4.20 Policy Schedules

Policies can be scheduled, unscheduled, and executed on demand. A policy run scans the pair’s path, then moves the files that satisfy the criteria for the move. While policy runs are in progress, performance is slower. It is best to schedule policy runs in off-peak hours so that the user experience is not adversely affected.

Multiple policies can be scheduled to run at the same time. The policies are grouped for the run according to the direction files are to be moved: Primary to Secondary, then Secondary to Primary. When policies are run in combination, a file is moved if its conditions meet the rules defined in any one of the policies. That is, the different policies are enforced with an OR condition. The rules within an individual policy are enforced as an AND condition.

Only one scanning action can be performed on a pair at any given time. Actions include the following:

Dynamic File Services does not queue the requests for activities. If the pair is busy, the pending action might not run.

For interval-based policies, the policy can start whenever the pair is available during the specified interval. If the pair is busy at the beginning of the interval, the pending action retries to start itself until the end of the interval. After it starts, the policy runs until complete, or until the end of the interval, depending on which event occurs first.

For policies that begin at a given start time and run until complete, if the pair is busy at the scheduled start time, the pending action retries to start itself for up to 20 minutes beyond the scheduled start time. If you schedule the policies to start at the same time, they can run concurrently. If you schedule policies to begin at different times, there must be sufficient time available for one policy to complete before another is scheduled to begin.

For example, if PolicyA and PolicyB are scheduled to run on the same pair at 12:00 a.m. and 12:05 a.m. respectively, and each policy takes 30 minutes to complete, PolicyB probably never runs. However, if you schedule the two policies to start at the same time, both policies are run in combination.

To avoid scheduling conflicts, we recommend that you use one of the following approaches when scheduling policies for a pair:

For information about how scheduling works, see Section 10.4.1, Understanding How Changes Affect the Scheduled Run Interval.