Knative is not just a hot topic in software development, it's a whole new way to look at services and functions. As a developer, what do you need to know to take advantage of this cutting-edge technology? Are there important design or implementation considerations? Let's take a look.
Front-end developers
If you're a front-end developer, using, say, React or Angular or Vue, your life remains the same. That's a broad and sweeping statement, and perhaps there are some edge cases where things will change. Those aside, however, as a front-end developer you need not worry about Knative. Your code will talk to a RESTful (or gRPC-based) service regardless. What they do on that end is outside of your control. Life remains the same; it's all good, and you can continue to ship at 5 p.m. Friday and go home. **evil grin**
Server-side developers
If you're a server-side developer, in theory (in theory, everything works in practice), you don't need to consider Knative. But you probably should.
Knative Eventing and Scaling will likely have an impact on the design of your systems. Although microservices architecture is fueled by Domain Driven Design, there have been discussions and debates about when to use a service and when to use a function. They used to be different, but with Knative they are now one and the same. Any service can now scale to zero, which is one of the core tenets of "serverless" computing.
Given that, it may be best to break up your services based on the need to scale to zero. For example, if one particular service is seldom used, it might be okay for that to scale to zero—keeping in mind that "scale to one" takes longer than scaling to two or more. Other services might need to be available 24x7 just as before.
In other words, you can build your code without regard to whether it's being treated as a service or a function; Knative will take care of that.
How you design your system may change.
Eventing
Knative Eventing means your services can now embrace Event-Driven Architecture. Allowing events to trigger functions is faster than calling them from your code; you can dump events into a queue and move on while they are processed. This approach also means you cannot rely on sequential timing in your system, because some events and processes may complete in a sequence you cannot anticipate.
Conclusion
There is no question that Knative has brought change to the world of microservices and serverless functions, and we can only assume that some yet-to-be-developed technologies will build on this. Although making wholesale changes to your system just to incorporate the latest and greatest technologies is most often not a good idea, you should stay informed and prepared. I hope this short article helps point you in the right direction.
Last updated: September 3, 2019