9 Fundamentals To A Successful Microservice Design

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The human body is a combination of different systems most of which are independent yet, working together as one. Each system has a specific functionality of its own. All the organs with a multitude of other supporting frameworks form a fully functioning body. Now, if applied to software systems, this is the concept of a microservice architecture.

In technical terms, a microservice system allows development of single function modules. This trend of developing single function modules has increased agility, performance and cost efficiency for organizations both large and small while enabling continuous testing and early delivery. But, before we delve deeper into the fundamentals of microservice design let us have a look at its advantages.

Advantages Of Microservice Architecture

Technological Flexibility

Increased Efficiency

Products Not Projects

Fundamentals to a successful microservice design

1. The Scope Of Functionality

When we talk about the scope of a microservice, we are referring to the features of an independent software module. The ability of microservices to perform as a nearly-stateless system allows it to be developed independently. It thus becomes imperative to identify functionalities that a microservice will implement. This helps to understand what a microservice is responsible for? To realize the intended functionality that each microservice should serve. Not only to prevent overload but to serve different scenarios as well. For example, a piece of code is called multiple times in a monolithic setup, creating a microservice will make it easier to access and use. Minimizing the amount of code will only improve efficiency and avoid bloated services.

The question comes as to how one can go about defining the scope of a microservice. Though there isn’t a well-defined set of rules to achieve this, there are a few sets of guidelines or best practices if you may to define a scope. Following are some of the steps that you can take to define your microservice.

  • The first step is to identify the pieces of code that are replicated under various modules. How often do you see them repeat? and how much effort goes into getting them setup each time in different modules? If the answer to all of these are high, then the scope of the microservice would be to handle just the repeating pieces of code.
  • Another step that you can take is to check if a module is not dependent on other modules or in simpler terms, check if it’s possible that a module is loosely coupled with the rest of the services. If so, then the scope of the microservice will be the scope of the entire module.
  • Another very important metric to consider while defining the scope is to check if the features would be used with a heavy load. This would check if the microservice would have to be scaled up in the near future.If it does, then it’s a good idea to define the scalable bits as the scope of a microservice rather than combine it with other features.

2. High Cohesion Combined With Loose Coupling

When breaking down a monolithic architecture into smaller services or components, it is important to combine similar functionalities. This combination of related logic into a single unit is known cohesion. The higher the cohesion, the better is the microservice architecture. A low cohesion would indicate too much communication between different services leading to a poor system performance.

3. Unique Source Of Identification

After an order is placed on an e-commerce website, the user is provided with an order ID. This order ID once generated contains all the information regarding the order. As a microservice, the order ID is the only source for any information regarding the order service. So, if any other service seeks information regarding the order service, the order ID acts as the source of information rather than its actual attributes.

4. API Integration

Well, the simple answer would be the use of an API (Application Programming Interface). The fundamental of microservice design is using the correct API. This is crucial to maintaining communication between the service and the client calls. Easy transition and execution are important for proper functioning.

Another important thing to note while creating an API is the domain of the business. This definition of the domain will ease out the process of differentiating the functionality. There are several clients which are external to the system. These clients could be other applications or users. Whenever a business logic is called, it is handled by an adapter (a message gateway or web controller) which returns the request and makes changes to the database.

5. Data Storage Segregation

6. Traffic Management

This high traffic demand needs management. A specific way of calling and being called is the answer to a smooth flow of traffic. The services should be able to terminate any such instances which cause delay and affect the performance.

This can also be achieved using a process known as ‘auto-scaling’ which includes constant tracking of services with prompt action whenever required. In some cases, a ‘circuit breaker pattern’ is important to supply whatever incomplete information is available in case of a broken call or an unresponsive service.

7. Automating The Process

8. Minimal Database Tables (Preferably Isolated Tables)

9. Constant Monitoring

Hence, for designing a microservice architecture, it is important to establish a process for actively monitoring the storage of the data in a central location. This will help reflect the frequent changes without affecting the performance of the system. In a common scenario, the microservice monitoring tools will monitor individual services and later combine the data by storing it in a centralized location. This is a necessary step while following micro-services design principles.

Realizing the crucial part played by an API in a successful microservice architecture. One must also have a process to constantly monitor the API performance. API performance monitoring is crucial to any microservice architecture in order to make sure the functionality stays up to the mark in terms of speed, responsiveness and overall performance of the product.

Limitations Of Microservice Architecture

1. Development Environment Overload

2. DevOps Complexity

3. Increase In Resource And Network Usage

4. Testing

5. Security

Apart from that, each module might talk to other modules and tracking the flow of data becomes very difficult. Additional measures such as API gateways with load balancing is required to ensure the behaviour is consistent. These additional steps cause overhead on each of the microservice.

6. Application Complexity

7. High Initial Investment

Is It worth It?

In addition, it overcomes the delays and flaws while increasing flexibility and performance. Keeping the above mentioned in mind it is safe to say that microservice architecture is necessary for a successful software system.

Many enterprises including names like PayPal, Twitter, LambdaTest and Netflix have backed up the reliability of microservice architecture for deploying a more scalable, functional and robust software.

Written by

Product Growth at @lambdatesting (www.lambdatest.com)

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