On Tue, Apr 9, 2013 at 12:37 PM, Steven Schlansker <ste...@likeness.com>wrote:
> > On Apr 9, 2013, at 11:25 AM, Scott Marlowe <scott.marl...@gmail.com> > wrote: > > > One of the most common causes I've seen for this is linux's vm.*dirty* > settings to get in the way. Like so many linux kernel "optimizations" this > one looks good on paper but gives at best middling improvements with > occasional io storms that block everything else. On big mem machines doing > a lot of writing IO I just set these to 0. Also tend to turn off swap as > well as it's known to get in the way as well. > > > > settings for /etc/sysctl.conf > > vm.dirty_background_ratio = 0 > > vm.dirty_ratio = 0 > > > > I'll +1 on the "you have to tune your Linux install" advice. > > I found the "PostgreSQL 9.0 High Performance" book to be worth its weight > in gold. A few days spent with the book and research on mailing lists > improved our PostgreSQL performance multiple times over, and responsiveness > under load by orders of magnitude. > > > http://www.amazon.com/PostgreSQL-High-Performance-Gregory-Smith/dp/184951030X > Yep. That's probably the single most useful performance tuning book anyone working with dbs can own. Even if you don't run postgresql, the hardware tuning and testing section is fantastic.
