Symptoms

AD look up provider timing out.
 

Diagnoses

Company has a large number of domain users and recently they were getting more users having issues to start a workflow process because it's potentially taking too long to search and validate users from the domain.

Sample error:
1 24408 K2:DOMAINuser1 from 101.225.5.203:80 does not have rights to Start Process Workflow1Workflow

 

Resolution

Provided coldfix to customer. After it was applied, allowed time for customer to test. After period, CPU usage did go down and users were no longer getting dropped.