microservices-demo

This is a very basic implementation of a simple microservices architecture.

The technologies that will be used:

• Node.js
• Docker
• Kubernetes
• Skaffold

Lessons to learn from the current project

1. Data Handling

• this is a big challenge in a microservices architecture
• it gets more complex as the data model is larger

2. Sharing data between services

• there is more than way of sharing data between services:
  • sync communication: when one services call directly the API of another service
  • async communication: focuses on communicating changes using events sent to an event bus (the preferred method)
  • combination between sync and async communication

3. Async communication

• as previously noted, the async communication involves the use of an event bus
• it is up to the event bus to delivering the events to all interested services inside of our application
• the services can react to events
• with this communication method, every service ends up being self-sufficient
  • if any other service fails, we can have the rest of our application work, since there are no strict dependencies between services

4. Docker

• Docker makes it easy to package up services

5. Kubernetes

• Kubernetes is a container orchestrator
• it is a pain to do the setup
• makes really easy to deploy & scale services

Issues with the current project

• duplicate code
• really hard to picture the flow of events
• really hard to remember what properties an event should have
• really hard to test the event flows
• the machine that runs Kubernetes and Skaffold might get slow
• if we emit very quickly a series of events we might break our data model
  • maybe events will end up flow in our application out-of-order