Hi, I want to know if there is any open source testing tool for cloud computing. We have built a cloud framework with Xen, Eucalyptus, Hadoop, HBase as different layers. I am not looking at testing each of these tools separately, but i want to test them from the perspective of fitting into a cloud environment (for example scalability of xen hypervisor to handle multiple VMs). Would be great if you can suggest me some tool (open source) for the above.