What does this HA mean? Well, you can now have multiple servers in a server cloud that handle incoming agent connections. If one of the servers fails or is put into maintenance mode, the agent will transparently fail over to another server in the cloud.
Setup of HA is also quite easy: just upgrade to RHQ 1.1 and it comes for free. When you add a 2nd server and have it point to the same back end database, it will automatically join the server cloud.
You need to pay attention to two things though:
- All hosts for agents and servers need to have valid forward and reverse mappings in RHQ 1.1 -- even if you don't use HA
- If you are using more than one server, you obviously need to increase the allowed connections on your database.
And as always: make sure that the clocks of the involved machines are in sync (e.g. by using ntp).
Watch out for more upcoming posts about RHQ 1.1 and JBoss ON 2.1, which was announced for this october too.