OpenStack Project Architecture Overview
by Ken Pepple
I thought it would be a good chance to revisit my earlier blog post on
OpenStack Compute ("Nova") architecture. This time around, instead of detailing the architecture of just a single service, I'll look at all the pieces of the OpenStack project working together.
To level-set everyone's understanding, let's briefly review the OpenStack project components and history. Founded in 2010 by Rackspace and NASA, the project has
released four versions and is set to release the fifth ("Essex" or 2012.1)
in April. Originally, it consisted of a trio of "core" services:
-
Object Store ("Swift") provides object storage. It allows you to store or retrieve files (but not mount directories like a fileserver). Several companies provide commercial storage services
based on Swift. These include KT, Rackspace (from which Swift originated) and my company
Internap. In fact, the images for this blog post are being served via the Internap Swift implementation. -
Image ("Glance") provides a catalog and repository for virtual disk images. These disk images are mostly commonly used in OpenStack Compute. While this service is technically optional,
any cloud of size will require it. -
Compute ("Nova") provides virtual servers upon demand. Similar to Amazon's EC2 service, it also provides volume services analogous to Elastic Block Services (EBS).
Internap provide a commercial compute service built on Nova and it is used internally at
Mercado Libre and NASA (where it originated).
The upcoming release promotes two new projects to "core" project status:
-
Dashboard ("Horizon") provides a modular web-based user interface for all the OpenStack services.
-
Identity ("Keystone") provides authentication and authorization for all the OpenStack services. It also provides a service catalog of services within a particular deployment.
These new projects provide additional infrastructure to support the original three projects.