On Wed, 2006-05-24 at 14:00, Tom Lane wrote: > "Florian G. Pflug" <fgp@xxxxxxxx> writes: > > You can (at least on linux, I assume it's the same for BSD) set the > > "keepalive" flag of a connection. This results in empty packets being > > sent every 30 seconds or so, and the connection is reported to be dead > > if no ACK is received within a timeout. > > > I don't know if postgres has a flag to disable/enable this. If not, I'd > > guess it would be quite trivial to add that. > > Postgres has always (well, for as long as I can remember) enabled > keepalive checks on client TCP connections. However, the default > timeouts on TCP keepalive are not "30 seconds or so", but well over > an hour according to the RFC specifications. > > Some platforms allow you to fool with the timeouts, some don't. > If you have one that does, recent PG versions will let you configure > that. > > I'm not sure whether this will actually solve the OP's problem, because > if the clients are actually still there but not doing anything, the > connection is not going to time out. This is mainly something that > helps with flaky networks, broken Windoze boxes that forget they have > connections, that sort of thing... Note that we had a problem like this because the router / firewalls between our app servers and postgresql servers had a timeout of 30 minutes, and would drop the idle connections after that time. Setting our tcp_keepalive to 5 minutes or so made the problem of the postgresql clients seeing broken connections go away.
