### Environment * Dubbo version: 2.6.x * Operating System version: mac * Java version: 1.8
### Steps to reproduce this issue 1. when use multicast as registry (It work well when using zookeeper) 2. use @Reference to get the consumer You can write a demo base on dubbo demo module, just modify 3 files. 1.Add new configuration file (dubbo-demo2-consumer.xml): ``` <?xml version="1.0" encoding="UTF-8"?> <beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"; xmlns:dubbo="http://dubbo.apache.org/schema/dubbo"; xmlns:context="http://www.springframework.org/schema/context"; xmlns="http://www.springframework.org/schema/beans"; xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd http://dubbo.apache.org/schema/dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd";> <!-- consumer's application name, used for tracing dependency relationship (not a matching criterion), don't set it same as provider --> <dubbo:application name="demo-consumer"/> <!-- use multicast registry center to discover service --> <dubbo:registry address="zookeeper://127.0.0.1:2181"/> <!-- generate proxy for the remote service, then demoService can be used in the same way as the local regular interface --> <dubbo:annotation/> <context:component-scan base-package="com.alibaba.dubbo.demo.consumer"> <context:include-filter type="annotation" expression="com.alibaba.dubbo.config.annotation.Reference"/> </context:component-scan> </beans> ``` 2.new service to consumer package: ``` @Service public class ConsumerService { @Reference(parameters = {"k1", "v1"}) private DemoService demoService; public void testReference() { System.out.println(demoService.sayHello("www.world")); } } ``` 3.new main File : ``` public class Consumer2 { public static void main(String[] args) { //Prevent to get IPV6 address,this way only work in debug mode //But you can pass use -Djava.net.preferIPv4Stack=true,then it work well whether in debug mode or not System.setProperty("java.net.preferIPv4Stack", "true"); ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(new String[]{"META-INF/spring/dubbo-demo2-consumer.xml"}); context.start(); ConsumerService consumerService = (ConsumerService) context.getBean(ConsumerService.class); // get remote service proxy while (true) { try { Thread.sleep(1000); consumerService.testReference(); // call remote method } catch (Throwable throwable) { throwable.printStackTrace(); } } } } ``` ### Actual Result when start the consumer, the program has no response. so I print the jstack trace as follow: ``` Found one Java-level deadlock: ============================= "DubboMulticastRegistryReceiver": waiting to lock monitor 0x00007fde47292668 (object 0x000000076eb01868, a java.util.concurrent.ConcurrentHashMap), which is held by "main" "main": waiting to lock monitor 0x00007fde4a810488 (object 0x000000076eb5e4c0, a com.alibaba.dubbo.registry.integration.RegistryDirectory), which is held by "DubboMulticastRegistryReceiver" Java stack information for the threads listed above: =================================================== "DubboMulticastRegistryReceiver": at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:188) - waiting to lock <0x000000076eb01868> (a java.util.concurrent.ConcurrentHashMap) at org.springframework.beans.factory.support.AbstractBeanFactory.isTypeMatch(AbstractBeanFactory.java:492) at org.springframework.beans.factory.support.DefaultListableBeanFactory.doGetBeanNamesForType(DefaultListableBeanFactory.java:432) at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanNamesForType(DefaultListableBeanFactory.java:403) at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanNamesForType(DefaultListableBeanFactory.java:389) at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveNamedBean(DefaultListableBeanFactory.java:1002) at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:345) at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:340) at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1092) at com.alibaba.dubbo.config.spring.extension.SpringExtensionFactory.getExtension(SpringExtensionFactory.java:67) at com.alibaba.dubbo.common.extension.factory.AdaptiveExtensionFactory.getExtension(AdaptiveExtensionFactory.java:47) at com.alibaba.dubbo.common.extension.ExtensionLoader.injectExtension(ExtensionLoader.java:521) at com.alibaba.dubbo.common.extension.ExtensionLoader.createExtension(ExtensionLoader.java:497) at com.alibaba.dubbo.common.extension.ExtensionLoader.getExtension(ExtensionLoader.java:309) - locked <0x000000076b5ff4d8> (a com.alibaba.dubbo.common.utils.Holder) at com.alibaba.dubbo.common.extension.ExtensionLoader.getActivateExtension(ExtensionLoader.java:193) at com.alibaba.dubbo.common.extension.ExtensionLoader.getActivateExtension(ExtensionLoader.java:172) at com.alibaba.dubbo.rpc.protocol.ProtocolFilterWrapper.buildInvokerChain(ProtocolFilterWrapper.java:48) at com.alibaba.dubbo.rpc.protocol.ProtocolFilterWrapper.refer(ProtocolFilterWrapper.java:108) at com.alibaba.dubbo.rpc.Protocol$Adaptive.refer(Protocol$Adaptive.java) at com.alibaba.dubbo.registry.integration.RegistryDirectory.toInvokers(RegistryDirectory.java:387) at com.alibaba.dubbo.registry.integration.RegistryDirectory.refreshInvoker(RegistryDirectory.java:253) at com.alibaba.dubbo.registry.integration.RegistryDirectory.notify(RegistryDirectory.java:223) - locked <0x000000076eb5e4c0> (a com.alibaba.dubbo.registry.integration.RegistryDirectory) at com.alibaba.dubbo.registry.support.AbstractRegistry.notify(AbstractRegistry.java:414) at com.alibaba.dubbo.registry.support.FailbackRegistry.doNotify(FailbackRegistry.java:280) at com.alibaba.dubbo.registry.support.FailbackRegistry.notify(FailbackRegistry.java:266) at com.alibaba.dubbo.registry.multicast.MulticastRegistry.registered(MulticastRegistry.java:333) at com.alibaba.dubbo.registry.multicast.MulticastRegistry.receive(MulticastRegistry.java:209) at com.alibaba.dubbo.registry.multicast.MulticastRegistry.access$100(MulticastRegistry.java:54) at com.alibaba.dubbo.registry.multicast.MulticastRegistry$1.run(MulticastRegistry.java:104) at java.lang.Thread.run(Thread.java:748) "main": at java.lang.Object.wait(Native Method) - waiting on <0x000000076eb5e4c0> (a com.alibaba.dubbo.registry.integration.RegistryDirectory) at com.alibaba.dubbo.registry.multicast.MulticastRegistry.doSubscribe(MulticastRegistry.java:278) - locked <0x000000076eb5e4c0> (a com.alibaba.dubbo.registry.integration.RegistryDirectory) at com.alibaba.dubbo.registry.support.FailbackRegistry.subscribe(FailbackRegistry.java:196) at com.alibaba.dubbo.registry.multicast.MulticastRegistry.subscribe(MulticastRegistry.java:394) at com.alibaba.dubbo.registry.integration.RegistryDirectory.subscribe(RegistryDirectory.java:159) at com.alibaba.dubbo.registry.integration.RegistryProtocol.doRefer(RegistryProtocol.java:306) at com.alibaba.dubbo.registry.integration.RegistryProtocol.refer(RegistryProtocol.java:287) at com.alibaba.dubbo.rpc.protocol.ProtocolListenerWrapper.refer(ProtocolListenerWrapper.java:65) at com.alibaba.dubbo.rpc.protocol.ProtocolFilterWrapper.refer(ProtocolFilterWrapper.java:106) at com.alibaba.dubbo.rpc.Protocol$Adaptive.refer(Protocol$Adaptive.java) at com.alibaba.dubbo.config.ReferenceConfig.createProxy(ReferenceConfig.java:394) at com.alibaba.dubbo.config.ReferenceConfig.init(ReferenceConfig.java:333) at com.alibaba.dubbo.config.ReferenceConfig.get(ReferenceConfig.java:163) - locked <0x000000076eb00f18> (a com.alibaba.dubbo.config.spring.ReferenceBean) at com.alibaba.dubbo.config.spring.ReferenceBean.getObject(ReferenceBean.java:66) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at com.alibaba.dubbo.config.AbstractConfig.toString(AbstractConfig.java:466) at java.lang.String.valueOf(String.java:2994) at java.lang.StringBuilder.append(StringBuilder.java:131) at com.alibaba.dubbo.config.spring.beans.factory.annotation.AbstractAnnotationConfigBeanBuilder.build(AbstractAnnotationConfigBeanBuilder.java:79) at com.alibaba.dubbo.config.spring.beans.factory.annotation.ReferenceAnnotationBeanPostProcessor.buildReferenceBean(ReferenceAnnotationBeanPostProcessor.java:385) at com.alibaba.dubbo.config.spring.beans.factory.annotation.ReferenceAnnotationBeanPostProcessor.access$100(ReferenceAnnotationBeanPostProcessor.java:65) at com.alibaba.dubbo.config.spring.beans.factory.annotation.ReferenceAnnotationBeanPostProcessor$ReferenceFieldElement.inject(ReferenceAnnotationBeanPostProcessor.java:363) at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88) at com.alibaba.dubbo.config.spring.beans.factory.annotation.ReferenceAnnotationBeanPostProcessor.postProcessPropertyValues(ReferenceAnnotationBeanPostProcessor.java:92) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1268) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:553) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:312) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) - locked <0x000000076eb01868> (a java.util.concurrent.ConcurrentHashMap) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:308) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:761) at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543) - locked <0x000000076ec5b718> (a java.lang.Object) at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139) at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:93) at com.alibaba.dubbo.demo.consumer.Consumer2.main(Consumer2.java:15) Found 1 deadlock. ``` [ Full content available at: https://github.com/apache/incubator-dubbo/issues/2539 ] This message was relayed via gitbox.apache.org for [email protected]
