Microservices is a new type of software architecture that is making the rounds in the world of software development. Before you dismiss it as yet another fancy term in this crowded market, let me tell you that this is gaining ground as it's appealing and practical. We've seen many projects that use this architecture, and the feedback has been impressive. In fact, it's slowly becoming the default architecture for building large enterprise applications.
Before going into the nitty-gritty details, let's look at how applications are being built using the, older, more traditional monolithic architecture.
Though monolithic applications have been successful, many developers are becoming frustrated with it. The main problem is change cycles are tied, which means even if you make a small change, the entire server-side application has to be rebuilt and deployed. When you move applications to the cloud, change cycles have to be short, so rebuilding the entire application each time is definitely not a practical thing for you to do. Also, maintaining a good modular structure and scaling are hard to implement in this architecture.
Due to these practical problems, microservices architecture is gaining popularity as it addresses many of the problems that come with monolithic architecture.
So, what is microservices architecture anyway?
At its core, microservices allows you to build flexible software components that can be deployed independently. Each of these components has its own development and deployment lifecycle, and they communicate with other components in different ways such as push messaging and RESTful Web Services.
These different components can be plugged together to create a complete system. The obvious advantage is flexibility, as you can replace or upgrade any component at any time. Also, the components are not tightly coupled, so you won't have to rebuild the application every time you make a change. To top it off, each component can be built using a separate programming language, database, and hardware, depending on what fits best.
Of course, there are also downsides. For example, remote calls tend to be more expensive than in-process calls, and the workaround for this can lead to an awkward implementation of API calls. Also, testing them is complicated, and in some cases, it can even bring up new problems related to network latency and performance.
Despite these drawbacks, microservices are the in-thing now simply because of the flexibility it offers. This flexibility can be a vital aspect for moving and deploying applications in the cloud. This is why microservices is not another new-kid-on-the-block that you can ignore.
Many major companies like Netflix, eBay, Twitter, SoundCloud, PayPal, and Amazon have already started implementing microservices, and they've been a huge success. Research conducted by NGINX among 1,800 IT professionals shows that two-thirds of organizations say they are using or investigating a microservices architecture, while one-third are already using it in production.
So, now that you know what microservices are, and why they're changing the face of software architecture, let's look at some of its best practices.
Best practices are an absolute necessity in a microservices architecture because now you have to manage many independent systems that work in tandem with each other. Logs will tend to be all over the place, and achieving consistency can be a nightmare in a distributed environment. So, to make the most of the benefits of a microservices architecture, you need to have the right tools and processes that'll help you stay on top of it.
Here are some best practices that we think are essential for a clean and well-connected system based on microservices architecture.
Establish the standards
The first thing you need to do is establish standards for common tasks like logging, communications, deployment, and monitoring. In other words, create a platform with a set of standards and tools that will make it easy to operate and create different components.
You can even consider having a central control panel that has links to various internal tools and standards.
Each component will be a service in your system, and depending on the overall size of your application, you can have hundreds or even thousands of services. Each service is independent and represents a single business capability. That said, you have to ensure that every service is small enough to focus on only a single capability, and at the same time, large enough to minimize frequent communications with other services.
In other words, every service should be independent, and should not any require coordination with other services, if no API changes are made. Remember, each service is a codebase and library by itself, and should not depend on any shared resources. This is the cornerstone of microservices architecture.
If you have multiple services that are reading and writing into the same database, you need to coordinate the deployment of all those services. The process of sharing the same database, in a way, would lead to coupling, and this is definitely not what we want.
This is why it's a good idea to ensure that each service has its own private data. In addition, private data gives you the advantage of choosing the database you want for each service.
You can also choose to keep all the different databases on the same dataserver, provided each service has no knowledge of the others' database.
A domain-driven design is based on something called a bounded context that helps you to identify natural and sensible boundaries for your services. Essentially, this means related data and processes are encapsulated within the same domain, and multiple bounded contexts communicate over a public interface like APIs and events.
The domain should also include models and all its related attributes, so the need for communication with other domains is minimal or zero.
One of the key aspects of microservices is security. There is always the possibility for a microservice to be used by another app in the cloud, or possibly even an external partner. In such a case, it's important to implement APIs with varying levels of security. In fact, no distinction should be made between internal and external APIs, and common API security standards that are consistent with global policies should be implemented.
Some companies even prefer to use a zero-trust environment for APIs, which means they implement security practices such as injection-threat protection in their API platforms itself.
With such measures in place, you reduce the chances of exposure to potential security breaches.
In short, microservices architecture is the way forward as it caters better to the changing app development scene. The days of monolithic architecture are numbered, as many companies are moving toward a decoupled and component-based architecture that will give them the flexibility to experiment with different technologies based on their needs.
At the same time, microservices comes with its own share of potential pitfalls, especially in the realm of security and shared resources. To wade through these complexities, you need a set of best practices that are based on common sense and business needs, and we hope the above aspects can get you started in this direction.