Scheduling DDM probes

DDM scheduled probes have a one hour scheduling window. For example, if a probe is scheduled to run at 1:00, it is actually scheduled to run between 1:00 and 2:00. The probe is not considered to be a missed probe until after that one hour expires. This applies to all missed probe options: run on startup, ignore, and run in next time period. The missed probe option only takes affect after the one hour scheduling window expires.

When deploying DDM probes in your domain, consider how replication affects probe scheduling. New or rescheduled probes use the new schedule after the new or revised Probe document replicates across the domain.

Consider these examples:

• A Web Best Practices probe is set to run weekly, every Tuesday at 3:45 A.M. The How should missed probes be handled field is set to Run missed probe at startup.
• You change the schedule or you reset the How should missed probes be handled value for the probe. The change is made on one server, but the change has not yet replicated to all servers in the domain.
• You launch a server. The probe runs according to the original schedule because the updated schedule is not recognized until the schedule change has replicated to all servers in the domain.

You can schedule probes to run daily, weekly, on a specific day during the month, or at almost any other time. You also specify the repeat interval for the probe. You can schedule probes to run on individual servers or on groups of servers.

Set up the probe schedule on the Schedule tab of the Probe document when creating or editing a probe.

If the DDM database (DDM.NSF) contains unusual Event documents, or documents that were generated or updated at unexpected times, determine whether a schedule change was made to the Probe document for the probe that generated the Event documents. A probe schedule change may have generated unexpected Event documents.