Resilience4j with Spring Boot
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The document outlines a presentation on resilience4j, a fault tolerance library designed for Java 8 and functional programming, which offers various modules such as circuit breaker, retry, rate limiter, and bulkhead. Key concepts include the use of these modules to maintain service availability and resilience in distributed systems, along with implementation guidelines and example configurations. Attendees are reminded to provide feedback and respect session etiquette, including punctuality and minimizing disturbances.
Resilience4j with Spring Boot
- 1. Presented By: Resilience4j With Spring Boot Shashikant Tanti & Deepak Kumar
- 2. KnolX Etiquettes Punctuality Join the session 5 minutes prior to the session start time. We start on time and conclude on time! Feedback Make sure to submit a constructive feedback for all sessions as it is very helpful for the presenter. Silent Mode Keep your mobile devices in silent mode, feel free to move out of session in case you need to attend an urgent call. Avoid Disturbance Avoid unwanted chit chat during the session.
- 3. Our Agenda 01 What is Resilience4j? 02 Why Resilience4j? 03 Resilience4j Modules 04 How to use Resilience4j in your project? 05 Demo
- 4. What is Resilience4j? ● Resilience4j is an easy-to-use fault tolerance library inspired by Netflix Hystrix, but designed for Java 8 and functional programming. ● In Resilience4j you donʼt have to go all-in, you can pick what you need.
- 5. Why Resilience4j? ● This library is capable of handling the asynchronous calls ● Resilience4j is designed for Java8 and functional programming ● Resilience4j enables the resilience in complex distributed systems where failure might take place ● Resilience4j is lightweight because it only uses Vavr, which does not have any other external library dependencies.
- 6. How to use Resilience4j in your projects? You can simply use the following dependency in your maven project and get started with the Resilience4j To add the Resilience4j dependency to your project, you need to add the following dependency to your pom.xml file: <dependency> <groupId>io.github.resilience4j</groupId> <artifactId>resilience4j-spring-boot2</artifactId> <version>1.3.3</version> </dependency>
- 7. Resilience4j Module ● Circuit Breaker ● Retry ● Rate Limiter ● BulkHead ● Time Limiter ● Cache
- 8. Circuit Breaker Module ● The circuit breaker is essentially a pattern that helps to prevent cascading failures in a system. ● The circuit breaker pattern allows you to build a fault-tolerant and resilient system that can survive gracefully when key services are either unavailable or have high latency. ● Circuit breaker pattern is generally used in microservices architecture where there are multiple services involved but it can be used otherwise as well.
- 9. Circuit Breaker Module The circuit breaker has the following 3 states Closed – Closed is when everything is normal, in the beginning, it will be in the closed state and if failures exceed the threshold value decided at the time of creating circuit breaker, the circuit will trip and go into an open state. Open – Open is the state when the calls start to fail without any latency i.e calls will start to fail fast without even executing the function calls.
- 10. Circuit Breaker Module Half-open – In half-open state what will happen is, the very first call will not fail fast and all other calls will fail fast just as in the open state. If the first call succeeds then the circuit will go inthe closed state again and otherwise, it will go into the open state again waiting for the reset timeout.
- 11. Circuit Breaker
- 12. BulkHead Pattern The BulkHead Pattern is a type of application design that is tolerant of failure. In a bulkhead architecture, elements of an application isolated into pools so that if one fails, the other will continue of function. BulkHead Implementation framework 1. Hystrix 2. Resilience4j
- 13. BulkHead Pattern
- 14. When to use BulkHead Pattern 1. Apply the bulkhead pattern whenever you want to scale a service independent of other services. 2. Isolate resources used to consume a set of backed services, especially if the application can provide some level of functionality even when one of the service is not responding. 3. Apply the bulkhead pattern to fault isolate components of varying risk or availability requirements. 4. Protect the application from cascading failure.
- 15. Retry Module ● There can be scenarios when there are intermittent network connectivity errors causing your service to be unavailable. ● These issues are generally self-correcting and if you retry the operation after a small delay its most probably going to succeed. ● Retry pattern help to resolve transient failures in distributed architecture by automatically hit the target resource again after some specific time.
- 16. user-service catalog-service Resilience4j: retry: instances: userService: maxRetryAttempts: 4 waitDuration: 5s Service A Service B Failure response Retry 1 2 3 4
- 17. The faults are expected to be short lived, and repeating request that failed previously could succeed on a subsequent attempt. ● Calling an HTTP service from another REST endpoint. ● Calling a web service. ● No or slow responses due to a large number of requests towards the resource(database or service). When to use Retry
- 18. 1. Setting a limit on the amount of time we are willing to wait for an operation to complete is called time limiting. 2. If the operation does not complete within the time specified, we want to notified about it with a timeout error. Time Limiter
- 19. Resilience4jʼs TimeLimiter can be used to set limits (timeouts) on asynchronous operations implemented with completableFuture. Configuration timeoutDuration:2s cancelRunningFuture:true Resilience4j Time Limiter
- 20. Rate limiter pattern helps us to make services highly available just by limiting the number of calls we could process in a specific window. Rate limiting specified in terms of 1. Requests per second(rpc) 2. Requests per minute(rpm) 3. Requests per hour(rph) Rate Limiter Pattern
- 22. ● https://resilience4j.readme.io/docs/getting-started ● https://github.com/resilience4j/resilience4j ● https://blog.knoldus.com/circuit-breaker-with-resilience4j/ ● https://blog.knoldus.com/retry-with-resilience4j/ References
- 23. Thank You ! Thank You ! Demo
- 24. Do remember to submit feedback!
- 25. Thank You !