, there is always
> > the possibility that you lose some transactions, unless you use synchronous
> > replication.
> >
> > Yours,
> > Laurenz Albe
> > --
> > Cybertec | https://www.cybertec-postgresql.com[https://www.cybertec-postgresql.com]
> >
> >
> >
> >
> >
>
>