From mboxrd@z Thu Jan  1 00:00:00 1970
From: nicolas.pouillard@gmail.com (Nicolas Pouillard)
Date: Tue, 08 Sep 2009 17:14:22 +0200
Subject: [sup-talk] sup-sync and xapian memory usage
In-Reply-To: <1252419716-sup-3031@roughage.com.au>
References: <20090907170450.GO14010@pimlott.net> <1252348258-sup-415@zyrg.net>
	<1252350686-sup-8800@ntdws12.chass.utoronto.ca>
	<1252350896-sup-5026@zyrg.net> <1252415772-sup-7288@masanjin.net>
	<1252419716-sup-3031@roughage.com.au>
Message-ID: <1252422827-sup-805@peray>

Excerpts from Richard Heycock's message of Tue Sep 08 16:27:10 +0200 2009:
> Excerpts from William Morgan's message of Tue Sep 08 23:39:12 +1000 2009:
> > Reformatted excerpts from Rich Lane's message of 2009-09-07:
> > > Excerpts from Ben Walton's message of Mon Sep 07 15:11:58 -0400 2009:
> > > > Excerpts from Rich Lane's message of Mon Sep 07 14:33:06 -0400 2009:
> > > > > Xapian keeps writes buffered in memory. Try setting the
> > > > > environment variable XAPIAN_FLUSH_THRESHOLD to a smaller value
> > > > > (the default is 10000 documents) and see if that helps.
> > > > 
> > > > Does this explain the lag at shutdown?  Xapian is flushing writes to
> > > > disk?
> > > 
> > > Yep.
> > 
> > Good to know. Is there a way to force a flush in Xapian? Just curious.
> > The delay is a little scary sometimes. Maybe it just needs an
> > appropriate message somewhere.
> 
> Xapian, by default, flushes every 10 000 documents which in email terms
> is a pretty long time! You can force a flush but it does increase your
> IO significantly. Having said that emails are fairly small so flushing
> every 10 or 20 emails might not be too bad.
> 
> Maybe it could be dynamic, if there is a high volume of incoming emails
> flushing could be done after 50 or 100 emails or a timer based flush
> might be easier.

Should the '$' command, force a write of the Xapian database?

-- 
Nicolas Pouillard
http://nicolaspouillard.fr