Reliable does not mean "to fail never", but it means to be able to recover from failures. How to handle reliability change in the k8s world?

1. Sviluppare applicazione “reliable”
con .net core e AKS
Alessandro Melchiori - @amelchiori
CodicePlastico

2. What does “reliable” mean?
Reliable applications are:
● Resilient and recover gracefully from failures, and they continue to function with minimal
downtime and data loss before full recovery.
● Highly available (HA) and run as designed in a healthy state with no significant downtime.

3. What does “reliable” mean?
Reliable applications are:
● Resilient and recover gracefully from failures, and they continue to function with minimal
downtime and data loss before full recovery.
● Highly available (HA) and run as designed in a healthy state with no significant downtime.

4. Instead of trying to prevent failures altogether, the goal
is to minimize the effects of a single failing component.

5. With the network of microservices - service-to-service communication
can become challenging

6. /api/values
/api/values/detaile
d

7. DEMO

9. /api/values
/api/values/detaile
d

10. /api/values
/api/values/detaile
d

11. /api/values
/api/values/detaile
d

12. /api/values
/api/values/detaile
d

13. DEMO

14. AND NOW?

15. Circuit breaker

16. Circuit breaker
/api/values
/api/values/detaile
d

17. Transient errors: retry pattern
/api/values
/api/values/detaile
d

18. Transient errors: retry pattern
/api/values
/api/values/detaile
d

19. Welcome Polly!

20. DEMO

21. Welcome
Kubernetes

22. Pod overview
● Is the basic building block of Kubernetes
● Represents a running process on the cluster
● Consists of either a single container or a small
number of containers that are tightly coupled
and that share resources

23. Pod overview
● Is the basic building block of Kubernetes
● Represents a running process on the cluster
● Consists of either a single container or a small
number of containers that are tightly coupled
and that share resources

24. The sidecar pattern consists of a main application plus a helper container with a responsibility
that is essential to your application, but is not necessarily part of the application itself.
SIDECAR PATTERN

25. Sidecar pattern
The most common sidecar containers are logging utilities, sync services,
watchers, and monitoring agents.
LOGGING MONITORING
WATCHERSSYNC

26. Traefik
An open-source reverse proxy and load balancer for
HTTP and TCP-based applications that is easy, dynamic,
automatic, fast, full-featured, production proven, provides
metrics, and integrates with every major cluster
technology... No wonder it's so popular!

27. SRV
SRV
SRV

28. Traefik middleware

29. Traefik circuit breaker
# Latency Check
[http.middlewares]
[http.middlewares.latency-check.circuitBreaker]
expression = "LatencyAtQuantileMS(50.0) > 100"

30. DEMO
K8s pod multicontainer config

31. Others Traefik middlewares
● RATELIMIT:
The RateLimit middleware ensures that services will receive a fair number of requests,
and allows you define what is fair
● RETRY:
The Retry middleware is in charge of reissuing a request a given number of times to a
backend server if that server does not reply.

32. Cross-cutting concerns
● Logs
● Metrics
● Datadog
● InfluxDB
● Prometheus
● StatsD
● Tracing: the tracing system allows developers to
visualize call flows in their infrastructure.
● Zipkin
● Datadog
● Instana
● ...

33. ALESSANDRO MELCHIORI
Founder & Software developer @CodicePlastico
alessandro@codiceplastico.com
@amelchiori

34. Grazie!