1.前言
上篇文章讲了Resilience4J实现熔断功能，文章详见：Spring Boot集成Resilience4J实现断路器功能 | Harries Blog™，本篇文章主要讲述基于Resilience4J实现限流/重试/隔离。
2.代码工程
pom.xml
<dependency>
<groupId>io.github.resilience4j</groupId>
<artifactId>resilience4j-spring-boot3</artifactId>
<version>2.0.2</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-aop</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
限流
@RequestMapping("/hello")
@RateLimiter(name="ratelimitApi",fallbackMethod = "fallback")
public ResponseEntity<String> showHelloWorld(){
return new ResponseEntity<>("success",HttpStatus.OK);
}
public ResponseEntity fallback(Throwable e){
log.error("fallback exception , {}",e.getMessage());
return new ResponseEntity<>("your request is too fast,please low down", HttpStatus.OK);
}
重试
@RequestMapping("/retry")
@Retry(name = "backendA")//use backendA ，if throw IOException ,it will be retried 3 times。
public ResponseEntity<String> retry(String name){
if(name.equals("test")){
i++;
log.info("retry time:{}",i);
throw new HttpServerErrorException(HttpStatusCode.valueOf(101));
}
return new ResponseEntity<>("retry",HttpStatus.OK);
}
隔离
@RequestMapping("/bulkhead")
@Bulkhead(name = "backendA")
public ResponseEntity<String> bulkhead(){
return new ResponseEntity<>("bulkhead",HttpStatus.OK);
}
配置文件
spring:
application.name: resilience4j-demo
jackson.serialization.indent_output: true
management:
endpoints.web.exposure.include:
- '*'
endpoint.health.show-details: always
health.circuitbreakers.enabled: true
resilience4j:
circuitbreaker:
configs:
default:
registerHealthIndicator: true
slidingWindowSize: 10
minimumNumberOfCalls: 5
permittedNumberOfCallsInHalfOpenState: 3
automaticTransitionFromOpenToHalfOpenEnabled: true
waitDurationInOpenState: 5s
failureRateThreshold: 50
eventConsumerBufferSize: 10
ratelimiter:
instances:
ratelimitApi:
limit-for-period: 5
limit-refresh-period: 1s
timeout-duration: 100ms
retry:
instances:
backendA:
maxAttempts: 3
waitDuration: 10s
enableExponentialBackoff: true
exponentialBackoffMultiplier: 2
retryExceptions:
- org.springframework.web.client.HttpServerErrorException
- java.io.IOException
bulkhead:
instances:
backendA:
maxConcurrentCalls: 10
以上只是一些关键代码，所有代码请参见下面代码仓库
代码仓库
- GitHub - Harries/springboot-demo: a simple springboot demo with some components for example: redis,solr,rockmq and so on.(Resilience4J)
3.测试
1.启动Spring Boot应用程序
测试限流
public class ThreadTest {
public static void main(String[] args) {
for(int i=0;i<6;i++){
new Thread(()->{
System.out.println(new RestTemplate().getForObject("http://localhost:8080/hello",String.class));
}).start();
}
}
}
运行main方法
io.github.resilience4j.bulkhead.BulkheadFullException: Bulkhead 'backendA' is full and does not permit further calls
at io.github.resilience4j.bulkhead.BulkheadFullException.createBulkheadFullException(BulkheadFullException.java:49) ~[resilience4j-bulkhead-2.0.2.jar:2.0.2]
at io.github.resilience4j.bulkhead.internal.SemaphoreBulkhead.acquirePermission(SemaphoreBulkhead.java:164) ~[resilience4j-bulkhead-2.0.2.jar:2.0.2]
at io.github.resilience4j.bulkhead.Bulkhead.lambda$decorateCheckedSupplier$0(Bulkhead.java:68) ~[resilience4j-bulkhead-2.0.2.jar:2.0.2]
at io.github.resilience4j.bulkhead.Bulkhead.executeCheckedSupplier(Bulkhead.java:471) ~[resilience4j-bulkhead-2.0.2.jar:2.0.2]
at io.github.resilience4j.spring6.bulkhead.configure.BulkheadAspect.handleJoinPoint(BulkheadAspect.java:194) ~[resilience4j-spring6-2.0.2.jar:2.0.2]
at io.github.resilience4j.spring6.bulkhead.configure.BulkheadAspect.proceed(BulkheadAspect.java:147) ~[resilience4j-spring6-2.0.2.jar:2.0.2]
at io.github.resilience4j.spring6.bulkhead.configure.BulkheadAspect.lambda$bulkheadAroundAdvice$1(BulkheadAspect.java:120) ~[resilience4j-spring6-2.0.2.jar:2.0.2]
at io.github.resilience4j.spring6.fallback.FallbackExecutor.execute(FallbackExecutor.java:37) ~[resilience4j-spring6-2.0.2.jar:2.0.2]
at io.github.resilience4j.spring6.bulkhead.configure.BulkheadAspect.bulkheadAroundAdvice(BulkheadAspect.java:121) ~[resilience4j-spring6-2.0.2.jar:2.0.2]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) ~[na:na]
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
at java.base/java.lang.reflect.Method.invoke(Method.java:568) ~[na:na]
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:637) ~[spring-aop-6.1.2.jar:6.1.2]
测试重试
访问http://127.0.0.1:8080/retry?name=test
2024-08-03T23:16:32.092+08:00 INFO 5097 --- [resilience4j-demo] [nio-8080-exec-9] c.e.r.controller.HelloWorldController : retry time:1
2024-08-03T23:16:42.120+08:00 INFO 5097 --- [resilience4j-demo] [nio-8080-exec-9] c.e.r.controller.HelloWorldController : retry time:2
2024-08-03T23:17:02.142+08:00 INFO 5097 --- [resilience4j-demo] [nio-8080-exec-9] c.e.r.controller.HelloWorldController : retry time:3
2024-08-03T23:17:02.165+08:00 ERROR 5097 --- [resilience4j-demo] [nio-8080-exec-9] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed: org.springframework.web.client.HttpServerErrorException: 101 SWITCHING_PROTOCOLS] with root cause
org.springframework.web.client.HttpServerErrorException: 101 SWITCHING_PROTOCOLS
at com.et.resilience4j.controller.HelloWorldController.retry(HelloWorldController.java:37) ~[classes/:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) ~[na:na]
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
at java.base/java.lang.reflect.Method.invoke(Method.java:568) ~[na:na]
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:352) ~[spring-aop-6.1.2.jar:6.1.2]
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:196) ~[spring-aop-6.1.2.jar:6.1.2]
测试隔离
public class ThreadTest {
public static void main(String[] args) {
/* for(int i=0;i<6;i++){
new Thread(()->{
System.out.println(new RestTemplate().getForObject("http://localhost:8080/hello",String.class));
}).start();
}*/
for(int i=0;i<11;i++){
new Thread(()->{
System.out.println(new RestTemplate().getForObject("http://localhost:8080/bulkhead",String.class));
}).start();
}
}
}
运行main方法
2024-08-03T23:17:36.943+08:00 ERROR 5097 --- [resilience4j-demo] [nio-8080-exec-5] c.e.r.controller.HelloWorldController : fallback exception , RateLimiter 'ratelimitApi' does not permit further calls