Current behaviour on Linux :
i.e. only one running instance.
And current behaviour on Windows :
i.e. several running instances - for example it's possible to start one instance using service and another one from console.
Thus we have an inconsistency in behaviour under different OSs. And moreover in case of Windows this behaviour is misleading and error-prone.
So IMO would be better to disallow multiple instances on Windows. In order to do this following options should be added to wrapper.conf ( http://wrapper.tanukisoftware.com/doc/english/prop-single-invocation.html ) :
With this option enabled, attempt to start second instance will lead to a following message :