From the time software came into existence, application software has been booming to leverage the benefit of the computing paradigm. During this cycle, it has transformed decades of design and architectural thinking, and has crossed all aspects of application development and management needs, be it configurability, reusability, maintainability, scalability or security (a good list is of these “ilities” is here).
While many have been addressed, one “ility” that has turned a lot of eyes and attention in the last few years is deployability. More than that, it is the ability to do so continuously. This requirement has changed the thinking of building software for two main reasons: (a) Businesses have started asking to release software faster than ever, even in verticals unheard of before; and (b) Cloud and infrastructure as code has made faster deployment a easier possibility. When you look at application design with deployability in mind, given the need to be agile, what you end up getting is a microservice.
Most applications of old style addressed most “ilities” in an architecture but did not consider “continuous deployability” as a core need as well. I call these monolith from a deployment perspective. They are tightly coupled, and for any small change a complete build of the application was necessary.
Now the question is, Should you really look at microservice as a silver bullet to deploy all software? Should you consider that as the de facto standard to deliver any application functionality? Will applications cease to exist the way we know? Here are my thoughts. As usual, feel free to add yours or write to me personally, as some of you do as well.
Applications as monoliths will stay as they are
- Monoliths have evolved over generations of design and architecture tests and stood the test of time. The focus on modular development is, in fact, a way of creating modules, which are built with separation of concerns in mind.
- Monoliths were built to run for a long time. It had addressed some of the “ilities” well before they became considerations.
- Applications will remain easier to debug, as most of the debuggable areas are in developer’s hand, instead of having to work with a team.
- Applications will perform better, as they can share data in memory; they don’t have to do out-of-process calls to get one task executed.
- Applications will be more secure, as they will be a black box from an end user perspective or even a hacker perspective, with little coming out from the system.
Microservices will be a monolith-killer all the way
- Deploy, deploy and deploy to correct your problems away. Fail fast and fix faster is the mantra that you can practice.
- It helps bundle two-pizza teams owning microservices and hence embrace better ownership and faster response.
- The overall architecture to deliver an end-to-end use-case may become complex, but each piece of the jigsaw puzzle can be handled faster.
- In the faster-moving world, business wants to try a concept rather thinking through all the “ilities” ahead of time, and progressively make everything better. Microservices helps abstract all complexities much better.
- Microservices will help developers think out of box from day one, while helping business deliver smaller chunks, without having to make the system a “big ball of mud.”
At the end of the day, irrespective of the approaches, the key is to ensure the applications are managed well, changes are refactored well, the code that is written is readable and maintainable, and significant test assets are created to regress the entire system quickly. So whether it is a large system or microservices, you are able to make any necessary changes quickly and can deploy fast.
While microservices surely will help this new faster-deployment thinking, I—and I am sure you all—have also seen large monolithic systems that are making delivery at an astounding pace.