2013-04-04

Starting & Stopping Process Invocation

When running the coils.workflow.manager is constantly trolling for queued processes that are ready to run.  On the other hand the System Administrator needs to perform some maintenance and needs the system quiescent.... what to do?  Use the coils-workflow-control tool.  This tool [command] can be used on any node in an OpenGroupware Coils cluster to change the state of the coils.workflow.manager component.
coils-workflow-control --disable
coils-workflow-control --enable
coils-workflow-control --scan
Options
  • --disable : Disables the coils.workflow.manager component's starting of queued processes.  When disabled no new processes will be started.  Processes may still be created and queued, but execution will not commence.  Currently running processes will not be stopped, but no further processes will start.  It is 'safe' to kill the engine once no processes are running and the manager is in a disabled state.  NOTE: Currently the coils.workflow.manager component will always start in an enabled state even if it was disabled when shutdown - but it always waits approximately three minutes after start-up before starting any processes.
  • --enable : Enables the coils.workflow.manager component's starting of queued processes.  This just undoes a --disable request.  Enabling an already enabled engine has no effect.
  • --scan : Request that the coils.workflow.manager component immediately check its process queue for available processes.  Normally there is no reason to use --scan as the component performs this check whenever a running process completes or fails, a new process is queued (via WebDAV for example) as well as at regular intervals.
If the Python module procname is installed on the workflow host processes will change their OS process name to contain the OpenGroupware Coils Process Id - with just this tool and regular sys-admin tools like "top" it is simple to monitor and control the execution of workflow processes.

No comments:

Post a Comment