Microservices describe an organizational, architecture-based approach to software development in which software is composed of small (= micro) services that are independent of each other. These services communicate with each other via APIs (Application Programming Interface).
Microservices are characterized by:
- independence: The services within microservice architectures are developed, provided and operated independently of each other. This means: they do not affect the functionality of other services because they do not share code or implementation.
- Specialization: Each microservice is designed to perform a specific function and thus serves to solve a specific problem. If a service becomes too complex because more code is added, it should be divided into smaller services.
What are microservices for?
A microservice architecture serves several purposes. It:
- speeds up application development time
- simplifies scalability
- shortens time-to-market for new features
- enables innovation
Microservices vs. SOA vs. monolithic architecture
Microservices differ from SOA and monolithic architecture in key characteristics:
A microservice architecture is characterized by the fact that it creates applications through self-contained, independent components. These components execute each of the application processes as a service.
Communication between the services works using APIs via carefully defined interfaces. Thanks to the independence of the services, they can be updated, deployed, and scaled one at a time (unlike in monolithic systems).
Monolithic architecture (also called monolithic systems) describes the tight interconnectedness and thus dependency of processes that are executed as a single large service. Accordingly, since in monolithic systems only the architecture as a whole can scale, the code base gradually becomes more complex as features are added or enhanced.
In contrast to a microservice architecture, the increasing complexity makes it more difficult to experiment and implement new concepts. An additional disadvantage to microservices is risky application availability due to process dependencies.
The difference between SOA (Service Oriented Architecture) and microservice architecture consists - in addition to technical aspects - primarily in a different scope in each case:
In SOA, the aim is to standardize the way all web services in a single enterprise communicate and are integrated with each other. In contrast, microservice architecture is application-specific.
Advantages & Disadvantages of Microservice Architecture
If you're currently considering implementing microservices in your organization, take a look at the pros and cons at a glance.
Using a microservice architecture is worthwhile for your business for the following reasons:
- Agility: Microservices support working in small and independent teams, as they each take responsibility for their services. This clearly defined responsibility enables teams to work faster and shorten development cycles.
- Easy Deployment: Because continuous integration is enabled via microservice architectures, teams can also more easily test new concepts and stop them as needed. This experimentation lets developers update code much more easily, accelerating time-to-market for new features.
- Flexible Scaling: If an application feature becomes more in demand, independence allows developer teams to respond flexibly. Additionally, they can accurately measure the cost of a feature to identify inefficiencies and reduce costs.
- Technological Flexibility: Microservices give developers the freedom to choose the best tool to solve a task, rather than a one-size-fits-all solution. Also, developers can use different stacks and programming languages for different components.
- Reusable Code: Clearly defined services can be used as the basis or building block for a different set of functions.
- Resilience: Since the services are independent of each other, the risk of application failure is reduced accordingly. In the event of an error, the entire application does not immediately crash: Only a certain functionality is affected.
The introduction or conversion to a microservice architecture is associated with various challenges:
- More complex management: There are more services to manage, most of which are created by different teams of developers and possibly at different locations.
- More complex log data: Log data used for monitoring and problem resolution is correspondingly large and may differ between different services.
- Backward compatibility issues: New versions may cause compatibility with existing to suffer.
- Latency and connectivity issues: Multiple network connections increase the risk of connectivity and latency issues.
The above challenges can be addressed by a DevOps solution.
Components of Microservices
While any modern tool and language can be used for a microservice architecture. However, the following tools have become essential if you want to use microservices in your business:
- Containers, Docker and Kubernetes
- API gateways
- Messaging and event streaming
The introduction of microservices is worthwhile from the point where a monolithic architecture has become too cumbersome due to increasing complexity. This is because a microservice architecture, with its many independent services, ensures that an application can be restructured into smaller services.
In addition to its independence, a microservices architecture is also characterized by specialization, because: The individual services each address individual, specific problems.
In addition to the numerous advantages of microservices over a monolithic architecture, such as agility, flexible scaling, and ease of deployment, they also bring their own challenges: However, more complex management, more complex log data, and latency and connectivity issues can be addressed through the use of DevOps.