Question

I have noticed that when I call the /install flag on NServiceBus.host.exe an event log source is created under the Application event log. The trouble is, we have configured NServiceBus L4N to write events to the same source but under a custom event log.

This causes a problem because if we create the source under our custom event log the installation fails (NserviceBus installer throws a System.ArgumentException: Source blah already exists on the local computer).

So how can we stop the NServiceBus installer from trying to create the event source under the Application event log?

We are using NServiceBus 3.0.1.0

Thanks

EDIT – Full stacktrace

Creating EventLog source blah in log Application...

An exception occurred during the Install phase.
System.ArgumentException: Source blah already exists
on the local computer.

The Rollback phase of the installation is beginning.
Restoring event log to previous state for source blah
.
Service blah is being removed from the system...
Service blah was successfully removed from the system
.

The Rollback phase completed successfully.

Unhandled Exception: System.InvalidOperationException: The installation failed, and the rollback has been performed. ---> System.ArgumentException: Source blah already exists on the local computer.
   at System.Diagnostics.EventLog.CreateEventSource(EventSourceCreationData sourceData)
   at System.Diagnostics.EventLogInstaller.Install(IDictionary stateSaver)
   at System.Configuration.Install.Installer.Install(IDictionary stateSaver)
   at System.ServiceProcess.ServiceInstaller.Install(IDictionary stateSaver)
   at System.Configuration.Install.Installer.Install(IDictionary stateSaver)
   at Topshelf.Internal.Hosts.HostServiceInstaller.Install(IDictionary stateSaver) 
in d:\dev\open-source\topshelf\src\Topshelf\Internal\Hosts\HostServiceInstaller.cs:line 120
   at System.Configuration.Install.Installer.Install(IDictionary stateSaver)
   at System.Configuration.Install.TransactedInstaller.Install(IDictionary savedState)
   --- End of inner exception stack trace ---
   at System.Configuration.Install.TransactedInstaller.Install(IDictionary savedState)
   at Topshelf.Internal.Hosts.HostServiceInstaller.Register() in d:\dev\open-source\topshelf\src\Topshelf\Internal\Hosts\HostServiceInstaller.cs:line 61
   at Topshelf.Internal.Actions.InstallServiceAction.Do(IRunConfiguration configuration) in d:\dev\open-source\topshelf\src\Topshelf\Internal\Actions\InstallServiceAction.cs:line 42
   at Topshelf.Runner.Host(IRunConfiguration configuration, String[] args) in d:\dev\open-source\topshelf\src\Topshelf\Runner.cs:line 70
   at NServiceBus.Hosting.Windows.Program.Main(String[] args) in d:\BuildAgent-03\work\nsb.masterbuild1\src\hosting\NServiceBus.Hosting.Windows\Program.cs:line 122

Answer 1

The problem only occurs if we configure Log4net with the same event source name as the endpoint name.

So we can have use different source name in our event log (in our case, <endpoint-name>.l4n). This will work around the issue for now.