The tech industry is rapidly evolving to cater to the diverse needs of businesses and individuals. Creating an application that not only meets client expectations but is also easily scalable and ensures optimal availability relies heavily on the architecture of the software being developed. In this guide, we explore microservices as a promising application architecture that can enhance the overall quality of modern apps. When deciding between monolithic and microservice architectures, several factors such as team management, performance monitoring, and quality assurance must be considered. Continue reading to learn more about the advantages and disadvantages of microservices and when to utilize them to ensure your software achieves high performance.

What is Microservices?

The microservice architecture, intended to maximize maintainability, testability, deployability, and loose coupling, has gained prominence in the software industry. While it offers advantages, it is not a universal solution. This architectural approach involves breaking down applications into individual components, each functioning as an autonomous entity. The key tenet is to prevent service duplication or shared data storage, thereby facilitating abstraction and isolation within the system. When considering high-level microservices architecture, there are primarily two types to consider:

Stateless Microservices

This is the most prevalent scenario where session state is not maintained between requests. These microservices are well-suited for distributed systems, resulting in simpler and more maintainable systems. In the event that a service is removed, the overall process is unaffected.

Stateful Microservices

These microservices store session information to facilitate communication between multiple microservices. While the state adds complexity, there are instances where it is necessary - such as situations requiring multiple database round trips.

Considering Microservices vs. Monolithic Architecture

There are various reasons why someone might consider transitioning from a monolithic architecture to microservices. Those in the process of decomposition struggle with the transition, while others starting from scratch are concerned about data consistency. Before making a decision, it is important for application owners to evaluate if the current monolithic architecture is truly causing issues. During the initial phases of a project, a monolithic architecture may be more appropriate due to the complexity of building microservices and the associated infrastructure requirements. If time is of the essence, opting for a monolithic approach may be the more efficient choice. Some challenges encountered during the development of microservices include:

Operational teams facing difficulties

Unlike in a monolith where all application logic is contained within a single codebase, managing multiple microservices can be challenging for operational teams. Monitoring and managing the application as a whole becomes more complex due to the distributed nature of microservices.

Increased complexity in monitoring

Microservices architecture results in a less stable environment with numerous dependencies, making it harder to monitor the application effectively. Utilizing Docker containerization can provide a layer of abstraction that offers more control over processes.

Limited testing scenarios

Testing scenarios are restricted as it can be challenging to anticipate all possible interactions between services. This limitation can make testing, writing test cases, and implementing changes more difficult in a microservices environment.

Balancing Act of Scalability and Versatility in Microservices

The microservices architecture offers great flexibility, but scaling within this framework presents a significant challenge. Unlike traditional monolithic applications that can easily handle increased demand by adding more resources or instances, scaling microservices involves a multi-stage process. The initial hurdle is pinpointing which components are experiencing heightened demand. Once identified, any modifications made to these components must be carefully implemented to ensure compatibility with the overall system. Thus, there are three key factors to consider when scaling microservices:

Resource Allocation

The finite hardware properties of your systems, such as RAM and CPU specs, present a challenge when it comes to allocating resources to services. Prioritizing resources effectively can be difficult, but it is essential to identify the parts of your application with the highest demands. For example, if your application caters to both businesses and individuals, businesses may need to be prioritized over individuals.

Performance

Monitoring and measuring the overall performance of your application can be complex, as services operate and handle requests independently. Utilizing an application delivery controller can be beneficial for tracking and optimizing end-user performance.

Upgrades

When scheduling upgrades for your system, it is crucial to avoid upgrading all services simultaneously during maintenance periods. While individual upgrades can be time-consuming, upgrading related services together in a practical and systematic manner can streamline the process. When considering scaling in microservices, it's important to look beyond just the individual system when a service is upscaled. Instead, the service should scale both independently and holistically as part of the overall system.

Microservice architecture is a service-oriented application architecture that prioritizes decentralization to achieve high testability, efficient management, independent versioning, and deployment. There are two main types of Microservices: stateful, which involve storing session state during interactions such as multiple database queries, and stateless, which do not maintain any state. Despite these distinctions, all Microservices share common characteristics including decentralization, fault tolerance, versioning, and hidden implementation details. When scaling Microservices, it is essential to carefully consider resource allocation, proper timing for updates, and performance in order to successfully upscale and prevent application degradation.

When contrasting monolithic architecture with microservices, it is essential to recognize the unique benefits inherent to each architectural approach.