Windows Process Activation Service Test

The Windows Process Activation Service (WAS) manages application pool configuration and the creation and lifetime of worker processes for HTTP and other protocols. The World Wide Web Publishing Service (W3SVC) and other services depend on WAS.

This test monitors the Windows Process Activation Service and reports useful statistics revealing how well the service manages the worker processes and how healthy these worker processes are. This test is disabled by default. To enable the test, go to the enable / disable tests page using the menu sequence : Agents -> Tests -> Enable/Disable, pick the desired Component type, set Performance as the Test type, choose the test from the disabled tests list, and click on the < button to move the test to the ENABLED TESTS list. Finally, click the Update button.

Target of the test : An IIS web server

Agent deploying the test : An internal agent;

Outputs of the test : One set of results for every worker process on the IIS web server being monitored

Configurable parameters for the test
  1. TEST PERIOD - How often should the test be executed
  2. Host - The host for which the test is to be configured
  3. Port - The port to which the specified host listens
  4. website name - By default, this parameter is set to none. This implies that the test monitors all web sites, by default. If you want the test to monitor a specific web site alone, then specify that web site name here.


    If this test is configured with a web site name, then all other web site-related tests of the target IIS web server will report metrics for this web site only.

Measurements made by the test
Measurement Description Measurement Unit Interpretation

Active listener channels:

Indicates the number of currently active listener channels in the worker process.



Active protocol handlers:

Indicates the number of currently active protocol handlers in the worker process.



Health ping reply latency:

Indicates the average time taken by worker process to reply to last health ping.


You can monitor and improve application pool health by having the Windows Process Activation Service (WAS) ping an application pool's worker process at set intervals.

A delayed response from the worker process or the lack of any response might mean that the worker process does not have a thread to respond to the ping request, or that it is hanging for some other reason. Based on the results of the ping request, WAS can flag a worker process as unhealthy and shut it down.

By default, worker process pinging is enabled. You may have to adjust the ping interval and the ping response time to gain access to timely information about application pool health without triggering false unhealthy conditions, for example, instability caused by an application.

Total requests served:

Indicates the total number of requests served by the worker process.


This counter is only meaningful when request based recycling is enabled for the application pool.