JFall 2021

1. Cloud
Ana-Maria Mihalceanu

2. Hello! I am Ana
@ammbra1508
Java Champion, Certified Architect
Developer Advocate @ RedHat
Moved from to
“Control” enthusiast

3. What is resilience?
@ammbra1508
Normal
Behaviour
Faulty
Behaviour
Unexpected event occurs
Unexpected
condition occurs
Degraded
Mode
Behaviour
Feedback control mitigates
malfunction
Recovery control restores expected behaviour
Detection control recognizes malfunction

4. What is resilience?
@ammbra1508
Normal
Behaviour
Faulty
Behaviour
Unexpected event occurs
Unexpected
condition occurs
Degraded
Mode
Behaviour
Feedback control mitigates
malfunction
Recovery control restores expected behaviour
Detection control recognizes malfunction

5. Where to start?
@ammbra1508

6. In other words…
@ammbra1508
Recovery
Control @CircuitBreaker, @Fallback
Feedback
Control
@CircuitBreaker, @Retry, @Fallback
Detection
Control
@CircuitBreaker, @Timeout, @Retry

8. My recipe
@ammbra1508
Deployment activity
v1
Deployment activity
v2
Service activity
Istio
Kubernetes

9. Circuit breaker with Istio
@ammbra1508

10. @ammbra1508
Load shedding drops some
proportion of load by dropping traffic
as the server approaches overload
conditions.
source: Site Reliability Engineering book

11. Rate Limiting
@ammbra1508

12. Concurrency control based on request priority
@ammbra1508

13. What about autoscaling?

14. Interplay autoscaling and load shedding
@ammbra1508
Autoscaling condition
Workload increases
Load shedding starts and
reduces resource stress
Increased
traffic
continues
Load
shedding
stops
Yes
No
Trigger
autoscaling

15. Fallback with Skupper
@ammbra1508

16. @ammbra1508
Code made available at
https://github.com/ammbra/resilience

17. Download
red.ht/quarkus-spring-devs
Download
dn.dev/istio-istiobook