It seems like gateway is caching the roster?

I registered a msn account, then the second time I listed the roster of this msn account it seems obvious faster.

That is exactly true. =) Though it’‘s not really the gateway plugin itself that’'s doing it. The gateway plugin creates non-persistent rosters that sort of attach to your real roster. They are stored in memory (I believe) and only exist as long as the server is running. (if you restart the server the cached roster goes away) Upon connecting to MSN (or any of the services), your roster is pulled down from the legacy service and compared with your current XMPP roster and only modifications are made.

thanks, jade. They are stored in memory, I also found this documentation:

http://wiki.igniterealtime.org/display/WILDFIRE/HowtoconfigureWildfire’'scaches

which is good, except no default expirationTime value there. I didn’'t find somewhere else too. maybe I should take a look at the wildfire source code?

I found out the default expiration time is 6 hours from wildfire source code.