In this version of the experts series, we will discuss the common challenges with testing microservices i.e. the sheer number of services that make up an application, as well as the number of dependencies between the services.
What Are Microservices?
A microservice is a framework that structures an application as an assembly of smaller and more simple services that are:
The microservices architecture also enables frequent, rapid, and reliable delivery of large, complex applications as web apps continue to grow and be more complex.
Why Should Teams Use Microservices?
Microservices are used as a way to break up an application or service into multiple independent applications that can be run on different hardware or servers. Elements of the system are loosely-coupled which allows for ease of change and elastic scaling. If some part of your application’s functionality fails, it doesn’t affect the entire system and your app continues to work.
In microservices architecture, each service is defined by its characteristics, some of which are:
- Independently deployable by fully automated machinery
- Using different programming languages
- Using varied technologies and databases
- Using different data storage technologies
Advantages and Disadvantages of Microservices
- Deployment flexibility
- Technology flexibility
- Architecture complexity
- Not suitable for small applications
- May impact performance
The Rise of Microservices
The main reason why the digital industry is switching towards a microservices architecture is because it allows each component to scale quickly, and without a headache, particularly when tools like Kubernetes are used. Using microservices, you don't have to scale your whole application.
We’ve recently seen the following trends in the microservice market:
1. Market Growth
Product companies are recognizing the benefit of adapting to the hybrid cloud and microservice architecture. The scalability of microservices makes it easier for developers to update the applications at an on demand basis.
2. Frameworks For Web Services
The microservices framework provides developers with out-of-the-box capabilities to implement service design patterns and automated coding.
3. Demand For Frequent App Updates
Users now demand rich, dynamic, and interactive applications. As a result, app companies make updates, at times several releases a day. Microservices can help app companies meet this frequency demand.
How to Test Microservices?
Microservices architecture consists of dedicated, small services that are assembled together to create a complete application or task. When every microservice is independent and represents a single responsibility, these services become highly testable.
Microservices Testing Strategies
Aims at taking the smallest piece of a microservice (a unit) and analyzing if the microservice behaves in the same way as expected.
Helps technical teams evaluate the performance and communication between the components and analyze any flaws in the interface.
Includes taking one piece of the system and testing it in isolation by creating a double test. Later, the changes are implemented in the system through internal code interfaces.
A 'contract' is how a specific result or output is expected for certain inputs. Contract testing ensures that consumers receive the same results from a service, even if the service provider changes.
End to End (E2E) Testing
Evaluates the performance of the complete system and ensures that microservice adheres to all the business requirements.
Microservices Testing & Implementation Tools
- Postman, Jmeter, and SwaggerUI: Microservices have their respective API endpoints to communicate with each other – this makes microservices highly testable. These tools can help QA engineers analyze microservices with built-in or third-party libraries such as Apache HttpClient, RestAssured, WireMock, SpecFlow, and RestSharp. The tools include capabilities like stubbing and mocking web services to verify responses from the endpoints.
- Docker, LXD, and CRI-O: Microservices are distributed in nature. To implement these, we need a testing technology that has somewhat similar characteristics. Containers are lightweight and can easily create, deploy, and run distributed applications. Multiple implementation containers can be used to implement a microservices architecture.
- Logstash, Graylog, and Prometheus: The biggest challenge when working with microservices is its complexity and distribution that can result in multiple failures. So, monitoring the changes in microservice is important as these tools can help you overcome the monitoring challenges.
Microservices is an architectural style that continue to grow in popularity. Their ability to segregate large applications into smaller, more reasonable and independent modular services allow teams to create and test applications at a much more efficient level which can lead to faster and more reliable release cycles.
If your team has questions about the microservice architecture or if you're looking to augment your QA team - QASource can help. Our engineers are tool agnostic, experts in their respected domains, and have years of experience working in a microservices environment.
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