Symptoms
A WSNM service restart is observed in the window application event viewer logs similar to the below:
Event ID : 10002
Level : Information
General Message: Shutting down application or service 'VMware Horizon View Agent'.
End User sessions get locked unexpectedly. Within the Horizon Administration console, the machine may report as not available with a status of protocol error or overlapped requests.
Purpose
This article provides recommendations and best practices to avoid Horizon Agent service restart during active sessions.
Cause
Service Name: VMware Horizon View Agent
FullPath: C:\Program Files\VMware\VMware View\Agent\bin\wsnm.exe
DisplayName: VMware Horizon View Agent
File Description: VMware Horizon View Framework Node Manager 64-bit
The Horizon WSNM service depends on the following: 1. Ancillary Function Driver for Winsock (Afd) 2. Remote Desktop Services (TermService) 3. TCP/IP Protocol Driver (TcpIp) 4. Windows Event Log (Eventlog)Sample Screenshot:
When an application restarts any or all of these dependent services, WSNM will get restarted. If there are any active user sessions during this service restart, those active sessions will enter an inconsistent state.
Impact / Risks
Horizon session requests can fail with an unpredictable error.
Resolution
The system core services, as listed, as assumed to remain up during the system's lifecycle and the cycle of the WSNM service.It is expected to ensure that no application or admin restarts the WSNM service directly or indirectly when there are active horizon user sessions.
As can be seen from the windows registry, WSNM is dependent on the following services: \HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WSNM\DependOnService 1. Ancillary Function Driver for Winsock (Afd) 2. Remote Desktop Services (TermService) 3. TCP/IP Protocol Driver (TcpIp) 4. Windows Event Log ( Eventlog) In a scenario where any of these services including WSNM have to be restarted, make sure there is no active horizon session on the machine. If any of these services are getting restarted automatically, it is advised to find the cause of the restart, which could be an underlying system issue. Check the System and Application event logs for more information.
