Microservices Architecture: What It Is, How It Works, and Its Advantages

Digitization has caused a massive shift in what customers expect from digital services, prompting businesses to migrate away from inflexible monolithic systems and embrace modern microservices architecture.

And this is happening at scale. In a report by Gartner, 74% of organizations said they’re already using microservices architecture—and 23% plan to do so. That’s over 90% of businesses.

But are you one of them?

In this guide, we’ll discuss what microservices architecture is, its main components and characteristics, and why it offers crucial advantages over other types of architectural approaches.

What is microservices architecture?

Microservices architecture is a modern architectural approach to software development in which applications are built as a collection of small, independent components. 

This means that every individual service has a unique, task-oriented business capacity. Each service communicates over the network using simple representational state transfer (REST) APIs, message queues, and other lightweight protocols to deliver agility and modularity to DevOps. 

And, each component can be developed, deployed, scaled, and maintained independently. This makes applications more flexible, less susceptible to failure, and supportive of continuous integration and continuous deployment (CI/CD).

Here is a microservices architecture diagram to illustrate the typical structure of microservices:

Image sourced from Medium

Microservices directly resolve the limitations of traditional, monolithic architecture—an approach that deploys applications as large, tightly coupled units that are interdependent within a solitary codebase.

Main components of microservices architecture

Microservices-based architecture consists of several key components, including:

• Microservices: The main components are the microservices themselves—a set of small, loosely coupled services that function independently, each with specific capabilities that encapsulate unique business logic.
• API gateway: An API gateway creates a centralized entry point for external client communications. They manage a variety of requests including filtering, routing, load balancing, caching, authentication, and SSL termination. 
• Communication protocols: Microservices rely on communication protocols to achieve smooth interaction between client-side and server-side applications, systems, and services. Protocols like HTTP, REST, and gRPC facilitate synchronous communication. Asynchronous communications are typically delivered via messaging queues and event buses.
• Service registry and discovery: A service registry is a virtual database that manages microservices details like addresses, locations, and metadata. API gateways use service registries to discover services and route requests. This enables microservices to locate and communicate with each other dynamically within distributed environments.
• Containers: Many microservices architectures package microservices and their dependencies into semi-isolated containers, facilitating more efficient orchestration, service discovery, and security.
• Load balancing: A load balancer evenly distributes incoming traffic. It directs network and application requests across multiple service instances to ensure that no service becomes overloaded with requests. As well as boosting performance and minimizing downtime, load balancing enhances fault tolerance and scalability.
• Monitoring and logging: Microservices architecture integrates application logging and monitoring tools to achieve full visibility into the distributed environment. It enables accurate issue diagnostics, health and behavioral analysis, and visualization.

Characteristics of microservices architecture

Microservice-based architecture exhibits key characteristics that set it apart from other architectural approaches. Let’s take a look at the main four characteristics that underpin microservices:

Independent components

The defining characteristic of microservices architecture is its loosely coupled components. Each service is a separate codebase that can be entirely built and maintained independently, without compromising the other services.

Decentralized operations

Microservices decentralize operations, specifically governance and data management. 

Using a decentralized governance model, teams can make technological, design, and implementation decisions in alignment with the unique needs of the service they manage. In doing so, they can leverage individualized solutions and tools, whether created in-house or supplied by a third party.

Data management is also decentralized as each service is responsible for managing its own database. This provides autonomy by ensuring that the best data storage, control, and management tools and strategies are used for each service.

Fault tolerance

Redundancy and resilience are built into the core of microservices architectures, ensuring continuous operation in the face of failures or faults. 

In traditional monolithic architectures, services are so tightly coupled into a unified, interdependent system that if one component fails, it can trigger a chain reaction of failing components. Not only does this lead to cascading outages and full-system downtime, but it can be difficult to pinpoint the root cause of the failure, slowing down error handling and recovery.

Microservices all operate independently. Should one component fail, patterns and techniques like circuit breakers, bulkheads, timeouts, and retry can be rapidly and autonomously executed to halt requests, isolate faulty services, and reroute messages to healthy components. 

