A Comprehensive Guideline To Microservices Architecture

Your organization may still be plagued by applications developed in the monolithic era when centralized multi-tier architectures created entire applications in a single code base.

This client-server model was an excellent choice in an era when the desktop ruled IT. However, with the rise of mobile devices and the cloud, back-end data must always be available on a wide range of devices. Monolithic architectures require the entire application to be updated whenever changes are made, which reduces functionality. Each time you add or try to support a new context, you introduce the potential for new bugs. Even worse, because you’re tied to a single codebase, you can’t scale up specific features or services, and you have to scale up your entire application.

In microservices, code is split into independent services and run as separate processes. Outputs from services are used as inputs to other services in the orchestration of independent communication services. Microservices are especially useful for businesses that don’t anticipate what kind of devices their applications will support.

With microservices, companies can develop applications that provide a consistent user experience across platforms:

• Website
• Mobile
• IoT

Netflix, PayPal, Amazon, eBay, and Twitter are just a few examples of companies using microservices today.

What is Microservice?

A microservice or microservices architecture is a cloud-native architectural approach in which an application is composed of many small, independently deployable components (services). The characteristics of microservices are as follows:

• Each microservice has its own technology stack, including databases and data management models.
• Microservices use REST APIs, event streaming, and message brokers to communicate with each other.
• The boundaries between services are often referred to as context boundaries.
• While much of the discussion about microservices revolves around architectural definitions and characteristics, their value can be understood more generally through the simplest business and organizational benefits.

These benefits include:

• Easier Code Updates: You can update your code more easily, and new functions and features can be added without affecting the entire application.
• Flexibility in Technology Stacks: Teams can use different stacks and programming languages for each component.
• Independent Scaling: Components can be scaled independently of each other, reducing waste and costs associated with scaling the entire application due to one overloaded function.

What is a Monolithic Service?

A monolithic system is constructed as a single unit or block. This is the approach taken in building monolithic applications, where APIs, databases, services, load balancers, and other components act as a unified entity embedded within a single application framework. On the other hand, microservices separate each aspect of an application into independent services that communicate through APIs. Individual teams are typically responsible for each of these services.

Have you ever worked on a project with the following characteristics?

• Released every few months.
• Encompassing a wide range of features and functions.
• Involving a large team size.
• Posed challenges in debugging.
• Faced difficulties in adopting new technologies.

These characteristics align with those of monolithic applications. Monolith applications are usually quite extensive, often exceeding 100,000 lines of code, and sometimes even surpassing 1 million lines.

If you construct your software using a monolithic architecture (single block), all modules (such as views, business logic, databases, and reports) are consolidated into a single, extensive project. During deployment, this code block is deployed to the server and configured to run.

While the monolithic architecture is straightforward, it facilitates coding and works well for small systems, its limitations become evident when dealing with complex software. Modules are tightly bundled together, meaning that upgrading a single module necessitates redeploying the entire codebase. Consequently, end users might experience a loss of system functionality during deployment. Additionally, if your system serves a substantial number of users, server upgrades might become necessary.

Challenges posed by monolithic applications include:

• Limited application scalability and adaptability to change.
• Complex interdependencies between applications lead to intricate updates.
• Tight coupling of applications impacts the entire system.
• The requirement to redeploy the entire application after each update.

Comparing Microservices and Monolithic Architectures

When it comes to monolithic architectures and microservices, it’s easy to think that newer is better. However, the issue of monolithic applications and microservices is a little more complicated than just the old versus the new.

Depending on what you need, a monolithic or microservices architecture can be the key to unlocking your organization’s potential.

Let’s take a closer look at the advantages and disadvantages of each.

