ZooKeeper Version 3.4.x Compatibility

ZooKeeper 3.4.x is now at end-of-life. Consequently, the latest versions of Curator have removed support for it. If you wish to use Curator with ZooKeeper 3.4.x you should pin to version 4.2.x of Curator. Curator 4.2.x supports ZooKeeper 3.4.x ensembles in a soft-compatibility mode. To use this mode you must exclude ZooKeeper when adding Curator to your dependency management tool.

Maven

<dependency>
    <groupId>org.apache.curator</groupId>
    <artifactId>curator-recipes</artifactId>
    <version>4.2.0</version>
    <exclusions>
        <exclusion>
            <groupId>org.apache.zookeeper</groupId>
            <artifactId>zookeeper</artifactId>
        </exclusion>
    </exclusions>
</dependency>

Gradle

compile('org.apache.curator:curator-recipes:$curatorVersion') {
  exclude group: 'org.apache.zookeeper', module: 'zookeeper'
}

You must add a dependency on ZooKeeper 3.4.x also.

Curator will detect which ZooKeeper library is in use and automatically set ZooKeeper 3.4 compatibility mode as needed. In this mode, all features not supported by 3.4 are disabled. It is up to your application code to "do the right thing" and not use these features. Use the isZk34CompatibilityMode() method to determine which mode Curator is using at runtime.

Testing With ZooKeeper 3.4.x

Note: If you wish to use Curator's TestingServer with ZooKeeper 3.4.x you must use the older version of it (in addition to the instructions above):

Maven

<dependency>
    <groupId>org.apache.curator</groupId>
    <artifactId>curator-test</artifactId>
    <version>2.12.0</version>
    <exclusions>
        <exclusion>
            <groupId>org.apache.zookeeper</groupId>
            <artifactId>zookeeper</artifactId>
        </exclusion>
    </exclusions>
    <scope>test</scope>
</dependency>

Gradle

testCompile('org.apache.curator:curator-test:2.12.0') {
  exclude group: 'org.apache.zookeeper', module: 'zookeeper'
}

Curator 5.0 Breaking Changes

Curator 5.0 contains a few non-backward compatible/breaking changes from previous versions.

• ZooKeeper 3.4.x is no longer supported (the associated Compatibility classes/methods have been removed). If you still need to use Curator with ZooKeeper 3.4.x you will need to use a previous version. Click here for details.
• The old ListenerContainer classes have been removed so as not to leak Guava classes into Curator APIs. Instead use the new StandardListenerManager.
• Exhibitor support has been removed.
• ConnectionHandlingPolicy and related classes have been removed.
• The Reaper and ChildReaper classes/recipes have been removed. You should use ZooKeeper container nodes instead.
• newPersistentEphemeralNode() and newPathChildrenCache() were removed from GroupMember.
• ServiceCacheBuilder<T> executorService(CloseableExecutorService executorService) was removed from ServiceCacheBuilder.
• ServiceProviderBuilder<T> executorService(CloseableExecutorService executorService) was removed from ServiceProviderBuilder.
• static boolean shouldRetry(int rc) was removed from RetryLoop.
• static boolean isRetryException(Throwable exception) was removed from RetryLoop.