4 What’s Next?

This primer can only provide a short introduction into Microservices. Therefore, it is an important question how to go on after reading this brochure.

4.1 Microservices: Just a Hype?

Microservices are more than just a hype. Amazon employs the distribution into teams with their own technologies already since 2006. This architecture and this approach is what is nowadays called Microservices. Pioneers like Netflix rightly expected so great advantages from this architecture approach that they were willing to heavily invest into the creation of the necessary infrastructures. Nowadays the technologies they created are available for everybody so that the introduction and the use of Microservices are much easier and less costly.

In addition, the trends to agility, Continuous Delivery and Cloud are reflected by Microservice-based architectures. Even beyond these criteria there are good reasons for Microservices – ranging from individual scalability to robustness. Therefore, Microservices are not only a good supplement for a number of trends, but they represent also a solution for different problems. The trend to use Microservices is thus based on a number of reasons. Therefore it is extremely unlikely that it will just be a short-lived hype.

4.2 Self-contained Systems

An approach based on Microservices are Self-contained Systems. They focus on coarse-grained systems which allow teams to work independently. They should be integrated on the UI level and only use asynchronous communication among each other. This is a more coarse-grained architecture than Microservices. While Microservices can be used in many different scenarios and for many different purposes, as explained in chapter 3, Self-contained Systems represent a more specific approach to Microservices, which is custom-tailored to solve problems of large projects.

4.3 Examples

The primer discusses Microservices only theoretically and does not introduce technologies for implementation.

http://ewolff.com/microservices-demos.html shows several examples for the different options to implement microservices:

Synchronous Communication

There are several options for synchronous communication between microservices:

  • The Consul demo is written in Java with Spring Cloud / Boot. The demo uses Consul for service discovery, Apache httpd for routing, Hystrix for resilience and Ribbon for load balancing. It also provides a Prometheus installation for monitoring and an ELK stack for log analysis.
  • The Netflix demo uses the Netflix stack. The demo is written in Java with Spring Cloud / Boot. It uses Netflix Eureka for service discovery, Netflix Zuul for routing, Hystrix for resilience and Ribbon for load balancing.
  • Kubernetes is a system to run Docker containers in a cluster. The Kubernetes demo is written in Java with Spring Cloud / Boot. It uses Kubernetes for service discovery, routing and load balancing. The demo also uses Hystrix for resilience. The code does not depend on Kubernetes.
  • Cloud Foundry is a PaaS. It provides an application with an environment to run in. The Cloud Foundry demo is written in Java with Spring Cloud / Boot. Uses Cloud Foundry for deployment, service discovery, routing and load balancing. The demo also uses Hystrix for resilience. The code does not depend on Cloud Foundry.
Asynchronous Communication

Asynchronous communication makes it easier to deal with unreliable networks and services:

  • Kafka uses Kafka for communication. Kafka is a message-oriented middleware and allows systems to send messages to one another.
  • Atom uses REST / HTTP for asynchronous communication with the Atom format.
UI Integration

UI integration provides very loose coupling:

  • ESI shows how Edge Side Includes (ESI) can be used to integrate the UI of microservices. On microservice is written in Java with Spring Boot, the other one with Go. The Go microservices is built using multi stage Docker containers.
  • jQuery shows how jQuery can be used to integrate the UI of microservices.

The website for each demo explains how the demo can be built and started.

4.4 More literature

Additional literature such as the Microservices Book (there is also a German version) by the same author will be needed to appreciate the full scope of Microservices and to learn how to actually implement them technically.

The free booklet Microservices Recipes gives an overview of technologies that can be used to implement a microservices architecture. It explains the demos mentioned above in more detail and illustrates how the technology work and to provide a foundation for the implementation of a microservices architecture. There is also a German version).

The book Microservices - A Practical Guide contains a more detailed description of technologies for the implementation of microservices. In addition, it contains an introduction to microservices and an overview of technologies for the monitoring of microservices. There is also a German version).

4.5 Final Remark

A final remark: the risk associated with introducing Microservices is very limited: A first Microservice has just to be developed and brought into production. This Microservice can for instance supplement an existing deployment monolith. Should this approach not work out, it is very easy to remove the Microservice again.

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Notes