On Thu, Apr 1, 2010 at 9:09 AM, Heikki Linnakangas <heikki.linnakan...@enterprisedb.com> wrote: > Fujii Masao wrote: >> On Thu, Apr 1, 2010 at 11:00 AM, Robert Haas <robertmh...@gmail.com> wrote: >>> On Wed, Mar 31, 2010 at 9:58 PM, Fujii Masao <masao.fu...@gmail.com> wrote: >>>> You mean that we should change replication connection not to consume >>>> superuser_reserved_connections slots in 9.0? >>> Yes. > > I think it's good that walsenders can use the superuser reserved slots, > that way a client that opens max_connections connections can't block out > standby servers from connecting. > >> Preventing superuser connections from consuming >> superuser_reserved_connections >> slots seems strange for me. So I'm leaning toward just removing superuser >> privilege from replication connection again. Thought? > > That would be good, but I fear it's a bigger change than we should be > doing at this point. > > How about we adjust the backends math a bit: > > Currently: > > ReservedBackends = superuser_reserved_connections > MaxBackends = max_connections + autovacuum_max_workers + 1; > > Proposal: > > ReservedBackends = superuser_reserved_connections + max_wal_senders > MaxBackends = max_connections + autovacuum_max_workers + max_wal_senders + 1 > > So we implicitly reserve a slot and a superuser reserved slot for each > walsender. Walsenders use the slots reserved for superusers, but if you > set superuser_reserved_connections=3, there's still always at least > three slots available for superuser to log in with psql, even if the > maximum number of walsenders are connected.
That seems pretty reasonable to me. I haven't checked how much code impact there is. I know Tom doesn't think we should change it at all, but surely pre-beta is the time to fix nasty corner cases that were added by recently committed patches? ...Robert -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
