Hybrid cloud wizards: CloudVelocity and Ravello Systems

Ravello's Cloud Application Hypervisor

Whereas CloudVelocity moves clones to the cloud for development, production, or disaster recovery purposes, Ravello taps the cloud specifically for the development and testing of applications that will be deployed not in the cloud, but in-house.

Ravello's Cloud Application Hypervisor allows you to run an exact replica of your multitier production application -- including the VMware or KVM virtual machines -- on Amazon, Rackspace, or HP Cloud. You can test in the cloud, iron out the bugs, capture all the changes, then bring the new version of your application back into your data center.

Setup takes a different path than with CloudVelocity. Instead of offering a tool that burrows into your machines and copies them to the cloud, Ravello gives you a sandbox where you can upload your own VMs or start with Ravello's prebuilt virtual machine images, and draw up "blueprints" of your application.

This construction is done in a graphical Web interface that shows all of the machines as blocks. You drag and drop them onto a canvas, then sketch out the connections among them. Ravello offers a few of the standard Linux distros, and some machines are already configured for standard jobs like running a Web server. If you're uploading your own VMs, both Linux and Windows are supported. 

I found it pretty easy to set up a few machines, populate them with the software I was using, and save them as a blueprint. Then I could stamp out new versions. With the push of a button, I could spin up the whole works on Amazon.

One feature lets you preconfigure the firewall settings for each machine by opening or closing the ports for your software. When the machines are spun up, Ravello reaches in and opens and closes the ports to match what you want. This is a great feature because I find that half of what I do with a new machine is fiddle with the firewall. The distro's defaults never match what I need exactly.

The tool subtly encourages better security practices. As with CloudVelocity, you can connect the machines so that they use the internal IP addresses, keeping the second-tier machines like the database machine away from the public Internet. If you twiddle with the DNS correctly, the Web server will always be able to find the matching database machine in all the replicas.

But Ravello's real magic is a hypervisor for hypervisors that allows you to run VMware and KVM virtual machines inside the cloud machines. It's not just repackaging the contents of your servers in AMIs, but dropping the machines themselves onto the cloud.

You can make changes to these VMs, test them, and save them back to Ravello as a blueprint. When you're done, you can download them from Ravello and run them back on-premise.

To the cloud and back again

If you look at systems like Ravello and CloudVelocity from the perspective of, say, the programmers who toggled their software into the front panel of a computer, the layers and layers of hypervisors and operating systems and libraries and virtual machines is pure madness. The stack must be a million calls high.

But if you think like someone who just wants to get the server running before 5 p.m. on Friday, then it makes perfect sense. Everything is packaged together and everything more or less runs.

I was pleasantly surprised by the ease I found using both of these systems. Sure, it made sense for our great-grandparents to install software or configure the machine, but it's simpler to toss the VMs around as solid units.