How to limit the number of simultaneous runs based on runtime parameters

Discussion created by Michael_Lowry on Sep 3, 2015
Latest reply on Oct 8, 2015 by Michael_Lowry
I have an SQL job that activates thousands of instances of the same workflow, using ACTIVATE_UC_OBJECT. The SQL job’s post-process starts one instance of the target workflow for each row returned by the query; it passes some of the fields returned by the query as input parameters to the activated workflows. (It uses :PUT_PROMPT_BUFFER to pass these values.)

Two of the fields that are passed to the target workflow are called server_name and node_name. I need to limit the number of workflows that are running simultaneously, based on these fields:
  1. Based onserver_name: only 100 workflows may run simultaneously for any givenserver_name.
  2. Based onnode_name: only one workflow may run at any given time for any givennode_name.
There are only a few different values for server_name, so I could conceivably create SYNC objects for these, and assign them at runtime using :ATTACH_SYNC. So at least the first case seems relatively straightforward.

However, there are several thousand different values of node_name, and new values may appear in the DB table without notice. So it would be difficult to use SYNC objects for the second case. The activated workflows are assigned aliases that include server_name and node_name. So I thought it might be possible to use the Tasks running in parallel option to limit the number of tasks having a particular name. However, I discovered that this option enforces the limit based on the object name and not the task alias. So unfortunately, this won’t work either.

Does anyone have any other ideas?