On Tue, 2007-05-08 at 15:59, Sean Murphy wrote: > Scott Marlowe wrote: > > On Tue, 2007-05-08 at 12:19, Sean Murphy wrote: > >> Tom Lane wrote: > >>> Sean Murphy <Sean.Murphy@xxxxxxxxxxxxx> writes: > >>>> I'm WAY out of my depth here, but my impression, based on the > >>>> circumstances, is that there is some sort of an idle session timeout > >>>> kicking in (most likely on the client side) and dropping the connection. > >>> There's no such timeout in the Postgres server, for sure. I would > >>> actually bet that your problem is in some router between the client and > >>> the server. In particular, routers that do NAT address mapping > >>> typically have a timeout after which they will forget the mapping for an > >>> idle connection. If you've got one of those, see if it'll let you > >>> change the timeout. > >>> > >>> If you can't do that, you might think about teaching your client-side > >>> code to send dummy queries every so often. > >>> > >>> regards, tom lane > >>> > >> I've already maxed out the connection timeout at the firewall... and > >> I've been using dummy queries every five minutes, but it just feels like > >> a crutch to do so. > > > > Have you looked into tcp keepalive settings? > > > > net.ipv4.tcp_keepalive_intvl = 75 > > net.ipv4.tcp_keepalive_probes = 9 > > net.ipv4.tcp_keepalive_time = 500 > > > > Not sure if those settings will help with an NAT router or not but it's > > worth a try. Pgsql 8.2 can set those for you. > > > > I may be celebrating prematurely, Never stopped me :) > but resetting the tcp_keepalive > parameters seems to have done the trick - I left a pgAdmin connection > that *always* drops after inactivity up while I went to lunch and it was > still alive when I got back. > > Is there a way to alter the tcp_keepalive settings on an app-by-app > basis rather than for the whole system? Well, you could set it on individual workstations instead of on the server. I.e. if you set tcp_keepalive on your workstation to 500, but leave Wally and Dilbert set at the default 7200 then they'd still timeout and you wouldn't.
