An Introduction to Virtualization

When Should We User Containers?

Considering their limitation to a single kernel, containers are not an ideal solution for pure server consolidation. It might be well deployed in an environment that requires a very large number of similar servers consolidated onto a single platform, but we find that this is often not the case. However, what containers are ideal for is the rapid deployment of large amounts of accessible "servers" - i.e. for seminars or classrooms. Hosting companies have been employing this technology for years, providing their customers with fully functional and customizable "private servers", and the relatively low resource footprints of containers allow the system to be used on servers and workstations alike.

An interesting example of this is what we encountered in our very own lab recently. From time to time, we are asked to perform stress tests on existing web applications, using our in-house developed software, vApus. Quite often, these web servers are already serving people, so it is impossible for us to request our clients to change their system layout to best suit our testing. One particular client required us to test from several IP addresses at the same time, since he had a Network Load Balancing system in place to redirect every request coming from a certain IP to one and the same web server, while there were six web servers present. Instead of going out of our way to set up six separate systems, we simply got a very powerful testing client set up with containers, and used six of them to perform the necessary tests.

While we wouldn't recommend containers as the best solution for actual server consolidation, we are definitely excited about its ability to transparently divide an OS to serve a very large number of isolated virtual environments. Furthermore, it is our opinion that containers are an incredible solution for Virtual Desktop Infrastructures, considering their more than adequate usability and high deployment rates. Given a little more development time, we are convinced that containers will find a solid place in server rooms, sporting many impressive features that will make the virtualized platform as a whole even more interesting.