Microservices - definition & overview

Microservices are an important innovation in application development and deployment. The microservices application architecture represents a new approach to software development where developers build the application as a set of modular components or services, each with a specific task or business objective. Each modular component is known as a microservice, and microservices can interface with each other using Application Programming Interfaces (APIs).

Microservices have gained popularity in recent years as an alternative to the more traditional monolithic software architectures that developers use. Software developers have adopted the microservices architecture and approach to improve the process of building, testing and delivering software. New paradigms in software development, such as continuous delivery (CD) and the use of containers, also support the microservices architecture model.

Software architecture refers to an application’s basic structure and organization from the developers’ perspective. Software developers implement a software architecture by defining the software elements required to facilitate the application's function, the relations between those elements, and the properties of the various elements and relations that make up the application.

There are many software architectures that developers may choose to design or implement, but the most frequently compared alternative to the microservices architecture is the monolithic software architecture. We can compare three types of software architecture to further understand how microservices are implemented.

Monolithic software architecture

Monolithic architecture is a software development method used to create a single-tiered application where the user interface and data access code are combined into a single program on a single platform. A monolithic software application is a single executable that can perform every task needed to deliver a specific function.

Monolithic applications are defined by the absence of modularity –– the entire system functions as a whole, rather than as a system of parts. Monolithic applications are also self-contained, meaning they exist independently from other computing applications and are typically not designed to communicate directly with other applications.

Service-oriented architecture (SOA)

Microservices are a specific example of service-oriented software architecture. SOA is a strategy or methodology for software architecture design where application components supply specific services to other applications over a network, using an agreed or specified communication protocol or APIs.

In the SOA paradigm, a service is defined as a functional unit of code that performs a specific task and can be remotely and independently accessed and updated by software developers. Services are self-contained to facilitate individual access and may consist of other underlying services working together to deliver the required task or function.

Microservices software architecture

Microservices are a variation of the existing service-oriented architecture model. Like in SOA, microservices applications use specific components to deliver services to other parts of the application over a network. The key difference between microservices architectures and SOA are granularity and the implementation of lightweight protocols to manage communication between services.

Granularity

Granularity is a key consideration in the software development process. In defining the microservices architecture, development teams should determine how many microservices are required to deliver an application and how large or complicated each microservice should be. Developers want to divide applications into more parts to increase modularity and enable continuous delivery. However, dividing the application into too many parts can result in excessive runtime overhead and complexity.

Lightweight protocols

Streamlined and simplified communication between microservices is necessary to ensure that an application composed of many microservices can execute tasks quickly. Software developers use lightweight communication protocols, such as HTTP resource APIs, to ensure that microservices running their individualized processes can communicate with each other efficiently. Some software developers use a new technology called "Service Mesh" to streamline and secure data transfer between microservices that make up an application.

Over time, the benefits associated with microservices have become more important to software developers as the community moves towards new ways of conducting development, including continuous delivery and DevOps. Key benefits of microservices architectures include enhanced scalability, availability, modularity and maintainability of the application.

Scalability

With microservices-based applications, individual components of the application can be scaled as necessary without the need to scale all of the components together (as in monolithic applications). When scaling a monolithic application, developers have no choice but to deploy multiple instances of the entire application with no regard for which parts of the application are generating the excess demand. Developers that use microservices architecture can scale demand for individual services on an as-needed basis, significantly reducing the overall resource cost associated with increased user-ship.

Availability

Applications designed in the microservices architecture benefit from increased availability and uptime. In a monolithic structure, the entire application will probably fail if any singular part of the code is broken. Because the microservices architecture is comprised of individualized and compartmentalized application components, the failure or deactivation of a single service does not cause the entire application to fail.

Modularity

Software developers that use the microservices architecture benefit from its modularity. A modular application consists of individual components that can be selectively deployed, modified, or toggled on/off. An additional benefit to microservices is that they can be re-packaged and redeployed into new applications where the same function is required. This means that a software development company can re-purpose individual code modules for new applications without needing to rewrite them.

Maintainability

Applications that use the microservices architecture are easier and less costly to maintain than those that employ monolithic application architectures. If an individual microservices needs to be updated, it can be toggled off, updated and redeployed without making the entire application unavailable.

Each microservice is connected to a single business function, containing only a fraction of the entire application's code. This makes it easier for developers to trace a known error back to the relevant source code, more easily understand what the code is doing, and fix the problem without negatively impacting other microservices.

The complexity of microservices-based applications has meant that DevOps and software development have been forced to make compromises by splitting visibility across tools, settling for insecure platforms, or leaving data out entirely because of the licensing costs of analytics. Sumo Logic provides an observability solution for all of your data -– performance metrics, logs and events, and distributed transaction tracing –– on a highly scalable, secure, cost-effective analytics platform.

To resolve issues quickly, engineers need to be able to pinpoint problem areas, drill down, and explore the data with minimal restrictions. Modern observability tools have to empower engineers to leverage their expertise and find the unknown unknowns.

The Sumo Logic Microservices Observability Suite is built on the experience of managing real-time operations for a decade. This includes coverage for the data needed and the ability to make the best connections and highlight problems.