	Microservices	Monolithic
Introduction	The simple and fast development of the entire system	Requires separate resources, complicating deployment coordination
Scalability	New changes are difficult to maintain and process. Need to redeploy the whole system	Each element can be scaled independently with no downtime
Agility	Lack of flexibility and inability to adopt new technologies, languages, and frameworks	Integrate with new technologies to solve business objectives
Resilience	One bug or issue can affect the entire system	Failure of one microservice does not affect other services
Test	End-to-end testing	Independent components should be tested separately
Safety	Communication within the unit makes data processing safe	Interprocess communication requires API circumvention and raises security concerns
Developer	Large, indivisible databases make it impossible to distribute team efforts	Teams of developers can work independently with no downtime

Essential Technology for Microservices

Any modern tool or language can be used in a microservices architecture, but there are some core tools that are essential and close to the definition of microservices.

Containers, Docker, Kubernetes

To discuss Docker, we need to first delve into the concept of containers. Containers address a crucial challenge in the application development lifecycle. Developers write code within their individual local development environments. However, when the code is prepared for production deployment, a new challenge arises. The code performs flawlessly on my machine but encounters issues in the production environment. This predicament stems from various factors, such as distinct operating systems, diverse dependencies, and different libraries.

Docker stands out as the predominant container platform at present. It emerged in the market at an opportune moment and was open source right from the outset, establishing its dominance in the current landscape. As of now, approximately 30% of companies incorporate Docker within their AWS environments, and this figure continues to rise.

Docker and Kubernetes: The Need for an Orchestration System

Docker provides an open standard for packaging and distributing container applications, but it introduces new problems. How are all these containers coordinated and scheduled? How can you upgrade your app seamlessly without interrupting service? How do I know what I’ve done and restart at the right time?

A solution swiftly emerged to organize containers: Kubernetes, Mesos, and Docker Swarm are among the prominent solutions that offer an abstract approach to crafting clusters of machines that simulate larger entities, a crucial aspect in expansive environments.

However, managing containers in a production setting is far from easy; containers necessitate a dispatch system. So, what should this dispatch system accomplish?

• Handling High Container and User Loads: A single application might involve numerous containers and users interacting simultaneously. Managing and monitoring these interactions requires a purpose-built system capable of managing large volumes of containers and users effectively.
• Managing, Monitoring, and Communication: Establishing communication between containers and users while managing monitoring services is a challenge. Embedding each microservice with its own monitoring functionality can be redundant and inefficient, potentially leading to performance degradation and congestion.
• Efficient Load Distribution: In an unregulated environment, container load can skew due to user requests, resulting in server-level imbalances and inefficient resource allocation. Load balancing mitigates this by ensuring efficient resource distribution.
• Authentication and Security: Orchestration systems like Kubernetes offer infrastructure-level management of authentication and security, enforcing consistent policies across platforms rather than within applications.
• Cross-Platform Deployment: Orchestrators effectively oversee complex tasks such as container operations coordination, microservice availability, and synchronization in multi-cloud, cross-platform environments.

An orchestration system acts as a dynamic, comprehensive infrastructure for container-based applications. It governs external interactions while creating a secure and highly organized environment for their operation.

Kubernetes is well-suited for this role, contributing significantly to its widespread adoption.

API gateway

Microservices often communicate through APIs, especially when first establishing a state. It allows clients and services to communicate directly with each other, but is often a useful intermediary layer, especially as an application’s number of services grows over time. API Gateway acts as a reverse proxy for clients by routing requests, distributing requests across multiple services, and providing additional security and authentication.

There are multiple technologies that can be used to implement API gateways, including API management platforms, but microservice architectures can be implemented using containers and Kubernetes. Gateways are usually implemented using Ingress or, more recently, Istio.

Advantages of Microservices

Reducing Costs and Increasing Efficiency

Microservices are generally simpler and more efficient than monolithic applications, leading to overall cost savings. In addition, microservices are self-contained and do not require the level of coordination and communication that monolithic applications require. By enabling organizations to use the right technology for the task at hand, microservices can improve efficiency and reduce the number of errors. For example, choosing a different technology stack for each microservice can improve performance and scalability.

Increasing Agility and Scalability

Microservices can scale horizontally very easily, making them ideal for situations where scalability is required. Additionally, because microservices are small and modular, they can be deployed much faster than traditional monolithic applications. This increased agility will be of great benefit to organizations that need to respond quickly to market changes.

