On Sun, Nov 24, 2024 at 11:05 AM Subhash Udata <subhashud...@gmail.com> 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. > > Try to replicate from old->new version, because bug fixes in newer versions might have broken something in new->old replication. If you really can't tolerate any downtime, then shutdown and upgrade the Secondary server from 15.0 to 15.10. Once you start it back up, replication from the still-15.0 primary will catch back up to the now-patched Secondary. Fail over to the Secondary (now new-Primary), and then patch old-Primary to 15.10. > > 1. > - 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? > > pg_rewind is probably what you want. I've never used it, though. -- Death to <Redacted>, and butter sauce. Don't boil me, I'm still alive. <Redacted> lobster!
