I have implemented rabbitmq in my application and it's running on windows server 2008 server, the problem is that erl.exe taking high CPU usages like sometime it reaches 40-45% CPU usages, even in the ideal case (when not processing any queue) it takes at least 4-15% CPU usages.
What could be the reason for taking high CPU usages? Is there any setting or any other thing that I need to do.
You say that even when not processing a queue it is still at 4-15%, but is your application running? If you weren't before, try to monitor erl while no application is using Rabbit.
One thing that comes to mind is that you might be using the QueingBasicConsumer in a loop and that could be contributing to the CPU usage. If you are using QueingBasicConsumer and it is what is causing the hit, try substituting it with EventingBasicConsumer (such that you don't do busy waiting) and see if you have improvement.
Also, how is your application using Rabbit? According to the documentation every IConnection is backed up by a background thread and if you're creating a bunch of connections in your application it could be another reason for the slow down.