The core module was becoming too large.
By splitting it in cluster, monitor and tasks it becomes more manageable. It also reflects the documentation structure.
New admin test introduced a task in the queue which was picked up by the cluster on Travis. Switching cluster test to different list key should prevent this.
Workers now share a ctype with the sentinel to indicate if they are currently executing a task. This timer is incremented each guard loop until the worker resets it after finishing a job or until it reaches the TIMEOUT value and the worker is terminated by the sentinel.
Ilan Steemers