[sup-talk] sup-sync and xapian memory usage
nicolas.pouillard at gmail.com
Tue Sep 8 11:14:22 EDT 2009
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?
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