On Saturday, March 31, 2012, Jeff Janes <jeff.ja...@gmail.com> wrote: > On Saturday, March 31, 2012, Robert Haas <robertmh...@gmail.com> wrote: >> On Sun, Apr 1, 2012 at 1:40 AM, Jeff Janes <jeff.ja...@gmail.com> wrote: > >>> It looks like in your case tps was still scaling with clients when you gave >>> up, so clients was probably too small. >> >> What is kind of weird is that it actually seems to scale at almost >> exactly half of linear.
This is expected. A very common pattern in commits/fsync is to see alterations between 1 and C-1, or between 2 and C-2. To cure that, play with commit_delay. Don't make the mistake I did. Commit_delay is in micro seconds, not ms. That didn't mater when minimum kernel sleep was 10 or 4 ms anyway. Now with much finer sleeps, it makes a huge difference, so try ~5000. Cheers Jeff