[JDEV] Performance

[chetan s ithal]

Hi all ,
            I performed certain tests on Jabber . When I tried to send
messages at very short intervals (100 mSec) to a particular user(who is
not logged on) continuously , things slow down after certain interval of
time . Is it the case that Jabber checks for the presence of the user
every time prior to writing  off-line messages to the corresponding
user's xml file . Why the things slow down when load on the Jabber
increases ? How can I make it more scalable ? Can anyone shed some light
on this ?
Thanks in advance ......
chetan s ithal .