Unikernels

Chapter 6. What’s Ahead?

It’s important to remember that this is only the beginning of the journey. Unikernels are not the destination; they are, I believe, the path to a new future in the cloud. What can we expect along that path? We won’t know for sure until we get there, but here are a few ideas.

Transient Microservices in the Cloud

The potential impact of unikernels extends well beyond areas like resource utilization and system security. The arrival of the unikernel is poised to facilitate a radical reassessment of software architecture at the highest levels. With unikernels, one of the fundamental assumptions of most solution architectures is no longer valid: we cannot assume that all services in our architectures are persistent.

As we discussed earlier, machines were once expensive, large, and slow. This meant that each machine was loaded with thousands of software programs to meet the diverse needs of a large number of users. As a result, these expensive machines needed to be persistent—they had to be on any time anyone might possibly need any of the thousands of programs on the machine. So, by default, most machines were powered on and running 24 hours per day, 365 days per year, for the entire service life of the machine. People could assume that the needed software was always ready and waiting to process, even if it meant that the machine would sit idle for a significant part of its life.

But now, as we have seen, the rules have changed. Hardware is cheap, compact, ...