Using the Scheduler 'watch folder' feature

Event-driven control of Omniscope Server via XML Actions files 

The 'watch folder' function allows you to execute an XML Action from an external trigger (i.e. programmatically). It is an alternative to configuring scheduled tasks manually using the Scheduler user interface, or running tasks programmatically by creating a new Java process. Creating a new Java process to execute an XML action (as described in XML Actions) has an overhead of approximately 10 seconds which is avoided when using the 'watch folder'.

The Omniscope Server Scheduler includes other processes as well as the chronological scheduling loop. One of these is a process which watches a nominated folder (the 'watch folder') continuously while the Scheduler is running. Any XML Action files saved into this folder are detected by the Scheduler and executed immediately, then deleted in sequence, providing event-driven control of Server Scheduler. 

Please note: the Scheduler must be running for the watch folder to work.

(You can choose to configure the Server Scheduler to run as an always-on Windows service). 

Instructions

Create an XML Action file, with the extension ".xml", as described in XML Actions. You can create this using the Omniscope Server Scheduler user interface to create a sample XML file, export the file, then use it as  a model for modifying a custom XML text file to suit, either manually or programatically.

To execute an XML Action file on demand, copy it into the watch folder, by default found in "scheduler\watch" within the Omniscope installation folder. The location is configurable and depends on where you installed Omniscope. This would typically be one of the following locations: 

Installed for current user only:

Windows 7 and Vista:

C:\Users\<username>\AppData\Local\Visokio Omniscope app\scheduler\watch

Windows XP: 

C:\Documents and Settings\<username>\Local Settings\Application Data\Visokio Omniscope app\scheduler\watch

Installed for all users:

Windows 7 and Vista: C:\Program Files (x86)\Visokio Omniscope\scheduler\watch

Windows XP: C:\Program Files\Visokio Omniscope\scheduler\watch  

Note: <username> needs to be replaced with the actual user name of the person on that machine. 

If the Scheduler is running, this file will immediately be executed then deleted. After testing, refer to the Scheduler log to check for errors:

http://localhost:24679/

If you are repeatedly testing changes to an XML Actions file, be careful to copy (and not move) the XML Actions file to the watch folder, because it willl be automatically deleted after being executed. Also be sure to refresh the web browser showing the log frequently to check for errors.

Note: files dropped into the watch folder are executed in sequence and in no specific order, using the same JVM as the Scheduler. It is not currently possible to execute multiple tasks in parallel.