The document discusses implementing resilience in applications using Micronaut, focusing on error handling techniques such as retries and circuit breakers. It provides code examples of how to set up a client interface for fetching presentation information, incorporating features like backoff strategies and fallbacks. Additionally, it references relevant resources and tools to assist developers in achieving robust application performance.

1. Implementing Resilience with
Micronaut
Naresha K
@naresha_k
https://blog.nareshak.com/

2. About me
Developer, Architect &
Tech Excellence Coach
Founder & Organiser
Bangalore Groovy User
Group

4. • The Network is Reliable
• Latency is Zero
• Bandwidth is Infinite
• The Network is Secure
• Topology Doesn’t Change
• There is One Administrator
• Transport Cost is Zero
• The Network is Homogeneous
https://web.archive.org/web/20171107014323/http://blog.fogcreek.com/eight-fallacies-of-distributed-computing-tech-talk/
Fallacies of distributed computing

5. Timeout

6. package com.nareshak.demo
import io.micronaut.http.annotation.Get
import io.micronaut.http.client.annotation.Client
@Client(value = "http://localhost:8081/")
interface PresentationClient {
@Get("/{presentationId}")
PresentationInfo getPresentationInfo(Long presentationId)
}

7. micronaut:
http:
client:
read-timeout: 5s
application.yml

8. Retry

9. @Retryable(attempts = "5", delay = "2s", multiplier = "2.0")
PresentationInfo getPresentation() {
}

11. package com.nareshak.demo
import io.micronaut.http.annotation.Get
import io.micronaut.http.client.annotation.Client
import io.micronaut.retry.annotation.Retryable
@Client(value = "http://localhost:8081/")
@Retryable(attempts = "5", delay = "2s", multiplier = "2.01")
interface PresentationClient {
@Get("/{presentationId}")
PresentationInfo getPresentationInfo(Long presentationId)
}

12. Circuit Braker

14. package com.nareshak.demo
import io.micronaut.http.client.annotation.Client
import io.micronaut.retry.annotation.CircuitBreaker
@Client(value = "http://localhost:8081/")
@CircuitBreaker(reset = "60s", attempts = "1")
interface PresentationClient extends PresentationOps {
}

16. Fallback

17. package com.nareshak.demo
import io.micronaut.retry.annotation.Fallback
@Fallback
class PresentationClientFallback implements PresentationOps {
@Override
PresentationInfo getPresentationInfo(Long presentationId) {
new PresentationInfo(title: “TBD")
}
}

19. References
• https://github.com/naresha/agileindia2020resiliencemincronaut
• https://micronaut.io/

20. Thank You