Everything About Microservices You Should Know

Software developers are increasingly embracing microservices architecture, a server-side approach characterized by self-sufficient, interconnected services. Microservices architecture permits different teams to independently develop various services. It ensures the main workflow remains uninterrupted – a degree of adaptability seldom found in other architecture models. Moreover, the emerging concept of multi-runtime architecture is drawing increased interest. In this blog, we’ll delve into both microservices and multi-runtime architectures, highlighting their advantages and drawbacks when contrasted with traditional monolithic architecture.

What Exactly Are Microservices?

Microservices represent a software development technique where applications are constructed as a suite of small, independent services, each dedicated to a particular function and communicating through well-established APIs. This strategy facilitates application scaling and accelerates the development cycle. 

The advent of microservices architecture was driven by the need to overcome the constraints associated with traditional monolithic architectures. Traditional monolithic architectures are often rigid and less scalable, failing to satisfy numerous contemporary demands. In a monolithic framework, different processes are tightly integrated and function as a single cohesive unit. So, a demand spike in a specific process requires scaling the entire system. Since the application grows and its codebase enlarges, it becomes progressively more challenging to add new features or improve the monolithic application. In addition, monolithic systems pose a greater threat to the overall application’s uptime due to the interdependence and tight coupling of processes, where a fault in one process can lead to significant, widespread issues.

Why You Should Use Microservices Architecture?

Now, let’s delve deeper into some key features of microservices architecture!

#1 Modularity

Central to the microservices approach is modularity. This entails breaking down a software application into smaller, self-sufficient units, each tasked with a distinct function or responsibility. Known as services, these units function independently and interact with others through APIs. This modular design boots adaptability, allowing for individual services to be modified or expanded without affecting the whole system.

#2 Decentralization

Microservices embody decentralization in terms of both data handling and control. Contrary to the centralized data management in monolithic structures, microservices enable each unit to possess its data logic. Furthermore, microservices foster more robust and flexible data handling. Decentralized control allows teams to autonomously oversee their specific services, which accelerates development timelines and minimizes the need for extensive coordination.

#3 Scalability

Scalability stands out as a key benefit of microservices. Given their autonomous nature, services can be scaled out (by multiplying instances of the same service) based on demand. This feature of microservices is essential for managing fluctuating workloads and ensuring the application remains performant under increased demands.

#4 Independent Deployment

Microservices architecture permits the independent deployment of individual services. Consequently, enhancements, fixes, or new functionalities can be rolled out to a particular service without necessitating a pull application redeployment. This facilitates a more streamlined continuous deployment process, lowering the risks and costs associated with deployment activities.

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What Does Microservices Architecture Consist Of?

In addition to services, the microservices architecture incorporates components such as APIs, containers, elements of Service-Oriented Architecture (SOA), and cloud-based resources.

#1 APIs

APIs (Application Programming Interfaces) serve as essential connectors within microservices, facilitating communication between various services by handling requests and responses that drive the application’s operations. A pivotal component in this framework is the API gateway, which directs API calls between internal services and external clients while managing aspects like security, monitoring, and load distribution. This arrangement allows microservices to maintain their agility and efficiency.

#2 Containers

Containers are self-contained, executable software packages that include everything needed to run independently, such as code, runtime, system tools, and libraries. They operate in isolation from other software entities, enabling multiple containers to coexist on the same system. Typically, in a microservices setup, each service is encapsulated within its own container, which can be hosted on the same or interconnected servers.

Containers share the host system’s OS (Operating System) kernel, offering more efficient resource utilization and higher deployment density than traditional virtual machines (VMs). This efficiency, along with their quick startup and shutdown capabilities, makes containers particularly suited for the lightweight and modular nature of microservices. Container orchestration tools like Kubernetes further simplify microservices management by automating tasks such as container deployment, scaling, and recovery.

#3 Service-Oriented Architecture (SOA)

While sharing similarities with microservices, SOA is a distinct concept centered on integrating reusable software components via a unified interface, often facilitated by an enterprise service bus. This setup enables different services to interact with minimal understanding of each other’s internal mechanisms, typically using XML (Extensible Markup Language) and SOAP (Simple Object Access Protocol) for communication. SOA outstands in environments requiring transactional and reusable services but may not be as flexible for new developments or rapid deployment cycles, areas where microservices outstand.

Microservices can be viewed as an evolution of SOA, focusing more on application-level functionality rather than SOA’s broader enterprise scope. In some instances, SOA principles can complement microservices by promoting interoperability and reuse across an organization’s IT landscape.

#4 Cloud Computing

While containers and microservices can operate in various environments, they thrive in cloud-based infrastructures designed for large-scale, integrated services and dynamic scaling. Public clouds are particularly well-suited for microservices, offering scalable resources on-demand along with essential microservices tools like orchestration engines and API gateways, all under flexible pricing models. These cloud features are crucial for building and maintaining a robust microservices ecosystem.

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How Can We Migrate From Monolith to Microservices?

Migrating from monolith to microservices involves several key steps. Let’s check below!

Step 1: Evaluating the Current Infrastructure

Before embarking on a migration to microservices, it’s critical to evaluate your current setup:

• Business Objectives: Clarify the goals you hope to achieve through microservices, such as enhanced development speed, improved availability, innovation, or scalability/
• Service-Level Agreements (SLAs): Align SLAs with your deployment infrastructure and assess the SLAs of potential cloud service, particularly for serverless options.
• Infrastructure Assessment: Given the independent nature of microservices, evaluate your deployment tools and strategies, including how to handle deployment failures.
• DevOps Readiness: Ensure your teams are proficient in DevOps practices and have the necessary technology to support a microservices architecture’s agility.
• Security Measures: Microservices demand strong security protocols. Review your strategies for authorization, authentication, API security, communication safety, and network defenses.

