A process_class can reference multiple JobScheduler instances

Feature
A process class can be assigned a number of Agents. The JobScheduler selects the next available Agent to execute a job. Unavailable Agents are ignored.

<process_classes>
    <remote_schedulers>
        <remote_scheduler remote_scheduler="http://host1.com:4444" />
        <remote_scheduler remote_scheduler="http://host2.com:4444" />
        <remote_scheduler remote_scheduler="http://host3.com:4444" />
    </remote_schedulers>
</process_classes>

Should an Agent not be available then the following warning is added to the log and JobScheduler switches to the next Agent.

SCHEDULER-488 This remote JobScheduler '...' is not accessible: ...

Should no Agent be available then JobScheduler throws the following warning and waits for 30s bevore retrying the list of Agents:

SCHEDULER-489 No remote JobScheduler is accessible. Waiting before trying again

Prerequisites

• This feature works with JobScheduler Agents >= 1.8
• This feature is available for connections to Agents via HTTP and the Jetty Plugin:
  • Agents have to be configured for HTTP and the Jetty Plugin has to be operational.
  • The Jetty port is configured with the HTTP URL.

Implications

• Replacing *.process_class.xml configuration files.
  • At any time a configuration file *.process_class.xml can be replaced.
  • A changed process class configuration is not applied to running tasks. Changes are applied to tasks that will be started after the changes are effected.
• Should a modified process class not include any Agent, i.e. the jobs would be executed on the local host, then JobScheduler will kill all tasks of that process class that are waiting for an Agent. This includes stopping of jobs.