Re: Performance Problems

[John Morrissey <jwm@horde.net>]

On Mon, Nov 11, 2002 at 03:43:41PM -0800, Christoph Neumann wrote:
% OK.  How do I set "DB_TXN_NOSYNC".  I can't find a reference to it in the 
% Administrators Guide and the Faq-o-matic doesn't specify how to use this 
% value.  I did find "dbnosync" in "slapd-bdb" man page.  Is that the same 
% thing?

Nope. Add 'set_flags DB_TXN_NOSYNC' to your /var/lib/ldap/DB_CONFIG (or
wherever your BDB files live). It's not a good idea to use this outside of
batch adds, as transactions could still be cached (not yet forced to disk)
if the machine crashes with this option enabled.

You might also want to try 'set_cachesize 0 100000000 1' (or similar) in
your DB_CONFIG. http://www.sleepycat.com/docs/reftoc.html has more
information (can be daunting if you're new to BDB. If you're lost, contact
me offlist and I can give you a hand).

The thing I found made the biggest difference was using a RAM disk for the
initial add - it increased performance by a factor of ten or more in my
case. If you can't fit your entire BDB environment in memory, use the RAM
disk for some of your BDB files; it'll still help a bunch.

john
-- 
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