Lots of folks conflate cloud computing and virtualization, but these are not necessarily intrinsically related. Although most cloud servers today use a hypervisor like KVM or Xen to share compute hardware, there’s no reason it has to be this way. My takeaway from Gigaom Structure this week is that an alternative paradigm is emerging: Cloud without traditional virtualization.
Docker, Mesos, and CoreOS
The first day of Structure, just about every speaker mentioned Docker, Mesos, or both. And CoreOS got a lot of airtime, too. So what are these?
Let’s look at Docker first. It’s an open source project to “containerize” applications on Linux. Essentially, an application would be packaged up to run in its own space on a shared operating system. It’s kind of like the difference between Terminal Server and VDI – rather than have a whole virtualized operating system instance, Docker places apps in a sandbox on a shared OS.
Check out Nigel Poulton’s great overview of Docker and Jon Langemak’s examples of using Docker for more
So Docker reduces the overhead of virtualization, but how do you use these resources? That’s where Apache Mesos comes in. It’s a cluster manager for massive-scale systems: When you run an application, Mesos decides where in the cluster to run it and handles all the management work for you.
Speaking of low overhead, CoreOS seems to be the darling operating system for these new stripped-down servers. A fork of Google’s ChromeOS, CoreOS removes every non-essential service from the operating system. It’s an ideal partner for Docker!
Rackspace OnMetal
Certainly many companies will run their own server farm with Meso, CoreOS, and Docker, but what about companies that want more dynamic infrastructure? That’s where Rackspace’s newly-announced OnMetal comes in.
OnMetal is essentially an OpenStack server cloud without any hypervisor in the mix. It uses the familiar OpenStack API to spin up physical servers rather than virtual machines. These are ideal for running containerized applications.
And what servers they are! Rackspace is deploying an all solid state server around the Facebook-initiated Open Compute design. There are three different server configurations, with the sweetest being OnMetal I/O with dual LSI Nytro WarpDrive PCIe SSDs for 3.2 TB of high-performance storage.
Stephen’s Stance
Containerized applications on stripped-down bare-metal servers is more than an alternative vision for cloud computing. It’s a real game changer in the cloud! Essentially, we have an alternative to the Amazon AWS vision of virtualized cloud servers with real performance benefits. Exciting stuff!