Alarm retrieval and synchronization

On startup, the probe can retrieve active alarms from the EMS and do so regularly if required. The probe uses the CORBA push model to receive new alarms as the EMS generates them.

Startup and initial synchronization

At startup, the probe retrieves a list of all active alarms from the EMS if the InitialResync property is set to true. When the property is set to false, the probe does not receive the existing alarms.

Alarm retrieval

Once the probe has received any existing alarms, it connects to the Subscriber object and uses the CORBA notification push model to receive new alarms from the EMS. The probe receives those alarms as they are generated at the EMS.

The probe parses each alarm it receives and forwards it to the ObjectServer.


The probe can resynchronize with the EMS periodically. The frequency of any resynchronization is determined by the value of the ResyncInterval property. When the property has a value of 0, which is the default value, the probe never resynchronizes. Any other value of ResyncInterval defines the interval, in seconds, between successive resynchronization operations. For each operation the probe receives a list of all active alarms in the same way as it does at startup. The probe then resumes waiting for new alarms from the EMS. When resynchronizing, the probe receives alarms in batches when the ResyncBatchSize property has a positive value (the default value is 100). The minimum batch size is 1.

During normal operation, the probe requests a resynchronization at one of the following trigger points:
  • Initial resynchronization: This is performed when the probe starts, and is controlled by InitialResync property. This uses the resynchronization filters configured in the probe properties file.
  • Interval resynchronization: This is performed while the probe is running, and is controlled by ResyncInterval property. This also uses the resynchronization filters and is similar to the initial resynchronization.
  • resync command: This is performed from the command port without a filter.
  • resyncFilter command: This is performed from the command port with a filter passed to the command.

When the resynchronization operation is in progress, attempts to launch the command line resynchronization will be aborted with the response:

I-UNK-104-002: {"response":["Resync in progress. Abort command line resync."],"status":"200"}

Note: The probe is supplied with a script ( which removes events that have an occurrence date and time that is prior to that of the resynchronization ProbeWatch message. This script is triggered for the initial resynchronization, the interval resynchronization, and the resync command. The script is not triggered for the resyncFilter command.

Resynchronization filters

You can apply filters during a resynchronization operation to limit the number of alarms returned from the EMS. The probe provides two properties that enable you to define filters:

  • ResyncProbableCauseFilter
  • ResyncSeverityFilter

You can use either filter individually or both filters together.

The filters define values for alarms to exclude from a resynchronization operation when they contain a particular value. For example, if you set ResyncSeverityFilter to the value PS_MINOR, all alarms with that severity setting are excluded from the resynchronization operation.