Re: Keycloak and Postgres

On Wed, 5 Apr 2017 07:24:32 +0000
Marc Tempelmeier <marc(dot)tempelmeier(at)flane(dot)de> wrote:
>
> Can you elaborate a bit on this part:
> " Because of how Postgres caches changes, you may find that a failover requires some time in recovery mode."

https://www.postgresql.org/docs/9.6/static/wal-intro.html

The WAL requires that any unexpected shutdown of Postgres (where it doesn't get to explicitly
flush data pages to disk) go through a recovery cycle to fix anything in the WAL that is not
yet in the data pages.

Doing disk level replication and using that as a failover essentially duplicates a crash
on the PostgreSQL end when you failover.

--
Bill Moran <wmoran(at)potentialtech(dot)com>