Compatibility with dubbo registry zookeeper

[songxiaosheng]

Describe the bug
Please provide details of the problem, including the version of Spring Cloud that you
are using.

java.lang.RuntimeException: java.lang.ClassCastException: Cannot cast org.springframework.cloud.zookeeper.discovery.ZookeeperInstance to org.apache.dubbo.registry.zookeeper.ZookeeperInstance
	at org.apache.dubbo.common.function.ThrowableFunction.execute(ThrowableFunction.java:54) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.common.function.ThrowableFunction.execute(ThrowableFunction.java:69) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.registry.zookeeper.ZookeeperServiceDiscovery.doInServiceDiscovery(ZookeeperServiceDiscovery.java:188) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.registry.zookeeper.ZookeeperServiceDiscovery.getInstances(ZookeeperServiceDiscovery.java:147) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.registry.client.ServiceDiscoveryRegistry.subscribeURLs(ServiceDiscoveryRegistry.java:319) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.registry.client.ServiceDiscoveryRegistry.doSubscribe(ServiceDiscoveryRegistry.java:225) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.registry.client.ServiceDiscoveryRegistry.subscribe(ServiceDiscoveryRegistry.java:187) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.registry.ListenerRegistryWrapper.subscribe(ListenerRegistryWrapper.java:88) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.registry.integration.DynamicDirectory.subscribe(DynamicDirectory.java:184) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.registry.client.ServiceDiscoveryRegistryDirectory.subscribe(ServiceDiscoveryRegistryDirectory.java:134) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.registry.integration.RegistryProtocol.doCreateInvoker(RegistryProtocol.java:581) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.registry.integration.InterfaceCompatibleRegistryProtocol.getServiceDiscoveryInvoker(InterfaceCompatibleRegistryProtocol.java:65) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.registry.client.migration.MigrationInvoker.refreshServiceDiscoveryInvoker(MigrationInvoker.java:440) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.registry.client.migration.MigrationInvoker.migrateToApplicationFirstInvoker(MigrationInvoker.java:246) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.registry.client.migration.MigrationRuleHandler.refreshInvoker(MigrationRuleHandler.java:76) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.registry.client.migration.MigrationRuleHandler.doMigrate(MigrationRuleHandler.java:60) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.registry.client.migration.MigrationRuleListener.onRefer(MigrationRuleListener.java:249) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.registry.integration.RegistryProtocol.interceptInvoker(RegistryProtocol.java:546) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.registry.integration.RegistryProtocol.doRefer(RegistryProtocol.java:516) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.registry.integration.RegistryProtocol.refer(RegistryProtocol.java:498) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.qos.protocol.QosProtocolWrapper.refer(QosProtocolWrapper.java:85) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.rpc.protocol.ProtocolListenerWrapper.refer(ProtocolListenerWrapper.java:80) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.rpc.protocol.ProtocolSecurityWrapper.refer(ProtocolSecurityWrapper.java:107) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.rpc.cluster.filter.ProtocolFilterWrapper.refer(ProtocolFilterWrapper.java:71) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.rpc.protocol.ProtocolSerializationWrapper.refer(ProtocolSerializationWrapper.java:52) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.rpc.protocol.InvokerCountWrapper.refer(InvokerCountWrapper.java:48) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.rpc.Protocol$Adaptive.refer(Protocol$Adaptive.java) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.config.ReferenceConfig.createInvoker(ReferenceConfig.java:586) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.config.ReferenceConfig.createProxy(ReferenceConfig.java:432) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.config.ReferenceConfig.init(ReferenceConfig.java:295) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.config.ReferenceConfig.get(ReferenceConfig.java:231) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.config.utils.SimpleReferenceCache.destroyReference(SimpleReferenceCache.java:265) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.config.utils.SimpleReferenceCache.destroy(SimpleReferenceCache.java:218) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.config.utils.SimpleReferenceCache.destroy(SimpleReferenceCache.java:242) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.config.deploy.DefaultModuleDeployer.lambda$referServices$6(DefaultModuleDeployer.java:414) ~[dubbo-3.2.0.jar:3.2.0]
	at java.base/java.util.concurrent.ConcurrentHashMap$ValuesView.forEach(ConcurrentHashMap.java:4783) ~[na:na]
	at org.apache.dubbo.config.deploy.DefaultModuleDeployer.referServices(DefaultModuleDeployer.java:389) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.config.deploy.DefaultModuleDeployer.startSync(DefaultModuleDeployer.java:170) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.config.deploy.DefaultModuleDeployer.start(DefaultModuleDeployer.java:142) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.config.spring.context.DubboDeployApplicationListener.onContextRefreshedEvent(DubboDeployApplicationListener.java:113) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.config.spring.context.DubboDeployApplicationListener.onApplicationEvent(DubboDeployApplicationListener.java:102) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.config.spring.context.DubboDeployApplicationListener.onApplicationEvent(DubboDeployApplicationListener.java:47) ~[dubbo-3.2.0.jar:3.2.0]
	at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:176) ~[spring-context-6.0.8.jar:6.0.8]
	at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:169) ~[spring-context-6.0.8.jar:6.0.8]
	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:143) ~[spring-context-6.0.8.jar:6.0.8]
	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:413) ~[spring-context-6.0.8.jar:6.0.8]
	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:370) ~[spring-context-6.0.8.jar:6.0.8]
	at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:937) ~[spring-context-6.0.8.jar:6.0.8]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:587) ~[spring-context-6.0.8.jar:6.0.8]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:146) ~[spring-boot-3.0.6.jar:3.0.6]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:732) ~[spring-boot-3.0.6.jar:3.0.6]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:434) ~[spring-boot-3.0.6.jar:3.0.6]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:310) ~[spring-boot-3.0.6.jar:3.0.6]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1304) ~[spring-boot-3.0.6.jar:3.0.6]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1293) ~[spring-boot-3.0.6.jar:3.0.6]
	at com.michael.dubbo.ConsumerApplication.main(ConsumerApplication.java:19) ~[classes/:na]
Caused by: java.lang.ClassCastException: Cannot cast org.springframework.cloud.zookeeper.discovery.ZookeeperInstance to org.apache.dubbo.registry.zookeeper.ZookeeperInstance
	at java.base/java.lang.Class.cast(Class.java:3991) ~[na:na]
	at org.apache.curator.x.discovery.details.JsonInstanceSerializer.deserialize(JsonInstanceSerializer.java:87) ~[curator-x-discovery-5.1.0.jar:na]
	at org.apache.curator.x.discovery.details.ServiceDiscoveryImpl.queryForInstance(ServiceDiscoveryImpl.java:325) ~[curator-x-discovery-5.1.0.jar:na]
	at org.apache.curator.x.discovery.details.ServiceDiscoveryImpl.queryForInstances(ServiceDiscoveryImpl.java:393) ~[curator-x-discovery-5.1.0.jar:na]
	at org.apache.curator.x.discovery.details.ServiceDiscoveryImpl.queryForInstances(ServiceDiscoveryImpl.java:307) ~[curator-x-discovery-5.1.0.jar:na]
	at org.apache.dubbo.registry.zookeeper.ZookeeperServiceDiscovery.lambda$getInstances$2(ZookeeperServiceDiscovery.java:147) ~[dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.common.function.ThrowableFunction.execute(ThrowableFunction.java:52) ~[dubbo-3.2.0.jar:3.2.0]
	... 55 common frames omitted

