Re: keepalives on MacOS X

On Tue, Jun 29, 2010 at 12:42 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Yeah, a bit of rooting around in the Darwin sources shows that this
> value is used as a per-connection override for tcp_keepidle.  So it
> is a synonym.  Not sure if it's worth supporting when the other value
> can't be set too.  Maybe it'd be more useful to document that people can
> set the system-wide values if they're desperate.

Well, the default value for tcp_keepidle is 2 hours, and the default
value for tcp_keepintvl is 75 seconds.  Assuming that tcp_keepcount
defaults to something reasonable (I think the default on Linux is 9),
the lion's share of the time will be waiting for tcp_keepidle - so
just the ability to reduce that value to something reasonable should
help a lot.  It's also not much code - proposed patch attached.

Some documentation of how to change this stuff via sysctl on various
OSes wouldn't be a bad thing either - anyone feel like writing
something up?

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise Postgres Company