chapter eleven

11 Healthy microservices

 

This chapter covers

  • Techniques to ensure your microservices remain healthy
  • Leveraging observability to understand the behavior of our microservices
  • Debugging microservices and Kubernetes
  • Patterns for reliability and fault tolerance

Errors happen. Code has bugs. Hardware, software, and networks are unreliable. Failures happen regularly for all types of applications, not just for microservices. But microservices applications are more complex, and so problems can become considerably more difficult to debug as we grow our application. The more microservices we maintain, the greater the chance at any given time that some of those microservices are misbehaving!

We can’t avoid problems entirely. It doesn’t matter if they are caused by human error or unreliable infrastructure. It’s a certainty—problems happen. But just because problems can’t always be avoided, doesn’t mean we shouldn’t try to mitigate against them. A well-engineered application expects problems, even when the specific nature of some problems can’t be anticipated.

As our application evolves to be more complex, we’ll need techniques to combat problems and keep our microservices healthy. Our industry has developed many “best” practices and patterns for dealing with problems. We’ll cover some of the most useful ones in this chapter. Following this guidance will make your application run more smoothly and be more reliable, resulting in less stress and easier recovery from problems when they do happen.

11.1 Maintaining healthy microservices

11.2 Monitoring and managing microservices

11.2.1 Logging in development

11.2.2 Error handling

11.2.3 Logging with Docker Compose

11.2.4 Basic logging with Kubernetes

11.2.5 Kubernetes log aggregation

11.2.6 Enterprise logging, monitoring and alerts

11.2.7 Observability for microservices

11.2.8 Automatic restarts with Kubernetes health checks

11.3 Debugging microservices

11.3.1 The debugging process

11.3.2 Debugging production microservices

11.4 Reliability and recovery

11.4.1 Practice defensive programming

11.4.2 Practice defensive testing

11.4.3 Protect your data

11.4.4 Replication and redundancy

11.4.5 Fault isolation and graceful degradation

11.4.6 Simple techniques for fault tolerance

11.4.7 Advanced techniques for fault tolerance

11.5 Continue your learning

11.6 Summary