From: Josh Berkus <josh@agliodbs.com>
To: pgsql-performance@postgresql.org
Cc: Luke Lonergan <LLonergan@greenplum.com>
Cc: Andrew McMillan <andrew@catalyst.net.nz>
Cc: Matthew Schumacher <matt.s@aptalaska.net>
Subject: Re: Performance problems testing with Spamassassin
Date: Fri, 29 Jul 2005 09:47:03 -0700
Message-ID: <200507290947.03700.josh@agliodbs.com> (raw)
In-Reply-To: <3E37B936B592014B978C4415F90D662D0C4221@MI8NYCMAIL06.Mi8.com>
References: <3E37B936B592014B978C4415F90D662D0C4221@MI8NYCMAIL06.Mi8.com>
Luke,
> work_mem = 131072 # min 64, size in KB
Incidentally, this is much too high for an OLTP application, although I don't
think this would have affected the test.
> shared_buffers = 16000 # min 16, at least max_connections*2, 8KB
> each checkpoint_segments = 128 # in logfile segments, min 1, 16MB
> each effective_cache_size = 750000 # typically 8KB each
> fsync=false # turns forced synchronization on or off
Try changing:
wal_buffers = 256
and try Bruce's stop full_page_writes patch.
> I guess we see the real culprit here. Anyone surprised it's the WAL?
Nope. On high-end OLTP stuff, it's crucial that the WAL have its own
dedicated disk resource.
Also, running a complex stored procedure for each and every word in each
e-mail is rather deadly ... with the e-mail traffic our server at Globix
receives, for example, that would amount to running it about 1,000 times a
minute. It would be far better to batch this, somehow, maybe using temp
tables.
--
Josh Berkus
Aglio Database Solutions
San Francisco
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To: pgsql-performance@postgresql.org
Cc: josh@agliodbs.com, LLonergan@greenplum.com, andrew@catalyst.net.nz, matt.s@aptalaska.net
Subject: Re: Performance problems testing with Spamassassin
In-Reply-To: <200507290947.03700.josh@agliodbs.com>
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