In Windows Scheduler you can tell a scheduled task not to run if the task is already running. In some cases it would be nice to be able to tell a scheduled Workflow rule to not start if an instance of that workflow is already running.
Question
Question
Feature Request: Do Not Start a New Instance if Workflow is Already Running
Answer
See "single instance mode" in WF Admin Console\Server Configuration\Advanced Server Options:
This is amazing! Are there going to be courses at Empower to cover Workflow Advanced Server options? I feel like there are so many advanced items that I don't know about.
But this forces ALL workflows to be single instance and that is not what we are asking for.
We want to be able to designate individual workflows to be single instance. That way, when we have documents processing the workflow can run multiple instances like normal.
But if you have a scheduled workflow that sometimes runs longer than the start interval, it would be very good to have an option to tell just that workflow only start if it is not already running.
Looking at the screenshot are you not able to choose the workflow that you want it to apply to?
The default will apply to all workflows.
You absolutely definitely do not want that for this option.
But you can also apply it to individual workflows:
It had just not registered with me that there was a workflow selection dropdown in the screenshot. While not as convenient as an option in the scheduler, it does fill the request.
Thanks for the info Miruna!
Yeah, I was hoping the arrow in the screenshot would save me from having to type it all out
We can't put it in the schedule, because a workflow can have multiple starting rules.
Perhaps an option/checkbox could be added somewhere in the workflow settings/properties so it can be done from the designer?
@████████, if another instance tries to start with that setting enabled, do they get put in a queue or are they terminated?
Blake,
If another instance tries to start while another one is already active, Workflow will generate an entry in the Error Logs, but it will not create the instance at all, so it will not show up in the Workflow history.
If you try to manually initiate it from the Workflow Designer, then it will pop up an error indicating that another instance is already running, but again, it will not create the new instance at all.
There is one caveat; in my experience, if the "current" instance doesn't register as "active" it might still generate a second instance. This only seems to occur when you have things like Wait conditions or Scripts that don't seem keep the instance in an active state. I haven't had any major issues.