WMI contains an event infrastructure that produces notifications about changes in WMI data and services. WMI event classes provide notification when specific events occur.
User can create a semisynchronous or asynchronous query to monitor changes to event logs, process creation, service status, computer availability or disk drive free space, and other entities or events.
In C++, IWbemServices::ExecNotificationQueryAsync() is used to get the callback in case of event creation/deletion/modification.
AMPS (DASHService) uses WMI event registration mechanism to get notified about changes in deployment classes of SCCM. We observed following issues in large scale enterprise infrastructure while using this mechanism :
WMI Event Registration failed. While registration for change in event for class SMS_ApplicationAssignment, ExecNotificationQueryAsync() method failed with error code WBEM_E_QUOTA_VIOLATION.
WMI Event notification not received even if WMI Event registration was successful.Notification query failed with error code WBEM_E_CALL_CANCELLED.
AMD discussed with Microsoft about the same and filed following bugs for these issues: