Testing Microservices | What it is, Types and Top Challenges

The Microservice architectural approach is not recent in the software development world. Many companies and start-ups have switched to this architectural style and already reap its benefits. Automated Testing approaches and processes should adapt to the changes as well. In Testsigma we always keep up to date and we definitely can shed some light to the effective testing strategy for a microservices architecture. Want to make your  Automated Testing strategy an effective one? Let’s learn the ropes of the modern approaches in microservices testing!

What is Microservices Testing?

Microservices testing ensures that individual components of a microservices-based application perform correctly both in isolation and as part of a more extensive system. This entails individually testing each microservice using the unit, integration, and end-to-end testing methodologies to ensure its functionality, performance, and stability. The ultimate purpose of microservices testing is to ensure the whole system’s quality and to give end-users a seamless experience.

Microservices Testing Types

Microservices testing is an important part of microservices development since it encompasses numerous sorts of testing to assure the quality and dependability of microservices-based applications. The following are some examples of common microservices testing.

1. Unit testing

Unit testing is a sort of testing in which individual components or modules of a microservices-based application are tested in isolation. This testing ensures that each microservice works correctly and its code fulfills the necessary functionality and quality criteria.

2. Integration Testing

It is testing that examines several microservices’ interactions in a system. This testing seeks to uncover any difficulties that may develop due to the integration of various microservices, such as communication faults or data discrepancies.

Get to know here in a detailed comparison of Unit Testing VS Integration Testing

3. Contract Testing

Contract testing is a sort of testing in which the contracts or agreements between distinct microservices in a system are tested. The contracts describe each microservice’s expected inputs and outputs and the communication protocols used to interface with other microservices. Contract testing ensures that each microservice follows its contract and that any changes to the contract of a microservice do not impair the system’s overall operation.

Read about API Contract Testing.

4. End-to-End Testing

This testing comprises testing the entire microservices-based application, including all microservices and their interactions, from start to finish. Testing end-to-end is used to identify any problems that may arise due to the integration of several microservices, network delays, or other external factors that may impact the system’s overall performance and dependability.

5. Performance Testing

This testing method evaluates the performance and scalability of microservices-based applications under varying load situations. This testing aims to discover any bottlenecks or performance difficulties that may develop due to the system’s high traffic or load and to ensure the system can handle the predicted workload.

6. Security Testing

This method entails examining the security and privacy of microservices-based applications to ensure they are secure against threats such as unauthorized access, data breaches, and other security issues. Security testing aims to discover any security vulnerabilities and ensure the system is secure under applicable security standards and regulations.

How to Do Microservices Testing?

Step 1 – Identify Testable Microservices

Identify microservices to test by considering their features and interactions, ensuring focus on key system components. This stage ensures testing efforts are focused on the system’s key components.

Step 2 – Define Test Scenarios

Define test cases for microservices by describing their actions, inputs, and expected outputs. Cover a wide range of scenarios to ensure proper performance in various conditions, ensuring robust and dependable functioning.

Step 3 – Set Up Test Data

To conduct thorough testing, set up test data for each microservice, covering real-world scenarios and edge cases. Ensure the data accurately represents inputs and situations experienced in real-world operations.

Step 4 – Establish Test Environment

Establish a separate test environment for efficient isolation and testing of microservices, resembling production but allowing varied control. This separate environment prevents interference with live systems and ensures correct duplicate circumstances.

Step 5 – Implement Test Automation

To streamline the testing process and improve efficiency, leverage test automation. Develop automated tests for your microservices to execute the defined test scenarios repeatedly and reliably. Test automation reduces human error, accelerates testing cycles, and allows for frequent regression testing as your microservices evolve.

Step 6 – Execute Tests

Keep a close eye on test cases and automated tests to identify irregularities and failures. Properly document outcomes, including failures, problems, and unusual behavior, to ensure accuracy and efficiency.

Step 7 – Analyze Test Results

Analyze test findings to identify patterns, trends, and improvement opportunities. Examine problems, identify underlying reasons, and address them. Analyze test results to understand microservices’ quality and performance, enabling iteration and functionality enhancement.

Step 8 – Perform Integration Testing

Microservices often interact with one another, making integration testing crucial. Conduct integration tests to verify the seamless communication and compatibility between different microservices. By testing their interactions, you can ensure the smooth functioning of the entire system and catch any potential issues arising from service integration.

Step 9 – Conduct Performance and Load Testing

To evaluate the scalability and performance of your microservices, perform performance and load testing. Simulate high loads and measure how the microservices handle increased traffic and user activity. This step helps you identify potential bottlenecks, optimize performance, and ensure your microservices can handle the expected workload.

Step 10 – Monitor and Maintain

Testing microservices is a continuous activity, even after initial development and deployment phases. Regularly monitor their performance in the production environment and use efficient monitoring techniques to identify and fix issues, ensuring long-term stability and dependability.

Remember, microservices testing is a comprehensive and iterative process. Following these steps will guide you through a systematic approach to testing, enabling you to deliver high-quality microservices that meet the desired functionality, performance, and reliability standards.

Is Microservices Testing Complex?

Because of the dispersed nature of microservices-based applications and the requirement to test each microservice individually and as part of the more extensive system, microservices testing can be complicated. This might lead to many tests that are difficult to manage and maintain using typical testing methods.

Testsigma is an AI-driven unified platform that provides a complete end to end testing solution to simplify and streamline microservices testing. Testers can create, automate, and execute tests for each microservice and the whole system using Testsigma, ensuring quality and reliability at every level of the development cycle. The platform supports the testing needs of all ends that can assist teams in enhancing their testing efficiency and effectiveness, such as test data management, communication, and reporting. Overall, Testsigma can assist teams in overcoming the complexity of microservices testing and efficiently achieving their testing objectives.

Microservices Testing Strategies

A well-planned and well-executed testing strategy that tackles the inherent problems of microservices-based applications is required for effective microservices testing. Some common microservices testing strategies are as follows.

Shift left testing:

This approach incorporates testing early and frequently in the development cycle, beginning with the requirements collecting stage. This assists in identifying and addressing issues early on, minimizing the risk of faults entering production.

Service virtualization:

It is a technique for modeling or replicating the behavior of external dependencies or third-party services with which a microservice may interact. This can aid in isolating the evaluated microservice, decreasing testing complexity, and speeding up the testing process.

Canary testing:

It entails distributing a new version of a microservice to a small group of users or a production environment to test its functionality, performance, and stability before deploying it to the complete system. This enables immediate feedback and the ability to correct any faults before they negatively influence the overall system.

Chaos engineering:

It deliberately introduces errors or disturbances into a microservices-based application to assess its resilience and recovery ability. This method can assist in identifying flaws in the system’s architecture, infrastructure, or operations, as well as improving overall resilience and reliability.

Continuous testing:

This methodology involves continually testing throughout the development cycle, employing automation and communication technologies to ensure immediate response and ongoing improvement.

Load testing:

It is used to discover portions of an application that may not have been correctly built and may result in crashes due to excessive visitor flow. Each service call in a microservice travels across the network, making response times vulnerable to other network activities.

Resiliency testing:

Determining how the software reacts to potential infrastructure failures is necessary, such as a server serving a specific service being unavailable, crashing, or experiencing network traffic disturbances.

What is Microservices Architecture?

Microservices architecture simplifies programmes by dividing them into smaller, more manageable components. Microservices are specialised services that handle certain duties, similar to a well-coordinated team. These services are like to individual superheroes, each focusing on a certain corporate requirement. Microservices provide independence and modularity, enabling autonomous development, deployment, and scalability without affecting others. This method is comparable to building with LEGO bricks in that it allows for easy addition, removal, and change without causing disruption to the overall construction.

Microservices provide flexibility and agility in contrast to traditional monolithic design, which bundles the entire programme as a single unit. This method has gained hold in the business, especially among huge corporations, since it provides increased scalability, shorter development cycles, and the possibility to use different technology for different services. Microservices are more than just a fashionable buzzword; they are a method of adapting to changing business demands without the confines of a monolith.

So, whether you’re a startup aiming to scale rapidly or an established enterprise looking to modernize your application, microservices architecture offers a promising path to modular, scalable, and efficient software development.

Read here all about Test Architecture

How Does Microservices Architecture Work?

Consider your application to be a collection of tiny, specialised apps, often known as services, under the Microservices architecture. Each service specialises in a certain function, such as user authentication, payment processing, or inventory management. These services communicate with one another as needed to carry out their duties.

Consider it a team of professionals working together. Each member is an expert in their own field, and they work together and communicate to reach a shared objective. Similarly, in Microservices design, services communicate via well-defined interfaces, which are frequently implemented using technologies such as REST (Representational State Transfer) or GraphQL.

Order microservices and catalogue microservices, for example, communicate information and conduct tasks in a fluid manner. This modular and decentralised strategy allows teams to work independently on distinct services, resulting in faster and more efficient development and deployment. The interface connects the services, guaranteeing smooth communication and performance. This modular and decentralised design has various benefits, including scalability and the flexibility to add or delete services on demand without impacting the overall programme.

What are the Distinctive Features of the Microservice Architectural Approach?

Before we switch to  Automated Testing details, it is worth defining the difference between a classical or monolithic application architecture and a more granular, a microservices one. Monolithic applications use a single code base with all modules implemented to make the whole system work. Therefore, DevOps use a single build system to build and run the software application.

Drawbacks of Microservices Architecture:

Evidentially, there are some drawbacks to this architectural style:

• Firstly, in the monolithic codebase, newcomers hardly understand how the system is implemented as the system looks monstrous. 
• Secondly, with monoliths, an IDE very often becomes overloaded, the development process extends in time, code reviews become more complicated. 
• Also, building a monolith application could be a strain as if some module changes, the whole system has to be re-deployed from scratch.
• Big and heavy databases influence the whole system performance which is very important for end-users and businesses in particular.
• In addition to that, such monolith systems have low fault tolerance which means that a cost to recover a system might be truly expensive.

All in all, a new revolutionary approach appeared when all these obstacles were analyzed. The microservice architecture was created as a solution to solve all the bottlenecks mentioned above. In a microservice style, as it can be guessed, small autonomous services build a single software solution. 

These services are independent in terms of the isolated codebase, self-sufficient deployment process, and data persistence. That means that if a service should be updated or fixed, there is no need to re-deploy the entire system. This approach helps to mitigate risks and reliably deliver the pieces of product to a customer. Moreover, the services can communicate with each other via API according to the pre-defined standards or contracts. 

How to Build an Automated Testing Process for a Microservice Architecture?

Test automation, as well as manual testing, has to be properly planned at the very beginning as the incorrect approach can lead to non-beneficial processes and huge expenses. To avoid that we should, first of all, define our goals and to create a test strategy.

So, the steps to build a successful test automation process is the following:

1. Ask your customer as much as possible regarding his expectations from test automation.
2. Set quality goals and follow them when creating a test strategy and implementing tests themselves.
3. Analyze which testing types will help you to achieve your quality goals.
4. Stick to shift-left approach and adapt the whole development and testing process to it.
5. Write tests taking into account the fact that according to the testing pyramid the cost of test increases starting from Unit tests. The amount of tests increases starting from the end-to-end tests. So, it is a bad approach to having a few unit tests and implement a bunch of UI tests. That contradicts the shift-left approach helps to identify the issues as earlier as possible.

