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. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise Postgres Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
