Re: Questions on Upgrading PostgreSQL from 15.0 to 15.9 and Setting Up Streaming Replication

On 11/24/24 08:05, Subhash Udata wrote:
> Dear PostgreSQL Community,
>
> I have a production database setup with a primary server and a standby
> server. The database is currently running on *PostgreSQL 15.0*, and I
> plan to upgrade both servers to *15.9*.
>
> I have the following questions regarding the upgrade and replication
> process:
>
> 1.
>
> *Upgrade and Replication Compatibility*:
>
> * My plan is to perform a failover, promote the standby server
> (currently 15.0) to primary, and then upgrade the old primary
> server to version 15.9.
> * After upgrading the old primary server to version 15.9, I want
> to configure it as a standby server and set up streaming
> replication with the new primary server, which will still be
> running version 15.0.
> * Is it possible to establish streaming replication between these
> two versions (*15.0* as primary and *15.9* as standby)?
> 2.
>
> *Efficient Replication Setup*:
>
> * The production database is around *1TB in size*, and creating
> replication using |pg_basebackup| is taking more than 2–3 hours
> to complete.
> * Is there an alternative method to set up replication without
> taking a full backup of the entire cluster but instead using
> only the WAL files that have changed on both servers?

Why?

15.0 --> 15.9(actually you want the latest release 15.10) is a minor
upgrade it involves shutting down the servers installing the new version
binaries on each and restarting them.

You should read:

https://www.postgresql.org/support/versioning/

It would be a good idea to go through the Release Notes here:

https://www.postgresql.org/docs/15/release.html

To see what changed.

>
> Your guidance and recommendations on these questions will be greatly
> appreciated.
>
> Thank you for your time and support!
>
> Best regards,
>
> Subhash
>

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com