This inherent resiliency prevents service failures from cascading, minimizing disruptions and creating more stable, reliable systems.

Technology and language agnostic

Unlike other architectural approaches, microservices architecture is completely independent of specific technologies, languages, or platforms. 

This means that different services can be deployed on different platforms, built using different technologies, and programmed using different languages. 

As a result, microservices have a greater degree of flexibility. Developers can choose the most appropriate tools and languages for the specific use case of the service. And, all of these services can still communicate regardless of their language or tech stack.

Design patterns for microservices architecture

Microservices design patterns are reusable building blocks that developers can use to generate autonomous, independently deployable services. This mitigates the challenges of application design, reducing complexity, enhancing scalability, and increasing the velocity of application releases.

But which microservices architecture patterns might you use? The answer will depend on your specific business needs. 

There are lots of patterns available, each serving different use cases and coming with their own pros and cons:

• API gateway pattern: The API gateway pattern is like a reverse proxy service. It acts as a single entry point for client requests, routing them to the appropriate microservice and aggregating responses to enable mass communication. API gateway patterns shield clients from architectural complexities and offload authentication.

Image sourced from microservices.io

• Circuit breaker pattern: In the event of a service failure, a circuit breaker pattern will halt requests to the damaged services and/or reroute the message, preventing requests from hanging indefinitely. This prevents failures from cascading through your application.
• Database per service pattern: This example of microservices architecture pattern helps you integrate independent data management into individual service design. Each service has its own database that aligns with its unique needs, improving scalability and preventing points of failure from affecting the whole system.
• Strangler pattern: The strangler pattern incrementally replaces monolithic architecture with microservices, allowing for gradual modernization that prevents disruption to user experiences.
• Bulkhead pattern: A bulkhead pattern isolates services and compartmentalizes resources so that if one service fails, the others can continue to run as normal. 
• Saga pattern: Developers use the saga pattern to maintain the data consistency of ecommerce transactions that occur across multiple microservices. Saga manages distributed transactions by coordinating a sequence of local transactions. If a transaction fails, the action is rolled back.
• CQRS pattern: A command query responsibility segregation (CQRS) pattern separates data store read and write operations into two distinct parts; “commands” and “queries”. Commands (write operations) handle create, update, and delete requests. Queries (read operations) retrieve data and generate projections.
• Event source pattern: This pattern records changes to the application state as a sequence of events, providing visibility into historical states that can be used for audit trails and reconstructions.

Microservices architecture advantages over other approaches

94% of businesses currently using microservices agree that it is extremely important or very important to their operations, according to Statista. But can you get by using traditional architectural approaches, like monolithic architecture or service-oriented architecture?

Data sourced from Statista, image created by writer

Let’s look at the benefits of microservices architecture compared to other approaches to see why it’s superior:

Monolithic vs microservices architecture

To describe something as “monolithic” is to say that it’s “large, united, and difficult to change”.

Monolithic architecture is a traditional software design model. Large applications are constructed as single, self-contained units, where all components and functionalities (such as the database layers, business logic, and authorization) are tightly coupled together within one codebase. In this single-tiered application, the solitary codebase is responsible for handling multiple functions. 

It’s relatively easy to develop and deploy, so it can still suit some smaller programs. However, the disadvantages significantly outweigh these benefits, which has caused a monumental shift away from the legacy approach toward more modernized microservices.

For example, software built on monolithic architecture can only work if all components (and associated components) are available. If one service goes down,  it can cascade at speed because all of the other components are reliant on it, ultimately bringing down the entire application. 

Monolithic architecture is also much less scalable and adaptable. If you want to update any component or integrate it with a new technology, you’ll have to perform full-scale updates across your entire system and redeploy the application. This is complex, time-consuming, and leads to downtime, eliminating the possibility of continuous integration and deployment.

