Microservices are a key part of modern application delivery. From social networking apps to online retail to streaming video, almost every major software application today is built using microservices. But what are they? And how exactly do they improve software? Let’s examine their real-world benefits and also discuss the potential disadvantages of using microservices.

Service-oriented architecture (SOA) is the evolution of monolithic architecture in application development. SOAs precede microservices architectures and separate the application into smaller, more manageable pieces. These pieces are called services, and they are designed to communicate with each other using messages. Services are also designed to be independent of each other so that they can be replaced or upgraded without affecting the rest of the application.

SOAs are often used in web-based applications where they provide a way to separate business logic from presentation logic and data access from data storage.

Service-oriented architecture can be used to build applications that are easier to maintain and scale. It also helps in creating more modular and flexible applications.

The main benefits of using service-oriented architecture are:

• Easier maintenance and scaling

• More modular and flexible applications

• Reduced development time

An enterprise service bus (ESB) is a software application that provides a central point for inter-process communication. It is often used in the context of SOA to provide services to other applications.

The ESB allows an organization to build, deploy, and manage SOA solutions with ease. It manages, monitors, and coordinates all the services in an organization’s IT infrastructure.

This type of technology is gaining popularity, as it can be used for internal as well as external communication. Some examples of use cases are:

• Data integration
• Service discovery and registration
• Service orchestration
• Event notification and logging

Microservices architectures are the new kid on the block when it comes to application development. Though very similar to SOA, a microservices architecture was created to fill in the gaps left by its predecessor. This does not mean one is inferior to the other, but it really boils down to the use case. SOAs were designed to meet the needs of enterprises, which means that despite the services being separate, the systems were designed to be interdependent. The idea is to be able to reuse services for other parts of the business.

Microservices, on the other hand, are truly independent. A microservices architecture pursues data duplication versus data sharing, so there’s no impact to performance. Microservices also eliminate the need for an ESB.

The rise of software as a service (SaaS) apps and the widespread adoption of containers have created a growing demand for more efficient development methods. In response, applications themselves are changing — from monoliths that do many things well to distributed collections of independent services that address specific functions.

Some major benefits that microservices offer include:

1. Improved reliability

Each microservice performs a single logical function within the greater application. For this reason, developers provide updates that are isolated to just the service that needs the changes. Typically, there is a well-defined interface between microservices within an application. As long as that remains intact, the application can remain functional even as changes are being made in real time.

2. Reduced development time

Individual services provide a well-defined set of functionality for each component that can be built around specific requirements. This makes it simple to horizontally scale development efforts across multiple teams. And it makes it easier to quickly update or add new features.

3. Increased application functionality

Development teams are able to create individual components that can be reused in multiple contexts. They can create new applications that accommodate a broader array of users and deliver deeper functionality without duplicating efforts.

4. Loosely coupled resources

The architectural style allows each microservice to serve multiple applications and interfaces, reducing the number of custom implementations for developers. The independent design also means that changes to one microservice won’t impact another. However, this also means that load balancing is required to manage requests, both on the client and server sides.

Ultimately, microservices enable developers to focus on their applications’ specific functionality and avoid development issues that can arise from coupling multiple applications together. By breaking down an application into manageable pieces, developers can take advantage of new software development techniques, such as automated testing, to deliver high-quality results more quickly than ever before.

Microservices are also easier to maintain because the associated services are self-contained. All dependent services run on their own platform with separate management tools, providing more consistency. It also makes managing the entire collection of related components easier than if they were embedded in a larger monolithic application.

When developing enterprise applications, pursuing a microservices architecture is clearly superior to a monolithic architecture. But this doesn’t come without potential problems. There are some notable disadvantages to using microservices.

1. Potential for undefined microservices boundaries

If documentation and requirements are not well defined, it can be difficult to manage service dependencies and the overall application functionality. However, design patterns, also referred to as architecture patterns, are reusable solutions that can be used to bypass common issues.

2. Security vulnerabilities

Network security can also be a potential drawback with microservices. Each service is deployed independently and often has its own set of security controls. Consequently, it’s not always clear who has access to which component, and the potential for malicious activity increases as a result.

Calls between microservices are often API based, and as a result are made via network transport. The way these services communicate could potentially be an attack vector for cybercriminals. Developers have to use care when choosing the platforms and frameworks they will use to deploy their microservices. This also includes the configurations that will be used to secure them.

3. Complexity and difficulty to maintain code

The most significant disadvantage is that they are difficult to scale and maintain. This is because each service needs to be managed separately and independently from the other services in the system.

4. Errors that can be hard to fix

Given the granular and distributed nature of microservices, remediating errors can be tough. Unlike service-oriented or monolithic architecture, adjustments to one area of a microservices architecture do not affect the rest. This means your staff could end up spending more time identifying and troubleshooting issues.

There are a number of different deployment options for microservices. Typically, developers choose to deploy their microservice as a container-based service on a dedicated host. Or they may choose to use a platform as a service (PaaS) provider such as Akamai Cloud.

Using a PaaS provider offers a number of cloud native benefits — including the ability to easily scale services, and removal of the need to maintain the host. However, developers need to consider the risks that are associated with relying on an external cloud service provider. This option carries more risk than deploying their own infrastructure.

To ensure the security of microservices, developers should:

• Use HTTPS for encrypted data transmission
• Employ firewalls to protect services
• Implement logging mechanisms to monitor suspicious activity
• Secure API communication, as APIs often handle the communication between microservices and back-end services

Distributed systems: Microservices are inherently designed for distributed systems, in which each service can be hosted and scaled independently across different servers or even different data centers. This decentralization ensures that individual services can continue to function even if one component fails, enhancing resilience.

Automation in microservices: Automation is critical in microservices-based architectures. Tasks such as deployment, scaling, and monitoring are often automated to ensure continuous integration and delivery (CI/CD). Tools like Kubernetes and Docker automate the orchestration and scaling of microservices, making it easier to manage distributed systems.

Microservices also support infrastructure as code (IaC), in which configuration and infrastructure management are automated through code. This allows for consistent and repeatable deployments, reducing the chances of human error.