Step 2: Identifying Services for Migration

Determining which parts of your application to migrate first is important. Start with peripheral services that have fewer dependencies, making them easier to transition into microservices, such as customer-facing functions like order processing or notifications.

Also, prioritize areas where microservices can address specific challenges, like resolving performance bottlenecks.

Step 3: Data Strategy

In microservices, each service should ideally have its database, but splitting a monolithic database can be complex. You should consider these data management strategies:

• Database-Per-Service

In microservices frameworks, the database-per-service strategy is pivotal. This assigns a distinct database to every microservice to guarantee data segregation and reliability, thereby reducing cross-service disruptions.

Yet, this method introduces challenges in integrating and querying data between services, requiring robust communication protocols and well-established interfaces. Meticulous oversight of database changes is crucial to avert any impact on services. Employing suitable approaches, this design greatly enhances the scalability and resilience of microservices systems.

• Saga Pattern

The Saga pattern is essential for maintaining data coherence in transactions within distributed microservice systems. Instead of conventional database transactions, it breaks down the process into discrete, reversible steps. Should any segment encounter failure, the pattern triggers corrective measures to preserve data integrity. This distributed approach boosts the system’s robustness and ability to scale, albeit demanding meticulous coordination and management of failures.

• CQRS (Command Query Responsibility Segregation)

CQRS addresses the challenges of concurrent data modifications and retrievals within a service by dividing the operations into writing (commands) and reading (queries). This separation allows services to specialize and scale according to their primary functions. However, CQRS introduces added intricacy, especially in maintaining data uniformity across services. It’s crucial to weigh the advantages and disadvantages carefully against the system’s unique needs before adopting this approach.

• Event Sourcing

Event sourcing records every change in an application’s state as a series of events, instead of merely capturing the latest state. This method enables the reconstruction of the system’s state by replaying these events.

Within a microservices architecture, this approach allows each service to maintain an autonomous historical record, promoting independence and reducing dependencies. The events serve as a detailed log, beneficial for analytics, auditing, and more. Although event sourcing is advantageous for rectifying errors and managing issues, it necessitates meticulous management of event versions and the scalability of event storage.

• API Composition

API composition plays a key role in aggregating data from various services. When microservices each handle unique data sets, querying them directly from the client side can become complex. This approach employs a middleman, like an API composer or aggregator, to merge data from different services into a unified response. This streamlines the querying process for clients and enhances the efficiency of data 

• Shared Database

The Shared Database anti-pattern occurs when several microservices directly interact with the same database, bypassing APIs or messaging frameworks. This method undermines the independence of each service and endangers data accuracy. Moreover, it can lead to security weaknesses and hinder the system’s progression, as minor database modifications become complex, collaborative efforts.

Step 4: Enhancing Interservice Communication

In developing the communication strategy among services, it’s critical to structure the interactions thoughtfully:

• Direct Communication: This method features a straightforward, one-to-one exchange where each client request is handled by a single service.
• Collaborative Processing: In this approach, multiple services work together in a one-to-many relationship to address each request.

Additionally, communication can unfold in two primary modes:

• Synchronous: This mode involves immediate, direct interactions between the client and service, with the client awaiting a prompt reply. This immediacy can sometimes result in brief delays.
• Asynchronous: Here, the client does not expect an instant answer. This setup may employ a message broker, enabling services to post and subscribe to messages that they can address at their leisure.

Wherever feasible, adopting asynchronous communication is recommended from a strategic standpoint, as it boosts the overall resilience of the system and improves its capacity to manage varying loads.

Step 5: Testing and Deployment

The testing approach in a microservice architecture differs from the conventional single-unit testing of monolithic systems. In a microservices setup, the application necessitates a variety of testing strategies, including:

• Unit Testing: Evaluate the functionality of each service.
• Component Testing: Checks the functionality of larger parts or modules within the system.
• Integration Testing: Verifies the proper interaction and cooperation between different services.
• Performance Testing: Measures how well the system responds and remains stable under different scenarios.
• Contract Testing: Reviews the interactions and exchanges between the user and the service.
• End-to-End Testing: Assesses the comprehensive performance of the entire application from start to finish.

Each testing method ensures that the microservices function both as standalone units and collectively. Yet, testing in a microservices system presents unique hurdles. A fault in one service might impact others, making it difficult to pinpoint the source of the problem. The diverse range of communication methods and protocols necessitates expert knowledge. Moreover, the need to examine numerous endpoints and implement automated tests requires scriptwriting skills and a solid understanding of automation technologies.

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Some Limitations of Microservices

Deploying microservices, in contrast to monolithic architectures, introduces a more complex set of challenges, including:

• Handling dependencies between components becomes more challenging.
• Monitoring the application’s overall performance is less straightforward.
• Debugging becomes a more complex task.
• Integration testing requires more effort, including thorough testing of each API in sequence and the performance of the system as a whole.
• Ensuring high availability across multiple services often incurs increased costs.

Summary

Microservices have revolutionized the field of software development, presenting a groundbreaking shift away from the long-standing monolithic architectural approach. This modern strategy provides developers with a more effective way to create, oversee, maintain, deploy, and scale diverse applications, leveraging the power of cloud technology.

Furthermore, whether you are seeking to optimize your app which has the application of microservices, unlocking your business potential with AMELA’s wide range of IT consulting and solutions.

Contact us through the following information: 

• Hotline: (+84)904026070 
• Email: hello@amela.tech 
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Editor: AMELA Technology