Re: more descriptive message for process termination due to max_slot_wal_keep_size

At Tue, 04 Jan 2022 10:29:31 +0900 (JST), Kyotaro Horiguchi <horikyota.ntt@gmail.com> wrote in 
> So what do you say if I propose the following?
> 
> LOG:  terminating process %d to release replication slot \"%s\"
> because its restart_lsn %X/%X exceeds the limit %X/%X
> HINT: You might need to increase max_slot_wal_keep_size.

This version emits the following message.

[35785:checkpointer] LOG:  terminating process 36368 to release replication slot "s1" because its restart_lsn 0/1F000148 exceeds the limit 0/21000000
[35785:checkpointer] HINT:  You might need to increase max_slot_wal_keep_size.
[36368:walsender] FATAL:  terminating connection due to administrator command
[36368:walsender] STATEMENT:  START_REPLICATION SLOT "s1" 0/1F000000 TIMELINE 1
[35785:checkpointer] LOG:  invalidating slot "s1" because its restart_lsn 0/1F000148 exceeds the limit 0/21000000
[35785:checkpointer] HINT:  You might need to increase max_slot_wal_keep_size.

We can omit the HINT line from the termination log for non-persistent
slots but I think we don't want to bother that considering its low
frequency.

The CI was confused by the mixed patches for multiple PG versions. In
this version the patchset for master are attached as .patch and that
for PG13 as .txt.

regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center