We utilize heartbeat for High Availability. I'd like to add an additional ip address to the heartbeat cluster, but I don't want to do a full restart of the cluster in the process. Is there a signal I can send to heartbeat that would prompt it to re-parse the "haresources" file and action upon it? heartbeat -r does not appear to do the trick.
The problem was that I didn't wait long enough after executing "heartbeat -r" (the command that is executed in the init.d script when you run "service heartbeat reload".) After a few minutes, the IP showed up on the interface as expected.
You don't need to reload Heartbeat at all. Simply add the new IPaddr resource to your haresources file, something like this
and then start it
Of course, you should make sure to issue the IPaddr start on the active node. You should now be able to send and receive traffic on the just added IP address.
Hearbeat only has to be restarted on the secondary machine, hence avoiding any downtime related to resource management.
In this case, the primary node detects that the slave machine is 'dead' and forces a 'failover' which reloads the resources file and start the missing resources.
The logs are quite explicit when doing this: