sentinel 熔断降级
官网：https://sentinelguard.io/zh-cn/docs/circuit-breaking.html
熔断降级
熔断降级：服务由于响应慢、异常等原因触发熔断策略后，快速失败，避免线程堆积造成服务雪崩（熔断降级通常在调用端配置）
熔断策略
# 慢调用比例：SLOW_REQUEST_RATIO，以慢调用比例作为阈值
慢调用：如果一个请求的响应时间需要大于设置的慢调用响应时间（RT），该请求统计为慢调用；
熔断触发：单位统计时长（statIntervalMs）内请求数目大于设置的最小请求数目，并且慢调用的比例大于阈值，在熔断时长内自动触发熔断（调用方法时，抛出DegradeException）
熔断恢复：在熔断时长后，熔断器进入探测恢复状态（half-open状态），如果接下来的请求响应时间 < 设置的慢调用响应时间，则结束熔断如果接下来的请求响应时间 > 设置的慢调用响应时间，则继续在熔断时长内保持熔断# 异常比例 ：ERROR_RATIO，以请求异常比例作为阀值，阈值范围是[0.0, 1.0]
异常请求：请求调用抛出异常，则该请求统计为异常请求
熔断触发：单位统计时长（statIntervalMs）内请求数目 > 设置的最小请求数目，并且异常的比例 > 阈值，在熔断时长内自动被熔断
熔断恢复：在熔断时长后，熔断器进入探测恢复状态（HALF-OPEN 状态），如果接下来的一个请求执行成功，则结束熔断；如果请求执行失败，则继续在熔断时长内保持熔断# 异常数：ERROR_COUNT，以异常请求数作为阀值
异常请求：请求调用抛出异常，则该请求统计为异常请求
熔断触发：单位统计时长（statIntervalMs）内请求数目 > 设置的最小请求数目，并且异常请求 > 设置的异常请求数阀值，在熔断时长内自动被熔断
熔断恢复：在熔断时长后，熔断器进入探测恢复状态（HALF-OPEN 状态），如果接下来的一个请求执行成功，则结束熔断；如果请求执行失败，则继续在熔断时长内保持熔断
DegradeRule：熔断降级规则
public class DegradeRule extends AbstractRule {private int grade = 0; //熔断策略，支持慢调用比例（默认）、异常比例、异常数策略private double count; //限流阀值private int timeWindow; //熔断时间窗口，单位为秒private int minRequestAmount = 5; //最小请求数private double slowRatioThreshold = 1.0D; //慢调用比例阈值private int statIntervalMs = 1000; //统计时间窗口，默认1spublic DegradeRule() {}
AbstractRule
public abstract class AbstractRule implements Rule {private String resource; //限流资源private String limitApp; //调用来源、default、otherpublic AbstractRule() {}
实现原理
DegradeSlot
@SpiOrder(-1000)
public class DegradeSlot extends AbstractLinkedProcessorSlot<DefaultNode> {public DegradeSlot() {}public void entry(Context context, ResourceWrapper resourceWrapper, DefaultNode node, int count, boolean prioritized, Object... args) throws Throwable {this.performChecking(context, resourceWrapper); //检查熔断规则，如果触发熔断，直接抛出DegradeException异常this.fireEntry(context, resourceWrapper, node, count, prioritized, args);//追星后续限流操作}void performChecking(Context context, ResourceWrapper r) throws BlockException {List<CircuitBreaker> circuitBreakers = DegradeRuleManager.getCircuitBreakers(r.getName()); //获取资源相关的断路器if (circuitBreakers != null && !circuitBreakers.isEmpty()) {Iterator var4 = circuitBreakers.iterator();CircuitBreaker cb;do {if (!var4.hasNext()) {return;}cb = (CircuitBreaker)var4.next();} while(cb.tryPass(context)); //熔断窗口到期，检查单词请求是否可以通过throw new DegradeException(cb.getRule().getLimitApp(), cb.getRule());//熔断检查未通过，抛出DegradeException异常}}public void exit(Context context, ResourceWrapper r, int count, Object... args) {Entry curEntry = context.getCurEntry();if (curEntry.getBlockError() != null) {this.fireExit(context, r, count, args);} else {List<CircuitBreaker> circuitBreakers = DegradeRuleManager.getCircuitBreakers(r.getName());if (circuitBreakers != null && !circuitBreakers.isEmpty()) {if (curEntry.getBlockError() == null) {Iterator var7 = circuitBreakers.iterator();while(var7.hasNext()) {CircuitBreaker circuitBreaker = (CircuitBreaker)var7.next();circuitBreaker.onRequestComplete(context);}}this.fireExit(context, r, count, args);} else {this.fireExit(context, r, count, args);}}}
}
CircuitBreaker
public interface CircuitBreaker {DegradeRule getRule();boolean tryPass(Context var1);CircuitBreaker.State currentState();void onRequestComplete(Context var1);public static enum State {OPEN,HALF_OPEN,CLOSED;private State() {}}
}
AbstractCircuitBreaker
public abstract class AbstractCircuitBreaker implements CircuitBreaker {protected final DegradeRule rule;protected final int recoveryTimeoutMs;private final EventObserverRegistry observerRegistry;protected final AtomicReference<State> currentState;protected volatile long nextRetryTimestamp;public AbstractCircuitBreaker(DegradeRule rule) {this(rule, EventObserverRegistry.getInstance());}AbstractCircuitBreaker(DegradeRule rule, EventObserverRegistry observerRegistry) {this.currentState = new AtomicReference(State.CLOSED);AssertUtil.notNull(observerRegistry, "observerRegistry cannot be null");if (!DegradeRuleManager.isValidRule(rule)) {throw new IllegalArgumentException("Invalid DegradeRule: " + rule);} else {this.observerRegistry = observerRegistry;this.rule = rule;this.recoveryTimeoutMs = rule.getTimeWindow() * 1000;}}public DegradeRule getRule() {return this.rule;}public State currentState() {return (State)this.currentState.get();}public boolean tryPass(Context context) { //熔断检查if (this.currentState.get() == State.CLOSED) { //断路器为closed，返回truereturn true;} else if (this.currentState.get() != State.OPEN) { //断路器状态不为open，返回falsereturn false;} else {return this.retryTimeoutArrived() && this.fromOpenToHalfOpen(context);} //判断是否是请求重试时间，如果不是，直接返回false//如果是，断路器状态设置为HalfOpen，异步执行单次请求，//如果单次请求不通过，断路器状态切换为open，//如果单次请求通过，返回true，可执行后续限流操作}abstract void resetStat();protected boolean retryTimeoutArrived() {return TimeUtil.currentTimeMillis() >= this.nextRetryTimestamp;} //判断是否为请求重试时间protected void updateNextRetryTimestamp() {this.nextRetryTimestamp = TimeUtil.currentTimeMillis() + (long)this.recoveryTimeoutMs;} //下次重试时间：当前时间 + recoveryTimeoutMs（即rule.getTimeWindow() * 1000）protected boolean fromCloseToOpen(double snapshotValue) {State prev = State.CLOSED;if (this.currentState.compareAndSet(prev, State.OPEN)) {this.updateNextRetryTimestamp();this.notifyObservers(prev, State.OPEN, snapshotValue);return true;} else {return false;}}protected boolean fromOpenToHalfOpen(Context context) {if (this.currentState.compareAndSet(State.OPEN, State.HALF_OPEN)) {//使用cas将断路器状态设置为HALF_OPENthis.notifyObservers(State.OPEN, State.HALF_OPEN, (Double)null);Entry entry = context.getCurEntry();entry.whenTerminate(new BiConsumer<Context, Entry>() {public void accept(Context context, Entry entry) {if (entry.getBlockError() != null) {//请求出现异常，状态设置为openAbstractCircuitBreaker.this.currentState.compareAndSet(State.HALF_OPEN, State.OPEN);AbstractCircuitBreaker.this.notifyObservers(State.HALF_OPEN, State.OPEN, 1.0D);}}});return true; //如果没有异常，返回true} else {return false;}}private void notifyObservers(State prevState, State newState, Double snapshotValue) {Iterator var4 = this.observerRegistry.getStateChangeObservers().iterator();while(var4.hasNext()) {CircuitBreakerStateChangeObserver observer = (CircuitBreakerStateChangeObserver)var4.next();observer.onStateChange(prevState, newState, this.rule, snapshotValue);}}protected boolean fromHalfOpenToOpen(double snapshotValue) {if (this.currentState.compareAndSet(State.HALF_OPEN, State.OPEN)) {this.updateNextRetryTimestamp();this.notifyObservers(State.HALF_OPEN, State.OPEN, snapshotValue);return true;} else {return false;}}protected boolean fromHalfOpenToClose() {if (this.currentState.compareAndSet(State.HALF_OPEN, State.CLOSED)) {this.resetStat();this.notifyObservers(State.HALF_OPEN, State.CLOSED, (Double)null);return true;} else {return false;}}protected void transformToOpen(double triggerValue) {State cs = (State)this.currentState.get();switch(cs) {case CLOSED:this.fromCloseToOpen(triggerValue);break;case HALF_OPEN:this.fromHalfOpenToOpen(triggerValue);}}
}
使用示例
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服务端
application.yml
spring:application:name: nacos-providercloud:nacos:discovery:server-addr: localhost:8848dubbo:#registry:# address: spring-cloud://localhost:8848protocol:name: dubboport: -1
HelloService
public interface HelloService {String hello();
}
HelloServiceImpl
@DubboService
public class HelloServiceImpl implements HelloService {@Overridepublic String hello() {throw new RpcException("出错了");}
}
DemoApplication
@EnableDubbo //开启dubbo
@SpringBootApplication
public class DemoApplication {public static void main(String[] args) {SpringApplication.run(DemoApplication.class, args);}}
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消费端
application.yml
spring:application:name: nacos-providercloud:nacos:discovery:server-addr: localhost:8848dubbo:#registry:# address: spring-cloud://localhost:8848protocol:name: dubboport: -1
CustomDegradeRule
public class CustomDegradeRule implements InitFunc {@Overridepublic void init() throws Exception {DegradeRule degradeRule = new DegradeRule("com.example.demo.service.HelloService:hello()");degradeRule.setGrade(RuleConstant.DEGRADE_GRADE_EXCEPTION_COUNT).setCount(1).setMinRequestAmount(5).setTimeWindow(10);DegradeRuleManager.loadRules(Collections.singletonList(degradeRule));}
}
HelloService
public interface HelloService {String hello();
}
HelloController
@RestController
public class HelloController {@DubboReference//@DubboReference(mock = "true")private HelloService helloService;@RequestMapping("/hello")public String hello(){System.out.println(helloService.hello());return "success";}
}
DemoApplication
@EnableDubbo
@SpringBootApplication
public class DemoApplication {public static void main(String[] args) {SpringApplication.run(DemoApplication.class, args);}}
META-INF/services/com.alibaba.csp.sentinel.init.InitFunc
com.example.demo.config.CustomDegradeRule
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jmeter 测试
线程组、http请求
查看结果树
2022-04-06 17:08:19.155 WARN 4870 --- [client.listener] a.c.d.m.r.DubboServiceMetadataRepository : Current application will subscribe all services(size:2) in registry, a lot of memory and CPU cycles may be used, thus it's strongly recommend you using the externalized property 'dubbo.cloud.subscribed-services' to specify the services
2022-04-06 17:08:21.411 INFO 4870 --- [erverWorker-4-1] o.a.d.r.t.netty4.NettyServerHandler : [DUBBO] The connection of /192.168.5.9:54897 -> /192.168.5.9:20881 is established., dubbo version: 2.7.8, current host: 192.168.5.9
2022-04-06 17:08:23.509 INFO 4870 --- [nio-8081-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring DispatcherServlet 'dispatcherServlet'
2022-04-06 17:08:23.509 INFO 4870 --- [nio-8081-exec-1] o.s.web.servlet.DispatcherServlet : Initializing Servlet 'dispatcherServlet'
2022-04-06 17:08:23.523 INFO 4870 --- [nio-8081-exec-1] o.s.web.servlet.DispatcherServlet : Completed initialization in 13 ms
2022-04-06 17:08:23.550 ERROR 4870 --- [nio-8081-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.apache.dubbo.rpc.RpcException: 出错了] with root causeorg.apache.dubbo.rpc.RpcException: 出错了at com.example.demo.service.impl.HelloServiceImpl.hello(HelloServiceImpl.java:12) ~[na:na]at org.apache.dubbo.common.bytecode.Wrapper3.invokeMethod(Wrapper3.java) ~[na:na]at org.apache.dubbo.rpc.proxy.javassist.JavassistProxyFactory$1.doInvoke(JavassistProxyFactory.java:47) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.proxy.AbstractProxyInvoker.invoke(AbstractProxyInvoker.java:84) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.config.invoker.DelegateProviderMetaDataInvoker.invoke(DelegateProviderMetaDataInvoker.java:56) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.InvokerWrapper.invoke(InvokerWrapper.java:56) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.ExceptionFilter.invoke(ExceptionFilter.java:52) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at com.alibaba.csp.sentinel.adapter.dubbo.SentinelDubboProviderFilter.invoke(SentinelDubboProviderFilter.java:80) ~[sentinel-apache-dubbo-adapter-1.8.0.jar:na]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.monitor.support.MonitorFilter.invoke(MonitorFilter.java:89) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.TimeoutFilter.invoke(TimeoutFilter.java:46) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.dubbo.filter.TraceFilter.invoke(TraceFilter.java:77) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.ContextFilter.invoke(ContextFilter.java:129) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.GenericFilter.invoke(GenericFilter.java:152) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.ClassLoaderFilter.invoke(ClassLoaderFilter.java:38) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.EchoFilter.invoke(EchoFilter.java:41) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.dubbo.DubboProtocol$1.reply(DubboProtocol.java:145) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.remoting.exchange.support.header.HeaderExchangeHandler.handleRequest(HeaderExchangeHandler.java:100) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.remoting.exchange.support.header.HeaderExchangeHandler.received(HeaderExchangeHandler.java:175) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.remoting.transport.DecodeHandler.received(DecodeHandler.java:51) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.remoting.transport.dispatcher.ChannelEventRunnable.run(ChannelEventRunnable.java:57) ~[dubbo-2.7.8.jar:2.7.8]at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) ~[na:1.8.0_211]at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) ~[na:1.8.0_211]at java.lang.Thread.run(Thread.java:748) [na:1.8.0_211]2022-04-06 17:08:23.591 ERROR 4870 --- [nio-8081-exec-2] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.apache.dubbo.rpc.RpcException: 出错了] with root causeorg.apache.dubbo.rpc.RpcException: 出错了at com.example.demo.service.impl.HelloServiceImpl.hello(HelloServiceImpl.java:12) ~[na:na]at org.apache.dubbo.common.bytecode.Wrapper3.invokeMethod(Wrapper3.java) ~[na:na]at org.apache.dubbo.rpc.proxy.javassist.JavassistProxyFactory$1.doInvoke(JavassistProxyFactory.java:47) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.proxy.AbstractProxyInvoker.invoke(AbstractProxyInvoker.java:84) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.config.invoker.DelegateProviderMetaDataInvoker.invoke(DelegateProviderMetaDataInvoker.java:56) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.InvokerWrapper.invoke(InvokerWrapper.java:56) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.ExceptionFilter.invoke(ExceptionFilter.java:52) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at com.alibaba.csp.sentinel.adapter.dubbo.SentinelDubboProviderFilter.invoke(SentinelDubboProviderFilter.java:80) ~[sentinel-apache-dubbo-adapter-1.8.0.jar:na]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.monitor.support.MonitorFilter.invoke(MonitorFilter.java:89) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.TimeoutFilter.invoke(TimeoutFilter.java:46) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.dubbo.filter.TraceFilter.invoke(TraceFilter.java:77) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.ContextFilter.invoke(ContextFilter.java:129) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.GenericFilter.invoke(GenericFilter.java:152) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.ClassLoaderFilter.invoke(ClassLoaderFilter.java:38) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.EchoFilter.invoke(EchoFilter.java:41) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.dubbo.DubboProtocol$1.reply(DubboProtocol.java:145) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.remoting.exchange.support.header.HeaderExchangeHandler.handleRequest(HeaderExchangeHandler.java:100) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.remoting.exchange.support.header.HeaderExchangeHandler.received(HeaderExchangeHandler.java:175) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.remoting.transport.DecodeHandler.received(DecodeHandler.java:51) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.remoting.transport.dispatcher.ChannelEventRunnable.run(ChannelEventRunnable.java:57) ~[dubbo-2.7.8.jar:2.7.8]at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) ~[na:1.8.0_211]at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) ~[na:1.8.0_211]at java.lang.Thread.run(Thread.java:748) [na:1.8.0_211]2022-04-06 17:08:23.602 ERROR 4870 --- [nio-8081-exec-3] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.apache.dubbo.rpc.RpcException: 出错了] with root causeorg.apache.dubbo.rpc.RpcException: 出错了at com.example.demo.service.impl.HelloServiceImpl.hello(HelloServiceImpl.java:12) ~[na:na]at org.apache.dubbo.common.bytecode.Wrapper3.invokeMethod(Wrapper3.java) ~[na:na]at org.apache.dubbo.rpc.proxy.javassist.JavassistProxyFactory$1.doInvoke(JavassistProxyFactory.java:47) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.proxy.AbstractProxyInvoker.invoke(AbstractProxyInvoker.java:84) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.config.invoker.DelegateProviderMetaDataInvoker.invoke(DelegateProviderMetaDataInvoker.java:56) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.InvokerWrapper.invoke(InvokerWrapper.java:56) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.ExceptionFilter.invoke(ExceptionFilter.java:52) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at com.alibaba.csp.sentinel.adapter.dubbo.SentinelDubboProviderFilter.invoke(SentinelDubboProviderFilter.java:80) ~[sentinel-apache-dubbo-adapter-1.8.0.jar:na]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.monitor.support.MonitorFilter.invoke(MonitorFilter.java:89) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.TimeoutFilter.invoke(TimeoutFilter.java:46) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.dubbo.filter.TraceFilter.invoke(TraceFilter.java:77) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.ContextFilter.invoke(ContextFilter.java:129) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.GenericFilter.invoke(GenericFilter.java:152) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.ClassLoaderFilter.invoke(ClassLoaderFilter.java:38) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.EchoFilter.invoke(EchoFilter.java:41) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.dubbo.DubboProtocol$1.reply(DubboProtocol.java:145) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.remoting.exchange.support.header.HeaderExchangeHandler.handleRequest(HeaderExchangeHandler.java:100) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.remoting.exchange.support.header.HeaderExchangeHandler.received(HeaderExchangeHandler.java:175) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.remoting.transport.DecodeHandler.received(DecodeHandler.java:51) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.remoting.transport.dispatcher.ChannelEventRunnable.run(ChannelEventRunnable.java:57) ~[dubbo-2.7.8.jar:2.7.8]at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) ~[na:1.8.0_211]at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) ~[na:1.8.0_211]at java.lang.Thread.run(Thread.java:748) [na:1.8.0_211]2022-04-06 17:08:23.610 ERROR 4870 --- [nio-8081-exec-4] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.apache.dubbo.rpc.RpcException: 出错了] with root causeorg.apache.dubbo.rpc.RpcException: 出错了at com.example.demo.service.impl.HelloServiceImpl.hello(HelloServiceImpl.java:12) ~[na:na]at org.apache.dubbo.common.bytecode.Wrapper3.invokeMethod(Wrapper3.java) ~[na:na]at org.apache.dubbo.rpc.proxy.javassist.JavassistProxyFactory$1.doInvoke(JavassistProxyFactory.java:47) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.proxy.AbstractProxyInvoker.invoke(AbstractProxyInvoker.java:84) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.config.invoker.DelegateProviderMetaDataInvoker.invoke(DelegateProviderMetaDataInvoker.java:56) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.InvokerWrapper.invoke(InvokerWrapper.java:56) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.ExceptionFilter.invoke(ExceptionFilter.java:52) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at com.alibaba.csp.sentinel.adapter.dubbo.SentinelDubboProviderFilter.invoke(SentinelDubboProviderFilter.java:80) ~[sentinel-apache-dubbo-adapter-1.8.0.jar:na]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.monitor.support.MonitorFilter.invoke(MonitorFilter.java:89) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.TimeoutFilter.invoke(TimeoutFilter.java:46) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.dubbo.filter.TraceFilter.invoke(TraceFilter.java:77) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.ContextFilter.invoke(ContextFilter.java:129) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.GenericFilter.invoke(GenericFilter.java:152) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.ClassLoaderFilter.invoke(ClassLoaderFilter.java:38) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.EchoFilter.invoke(EchoFilter.java:41) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.dubbo.DubboProtocol$1.reply(DubboProtocol.java:145) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.remoting.exchange.support.header.HeaderExchangeHandler.handleRequest(HeaderExchangeHandler.java:100) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.remoting.exchange.support.header.HeaderExchangeHandler.received(HeaderExchangeHandler.java:175) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.remoting.transport.DecodeHandler.received(DecodeHandler.java:51) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.remoting.transport.dispatcher.ChannelEventRunnable.run(ChannelEventRunnable.java:57) ~[dubbo-2.7.8.jar:2.7.8]at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) ~[na:1.8.0_211]at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) ~[na:1.8.0_211]at java.lang.Thread.run(Thread.java:748) [na:1.8.0_211]2022-04-06 17:08:23.618 ERROR 4870 --- [nio-8081-exec-5] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.apache.dubbo.rpc.RpcException: 出错了] with root causeorg.apache.dubbo.rpc.RpcException: 出错了at com.example.demo.service.impl.HelloServiceImpl.hello(HelloServiceImpl.java:12) ~[na:na]at org.apache.dubbo.common.bytecode.Wrapper3.invokeMethod(Wrapper3.java) ~[na:na]at org.apache.dubbo.rpc.proxy.javassist.JavassistProxyFactory$1.doInvoke(JavassistProxyFactory.java:47) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.proxy.AbstractProxyInvoker.invoke(AbstractProxyInvoker.java:84) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.config.invoker.DelegateProviderMetaDataInvoker.invoke(DelegateProviderMetaDataInvoker.java:56) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.InvokerWrapper.invoke(InvokerWrapper.java:56) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.ExceptionFilter.invoke(ExceptionFilter.java:52) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at com.alibaba.csp.sentinel.adapter.dubbo.SentinelDubboProviderFilter.invoke(SentinelDubboProviderFilter.java:80) ~[sentinel-apache-dubbo-adapter-1.8.0.jar:na]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.monitor.support.MonitorFilter.invoke(MonitorFilter.java:89) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.TimeoutFilter.invoke(TimeoutFilter.java:46) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.dubbo.filter.TraceFilter.invoke(TraceFilter.java:77) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.ContextFilter.invoke(ContextFilter.java:129) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.GenericFilter.invoke(GenericFilter.java:152) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.ClassLoaderFilter.invoke(ClassLoaderFilter.java:38) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.filter.EchoFilter.invoke(EchoFilter.java:41) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.rpc.protocol.dubbo.DubboProtocol$1.reply(DubboProtocol.java:145) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.remoting.exchange.support.header.HeaderExchangeHandler.handleRequest(HeaderExchangeHandler.java:100) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.remoting.exchange.support.header.HeaderExchangeHandler.received(HeaderExchangeHandler.java:175) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.remoting.transport.DecodeHandler.received(DecodeHandler.java:51) ~[dubbo-2.7.8.jar:2.7.8]at org.apache.dubbo.remoting.transport.dispatcher.ChannelEventRunnable.run(ChannelEventRunnable.java:57) ~[dubbo-2.7.8.jar:2.7.8]at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) ~[na:1.8.0_211]at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) ~[na:1.8.0_211]at java.lang.Thread.run(Thread.java:748) [na:1.8.0_211]2022-04-06 17:08:23.640 ERROR 4870 --- [nio-8081-exec-6] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.RuntimeException: SentinelBlockException: DegradeException] with root causejava.lang.RuntimeException: SentinelBlockException: DegradeExceptionat com.alibaba.csp.sentinel.slots.block.BlockException.block(BlockException:0) ~[sentinel-core-1.8.0.jar:1.8.0]2022-04-06 17:08:23.644 ERROR 4870 --- [nio-8081-exec-7] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.RuntimeException: SentinelBlockException: DegradeException] with root causejava.lang.RuntimeException: SentinelBlockException: DegradeExceptionat com.alibaba.csp.sentinel.slots.block.BlockException.block(BlockException:0) ~[sentinel-core-1.8.0.jar:1.8.0]2022-04-06 17:08:23.649 ERROR 4870 --- [nio-8081-exec-8] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.RuntimeException: SentinelBlockException: DegradeException] with root causejava.lang.RuntimeException: SentinelBlockException: DegradeExceptionat com.alibaba.csp.sentinel.slots.block.BlockException.block(BlockException:0) ~[sentinel-core-1.8.0.jar:1.8.0]2022-04-06 17:08:23.653 ERROR 4870 --- [nio-8081-exec-9] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.RuntimeException: SentinelBlockException: DegradeException] with root causejava.lang.RuntimeException: SentinelBlockException: DegradeExceptionat com.alibaba.csp.sentinel.slots.block.BlockException.block(BlockException:0) ~[sentinel-core-1.8.0.jar:1.8.0]2022-04-06 17:08:23.658 ERROR 4870 --- [io-8081-exec-10] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.RuntimeException: SentinelBlockException: DegradeException] with root causejava.lang.RuntimeException: SentinelBlockException: DegradeExceptionat com.alibaba.csp.sentinel.slots.block.BlockException.block(BlockException:0) ~[sentinel-core-1.8.0.jar:1.8.0]说明：前5次输出RpcException，后5次由于触发熔断降级，抛出DegradeException
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dubbo mock降级
HelloServiceMock
public class HelloServiceMock implements HelloService {@Overridepublic String hello() {return "调用出错，本地降级";}
}
HelloController
@RestController
public class HelloController {//@DubboReference@DubboReference(mock = "true")private HelloService helloService;@RequestMapping("/hello")public String hello(){System.out.println(helloService.hello());return "success";}
}
查看结果树
# 消费端控制台输出
2022-04-06 17:04:08.691 INFO 4800 --- [ main] com.example.demo.DemoApplication : Started DemoApplication in 3.907 seconds (JVM running for 4.626)
2022-04-06 17:04:09.611 WARN 4800 --- [client.listener] a.c.d.m.r.DubboServiceMetadataRepository : Current application will subscribe all services(size:2) in registry, a lot of memory and CPU cycles may be used, thus it's strongly recommend you using the externalized property 'dubbo.cloud.subscribed-services' to specify the services
2022-04-06 17:04:11.063 INFO 4800 --- [erverWorker-4-1] o.a.d.r.t.netty4.NettyServerHandler : [DUBBO] The connection of /192.168.5.9:54787 -> /192.168.5.9:20881 is established., dubbo version: 2.7.8, current host: 192.168.5.9
2022-04-06 17:04:11.654 INFO 4800 --- [nio-8081-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring DispatcherServlet 'dispatcherServlet'
2022-04-06 17:04:11.654 INFO 4800 --- [nio-8081-exec-1] o.s.web.servlet.DispatcherServlet : Initializing Servlet 'dispatcherServlet'
2022-04-06 17:04:11.668 INFO 4800 --- [nio-8081-exec-1] o.s.web.servlet.DispatcherServlet : Completed initialization in 14 ms
调用出错，本地降级
调用出错，本地降级
调用出错，本地降级
调用出错，本地降级
调用出错，本地降级
2022-04-06 17:04:11.777 ERROR 4800 --- [nio-8081-exec-5] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.RuntimeException: SentinelBlockException: DegradeException] with root causejava.lang.RuntimeException: SentinelBlockException: DegradeExceptionat com.alibaba.csp.sentinel.slots.block.BlockException.block(BlockException:0) ~[sentinel-core-1.8.0.jar:1.8.0]2022-04-06 17:04:11.795 ERROR 4800 --- [nio-8081-exec-6] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.RuntimeException: SentinelBlockException: DegradeException] with root causejava.lang.RuntimeException: SentinelBlockException: DegradeExceptionat com.alibaba.csp.sentinel.slots.block.BlockException.block(BlockException:0) ~[sentinel-core-1.8.0.jar:1.8.0]2022-04-06 17:04:11.800 ERROR 4800 --- [nio-8081-exec-7] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.RuntimeException: SentinelBlockException: DegradeException] with root causejava.lang.RuntimeException: SentinelBlockException: DegradeExceptionat com.alibaba.csp.sentinel.slots.block.BlockException.block(BlockException:0) ~[sentinel-core-1.8.0.jar:1.8.0]2022-04-06 17:04:11.805 ERROR 4800 --- [nio-8081-exec-8] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.RuntimeException: SentinelBlockException: DegradeException] with root causejava.lang.RuntimeException: SentinelBlockException: DegradeExceptionat com.alibaba.csp.sentinel.slots.block.BlockException.block(BlockException:0) ~[sentinel-core-1.8.0.jar:1.8.0]2022-04-06 17:04:11.809 ERROR 4800 --- [nio-8081-exec-9] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.RuntimeException: SentinelBlockException: DegradeException] with root causejava.lang.RuntimeException: SentinelBlockException: DegradeExceptionat com.alibaba.csp.sentinel.slots.block.BlockException.block(BlockException:0) ~[sentinel-core-1.8.0.jar:1.8.0]说明：前5次请求服务端抛出RpcExeption，消费端使用mock降级；后5次由于消费端触发sentinel熔断，直接抛出DegradeException
