Failure to retrieve Performance Counters after reboot of LoadGen Agents or System under Tests servers

In load test scenarios, performance counters may intermittently fail to be retrieved from certain machines (load-bots or Citrix servers) following a reboot. If the machines are not rebooted, the error does not occur.

Typical error messages in the LoadGen Director log include:

ERROR - CreateNetworkConnection: [machine name]: ERROR: The following error occurred while trying to connect to the remote machine [machine name]: An unexpected network error occurred.WARN - {12272} EnumerateThePerformanceCountersMachines - 1: [machine name]: ERROR: The following error occurred while trying to connect to the remote machine [machine name]: An unexpected network error occurred.

Root Cause

The issue is caused by the Windows Workstation Service (service name LanmanWorkstation) not properly initializing or maintaining network redirector connections after a reboot. This service is responsible for establishing client network connections to remote servers—including those used for remote performance counter retrieval.

If this service is delayed, hung, or disabled, the LoadGen system cannot establish the required named-pipe or SMB connection and thus fails to collect performance counters.

Resolution

To restore proper performance-counter access after a reboot, perform the following steps before initiating a load test:

1. On the machine (either LoadGen Agents or Systems under Test servers) where counters cannot be collected, open an elevated command prompt:net stop LanmanWorkstationnet start LanmanWorkstationAlternatively, use Service Manager (services.msc) to locate the Workstation service and restart it.

2. Confirm the service startup type is set to Automatic so it starts properly on reboot.

3. Make sure dependent services such as Network Store Interface Service (NSI) or the SMB redirector (MrxSmb20) are also set to start automatically.

4. Retry your load test. Performance counters should now enumerate without error.

Why this works

The Workstation service handles client-side network redirection and named-pipe connections to remote servers. When it is compromised, the system cannot connect to remote performance counters, which rely on the same underlying SMB/named-pipe channels. Restarting the service restores these channels and re-enables the remote counter enumeration.

Additional best practices

• Verify that the LanmanWorkstation service status is Running and startup type is Automatic on all involved machines.
• Review the Event Log for errors such as “Error 2250: The service did not start due to a missing dependency”. Microsoft Learn
• Perform a test enumeration of counters after reboot and before launching the load test, to validate connectivity ahead of test execution.