Web Garden not equally distributing reqeust
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I have a WCF service hosted in IIS7 that is used as a relay to a WCF Windows service.  Both services are both using `InstanceContextMode.Single`.  

My first issue is that after time, the IIS hosted service starts to gradually slow to where request that once were around 10ms, are nos 10 seconds.  The degradation happens over hours.  I am confident the degrading response times are not due to the IIS hosted service waiting on the Windows service because I have other IIS hosted services that operate normally when communicating with the Win service.  So as a part of my debugging, I thought of putting the IIS hosted service in a Web Garden.

After kicking the allowed process workers up to 2, i expected the request to be balanced between the 2.  Instead, I see that one process is constantly getting the bulk of requests (CPU is around 20%-30%), and the other is not (always hovering around 1%-2% CPU).  

Is this normal behavior?  
Are there articles that describe how an IIS7 web garden distributes the requests load?