On 20/04/17 05:57, Michael Paquier wrote: > On Thu, Apr 20, 2017 at 12:40 PM, Michael Paquier > <michael.paqu...@gmail.com> wrote: >> On Thu, Apr 20, 2017 at 4:57 AM, Peter Eisentraut >> <peter.eisentr...@2ndquadrant.com> wrote: >>> I think the problem with a signal-based solution is that there is no >>> feedback. Ideally, you would wait for all walsenders to acknowledge the >>> receipt of SIGUSR2 (or similar) and only then proceed with the shutdown >>> checkpoint. >> >> Are you sure that it is necessary to go to such extent? Why wouldn't >> it be enough to prevent any replication commands generating WAL to run >> when the WAL sender knows that the postmaster is in shutdown mode? > > 2nd thoughts here... Ah now I see your point. True that there is no > way to ensure that an unwanted command is not running when SIGUSR2 is > received as the shutdown checkpoint may have already begun. Here is an > idea: add a new state in WalSndState, say WALSNDSTATE_STOPPING, and > the shutdown checkpoint does not run as long as all WAL senders still > running do not reach such a state. >
+1 to this solution -- Petr Jelinek http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
