On Thu, May 21, 2020 at 5:38 PM Santhosh Kumar <krssanth...@gmail.com> wrote:
> Hi Forum,
>  If I have a cluster with Synchronous replication enabled with three nodes, 
> for eg:
> [primary] [hot stand by 1] [host stand by 2]
> And for some unforeseen reasons, if primary fails, the failover will kick in 
> and hot stand by 1 will become new primary and  cluster setup will look like 
> this
> [new primary (hot stand by1)] [host stand by 2]
> My question here is, what will happen if the original primary which has 
> failed comes back. Will it become part of this high available replica cluster 
> automatically or it will be stale and disconnected from the cluster?

It won't become standby automatically as it would have diverged from
the new master.

> How can we automatically make the failed primary to be part of the cluster 
> with hot standby role? It would be of great help, if you can direct me to any 
> references details. Thank you, upfront.

I think pg_rewind can help in such situations.  See the docs of pg_rewind [1].

[1] - https://www.postgresql.org/docs/devel/app-pgrewind.html

With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com

Reply via email to