Zookeeper與Curator二三事【坑爹】

起因：我的Dubbo服務起不來：我本地Zookeeper3.4.11，Curator4.1

Caused by: org.apache.zookeeper.KeeperException$UnimplementedException: KeeperErrorCode = Unimplemented for /dubbo/com.demo.common.service.DemoService
    at org.apache.zookeeper.KeeperException.create(KeeperException.java:106) ~[zookeeper-3.5.4-beta.jar:3.5.4-beta-7f51e5b68cf2f80176ff944a9ebd2abbc65e7327]
    at org.apache.zookeeper.KeeperException.create(KeeperException.java:54) ~[zookeeper-3.5.4-beta.jar:3.5.4-beta-7f51e5b68cf2f80176ff944a9ebd2abbc65e7327]
    at org.apache.zookeeper.ZooKeeper.create(ZooKeeper.java:1549) ~[zookeeper-3.5.4-beta.jar:3.5.4-beta-7f51e5b68cf2f80176ff944a9ebd2abbc65e7327]
    at org.apache.curator.framework.imps.CreateBuilderImpl$17.call(CreateBuilderImpl.java:1183) ~[curator-framework-4.1.0.jar:4.1.0]
    at org.apache.curator.framework.imps.CreateBuilderImpl$17.call(CreateBuilderImpl.java:1160) ~[curator-framework-4.1.0.jar:4.1.0]
    at org.apache.curator.connection.StandardConnectionHandlingPolicy.callWithRetry(StandardConnectionHandlingPolicy.java:64) ~[curator-client-4.1.0.jar:na]
    at org.apache.curator.RetryLoop.callWithRetry(RetryLoop.java:100) ~[curator-client-4.1.0.jar:na]
    at org.apache.curator.framework.imps.CreateBuilderImpl.pathInForeground(CreateBuilderImpl.java:1157) ~[curator-framework-4.1.0.jar:4.1.0]
    at org.apache.curator.framework.imps.CreateBuilderImpl.protectedPathInForeground(CreateBuilderImpl.java:607) ~[curator-framework-4.1.0.jar:4.1.0]
    at org.apache.curator.framework.imps.CreateBuilderImpl.forPath(CreateBuilderImpl.java:597) ~[curator-framework-4.1.0.jar:4.1.0]
    at org.apache.curator.framework.imps.CreateBuilderImpl.forPath(CreateBuilderImpl.java:575) ~[curator-framework-4.1.0.jar:4.1.0]
    at org.apache.curator.framework.imps.CreateBuilderImpl.forPath(CreateBuilderImpl.java:49) ~[curator-framework-4.1.0.jar:4.1.0]
    at com.alibaba.dubbo.remoting.zookeeper.curator.CuratorZookeeperClient.createPersistent(CuratorZookeeperClient.java:76) ~[dubbo-2.6.5.jar:2.6.5]
    ... 33 common frames omitted

於是去了解這個版本對應關系如下：

Curator作為zookeeper的客戶端，並不是最新版的就沒問題，因為它的版本和zookeeper的版本有對應關系。

ZooKeeper 3.5.x

Curator4.0十分依賴Zookeeper3.5.X

ZooKeeper 3.4.x

Curator4.0在軟兼容模式下支持Zookeeper3.4.X，但是需要依賴排除zookeeper

<dependency>
    <groupId>org.apache.curator</groupId>
    <artifactId>curator-recipes</artifactId>
    <version>${curator-version}</version>
    <exclusions>
        <exclusion>
            <groupId>org.apache.zookeeper</groupId>
            <artifactId>zookeeper</artifactId>
        </exclusion>
    </exclusions>
</dependency>

同時必須加入Zookeeper3.4.X的依賴，並且呢，因為是軟兼容模式，一些3.4.X不具備的新特性是不能使用的。

低版本

對於Curator2.X是支持Zookeeper3.4.X的，所以如果目前你是Zookeeper3.4.X的版本，還是使用Curator2.X的吧，比如：

<!-- https://mvnrepository.com/artifact/org.apache.zookeeper/zookeeper -->
<dependency>
    <groupId>org.apache.zookeeper</groupId>
    <artifactId>zookeeper</artifactId>
    <version>3.4.13</version>
    <type>pom</type>
</dependency>

 

版本列表

同一個項目有三個版本也是醉了，貌似現在2.X和4.X是主打了，3.X被邊緣了？