On Wed, Jan 11, 2023 at 6:16 PM Hayato Kuroda (Fujitsu) <kuroda.hay...@fujitsu.com> wrote: > > > 2. > > I think users can set ' wal_receiver_status_interval ' to 0 or more > > than 'wal_sender_timeout'. But is this a frequent use-case scenario or > > do we see DBAs setting these in such a way by mistake? If so, then I > > think, it is better to give Warning message in such a case when a user > > tries to create or alter a subscription with a large 'min_apply_delay' > > (>= 'wal_sender_timeout') , rather than leaving it to the user's > > understanding that WalSender may repeatedly timeout in such a case. > > Parse_subscription_options and AlterSubscription can be modified to > > log a warning. Any thoughts? > > Yes, DBAs may set wal_receiver_status_interval to more than > wal_sender_timeout by > mistake. > > But to handle the scenario we must compare between min_apply_delay *on > subscriber* > and wal_sender_timeout *on publisher*. Both values are not transferred to > opposite > sides, so the WARNING cannot be raised. I considered that such a mechanism > seemed > to be complex. The discussion around [1] may be useful. > > [1]: > https://www.postgresql.org/message-id/CAA4eK1Lq%2Bh8qo%2BrqGU-E%2BhwJKAHYocV54y4pvou4rLysCgYD-g%40mail.gmail.com >
okay, I see. So even when 'wal_receiver_status_interval' is set to 0, no log/warning is needed when the user tries to set min_apply_delay>0? Are we good with doc alone? One trivial correction in config.sgml: + terminates due to the timeout errors. Hence, make sure this parameter + shorter than the <literal>wal_sender_timeout</literal> of the publisher. Hence, make sure this parameter is shorter... <is missing> thanks Shveta