Easy to Maintain and Update

Because microservices are small and self-contained, they are much easier to update than monolithic applications. Additionally, each microservice is responsible for a specific task, making updates less prone to errors. Therefore, the risk and time required for maintenance and updates can be greatly reduced.

Reducing Time to Market

Microservices also help companies get their products to market faster. By breaking your application into smaller, more manageable pieces, you can develop and release feature-by-feature. Products can often be brought to market faster than with a monolithic approach.

Expanding Independently

Microservices are independently deployable, giving organizations more control over their applications. This increased control is a great advantage for organizations that need to react quickly to market changes. Additionally, using microservices will help organizations avoid the “monolithic blue” that can occur when a monolithic application becomes too large and unwieldy.

Read more: What is the difference between a core system and a business system and the relationship with ERP?

Disadvantages of Microservices

High Complexity

Microservices have many advantages, but they also come with complexity. This complexity can pose significant challenges for organizations unfamiliar with microservices. Additionally, microservices are so independent that it can be difficult to track down and resolve errors.

Increasing Network Traffic

Because microservices are designed to be self-contained, they rely heavily on the network to communicate with each other. This can result in slow response times (network latency) and increased network traffic. Additionally, it would be difficult to track down errors that occur when multiple microservices are communicating with each other.

Code Reuse Restrictions

Microservices are typically written in multiple programming languages ​​and use different technology stacks, which limits code reuse. Sharing code between microservices increases development time and costs. is difficult.

Dependence on DevOps

To be successful with microservices, an organization must have a strong DevOps team. Because DevOps is responsible for deploying and managing microservices. Without a strong DevOps team, it can be difficult to successfully implement and manage microservices-based applications.

Global Testing and Debugging Difficulties

Testing and debugging microservices-based applications can be challenging as the applications are spread across multiple servers and devices. To effectively test and debug your application, you need access to all the servers and devices that are part of your system. That makes it difficult for large distributed systems.

Consider Microservices Carefully

As you can imagine, moving from a monolithic architecture to microservices is not for everyone. When you have a lot of important considerations to make and weigh some pros and cons, you need professional help from a trusted partner.

Relipa enables microservices for even the most complex monolithic application architectures. We can alleviate many of the inconveniences you may encounter when shifting.

Real-world Use Cases

If we raise four cases where microservices are suitable, we can think of the following.

• A system with a large scale and a wide range of functions

Microservices can be developed and operated by subdividing functions, making it easier to change and expand than monolithic systems.

• Systems with frequently changing business requirements and market conditions

Microservices let you deploy individual services independently, allowing you to quickly release new features and improvements.

• Systems that want to leverage different technologies and teams

With microservices, you can choose the most suitable technology and development language for each service, so you have a high degree of technical freedom. Also, since it can be developed in a small team, it is easy to communicate and manage progress.

• Systems that emphasize load balancing and availability

Microservices can distribute load according to each service, improving performance and cost efficiency. In addition, availability is also high because other services are less likely to be affected even if a failure occurs.

Real-life Microservice Use Cases

Amazon

Like many startups, Amazon was built as a monolith because it’s easier to create and launch apps in a monolithic architecture. However, as the company began to grow rapidly, it needed to develop many new features and quickly expand its online platform.

“This allowed us to create a very highly microservice architecture.”

Rob Brigham

AWS developer tools products

Amazon’s codebase became very large and complex in 2001. The company had to implement every change released by hundreds of software engineers. Developers had to spend a lot of time resolving all conflicts and merging all changes into one version.

Additionally, Amazon had to rebuild its code base and run a lot of tests to make sure the new version of the product worked correctly. The result was an unacceptable product delivery schedule. Aiming to simplify the pipeline, the company’s software engineers developed innovative ideas. They decided to take the monolith apart.

They thoroughly analyzed the codebase and assigned functional units that served a single purpose. Developers took the items and created independent microservices and connected them using API integration.

They then thoroughly analyzed all product development processes. Engineers at Amazon began developing an automated solution to eliminate idle time in their CI/CD pipelines.