Sample

When using dubbo to interact with spring, the registry type conversion is abnormal. Is spring cloud compatible with dubbo's application-level instance registry?

Dubbo Issue As follow

apache/dubbo#12243

[songxiaosheng]

Is there anyone who can support this feature? It requires compatibility between Dubbo and Spring. If compatibility is complete, it can be interconnected

[spencergibb]

I've edited your comment to improve the formatting. You might want to check out this Mastering Markdown guide for future reference.

I am unfamiliar with how dubbo work and what, if anything, we could do to make them compatible. Can you tell me what would need to change?

[songxiaosheng]

Thank you for your reply,
Dubbo and Spring Cloud Zookeeper are both based on the implementation of curator services. It is found that both use custom types when storing data, which makes them incompatible. If Dubbo and Spring Cloud can be compatible with each other's application level service data, interconnection can be achieved. However, both sides need to be compatible. The instance information of Dubbo and Spring Cloud needs to be changed together,

[songxiaosheng]

The service discovery code for Dubbo is as follows:
https://github.com/apache/dubbo/tree/3.2/dubbo-registry/dubbo-registry-zookeeper

[spencergibb]

I understand that from your previous comments. I don't have the dubbo expertise to do the work to even know what to do make them compatible. Pull requests welcome.

[songxiaosheng]

Okay, I'll take on this task. The interconnection between Spring Cloud Zookeeper and Dubbo Zookeeper helps enterprises better use scenarios where the two frameworks coexist