The "rest protocol"'s purpose in Dubbo 3.1.x? 新增加了

When I upgraded from 3.0.9 to 3.1.0, I found the following error when starting the project: 当我从3.0.9升级到3.1.0后，启动项目时发现以下报错：

2022-09-06 11:08:17.323 [main] ERROR o.a.d.r.client.ServiceDiscoveryRegistryDirectory - Unsupported protocol rest in notified url: DefaultServiceInstance{serviceName='sys-service', host='192.168.1.55', port=20001, enabled=true, healthy=true, metadata={preserved.register.source=SPRING_CLOUD}}, null from registry 【REGISTRY IP ADDRESS】 to consumer 192.168.1.55, supported protocol: [dubbo, injvm, mock, registry, service-discovery-registry, tri] java.lang.IllegalStateException: Unsupported protocol rest in notified url: DefaultServiceInstance{serviceName='sys-service', host='192.168.1.55', port=20001, enabled=true, healthy=true, metadata={preserved.register.source=SPRING_CLOUD}}, null from registry 【REGISTRY IP ADDRESS】 to consumer 192.168.1.55, supported protocol: [dubbo, injvm, mock, registry, service-discovery-registry, tri] at org.apache.dubbo.registry.client.ServiceDiscoveryRegistryDirectory.toInvokers(ServiceDiscoveryRegistryDirectory.java:300) at org.apache.dubbo.registry.client.ServiceDiscoveryRegistryDirectory.refreshInvoker(ServiceDiscoveryRegistryDirectory.java:251) at org.apache.dubbo.registry.client.ServiceDiscoveryRegistryDirectory.refreshOverrideAndInvoker(ServiceDiscoveryRegistryDirectory.java:179) at org.apache.dubbo.registry.client.ServiceDiscoveryRegistryDirectory.notify(ServiceDiscoveryRegistryDirectory.java:173) at org.apache.dubbo.registry.client.event.listener.ServiceInstancesChangedListener.addListenerAndNotify(ServiceInstancesChangedListener.java:235) at org.apache.dubbo.registry.client.ServiceDiscoveryRegistry.subscribeURLs(ServiceDiscoveryRegistry.java:325) at org.apache.dubbo.registry.client.ServiceDiscoveryRegistry.doSubscribe(ServiceDiscoveryRegistry.java:216) at org.apache.dubbo.registry.client.ServiceDiscoveryRegistry.subscribe(ServiceDiscoveryRegistry.java:184) at org.apache.dubbo.registry.ListenerRegistryWrapper.subscribe(ListenerRegistryWrapper.java:111) at org.apache.dubbo.registry.integration.DynamicDirectory.subscribe(DynamicDirectory.java:180) at org.apache.dubbo.registry.client.ServiceDiscoveryRegistryDirectory.subscribe(ServiceDiscoveryRegistryDirectory.java:124) at org.apache.dubbo.registry.integration.RegistryProtocol.doCreateInvoker(RegistryProtocol.java:571) at org.apache.dubbo.registry.integration.InterfaceCompatibleRegistryProtocol.getServiceDiscoveryInvoker(InterfaceCompatibleRegistryProtocol.java:65) at org.apache.dubbo.registry.client.migration.MigrationInvoker.refreshServiceDiscoveryInvoker(MigrationInvoker.java:436) at org.apache.dubbo.registry.client.migration.MigrationInvoker.migrateToApplicationFirstInvoker(MigrationInvoker.java:244) at org.apache.dubbo.registry.client.migration.MigrationRuleHandler.refreshInvoker(MigrationRuleHandler.java:73) at org.apache.dubbo.registry.client.migration.MigrationRuleHandler.doMigrate(MigrationRuleHandler.java:57) at org.apache.dubbo.registry.client.migration.MigrationRuleListener.onRefer(MigrationRuleListener.java:243) at org.apache.dubbo.registry.integration.RegistryProtocol.interceptInvoker(RegistryProtocol.java:536) at org.apache.dubbo.registry.integration.RegistryProtocol.doRefer(RegistryProtocol.java:506) at org.apache.dubbo.registry.integration.RegistryProtocol.refer(RegistryProtocol.java:488) at org.apache.dubbo.qos.protocol.QosProtocolWrapper.refer(QosProtocolWrapper.java:80) at org.apache.dubbo.rpc.protocol.ProtocolListenerWrapper.refer(ProtocolListenerWrapper.java:74) at org.apache.dubbo.rpc.cluster.filter.ProtocolFilterWrapper.refer(ProtocolFilterWrapper.java:71) at org.apache.dubbo.rpc.protocol.ProtocolSerializationWrapper.refer(ProtocolSerializationWrapper.java:52) at org.apache.dubbo.rpc.Protocol$Adaptive.refer(Protocol$Adaptive.java) at org.apache.dubbo.config.ReferenceConfig.createInvokerForRemote(ReferenceConfig.java:600) at org.apache.dubbo.config.ReferenceConfig.createProxy(ReferenceConfig.java:441) at org.apache.dubbo.config.ReferenceConfig.init(ReferenceConfig.java:295) at org.apache.dubbo.config.ReferenceConfig.get(ReferenceConfig.java:227) at org.apache.dubbo.config.utils.SimpleReferenceCache.get(SimpleReferenceCache.java:129) at org.apache.dubbo.config.deploy.DefaultModuleDeployer.lambda$referServices$6(DefaultModuleDeployer.java:383) at java.base/java.util.concurrent.ConcurrentHashMap$ValuesView.forEach(ConcurrentHashMap.java:4780) at org.apache.dubbo.config.deploy.DefaultModuleDeployer.referServices(DefaultModuleDeployer.java:363) at org.apache.dubbo.config.deploy.DefaultModuleDeployer.start(DefaultModuleDeployer.java:154) at org.apache.dubbo.config.spring.context.DubboDeployApplicationListener.onContextRefreshedEvent(DubboDeployApplicationListener.java:111) at org.apache.dubbo.config.spring.context.DubboDeployApplicationListener.onApplicationEvent(DubboDeployApplicationListener.java:100) at org.apache.dubbo.config.spring.context.DubboDeployApplicationListener.onApplicationEvent(DubboDeployApplicationListener.java:45) at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:176) at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:169) at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:143) at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:421) at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:378) at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:938) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:586) at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:147) at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:734) at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:408) at org.springframework.boot.SpringApplication.run(SpringApplication.java:308) at org.springframework.boot.SpringApplication.run(SpringApplication.java:1306) at org.springframework.boot.SpringApplication.run(SpringApplication.java:1295) at cc.uncarbon.module.SaasApiApplication.main(SaasApiApplication.java:10)

However port 20001 is the HTTP port of the downstream microservice 然而端口20001是下游微服务的HTTP端口

After tracking the code I found this: 跟踪代码后我发现：

The provider's configuration file does not actively set the rest protocol. This * should be actively added when registering with the registry. There seems to be no usage found in the feature announcement of version 3.1.0, please advise provider的配置文件中并没有主动设置 rest 协议，这个*应该是注册到注册中心时主动添加的。3.1.0版本的feature公告中好像没有发现用法，请指教

code position 代码位置 org.apache.dubbo.registry.client.event.listener.ServiceInstancesChangedListener#getAddresses

code of version 3.0.11 3.0.11代码 https://github.com/apache/dubbo/blob/8354db26cfd5518bfe177d5e12c045ac003cac54/dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/client/event/listener/ServiceInstancesChangedListener.java

原提问者GitHub用户uncarbon97