switchover and switchback assistance ...

Hi, folks;

I’m in the process of testing PG v12.7 hot streaming standby’s in async mode, and specifically in the area of reliable switchover and switchback operations.

I have created test primary’s and standby’s successfully with pg_ctl initdb and pg_basebackup respectively. I can switch over/switch roles (standby -> primary, primary -> standby) successfully one time. When I switch roles a second time, the standby becomes primary just fine but the primary to standby fails to open properly. Logfile messages for both primary and standby are attached as well as pg_wal and archive directory lists.

I shut down the primary first and then promote the standby. The only action I take on the standby side is to create the standby.signal file in $PGDATA. (Well almost. Initially, I do have to have an empty 00000000.history file in the archive locations or the standby’s fail to start.)

My archive directories are separate from each other and the archive command is the given test … cp -p example in the docs. archive_mode is ‘on’ on both sides.

Are there other undocumented manual steps I should be completing before starting the new standby?

I would appreciate review of the attached logs to help pinpoint the issue. Inst1 is the primary/standby/primary, and inst2 is the standby/primary/standby.

Many thanks!
David