To summarize, here’s a table that illustrates monolithic vs microservices architecture to highlight the key advantages of the latter:

Service-oriented architecture (SOA) vs microservices architecture

Service-oriented architecture (SOA) is another software development model that uses semi-loosely coupled software components to build applications. Each service can communicate to meet business objectives via an enterprise service bus (ESB), which is the common communication pattern between all components. 

So, exactly what are the differences between service-oriented architecture and microservices? 

Fundamentally, SOA is an enterprise-level approach, whereas microservices is an application-level approach. In SOA, components are designed to have full business capabilities, with resources being shared and reused across the entire business. 

Because of this, components aren’t fully decoupled, causing core interdependencies that limit vertical scaling, resource optimization, and agility.

This isn’t the same as microservices, where software components are smaller and specialized to complete one specific task. 

As a result, they don’t have the same interdependencies as SOA services, allowing for granular scaling, continuous deployment, and increased fault tolerance—all things that are lacking in SOA.

For example, SOA uses a centralized ESB to coordinate and control all communications. If the ESB fails, every service will be affected, posing serious risks to availability. Microservices eliminates this single point of failure as all components are completely independent.

We can think of microservices as the modernized iteration of SOA. Where SOA aims to resolve the limitations of monolithic architecture, microservices aims to resolve the limitations of SOA. 

We can see proof of this by referring back to Gartner’s microservices report, which found that migration to microservices led to reduced development lifecycles for 63% of respondents, along with increased agility, better scalability, and enhanced CI/CD support:

Image sourced from Gartner

Alt text: Graphic showing the key benefits of microservice architecture, including deployment speed, agility, scalability, support for autonomous software teams, and adherence to CI/CD

Real-world microservices architecture examples

What does microservice architecture look like when it’s applied in real-world settings? Here are three examples of microservice architecture providing significant business benefits:

Credicorp Bank

Credicorp Bank migrated from services oriented architecture to microservices to overcome technological challenges presented by their legacy architecture.

Specifically, they wanted to develop innovative financial services to keep up with customer needs and develop a 360° customer view. However, they were unable to modify with agility due to their highly coupled architecture and unnecessary connection layers.

Leveraging the OpenLegacy platform, Credicorp successfully migrated to a microservices architecture. They developed and deployed 27 new APIs with 70+ microservices in just ten weeks, reducing their development cycle by 65%.

And, by decoupling services and eliminating integration layers, they unified siloed data sources and gained a holistic, 360° view of customer data, boosting performance by 300%.

Farmacias 

The pharmaceutical company Farmacias also underwent a strategic shift from SOA to microservices. The goal? To reduce development and data integration lifecycles while enhancing digital services, products, and transactions for customers.

Leveraging a customized OpenLegacy connector, Farmacias were able to extract and analyze metadata from their legacy system databases and generate business-logic microservices and APIs. 

With a reduced reliance on ESBs, Farmacias got to work building a microservices architecture that supported the creation of next-gen digital services and products.

Bank Hapoalin

Bank Hapoalin were on a mission to accelerate application development and deployment lifecycles so they could respond to business requirements with steadfast agility. But there were two huge obstacles in the way—their rigid monolithic architecture and reliance on heavily customized ESBs.

So, Bank Hapoalin turned to OpenLegacy. Using the platform’s pre-built connectors, direct legacy-system connections, and automated microservices generation, they were able to expose the mainframe and expedite microservice generation at scale. 

Instead of taking months to deploy new services, Bank Hapoalin can now create five microservices every two weeks. Unhindered by complex middleware, they can quickly respond to customer needs with innovative digital products.

Microservices architecture can help you stay agile in a digitized world

Microservices architecture resolves the shortcomings of monolithic systems and SOA. It can help you develop next-generation services that are independently deployable, highly scalable, and tech/language agnostic. All of which enhances agility and supports CI/CD in a landscape that demands digital innovation. 

An abrupt shift to microservices architecture can come with added complexities, but there’s no need to migrate all at once. 

An incremental microservices approach can put you on the path to digital modernization, reducing the costs, risks, and complexities of moving from monolith to microservices.

Discover how to drive scalability, innovation, and efficiency with OpenLegacy’s microservices approach.