Evolving distributed systems

Transcript

1. Evolving distributed systems Zoltan Altfatter
2. Software architecture evolution
3. Testing Pyramid https://testing.googleblog.com/2015/04/just-say-no-to-more-end-to-end-tests.html
4. Testing microservices • Deploy all microservices and perform end to end tests • Mock other microservices in unit / integration tests
5. Deploy microservices to perform end-to-end tests Advantages - simulates production - real communication between services Disadvantages - long to run and set up - hard to debug
6. Mock other microservices in integration tests Advantages: - no infrastructure requirements - fast feedback Disadvantages: - you can go to production with passing tests but failing badly - the used services are mocked which might nothing to do with the reality
7. Consumer driven contract - The consumer describes to the service what he needs in a form of an executable integration test that describes how the consumer uses the service
8. Spring Cloud Contract Verifier + StubRunner - Ensures that HTTP / Messaging stubs are doing exactly what the actual server-side implementation will do - Provides a way to publish changes in contracts that are immediately visible - Promotes acceptance test driven development - Generates boilerplate test code used on the producer side
9. WireMock • WireMock is a simulator for HTTP-based APIs. • We can run WireMock within our Java application • Has the ability to return canned HTTP responses for requests matching criteria • We can run the WireMock server in its own process
10. Example architecture
11. contract-service
12. customer-service
13. Demo time https://github.com/altfatterz/2019-03-08-mimacom-lunch-and-learn