Brian Fehrle <brianf@xxxxxxxxxxxxxxxxxxx> wrote: > PostgreSQL 8.4.1 on x86_64-unknown-linux-gnu Please upgrade to the latest bug fix release of PostgreSQL: http://www.postgresql.org/support/versioning To see what bug and security fixes you're missing, look at release notes for 8.4.2 to 8.4.9 here: http://www.postgresql.org/docs/8.4/static/release.html There have been improvements in your areas of concern in 9.0 and 9.1, so you might want to start planning a major release upgrade. That's not as painful as it used to be, with pg_upgrade. > bgwriter_lru_maxpages | 500 FWIW, we do set this to 1000. > max_connections | 2000 This is probably your biggest problem. Unless you've got 1000 CPUs on this box, you should use a connection pooler which is transaction-oriented, limits the number of database connections, and queues requests for a new transaction when all connections are in use. This will almost certainly improve throughput and limit latency problems. You do not need 2000 connections to support 2000 cnocurrent users; such a setting will make it harder to provide 2000 concurrent users with decent and consistent performance. > effective_cache_size | 16GB Given your other settings, this seems likely to be low. I normally add the cache space reported by the OS to the shared_buffers setting. > shared_buffers | 16GB This is probably at least twice what it should be. If you are having problems with backends writing too many buffers and problems with clusters of I/O congestion, you might want to drop it to the 0.5 to 2.0 GB range. > wal_buffers | 8MB Might as well go to 16MB. > work_mem | 64MB Each of your connections can allocate this much space, potentially several times, at the same moment. Unless you really have a monster machine, 64MB * 2000 connections is just asking for out of memory failures at unpredictable peak load times. > One main thing is trying to lower 'spikey' disk IO so that > performance is more consistent at any given time. The advice above should help with that. -Kevin -- Sent via pgsql-admin mailing list (pgsql-admin@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-admin
