dubbo zookeeper not connected

springboot2.2.6.RELEASE + dubbo2.7.6 + ZooKeeper3.6.0，都为最新稳定版本。

启动时报异常：

java.lang.IllegalStateException: zookeeper not connected at org.apache.dubbo.remoting.zookeeper.curator.CuratorZookeeperClient.(CuratorZookeeperClient.java:83) ~[dubbo-2.7.6.jar:2.7.6] at org.apache.dubbo.remoting.zookeeper.curator.CuratorZookeeperTransporter.createZookeeperClient(CuratorZookeeperTransporter.java:26) ~[dubbo-2.7.6.jar:2.7.6] at org.apache.dubbo.remoting.zookeeper.support.AbstractZookeeperTransporter.connect(AbstractZookeeperTransporter.java:70) ~[dubbo-2.7.6.jar:2.7.6] at org.apache.dubbo.remoting.zookeeper.ZookeeperTransporter$Adaptive.connect(ZookeeperTransporter$Adaptive.java) ~[dubbo-2.7.6.jar:2.7.6] at org.apache.dubbo.configcenter.support.zookeeper.ZookeeperDynamicConfiguration.(ZookeeperDynamicConfiguration.java:70) ~[dubbo-2.7.6.jar:2.7.6] at org.apache.dubbo.configcenter.support.zookeeper.ZookeeperDynamicConfigurationFactory.createDynamicConfiguration(ZookeeperDynamicConfigurationFactory.java:37) ~[dubbo-2.7.6.jar:2.7.6] at org.apache.dubbo.common.config.configcenter.AbstractDynamicConfigurationFactory.lambda$getDynamicConfiguration$0(AbstractDynamicConfigurationFactory.java:39) ~[dubbo-2.7.6.jar:2.7.6] at java.util.concurrent.ConcurrentHashMap.computeIfAbsent(ConcurrentHashMap.java:1660) ~[na:1.8.0_60] at org.apache.dubbo.common.config.configcenter.AbstractDynamicConfigurationFactory.getDynamicConfiguration(AbstractDynamicConfigurationFactory.java:39) ~[dubbo-2.7.6.jar:2.7.6] at org.apache.dubbo.common.config.configcenter.DynamicConfiguration.getDynamicConfiguration(DynamicConfiguration.java:223) ~[dubbo-2.7.6.jar:2.7.6] at org.apache.dubbo.config.bootstrap.DubboBootstrap.prepareEnvironment(DubboBootstrap.java:857) ~[dubbo-2.7.6.jar:2.7.6] at org.apache.dubbo.config.bootstrap.DubboBootstrap.startConfigCenter(DubboBootstrap.java:603) ~[dubbo-2.7.6.jar:2.7.6] at org.apache.dubbo.config.bootstrap.DubboBootstrap.useRegistryAsConfigCenterIfNecessary(DubboBootstrap.java:671) ~[dubbo-2.7.6.jar:2.7.6] at org.apache.dubbo.config.bootstrap.DubboBootstrap.initialize(DubboBootstrap.java:509) ~[dubbo-2.7.6.jar:2.7.6] at org.apache.dubbo.config.bootstrap.DubboBootstrap.start(DubboBootstrap.java:740) ~[dubbo-2.7.6.jar:2.7.6] at org.apache.dubbo.config.spring.context.DubboBootstrapApplicationListener.onContextRefreshedEvent(DubboBootstrapApplicationListener.java:59) ~[dubbo-2.7.6.jar:2.7.6] at org.apache.dubbo.config.spring.context.DubboBootstrapApplicationListener.onApplicationContextEvent(DubboBootstrapApplicationListener.java:52) ~[dubbo-2.7.6.jar:2.7.6] at org.apache.dubbo.config.spring.context.OneTimeExecutionApplicationContextEventListener.onApplicationEvent(OneTimeExecutionApplicationContextEventListener.java:40) ~[dubbo-2.7.6.jar:2.7.6] at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172) ~[spring-context-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165) ~[spring-context-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139) ~[spring-context-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:403) ~[spring-context-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:360) ~[spring-context-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:897) ~[spring-context-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.finishRefresh(ServletWebServerApplicationContext.java:162) ~[spring-boot-2.2.6.RELEASE.jar:2.2.6.RELEASE] at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:553) ~[spring-context-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141) ~[spring-boot-2.2.6.RELEASE.jar:2.2.6.RELEASE] at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:747) [spring-boot-2.2.6.RELEASE.jar:2.2.6.RELEASE] at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) [spring-boot-2.2.6.RELEASE.jar:2.2.6.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) [spring-boot-2.2.6.RELEASE.jar:2.2.6.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) [spring-boot-2.2.6.RELEASE.jar:2.2.6.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1215) [spring-boot-2.2.6.RELEASE.jar:2.2.6.RELEASE] at cn.kevin.sbm.SbmApplication.main(SbmApplication.java:10) [classes/:na] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_60] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_60] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_60] at java.lang.reflect.Method.invoke(Method.java:497) ~[na:1.8.0_60] at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-2.2.6.RELEASE.jar:2.2.6.RELEASE]Caused by: java.lang.IllegalStateException: zookeeper not connected at org.apache.dubbo.remoting.zookeeper.curator.CuratorZookeeperClient.(CuratorZookeeperClient.java:80) ~[dubbo-2.7.6.jar:2.7.6] ... 37 common frames omitted

解决：application.properties中添加如下，加大与zk的连接时间，30秒，默认5秒钟。

dubbo.registry.timeout=30000