Dubbo 连接zookeeper时，提示“zookeeper not connected”
java.lang.IllegalStateException: zookeeper not connected
at org.apache.dubbo.remoting.zookeeper.curator.CuratorZookeeperClient.<init>(CuratorZookeeperClient.java:83) ~[dubbo-2.7.8.jar:2.7.8]
at org.apache.dubbo.remoting.zookeeper.curator.CuratorZookeeperTransporter.createZookeeperClient(CuratorZookeeperTransporter.java:26) ~[dubbo-2.7.8.jar:2.7.8]
at org.apache.dubbo.remoting.zookeeper.support.AbstractZookeeperTransporter.connect(AbstractZookeeperTransporter.java:70) ~[dubbo-2.7.8.jar:2.7.8]
at org.apache.dubbo.remoting.zookeeper.ZookeeperTransporter$Adaptive.connect(ZookeeperTransporter$Adaptive.java) ~[dubbo-2.7.8.jar:2.7.8]
at org.apache.dubbo.configcenter.support.zookeeper.ZookeeperDynamicConfiguration.<init>(ZookeeperDynamicConfiguration.java:56) ~[dubbo-2.7.8.jar:2.7.8]
at org.apache.dubbo.configcenter.support.zookeeper.ZookeeperDynamicConfigurationFactory.createDynamicConfiguration(ZookeeperDynamicConfigurationFactory.java:37) ~[dubbo-2.7.8.jar:2.7.8]
at org.apache.dubbo.common.config.configcenter.AbstractDynamicConfigurationFactory.lambda$getDynamicConfiguration$0(AbstractDynamicConfigurationFactory.java:39) ~[dubbo-2.7.8.jar:2.7.8]
at org.apache.dubbo.common.config.configcenter.AbstractDynamicConfigurationFactory$$Lambda$555/757779849.apply(Unknown Source) ~[na:na]
at java.util.concurrent.ConcurrentHashMap.computeIfAbsent(ConcurrentHashMap.java:1660) ~[na:1.8.0_25]
at org.apache.dubbo.common.config.configcenter.AbstractDynamicConfigurationFactory.getDynamicConfiguration(AbstractDynamicConfigurationFactory.java:39) ~[dubbo-2.7.8.jar:2.7.8]
at org.apache.dubbo.common.config.configcenter.DynamicConfiguration.getDynamicConfiguration(DynamicConfiguration.java:224) ~[dubbo-2.7.8.jar:2.7.8]
at org.apache.dubbo.config.bootstrap.DubboBootstrap.prepareEnvironment(DubboBootstrap.java:1034) ~[dubbo-2.7.8.jar:2.7.8]
at org.apache.dubbo.config.bootstrap.DubboBootstrap.startConfigCenter(DubboBootstrap.java:623) ~[dubbo-2.7.8.jar:2.7.8]
at org.apache.dubbo.config.bootstrap.DubboBootstrap.initialize(DubboBootstrap.java:521) ~[dubbo-2.7.8.jar:2.7.8]
at org.apache.dubbo.config.bootstrap.DubboBootstrap.start(DubboBootstrap.java:896) ~[dubbo-2.7.8.jar:2.7.8]
at org.apache.dubbo.config.spring.context.DubboBootstrapApplicationListener.onContextRefreshedEvent(DubboBootstrapApplicationListener.java:59) ~[dubbo-2.7.8.jar:2.7.8]
at org.apache.dubbo.config.spring.context.DubboBootstrapApplicationListener.onApplicationContextEvent(DubboBootstrapApplicationListener.java:52) ~[dubbo-2.7.8.jar:2.7.8]
at org.apache.dubbo.config.spring.context.OneTimeExecutionApplicationContextEventListener.onApplicationEvent(OneTimeExecutionApplicationContextEventListener.java:40) ~[dubbo-2.7.8.jar:2.7.8]
at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172) ~[spring-context-5.2.8.RELEASE.jar:5.2.8.RELEASE]
at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165) ~[spring-context-5.2.8.RELEASE.jar:5.2.8.RELEASE]
at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139) ~[spring-context-5.2.8.RELEASE.jar:5.2.8.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:404) ~[spring-context-5.2.8.RELEASE.jar:5.2.8.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:361) ~[spring-context-5.2.8.RELEASE.jar:5.2.8.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:898) ~[spring-context-5.2.8.RELEASE.jar:5.2.8.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:554) ~[spring-context-5.2.8.RELEASE.jar:5.2.8.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:143) ~[spring-boot-2.3.2.RELEASE.jar:2.3.2.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:758) [spring-boot-2.3.2.RELEASE.jar:2.3.2.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:750) [spring-boot-2.3.2.RELEASE.jar:2.3.2.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) [spring-boot-2.3.2.RELEASE.jar:2.3.2.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) [spring-boot-2.3.2.RELEASE.jar:2.3.2.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1237) [spring-boot-2.3.2.RELEASE.jar:2.3.2.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) [spring-boot-2.3.2.RELEASE.jar:2.3.2.RELEASE]
at com.th.DubboProviderApplication.main(DubboProviderApplication.java:17) [classes/:na]
Caused by: java.lang.IllegalStateException: zookeeper not connected
at org.apache.dubbo.remoting.zookeeper.curator.CuratorZookeeperClient.<init>(CuratorZookeeperClient.java:80) ~[dubbo-2.7.8.jar:2.7.8]
... 32 common frames omitted
dubbo 注册中心用的是zookeeper，引入的jar包是dubbo-dependencies-zookeeper.jar;使用的zookeeper客户端是curator ，使用curator客户端连接zookeeper是成功的，说明zookeeper服务是启动的且能正常运行的。
产生原因是：
从源码可以找到问题原因所在：因为zookeeper 的超时连接设置。
当前dubbo 和zookeeper的版本如下：
XML 配置方式解决方案
xml配置方式，配置了dubbo:registry的timeout，不生效，还是3s，配置：
<dubbo:registry address="zookeeper://127.0.0.1:2181" timeout="20000"/>
从源码可以看到， zookeeper的连接配置如下：
所以解决方式方案是timeout 配置在url 中，如下：
<dubbo:registry address="zookeeper://127.0.0.1:2181?timeout=20000"/>
properties 配置文件
读取配置文件连接超时源码如下
从源码可知，连接超时配置如下：
dubbo.config-center.timeout=6000
但是配置完后，重启并没有解决zookeeper连接失败的原因，然后修改为
dubbo.registry.timeout=60000
重启连接成功。