7.5.2 Virtual Hosts

The Job Farming Module holds a persistent object named system.hosts containing objects which represent virtual hosts as described in Section 6.2.3. The printed representation of virtual hosts is displayed in Example 7.4. Virtual hosts manage all information which is related to a real computation host:

• The virtual host polls the load of its real world counterpart on request.
• It tracks whether the host is currently reachable or not.
• Virtual hosts keep track of tasks that are running on them, and tasks that recently have terminated, in order to compute their effective load.
• They report status information using events; whether they consider themselves available for additional tasks (idle), or not (busy).