Service discovery overview
In Chapter 2, Scaffolding a Go Microservice, we created an application consisting of three microservices. The relationship between the services is illustrated in the following diagram:
Figure 3.1 – Relationship between our microservices
To make requests to each service, we used static addresses that we set in our code. The settings we used were as follows:
- Metadata service:
localhost:8081 - Rating service:
localhost:8082 - Movie service:
localhost:8083
This approach with pre-programmed service addresses has some significant limitations:
- Impact on scalability: Each time you need to add or remove instances, you need to update the code of each calling service
- Reliability issues: If an instance becomes unavailable for an extended period (for example, due to network failure), your services will keep calling it until you update their configuration
How do we address these limitations?
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