At Mon, 9 Mar 2020 21:13:38 +0900, Masahiko Sawada <masahiko.saw...@2ndquadrant.com> wrote in > On Mon, 9 Mar 2020 at 18:45, Peter Eisentraut > <peter.eisentr...@2ndquadrant.com> wrote: > > > > On 2020-03-09 09:11, Masahiko Sawada wrote: > > > I think after recovery is paused users will be better to restart the > > > server rather than resume the recovery. I agree with this idea but I'm > > > slightly concerned that users might not realize that recovery is > > > paused until they look at that line in server log or at > > > pg_stat_replication because the standby server is still functional. So > > > I think we can periodically send WARNING to inform user that we're > > > still waiting for parameter change and restart. > > > > I think that would be annoying, unless you create a system for > > configuring those periodic warnings. > > > > I imagine in a case like having set max_prepared_transactions but never > > actually using prepared transactions, people will just ignore the > > warning until they have their next restart, so it could be months of > > periodic warnings. > > Well I meant to periodically send warning messages while waiting for > parameter change, that is after exhausting resources and stopping > recovery. In this situation user need to notice that as soon as > possible.
If we lose connection, standby continues to complain about lost connection every 5 seconds. This is a situation of that kind. By the way, when I reduced max_connection only on master then take exclusive locks until standby complains on lock exchaustion, I see a WARNING that is saying max_locks_per_transaction instead of max_connection. WARNING: insufficient setting for parameter max_connections DETAIL: max_connections = 2 is a lower setting than on the master server (where its value was 3). HINT: Change parameters and restart the server, or there may be resource exhaustion errors sooner or later. CONTEXT: WAL redo at 0/60000A0 for XLOG/PARAMETER_CHANGE: max_connections=3 max_worker_processes=8 max_wal_senders=2 max_prepared_xacts=0 max_locks_per_xact=10 wal_level=replica wal_log_hints=off track_commit_timestamp=off WARNING: recovery paused because of insufficient setting of parameter max_locks_per_transaction (currently 10) DETAIL: The value must be at least as high as on the primary server. HINT: Recovery cannot continue unless the parameter is changed and the server restarted. CONTEXT: WAL redo at 0/6004A80 for Standb regards. -- Kyotaro Horiguchi NTT Open Source Software Center
