Monday, June 23, 2008

RHQ - tip of the day: is the resource down or the network?

RHQ and JBossON 2, that is built on top of RHQ are distributed systems. The agents managing resources can (and will) live on a different system than the server. So sometimes the question arises when a resource is marked as unavailable if the resource itself is down - or the connection between agent and server.

There is a heartbeat going on between the RHQ agents and the server: the agents are periodically reporting the availability of their managed resources to the server. Now if the server doesn't get those reports for some time, it will report the managed resource as being down. This might have three causes

  • The resource is really down
  • The agent is down
  • The network between agent and server is down
  • Combination of the above

So if a resource is down and you are not sure, go to its inventory tab and scroll to the bottom. There is a section "Agent Managing this Resource":

This shows the availability of the agent and when the last availability report for this resource was received.

If this one shows red, you really should have a look at the machine hosting the agent and the resource.

Technorati Tags:

No comments: