Scheduler Service Questions

Questions

Note that it is better to place discussion points inline, as sub-bullets, than to put them in comments where the context and flow is harder to reconstruct.

• What is the proposed purpose and scope of this service?
  
  A placeholder description is currently provided in the Description and Assumptions page; it would be desirable to replace this with a more concrete description.

• Is this service intended to provide roughly equivalent functionality to something like the Unix 'cron' utility, periodically scanning the time dimensions of various entities and triggering various actions?
  
  Many entities have a time dimension. For instance, a Loan or Exhibition will often have an ending date. Particularly with loans, if objects are not returned by the ending date, there may be a need to automatically send reminder notifications to the borrowers, or to have the loans automatically flagged for review, for possible renewal. There also appears to be a need for Generic Groups on which restrictions can be imposed for periods of limited duration. An example might be information around (metadata for) a group of CollectionObjects that are marked for retrospective cataloging, and thus are "frozen" for a limited time period, accessible for write access only to the cataloger/domain expert during that period. (This is a hypothetical case, not derived from workshop comments or functional team requirements, and there may be other, better examples.) In this and similar cases, there might then need to be a mechanism for automatically 'unfreezing' these groups, removing their restrictions.

• If a scheduler service takes "sweeps" at scheduled intervals, similar to the Unix 'cron' utility, will there need to be a mechanism to ensure that events it may trigger aren't inadvertently launched/created more than once?