Testing Pyramid for Microservices:

For the effective test approach creation of a non-monolith architecture, we should bear in mind that the overall system and isolated web services function as expected. If we talk about testing strategy, the adjusted to the new architecture test pyramid can depict the balanced approach taking into account the following different testing types:

The test pyramid has a Unit test as a primary layer. Developers implement them. At this level, we verify that core functions work correctly without external references. The more unit test we have, the more we can identify issues in the codebase at the earlier stages of the development process and avoid many other impacts on the whole system. This approach is called shift-left: when the Automated Testing is shifted at the earlier stages in the timeline, the recovery is less expensive.

The classical pyramid consists of component tests, integration tests, Contract tests, and Automated Testing. Component tests check service autonomy; integration tests verify external resources, and Contract tests verify service interaction. Spring Cloud Contract and Pact are the most reliable and effective tools for contract testing. It is essential to develop end-to-end tests only when all other tests are implemented. Before writing the test strategy, asking the customer about their expectations from test automation is essential.

Testsigma is built to assist to start your test automation smoothly. Now you can impress your customers with a cutting-edge automated testing approach!

Challenges of Testing Microservices

When it comes to testing methodologies, the peculiarities of microservices architecture present additional problems and concerns. Let’s talk about these traits and their challenges for testing:

1. Distributed Nature:

Microservices distributed across multiple servers and locations can cause delays and network traffic disruptions. To ensure system resilience, it’s crucial to build tests that manage network variability and mimic diverse situations, ensuring CI/CD pipelines are not disrupted.

2. Autonomous Deployment:

Microservices can be deployed independently with API compatibility, enabling flexibility but increasing testing complexity. Testing methodologies should cater to frequent deployments, with effective integration testing and versioning practices detecting compatibility and integration issues early.

3. Increased Test Area:

Microservices can be deployed independently with API compatibility, enabling flexibility but increasing testing complexity. Testing methodologies should cater to frequent deployments, with effective integration testing and versioning practices detecting compatibility and integration issues early.

4. Polyglot Nature:

Microservices require multiple programming languages and frameworks for each service, making a single test framework insufficient for all components. It’s crucial to include a variety of testing frameworks and tools to adapt to each microservice’s unique demands, ensuring proper testing throughout the system.

5. Dynamic Production Environment:

Microservices can be deployed independently and developed by autonomous teams, making production a constantly evolving goal. API contracts, contract testing, and monitoring methods are crucial for setting explicit boundaries and enforcing contracts between services. Continuous monitoring helps identify compatibility issues and maintain system integrity.

New testing methodologies are needed for microservice stability in distributed, dynamic contexts. Implementing unit, integration, end-to-end tests, test automation, contract testing, and extensive monitoring is crucial for efficient tackling these challenges.

Conclusion

Component, integration, contract, and automated tests comprise the traditional pyramid. Component tests provide service autonomy, integration tests ensure external resources are available, and contract tests ensure service interaction. Spring Cloud Contract and Pact are the most reliable and effective contract testing technologies. End-to-end tests should be created only after all other tests have been completed. When developing the test strategy, asking the customer what they want from test automation is critical.

Frequently Asked Questions

How do we test microservices?

Microservices testing necessitates a thorough methodology that considers the particular constraints of distributed systems. Shift-left testing, service virtualization, canary testing, chaos engineering, and continuous testing are all effective testing methodologies. Testers must also guarantee that each microservice is tested separately and as part of a larger system to ensure its functionality, performance, dependability, and security.

What tool is used to test microservices?

Open-source frameworks such as JUnit, RestAssured, WireMock, and cloud-based solutions such as Testsigma, Postman, and SoapUI are available for testing microservices. The tool selected is determined by the team’s specific testing requirements and the functionality necessary for the testing process.

Is a REST API a microservice?

A REST API can be part of a microservices architecture but not a microservice. Microservices are self-contained and autonomous chunks of functionality that can be deployed and managed separately. In contrast, REST APIs are web service that accesses and manipulates data using the HTTP protocol. A microservices-based application may use one or more REST APIs to connect with other microservices or external systems.