Microservices, or microservices architecture, is an architectural style for designing and building software applications as a collection of small, independent, and loosely coupled services. Microservices offer benefits such as scalability, agility, independent development, and improved fault tolerance. However, they also introduce challenges such as service orchestration, distributed data management, and increased complexity in system design and testing. The successful implementation of microservices requires careful consideration of the specific application requirements and a well-defined architectural strategy.
In this book, we are going to learn about microservices in general and how to architect and develop microservices in Node.js. The book is suitable for backend developers, full-stack developers, software architects, and frontend developers who want to get into the world of backend development and extend their capabilities. You will learn, in an in-depth manner, the major tips and tricks to learn how to build microservices architecture using Node.js. At the end of this book, you will be able to conceptualize, plan, and architect microservices using Node.js, as well as develop and debug them. These are the major skills that companies want their employees to have in order to design the perfect solution for every problem every time.
We’ll start this chapter with an introduction to microservices and decentralized architectures. We’ll also learn about some key concepts in microservices, such as service boundaries, loose coupling, scalability, resilience, and independent data management. Finally, we’ll overview some important abilities in microservices, including independent development and deployment, polyglot architecture, APIs, and continuous integration (CI).
By the end of this chapter, you’ll have learned the fundamentals of microservices and why they are so useful.
In this chapter, we’re going to cover the following main topics:
In this section, we’ll learn about two important concepts: microservices and decentralized architecture.
Microservices is an architectural style and approach to building software applications as a collection of small, loosely coupled, and independently deployable services. Meanwhile, in decentralized architecture, components or services are distributed across multiple nodes or entities.
Both microservices architecture and decentralized architecture promote modularity, scalability, fault tolerance, and autonomy. While microservices focus on building applications as a collection of small services, decentralized architecture focuses on distributing processing and decision making across multiple nodes. These architectural approaches can be combined to build highly scalable, resilient, and flexible systems that can adapt to changing requirements and handle complex workloads.
Let’s start with the microservices architecture.
In a microservices architecture, the application is broken down into multiple small services, each responsible for a specific business capability. These services are developed, deployed, and managed independently, communicating with one another through well-defined application programming interfaces (APIs) or message-based protocols.
Figure 1.1 shows a typical microservices architecture compared to a typical monolithic architecture.
Figure 1.1: A typical microservices architecture
In Node.js, microservices are typically developed using lightweight frameworks such as Express.js or Fastify. Each microservice is a separate application with its own code base and can be developed, deployed, and scaled independently. Microservices can be written in different programming languages such as Java and Python, but Node.js is often chosen due to its efficiency, event-driven nature, and large ecosystem of modules.
The key characteristics of microservices include the following:
Understanding these key characteristics is essential for designing, developing, and maintaining successful microservices architectures. Embracing these principles can lead to more scalable, resilient, and agile software systems that meet the demands of modern application development.
Now that you’ve been introduced to the concept of microservices architecture and learned about its key characteristics, let’s dive into the next concept: decentralized architecture.
Decentralized architecture, also known as distributed architecture, refers to an architectural approach where components or services are distributed across multiple nodes or entities rather than being centrally managed. This promotes autonomy, scalability, and fault tolerance by distributing processing, data, and decision making across multiple nodes.
Centralized architectures have a single point of control, making them easier to manage but potentially less scalable and more vulnerable to failures. Decentralized architectures distribute control and data, offering better scalability, fault tolerance, and performance, especially in large and dynamic systems.
Examples of centralized architectures include traditional client-server architectures, where clients communicate with a central server. Mainframes and many early computing systems followed centralized architectures.
Examples of decentralized architectures include blockchain networks, peer-to-peer file-sharing systems, and certain types of distributed databases. Also, some modern microservices architectures follow decentralized principles where services can function independently.
Figure 1.2 shows a typical decentralized architecture:
Figure 1.2: A typical decentralized architecture
The key aspects of a decentralized architecture include the following:
Understanding these key aspects is crucial when designing and implementing decentralized architectures. By leveraging the benefits of distribution, autonomy, and scalability, organizations can build robust and flexible systems capable of handling modern computing challenges.
In the next section, we’ll explore the principles of service boundaries and loose coupling.
Service boundaries and loose coupling are key principles in software architecture, especially in the context of microservices. Let’s explore these concepts in more detail.
Service boundaries refer to the logical or functional divisions within a software system, where each boundary represents a separate and independent service. In a microservices architecture, services are designed around specific business capabilities or bounded contexts. Each service is responsible for a well-defined set of functions, operations, or data.
The concept of service boundaries offers several benefits, such as the following:
Understanding and defining clear service boundaries are critical for successful microservices architectures. By focusing on modular and independent services, organizations can build scalable, maintainable, and adaptable systems that align with their business needs and support effective teamwork.
Loose coupling is a design principle that emphasizes reducing dependencies between software components or services. It allows components to interact with one another with minimal knowledge of one another’s internal workings. Loose coupling promotes independence, flexibility, and adaptability within a system.
Here are some key aspects of loose coupling:
By achieving loose coupling, systems become more modular, maintainable, and adaptable. This enables independent development and deployment, enhances scalability and resilience, and supports the seamless evolution of the software architecture over time.
Figure 1.3 shows the architecture of loosely coupled services:
Figure 1.3: Loosely coupled services
In Figure 1.3, each circle represents a component.
Service boundaries and loose coupling are closely related concepts in the context of building scalable and maintainable software systems. By defining clear service boundaries and ensuring loose coupling between services and components, organizations can create flexible, modular architectures that enable agility, scalability, and independent development.
