Registry Jobs are processes designed to be run asynchronously, usually via cron, intended to handle large operations not suitable for a single web transaction. Jobs were originally introduced in Registry v0.9.2 as CronShell, and in v2.0.0 were migrated to JobShell. As of Registry v3.3.0, Jobs are implemented via plugins (except for some existing Jobs, which will migrate to plugins in Registry v4.0.0, CO-1310).
Jobs are processed via Job Shell, and a Job can be run synchronously (from the command line), or it can be scheduled for asynchronous processing (via cron). When Jobs are run asynchronously, Job Shell will process all queued Jobs for a given CO sequentially in the order they were queued. It is not possible to queue two instances of the same Job within a CO. It is not currently possible to process Jobs within a CO in parallel, or to prioritize some Jobs over others.