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

I understand your point and appreciate the clarification.

I have reviewed the references and now have a better understanding of the
minor upgrade process.

However, my concern lies in the fact that we are working with production
servers, where downtime is not acceptable.

Additionally, if a failover occurs due to a network issue or any other
disaster, setting up replication again requires running the pg_basebackup
command. For large databases, this process becomes a significant challenge,
as running pg_basebackup for the entire cluster can be time-consuming and
resource-intensive.

On Sun, 24 Nov 2024 at 22:11, Adrian Klaver <adrian(dot)klaver(at)aklaver(dot)com>
wrote:

> On 11/24/24 08:36, Subhash Udata wrote:
> > The reason to upgrade from 15.0 to 15.9 is this
> > https://www.postgresql.org/support/security/CVE-2024-10979/
> > <https://www.postgresql.org/support/security/CVE-2024-10979/>
> >
> > Here it is mentioned that this vulnerability is fixed in 15.9
> > So our organization wants an upgrade from 15.0 to 15.9
>
> Sorry, I was not clear enough. When I said 'Why?' it was not referring
> to reason you wanted to upgrade, it was why go through the whole
> pg_basebackup process. Read this link:
>
> https://www.postgresql.org/support/versioning/
>
> for why that is not necessary.
>
> >
> > On Sun, 24 Nov 2024 at 21:48, Adrian Klaver <adrian(dot)klaver(at)aklaver(dot)com
> > <mailto:adrian(dot)klaver(at)aklaver(dot)com>> wrote:
> >
> > 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/
> > <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
> > <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 <mailto:adrian(dot)klaver(at)aklaver(dot)com>
> >
>
> --
> Adrian Klaver
> adrian(dot)klaver(at)aklaver(dot)com
>
>