Microservices

Rules

• Can be upgraded without clients need to be upgraded
• Define a clear public interface/contract
  • Make additivie changes
  • Create new endpoints
  • New properties on DTOs
  • Publish new version of it, previous version must still be supported

About

• Autonomous
• Single responsibility principle
  • Do one thing and do it well
• Should be able to deploy on it's own
• Public interface should be defined clearly
• Perform well
• Resilience to error
• Secure

• Own their own data
• Independently deployable
• Within specific boundaries

When do you need one

• When scaling

How to

Avoid upgrade issues

• Split up team ownership of microservices
  • First add new features
  • Then deploy updated microservice
  • Later update clients
• Automated tests
  • Ensure that older clients are supported
  • Run as part of CI build process
• Beware of shared code