On Thu, 2010-02-25 at 22:12 -0800, Tory M Blue wrote: > shared_buffers = 1500MB Some people tend to increase this to 2.2GB(32-bit) or 4-6 GB (64 bit), if needed. Please note that more shared_buffers will lead to more pressure on bgwriter, but it also has lots of benefits, too. > work_mem = 100MB This is too much. Since you have 300 connections, you will probably swap because of this setting, since each connection may use this much work_mem. The rule of the thumb is to set this to a lower general value (say, 1-2 MB), and set it per-query when needed. > checkpoint_segments = 100 > checkpoint_warning = 3600s What about checkpoint_timeout? Please note that even if checkpoint_segments = 100, if timeout value is low (say 5 mins), PostgreSQL will probably checkpoint every checkpoint_timeout minutes (unless PostgreSQL creates $checkpoint_segments xlogs before checkpoint_timeout value). Depending on your workload, this may not be intended, and it may cause spikes -- which will lead to the issues you complain. I'll stop here, and suggest you read this: http://www.westnet.com/~gsmith/content/postgresql/chkp-bgw-83.htm for details about this subject. As noted there, if you are running 8.3+, pg_stat_bgwriter will help you to tune checkpoint & bgwriter settings. -HTH. -- Devrim GÜNDÜZ PostgreSQL Danışmanı/Consultant, Red Hat Certified Engineer devrim~gunduz.org, devrim~PostgreSQL.org, devrim.gunduz~linux.org.tr http://www.gunduz.org Twitter: http://twitter.com/devrimgunduz
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