Microservices are a type of software architecture that is gaining popularity.
What does the term “microservices” mean exactly? What sort of architecture falls within the microservices? Despite the abundance of materials online, none of them are easy for beginners to understand. In my opinion, this concept is actually rather straightforward and is easily explainable. Nowadays, developers need to do changes to an application and need to deploy it as soon as possible without redeploying the whole application. This problem led to the microservices development paradigm. This is my 42nd Medium article.
You must first understand the development of software architecture in understanding microservices. Software that had all functionalities created at once was known as monolithic software in the early days of software development. Like an integrated machine, the entire piece of software exists as one unit.
In the monolithic architecture, it is conceivable that the more functions of the software will be the more complex and many shortcomings will be exposed.
- All functions are coupled together, affect each other, and are ultimately difficult to manage.
- Even if only one line of code is modified, the entire software must be rebuilt and deployed, which is very costly.
- Because the software is made into a whole, it is impossible for each function to be developed and tested separately, but only as a whole, so the waterfall development model must be adopted.
In short, large-scale software with monolithic architecture is not only slow to develop but also forms complex code that is difficult to maintain and upgrade and becomes a heavy burden for programmers.
It has long been suggested that the monolithic architecture must be divided, the coupling of the code must be broken, and the program should be divided into independent functional units in order to address the aforementioned issues. The term “service-oriented architecture” (SOA) first appeared about 20 years ago, when functional units could be provided remotely as “services”.
Software that continually performs a certain function in the background is known as a service. The most popular service is the Web service, which offers external web access through port 80.
“Service-Oriented Architecture” is to split a single large program into independent services like smaller programs. The services are connected by communication protocols and each service is a separate, independently operating entity that performs various tasks.
This architecture has many advantages. Those are,
- Each service has a single function which is equivalent to a small software and convenient for development and testing.
- Each service runs independently, which simplifies the architecture and improves reliability.
- The same service might be used for multiple purposes, therefore encouraging and supporting code reuse.
- For easy upgrades, different services can be developed and deployed independently.
- Good scalability, simple addition of more machines and functionalities, and capacity to bear heavy loads
- Less probability to have a single point of failure because a service won’t affect by another service’s failures.
Language is not a factor in service-oriented design, as opposed to monolithic architecture. Different services may need to be deployed in various environments and systems, and they may be built using various languages and tools. This indicates that the service-oriented architecture operates on several servers by default, each of which offers a service, and the combination of numerous servers creates a full-fledged network application.
Microservices design focuses on categorizing programs that are otherwise huge and cumbersome. Each microservice is focused on a certain feature or function of an application. Several of these microservices are combined to make a single, efficient application.
This instinctive, functional split of an application has a lot of advantages. The user interface can be used by the client to make requests. Simultaneously, one or more microservices are engaged to accomplish the desired operation via the API gateway.
Advantages of Microservices Architecture
In application development using microservice architecture is a beneficial approach. A microservice is an independent process. This process can run locally, on another server, or in the cloud (such as cloud services and cloud function FaaS). Its characteristics are the same as service-oriented architecture, but because it is lighter, the decoupling and service-oriented functions can be done more thoroughly. Also, it can be standardized, the same container will have the same result no matter where it is run, so there are many SaaS products on the market that provide standardized microservices.
- Scaling up requires less development work.
As microservices are self-contained, smaller development teams may work on different components simultaneously to update current functionality. This makes it much easier to not just discover and scale hot services independently of the rest of the app, but also to enhance the app as a whole.
Each microservice setups a full-stack application. At any point, microservices are to be deployed independently. It’s simple for development teams to work on one microservice to solve bugs and then redeploy it without redeploying the entire application because microservices are granular in nature.
Even a minor component failure might render the entire application inoperable in a monolithic application. Determining the mistake can occasionally be time-consuming. Since the entire program is separated into independent, fully functional software components, identifying the problematic component is simple when using microservices. Other unrelated units will still work even if errors happen.
- No reliance on a single tech stack
A set of programming languages, front-end and back-end tools, frameworks, databases, and other similar elements are collectively referred to as a technological stack and are used by developers to create applications. Developers can choose a technology stack with microservices that is most suited for a certain microservice and its functions.
Microservice architecture accelerates and optimizes software development. Agile deployment aptness combined with flexible application of various technologies significantly reduces the development cycle duration. Microservices architecture is used for data processing tasks, media content (ie. Netflix, Amazon Prime), website migration, handling transactions and generating invoices.
Docker, which debuted in 2014, completely changed how software is developed. It enables program containerization, uses a minimal amount of system resources, and lets each container create its own operating environment.
Evidently, “service-oriented architecture” can be implemented using containers, and each service now resides in a container rather on a server. Multiple servers are not required in this method. To construct a service-oriented architecture, which was previously impossible, the system runs several containers in the most basic scenario. Microservices are the name of this implementation. Microservices are service-oriented architectures that make use of container technology. Although it still uses “service” as a functional unit, the implementation is now lightweight, just requiring a new container (a process), thus the term “microservice”.
Challenges in microservice
From deployment through operation and maintenance, the microservices architecture has its share of difficulties. Some of the hurdles are discussed below.
- Inter-service communication
A microservice frequently need to communicate and interact with another microservice to meet certain demands or complete particular tasks. This demand maintains a fully functional API providing a channel of communication between various services making up the application.
When many microservices are implemented as a component of an application, each of these services has a unique logging method. As a result, there are significant amounts of dispersed log data that are unstructured and challenging to manage.
Distributed transactions are those that need a number of microservices to be deployed and operating correctly in order to complete. This implies that a transaction involves several microservices and databases, and it will fail if even a little error is in just one of them.
In a microservices architecture, codependency between two or more application services or modules is referred to as a cyclic dependency. It may be challenging to grow the application or separately deploy and manage microservices due to cyclical dependencies. Additionally, they are notorious for making code harder to maintain. Decoupling becomes very hard if they continue for a while.