On Tue, Jun 22, 2010 at 18:16, Robert Haas <robertmh...@gmail.com> wrote: > On Tue, Jun 22, 2010 at 9:27 AM, Magnus Hagander <mag...@hagander.net> wrote: >>> I am inclined to punt the keepalives_interval, keepalives_idle, and >>> keepalives_count parameters to 9.1. If these are needed for >>> walreciever to work reliably, this whole approach is a dead-end, >>> because those parameters are not portable. I will post a patch later >>> today along these lines. >> >> Do we know how unportable? If it still helps the majority, it might be >> worth doing. But I agree, if it's not really needed for walreceiver, >> then it should be punted to 9.1. > > This might not be such a good idea as I had thought. It looks like > the default parameters on Linux (Fedora 12) are: > > tcp_keepalive_intvl:75 > tcp_keepalive_probes:9 > tcp_keepalive_time:7200 > > [ See also http://tldp.org/HOWTO/TCP-Keepalive-HOWTO/usingkeepalive.html ] > > That's clearly better than no keepalives, but I venture to say it's > not going to be anything close to the behavior people want for > walreceiver... I think we're going to need to either vastly reduce > the keepalive time and interval, or abandon the strategy of using TCP > keepalives completely. > > Which brings us to the question of portability. A quick search around > the Internet suggests that this is supported on recent versions of > Linux, Free/OpenBSD, AIX, and HP/UX, and it appears to work on my Mac > also. I'm not clear how long it's been implemented on each of these > platforms, though. With respect to Windows, it looks like there are > registry settings for all of these parameters, but I'm unclear whether > they can be set on a per-connection basis and what's required to make > this happen.
I looked around quickly earlier when we chatted about this, and I think I found an API call to change them for a socket as well - but a Windows specific one, not the ones you'd find on Unix... -- Magnus Hagander Me: http://www.hagander.net/ Work: http://www.redpill-linpro.com/ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
