[JDEV] Performance

[Anders Qvist]

On Thu, 27 Apr 2000, chetan s ithal wrote:

> The issue I was trying to convey was that that Jabber was getting slowed
> down tremendously when faced with a load of messages for offline,
> do-not-disturb, away etc. clients. Writing the messages to XML files was
> a slow process, but even slower was that the server would check for the
> recipient's availability and offline settings each time (by checking
> state of the recipient's client) before writing to the XML file.
[snip]

Using XDBM should solve writing speed/memory overhead. This is because a)
it can make additions anywhere in a XML structure (it appends to the 
end of the file) and b) keeps a local cache of recently accessed XML tags.
All the rest of the XDBM file is stored only on disk, just like (G)DBM. Of
course, XDBM pays in disk space for this (the XDBM file being very similar
to a FAT file system where each tag can be seen as a file/directory), but
disk is a lot cheaper than RAM.

For XDBM, see http://www.bowerbird.com.au/XDBM. As soon as I have a
release of Josh, I intend to whip up a test xdb module for using XDBM as
backend storage in Jabber.

Anders "Quest" Qvist
NetGuide Scandinavia

And we who listen to the sky, or walk the dusty grade,
Or break the very atoms down, to see how they are made,
Or study cells, or living things, seek truth with open hand;
The profoundest act of worship is to try to understand.

-- Catherine Faber, "The Word of God"