Slides for my talk at https://www.meetup.com/Bangalore-Distributed-Systems-Meetup/events/241113213/ Links: https://github.com/ravichaturvedi/retrier https://github.com/ravichaturvedi/talk-resilient-microservices

1. Building Resilient Microservices
Ravi Chaturvedi
Software Engineer - Terracotta R&D

2. Agenda
• Microservices
• Failures
• Resilience

3. Microservices

4. “…in the pursuit of Scalability, Agility and Simplicity”

5. “Microservices is a variant of the service-
oriented architecture (SOA) architectural style
that structures an application as a collection of
loosely coupled services.”
— Wikipedia

6. “Driving force behind SOA is Integration.”
“Driving force behind Microservices is Scalability.”

7. Load Balancer
Monolithic - Architecture
API
Manager 1 Manager 2
Manager 3
Data Access

8. ESB
App1 App2 App3
SOA - Architecture
Enterprise Web Portal

9. API Gateway (Reverse Proxy)
Microservice 1 Microservice 2 Microservice 3
Microservices - Architecture
Microservice 4
Service
Discovery

10. Microservice — Complexity
• Communication
• Orchestration
• Log Aggregation
• Application Metric
• Request Tracing
• Health Checks

11. Demo

12. Failures

13. “…whatever can go wrong, will go wrong.”
— Murphy’s law

14. What can go wrong? — Software
• Bug
• Dependent service Issue
• Backpressure
• …

15. What can go wrong? — Hardware

16. 90% Avail. Per Component
(72 hours/month)
99% Avail. Per Component
(7.20 hours/month)
99.9% Avail. Per Component
(43 mins/month)
1 - (.90)^3 ~ 26% 1 - (.99)^30 ~ 26% 1 - (.999)^300 ~ 26%
1 - (.90)^6 ~ 45% 1 - (.99)^60 ~ 45% 1 - (.999)^600 ~ 45%
1 - (.90)^9 ~ 60% 1 - (.99)^90 ~ 60% 1 - (.999)^900 ~ 60%
Service Failure Probabilities
P(Service Failure) = 1 - P(All Component Success)
P(Service Failure) = 1 - P(Individual Component Success) ^ Component Count

17. “Failures are Inevitable.”

18. Resilience

19. What will you do?

20. Retry

21. “ …side-affect free or idempotent operations”
“Immutability for Data Structure,
Idempotency for Operations”

22. Retry — Count

23. Retry for result on Count

24. Retry — Requirements
• On specific exception
• Till timeout expires
• Exponential Backoff
• Nested Exception
• …

26. Retrier — Contd.

27. What this does?

28. Circuit Breaker

30. Hystrix — Contd.

31. Demo

32. Thank You!

33. Q & A