Netflix

Netflix presents one of the most recent business cases for the adoption of microservices. Initially, the company’s debut web application followed a monolithic architecture. As the popularity of this service soared, it rapidly expanded.

Subsequently, Netflix engineered a robust microservices architecture on the AWS platform. This architecture effectively segregates engineering teams, empowering them to craft, evaluate, and deploy a multitude of services independently.

This innovative approach, however, was not without its challenges. As the volume of customer requests surged, the company grappled with efficiently processing them, leading to multiple database failures.

To counter these challenges, Netflix resolved to transition from an on-premises database to a cloud-based solution offered by Amazon Web Services (AWS). Cloud servers, with their inherent horizontal scalability, allowed the company to effortlessly allocate sufficient resources for handling the inflow of requests.

An essential step towards this transition was decoupling the existing monolithic architecture to facilitate the migration of the database to the cloud. It took Netflix a span of two years to make this architectural shift from a monolith to microservices. This transformation was fueled by the recognition of the positive impact that decoupled architecture had on their operations.

In sum, Netflix’s journey underscores the significance of microservices in modernizing and optimizing complex business operations, particularly in a rapidly evolving digital landscape.

Uber

Uber’s inception involved a monolithic architecture, encompassing a singular codebase responsible for handling all operational facets. This architecture incorporated the essential functions of linking drivers with passengers, processing payments, managing trips, and more.

As Uber’s growth accelerated, the company encountered significant hurdles in swiftly expanding its services. The monolithic setup demanded developers redeploy the entire codebase for implementing even minor changes. Consequently, even slight modifications reverberated throughout the entire codebase, necessitating extensive testing before new features could be released.

Dissatisfied with the considerable consumption of developer resources and time for each new feature rollout, the company pursued a transformative path. They resolved to fragment the application into multiple microservices, marking a paradigm shift.

The adoption of a microservices architecture had transformative effects. It led to augmented system flexibility and granted autonomy to various teams within the organization.

Thanks to this adopted solution, the company achieved the capability to independently scale distinct services. This encompassed pivotal domains such as billing, travel management, driver administration, and notifications. Importantly, developers were no longer burdened with the need to comprehensively update the entire codebase for minor updates.

In a nutshell, Uber’s evolution from a monolithic architecture to a microservices-based one showcases how strategic architectural shifts can enhance agility, autonomy, and efficiency, particularly in the dynamic and fast-paced realm of modern technology-driven enterprises.

Cases Not Suitable for Microservices

If I had to raise three cases where microservices are not suitable, I would consider the following:

• The small system with simple functions

Microservices increase the cost and complexity of designing and managing them, reducing the benefits of the system as a whole.

• Systems with stable business requirements and market environment

Microservices are easy to adapt to changes and extensions, but you need to pay attention to data consistency and security. Since the services are loosely coupled and independent, it is easy to add new functions individually. If changes are small, a monolithic system may be sufficient.

• Systems you want to develop with the same technology or team

Microservices have the advantage of being able to select the most suitable technology and development language for each service, but at the same time, it also increases technical diversity and learning costs. Organizational changes may also be required, as small teams are encouraged to develop.

Read more: What is MVP development? Introducing the Detailed Development Process, Noted Points, and Use Cases

Summary

To recapitulate, microservice architectures have many advantages over traditional monolithic architectures.

There are three advantages:

• Faster performance
• Easier scalability
• Easier code reuse

However, microservices architecture also has many disadvantages, such as more complex development and deployment, and higher implementation costs. Therefore, it is important to weigh the pros and cons of microservices before deciding whether they are the right solution for your organization.

With over 7 years of experience in developing web application systems, Relipa has gradually established itself in the market. Relipa’s experts are not only proficient in web programming languages but also flexible in applying the latest frameworks. We are committed to meeting all customer requirements from design to implementation, with guaranteed quality and fast project completion times.

In addition, if you have any requests regarding migrating from monolith applications to microservices or adopting microservices, please contact us. With our dedication and professionalism, we believe in bringing satisfaction to our customers.