Add support for the replication of hot folders from supervisor to workload Job Schedulers

1. Improvement

Create a central point of configuration for multiple Job Scheduler instances. Ideally a single directory structure on one host is used to manage configuration files for remote Job Scheduler instances. Configuration files can be copied to folders that reflect the directory structure of hot folders on remote Job Scheduler instances.

2. Solution

This solution is applicable for Supervisor instances that replicate configuration files to remote Workload instances. Replication is unidirectional, i.e. no changes should be applied manually to configurations on remote Workload instances as this would offend the principle of a central point of configuration on the Supervisor node. This implies that operations offered by the HTML interface of a remote instance to remove Job Scheduler objects should not be used or should be disabled.

Detail a): Remote Job Scheduler instances fetch the current configuration from the Supervisor on start-up of the remote instance. This implies that exclusively changes to configuration files are replicated (addition, removal, update of files) on a per file basis.

Detail b): Whenever a change applies to a directory structure (intended for a remote instance) in the Supervisor configuration directory then the Supervisor instance notifies the remote instance that would synchronize the respective files. Directories on the Supervisor node that are intended for replication to Workload instances make use of the naming convention "#[SchedulerID]" where [SchedulerID] is the Job Scheduler ID of the remote instance.

Detail c): No permant TCP connections shall be created for the synchronization of configuration files. As TCP connections are costly on Windows systems. Such connections shall be closed as soon as the synchronization is terminated. In case of TCP congestion the synchronization is postponed until a TCP connection becomes available.

3. Scope

This solution applies to one Supervisor instance and any number of remote Job Scheduler instances that are connected to the Job Scheduler via <config main_scheduler="..."/>