OpenStack workshop, part 3:Gimmicks, extensions, and high availability

Wide Load

Article from ADMIN 14/2013

By Martin Loschwitz

OpenStack has a number of useful extensions that can help admins protect their cloud against failures.

The second part of this workshop [1] was, admittedly, not much fun – before an OpenStack installation sees the light of day, the admin has about a thousand things to take care of. However, the reward for all this effort is a cloud platform that seamlessly scales horizontally and uses state-of-the-art technology, such as Open vSwitch, to circumnavigate many technical problems that legacy virtualization environments face.

Once the basic installation is in place, it's time to tweak: How can cloud providers add value to their software? How can you future-proof the installation? How can you best mitigate an infrastructure failure in OpenStack? This third episode of the OpenStack workshop delves into the depths of these questions, beginning with some repairs that might well see some cloud customers getting very excited.

Quantum, Horizon, and Floating IPs

An elementary function in OpenStack is floating IPs, which let you assign public IP addresses to virtual machines as needed so they're accessible from the Internet. Public IPs can be assigned dynamically to the existing instances. The origin of this function lies with the idea that not every VM will be accessible from the Internet: On one hand, you might not have enough IPv4 addresses in place; on the other hand, a database usually doesn't need a public IP. In contrast, web servers (or at least their upstream load balancers) really should be accessible on the web.

In the previous version of OpenStack, "Essex," the world was more or less still in order in this respect: Nova Network took care of the network itself as a component of the OpenStack computing environment, and Quantum was nowhere in sight. Assigning floating IPs was an internal affair in Nova, and the Horizon web interface, for example, is expressly designed for the job: If a customer wants to assign a floating IP

...

Use Express-Checkout link below to read the full article (PDF).