On Wed, 2021-01-13 at 09:27 +0100, Jan Peters wrote: > we are running postgresqlserver on s390 zLinux machines. The distribution > is RedHat 7 and RedHat 8, so we do not have the many x86 tools available. > > We always run 2 instances with a replication (streaming) async mode, the replica > is in hot_standby and we use it for read-only accesses. About the setup we have the following question: > > How is an orderly failover accomplished? Our current procedure is. > > 1. primary stop > 2. promote replica to primary > 3. create standby.signal on old primary > 4. change primary_conninfo on old primary > 5. start old primary as new replica > > Is this processing correct? Are there any other steps that simplify a failover? > How can we be sure that all changes have been transferred from the old master to the replica? What you describe is not a failover, but a switchover. If you shut down the primary server cleanly, all changes will be replicated, so you should be good. During a failover, that is, if the primary suddenly fails, there is always the possibility that you lose some transactions, unless you use synchronous replication. Yours, Laurenz Albe -- Cybertec | https://www.cybertec-postgresql.com
