First off, thanks for a great plugin!
I noticed that the Jabber/Instant Messaging Plugin combo reconnects every time the Manage Jenkins / Configure System 'form post' occurs, even if no Jabber config changes are made. The connection is made ~30 seconds after the post occurs.
More importantly, every time a slave is added/removed/updated, the same reconnect occurs. (even though no Jabber config changes were made). In our environment, this happens very frequently, since we are using virtual slaves.
While this reconnect is occurring, any IM notifications which normally would be sent by the Jabber plugin are not sent. In our environment, this means that pretty frequently, we are missing IM notifications due to the reconnect process.
It would be great if the Jabber / IM plugins only reconnected when the necessary rather than every time the system config page is saved. This would significantly reduce the possibility of 'missed IMs' when running in an environment with dynamically added/removed slaves.