Document bamboo.agent.heartbeatInterval property

Hi Andrew,

Can you please document the new mechanism for configuring the remote agent heartbeat interval?

It's set by:

1. Adding -Dbamboo.agent.heartbeatInterval=interval_in_seconds at the appropriate location in the Bamboo server's command line; or
2. Adding <property name="bamboo.agent.heartbeatInterval">interval_in_seconds</property> at the appropriate location in bamboo.cfg.xml.

The server needs to be restarted to implement the change.

If neither of these mechanisms are used, the default heartbeat interval is 5 seconds.

Give me a shout if you need any more information, or if you'd like me to proof-read.

Cheers,
Adrian