Re: Question about timelines

On Wed, Jul 29, 2015 at 3:46 PM, Torsten Förtsch
<torsten(dot)foertsch(at)gmx(dot)net> wrote:
> Hi,
>
> we have a complex structure of streaming replication (PG 9.3) like:
>
> master --> replica1
> |
> +-----> replica2 --> replica21
> |
> +------> replica22 --> replica221
>
> Now I want to retire master and make replica2 the new master:
>
> +------> replica1
> |
> replica2 --> replica21
> |
> +------> replica22 --> replica221
>
> replica2 is currently a synchronous replica.
>
> If I "promote" replica2 a new timeline is created. Hence, I have to
> instruct all other replicas to follow that new timeline
> (recovery_target_timeline = 'latest' in recovery.conf).

PostgreSQL 9.3 supports cascade standby to follow automatically the new master
after the timeline switch. In your case even if the timeline is
changed, you need to start
the standby setup for "replica1" only from scratch. All others follows
automatically
the new master.

Regards,
Hari Babu
Fujitsu Australia