In the next section, we’ll dive into independent development and deployment and polyglot architecture.
Independent development and deployment and polyglot architecture are some of the crucial abilities to succeed with microservices. Independent development and deployment allows teams to do the work autonomously. With a polyglot architecture, teams can use the best programming languages, frameworks, and so on, to deliver the software in its best quality.
Independent development and deployment refers to the ability to develop and deploy individual components or services of a software system independently, without tightly coupling them to other components. This approach is a fundamental principle in microservices and allows teams to work autonomously, focusing on specific services or functionalities.
Here are some key aspects and benefits of independent development and deployment:
Understanding the significance of independent development and deployment is crucial for embracing agile development practices and building scalable, adaptable, and maintainable software systems. Empowering teams to work independently enhances productivity, innovation, and collaboration, ultimately leading to successful outcomes in a rapidly evolving technological landscape.
Now, let’s take a look at the concept and key aspects of polyglot architecture.
Polyglot architecture refers to the practice of using multiple programming languages, technologies, and frameworks within a software system. In a polyglot architecture, different services or components may be implemented using different languages or technologies that best fit their specific requirements.
Here are some key aspects and benefits of polyglot architecture:
However, adopting a polyglot architecture also comes with challenges, such as increased complexity in terms of deployment, maintenance, and collaboration across teams with diverse technology stacks. Proper governance, documentation, and knowledge-sharing practices are necessary to ensure effective coordination and mitigate potential drawbacks.
Figure 1.4 shows a simple polyglot architecture:
Figure 1.4: A simple polyglot architecture
Overall, independent development and deployment, along with a polyglot architecture, empowers teams to work autonomously, leverage the best-fit technologies, and deliver software systems that are scalable, efficient, and aligned with the specific requirements of each component or service.
In the next section, we look at some additional crucial aspects: scalability, resilience, and independent data management.
Scalability and resilience are some key concepts in microservices to keep in mind while building robust and high-performing software. Also, in microservices, every service has its own database, so every data storage is independent.
Scalability and resilience are crucial aspects of building robust and high-performing software systems. Let’s explore these concepts in more detail.
Scalability refers to the ability of a system to handle increased workloads and accommodate growing demands without sacrificing performance. It involves the capability to scale up or scale out the system to ensure optimal resource utilization and responsiveness.
Here are key considerations for achieving scalability:
Scalability and resilience are closely interconnected. Scalable systems are often designed with resilience in mind, and resilient systems can better handle increased workloads through scalable architecture. By incorporating these characteristics into their designs, developers can create robust and reliable software systems capable of adapting to changing demands and providing a positive user experience even in challenging conditions.
Independent data management refers to the practice of managing data within individual services or components in a decentralized manner. In a microservices architecture, each service typically has its own data store or database, and the responsibility for data management lies within the service boundary.
Here are key considerations for independent data management:
Independent data management allows services to evolve and scale independently, promotes team autonomy, and reduces interdependencies between services.
Figure 1.5 shows the data management process:
Figure 1.5: Data management process
However, the data management process also introduces challenges related to data consistency, synchronization, and overall system-wide data coherence. Organizations should carefully design data management strategies and employ appropriate patterns and technologies to address these challenges while maintaining the benefits of independent data management.
In the next section, we’ll learn about APIs, communication, and CI.
API stands for application programming interface. It is a set of rules and protocols that allows different software applications to communicate and interact with one another. APIs define how different software components should interact, what data they can exchange, and what operations they can perform. CI is a common software practice that allows contributors from all over the world to contribute to one shared code repository.
APIs play a vital role in enabling communication and interaction between different components, services, or systems within a software architecture. APIs define how different entities can interact with one another, exchange data, and invoke functionalities.
Here are the key considerations related to APIs and communication:
APIs provide a way for developers to access the functionality of a system or service without having to understand its internal implementation details. They abstract the underlying complexity and provide a standardized interface that allows applications to request and exchange data in a consistent and predictable manner.
Figure 1.6 shows an example of a REST API:
Figure 1.6: A REST API
APIs play a fundamental role in modern software development, enabling seamless integration and collaboration between different systems. They provide a way to access data and services from external sources, allowing applications to extend their functionality and interact with a wide range of services and resources.
CI is a software development practice that involves frequently integrating code changes from multiple developers into a shared code repository. The key goal of CI is to automate the integration process and detect integration issues early.
Here are the key aspects of CI:
Additional reading
Jenkins: https://www.jenkins.io/doc/
Travis CI: https://docs.travis-ci.com/user/for-beginners/
GitLab CI/CD: https://docs.gitlab.com/ee/ci/
Figure 1.7 shows CI in action:
Figure 1.7: CI in action
The benefits of CI include early detection of integration issues, faster feedback cycles, improved collaboration, and reduced integration complexities. CI ensures that the software remains in a releasable state at all times, enabling teams to deliver high-quality software with speed, reliability, and reduced risks.
Microservices and Node.js are two powerful concepts that can greatly impact the development of modern software systems. Here is a summary of the key points to consider when exploring the combination of microservices and Node.js:
In summary, leveraging the power of microservices and Node.js can enable the development of flexible, scalable, and maintainable software systems. By embracing the modular nature of microservices and harnessing the asynchronous capabilities of Node.js, developers can build highly responsive, distributed applications that can adapt to changing requirements and handle complex workloads effectively.
In the next chapter, we’ll cover the core principles of microservices. We’ll dive into more details about microservices and its best practices while developing in Node.js.
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