Re: AW: AW: AW: broken backup trail in case of quickly patroni switchback and forth

"Zwettler Markus (OIZ)" <Markus(dot)Zwettler(at)zuerich(dot)ch> wrote on 2019/11/07
11:32:42 AM:

> From: "Zwettler Markus (OIZ)" <Markus(dot)Zwettler(at)zuerich(dot)ch>
> To: Adrian Klaver <adrian(dot)klaver(at)aklaver(dot)com>, "pgsql-
> general(at)lists(dot)postgresql(dot)org" <pgsql-general(at)lists(dot)postgresql(dot)org>
> Date: 2019/11/07 11:33 AM
> Subject: [EXTERNAL] AW: AW: AW: broken backup trail in case of
> quickly patroni switchback and forth
>
> 3)
> Patroni does only failovers. Also in case of regular shutdown of the
> primary. A failover is a promote of the standby + automatic
> reinstate (pg_rewind or pg_basebackup) of the former primary.

This is not accurate. Patroni does controlled switchovers as well as
failovers. Controlled switchover issues a fast shutdown to Postgres, hard
ones issue an immediate shutdown. From this point, it's how Postgres
responds to those that matter.

Fast shutdown will attempt to ensure the wal stream is transmitted to the
replica and the wal files are archived. Immediate shutdown will not do any
of this. This issue explains more about when Patroni may choose an
immediate shutdown (it might not be totally accurate anymore as it's a year
old).

https://github.com/zalando/patroni/issues/837#issuecomment-433686687

I agree with the Patroni folks that this is not a Patroni issue, but simply
how Postgres responds to the required shutdown types.