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Message-ID: <6c498f0e-64f9-449a-9b90-5cd72d00e2ef@aklaver.com>
Date: Sun, 24 Nov 2024 08:18:49 -0800
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Subject: Re: Questions on Upgrading PostgreSQL from 15.0 to 15.9 and Setting
 Up Streaming Replication
To: Subhash Udata <subhashudata@gmail.com>, pgsql-general@postgresql.org
References: <CAD=40Z3Rvbx46SxYBBdLvgSObXCP+Firszz++rDTXmGX795D2Q@mail.gmail.com>
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From: Adrian Klaver <adrian.klaver@aklaver.com>
In-Reply-To: <CAD=40Z3Rvbx46SxYBBdLvgSObXCP+Firszz++rDTXmGX795D2Q@mail.gmail.com>
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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.klaver@aklaver.com