It depends. It is a switchover if Patroni could to a clean shutdown. But, it 
might start killing processes after a certain period if a normal shutdown after 
SIGTERM didn't happen. This would not be a switchover anymore. In other words 
there is no guarantee for a "clean" switchover. This might be the reason why 
the Patroni guys are always talking about failover only.

It's not a Patroni issue but it's triggered by Patroni as it will do "some kind 
of switchover" on a regular shutdown.



"Zwettler Markus (OIZ)" 
<markus.zwett...@zuerich.ch<mailto:markus.zwett...@zuerich.ch>> wrote on 
2019/11/07 11:32:42 AM:

> From: "Zwettler Markus (OIZ)" 
> <markus.zwett...@zuerich.ch<mailto:markus.zwett...@zuerich.ch>>
> To: Adrian Klaver 
> <adrian.kla...@aklaver.com<mailto:adrian.kla...@aklaver.com>>, "pgsql-
> gene...@lists.postgresql.org<mailto:gene...@lists.postgresql.org>" 
> <pgsql-general@lists.postgresql.org<mailto:pgsql-general@lists.postgresql.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.

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