Re: Return of the Solaris vacuum polling problem -- anyone remember this?
Tom Lane <tgl@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Josh Berkus <josh@agliodbs.com>
Cc: PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2010-08-18T21:02:49Z
Lists: pgsql-hackers
Josh Berkus <josh@agliodbs.com> writes: >> Most likely that's the libc implementation of the select()-based sleeps >> for vacuum_cost_delay. I'm still suspicious that the writes are eating >> more cost_delay points than you think. > Tested that. It does look like if I increase vacuum_cost_limit to 10000 > and lower vacuum_cost_page_dirty to 10, it reads 5-7 pages and writes > 2-3 before each pollsys. The math seems completely wrong on that, > though -- it should be 50 and 30 pages, or similar. I think there could be a lot of cost_delay points getting expended without any effects visible at the level of strace. Maybe try fooling with vacuum_cost_page_hit and vacuum_cost_page_miss, too. regards, tom lane