Switching a master domain manager or dynamic domain manager

Switching a master domain manager or dynamic domain manager affects the running dynamic workload broker server.

The installation of a master domain manager or dynamic domain manager and of its backup workstations includes also the installation of a dynamic workload broker server.

You might have to switch the master domain manager or dynamic domain manager because, for example, the system running the current workstation is down. When a conman switchmgr command is submitted, an automatic process is triggered by which the old server stops the dynamic scheduling services and the new server starts a new instance of the dynamic workload broker server when the older server has completed the switch. This process ensures that there is only one active dynamic workload broker server running at a time.

You can configure this automatic switch broker process on instances at version 9.5 or later, by modifying the following properties contained in the SwitchBroker.properties file located in TWA_DATA_DIR/broker/config/SwitchBroker.properties:
Table 1. Configurable properties for automatic switch broker process
Property Description
Master.Switch.HostName The master domain manager name used to identify the active master.
Master.Switch.ExpiringTime The number of seconds the new master waits before becoming the active master. The default value is 300 seconds.
Master.Switch.PollingTime The time interval, in seconds, between the database checks made by the new master on the status updates of the old master. The default is 5 seconds.
When the switchmgr command is submitted, the new master begins monitoring the database (with the frequency specified by Master.Switch.PollingTime), to verify when the state changes for the old master. If there is no response from the old master (because of a crash or because the old master is at a product level version earlier than V9.5) then the new master waits for a maximum of two intervals specified by Master.Switch.PollingTime (10 seconds), and then automatically promotes itself as the new active master. If, instead, a status update is detected in the database while polling, the new master waits the amount of time specified by Master.Switch.ExpiringTime before declaring itself the new active master. As soon as the old master completes the switch procedure, then the new master declares itself as the active master without waiting for the expiry of the Master.Switch.ExpiringTime.

The properties must be modified on both the master domain manager or dynamic domain manager and their backups at version 9.5 or later.

Here is the procedure to follow every time you switch the master domain manager or dynamic domain manager if you run dynamic scheduling in your network:
  1. Set the job fence to go priority level. For further details, see fence.
  2. Switch the master domain manager or dynamic domain manager to a backup workstation. Use either the conman switchmgr command or the Dynamic Workload Console. For more information about both methods, see switchmgr.
  3. Once the switch has been performed, restore the job fence to zero. For further details, see switchmgr.