Hazelcast Discovery Plugin for Apache ZooKeeper
- Configuration
- Compatibilities

Hazelcast Apache ZooKeeper Discovery Plugin

This plugin provides a service-based discovery by using Apache Curator to communicate with your Zookeeper server.

You can use this plugin with Discovery SPI enabled Hazelcast 3.6.1 and higher applications.

Configuration

Server XML Config

<hazelcast xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xsi:schemaLocation="http://www.hazelcast.com/schema/config
                               http://www.hazelcast.com/schema/config/hazelcast-config-4.0.xsd"
           xmlns="http://www.hazelcast.com/schema/config">

    <properties>
        <property name="hazelcast.discovery.enabled">true</property>
    </properties>

    <network>
        <join>
            <multicast enabled="false"/>
            <discovery-strategies>
                <discovery-strategy enabled="true" class="com.hazelcast.zookeeper.ZookeeperDiscoveryStrategy">
                    <properties>
                        <property name="zookeeper_url">{ip-address-of-zookeeper}:{port-of-zookeeper}</property> 
                        <!--defaults to /discovery/hazelcast -->
                        <property name="zookeeper_path">{path-on-zookeeper}</property> 
                        <!--Name of this Hazelcast cluster. You can have multiple distinct clusters to use the same ZooKeeper installation.-->
                        <property name="group">{clusterId}</property>
                    </properties>
                </discovery-strategy>
            </discovery-strategies>
        </join>
    </network>
</hazelcast>

Client XML Config

<hazelcast-client xsi:schemaLocation="http://www.hazelcast.com/schema/client-config hazelcast-client-config-4.0.xsd"
                  xmlns="http://www.hazelcast.com/schema/client-config"
                  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

    <properties>
        <property name="hazelcast.discovery.enabled">true</property>
    </properties>

    <network>
        <aws enabled="false"/>
        <discovery-strategies>
            <discovery-strategy enabled="true" class="com.hazelcast.zookeeper.ZookeeperDiscoveryStrategy">
                <properties>
                    <property name="zookeeper_url">{ip-address-of-zookeeper}:{port-of-zookeeper}</property>
                    <!--Default: /discovery/hazelcast -->
                    <property name="zookeeper_path">{path-on-zookeeper}</property>
                    <!--Name of this Hazelcast cluster. You can have multiple distinct clusters to use the same ZooKeeper installation.-->
                    <property name="group">{clusterId}</property>
                </properties>
            </discovery-strategy>
        </discovery-strategies>
    </network>

</hazelcast-client>

Server Programmatic Config

Config config = new Config();
config.getNetworkConfig().getJoin().getMulticastConfig().setEnabled(false);
config.setProperty("hazelcast.discovery.enabled", "true");

DiscoveryStrategyConfig discoveryStrategyConfig = new DiscoveryStrategyConfig(new ZookeeperDiscoveryStrategyFactory())
  .addProperty(ZookeeperDiscoveryProperties.ZOOKEEPER_URL.key(), "{ip-address-of-zookeeper}:{port-of-zookeeper}")
  .addProperty(ZookeeperDiscoveryProperties.ZOOKEEPER_PATH.key(), "{path-on-zookeeper}")
  .addProperty(ZookeeperDiscoveryProperties.GROUP.key(), "{clusterId}");
config.getNetworkConfig().getJoin().getDiscoveryConfig().addDiscoveryStrategyConfig(discoveryStrategyConfig);

Hazelcast.newHazelcastInstance(config);

Client Programmatic Config

ClientConfig config = new ClientConfig();

config.setProperty("hazelcast.discovery.enabled", "true");

DiscoveryStrategyConfig discoveryStrategyConfig = new DiscoveryStrategyConfig(new ZookeeperDiscoveryStrategyFactory())
  .addProperty(ZookeeperDiscoveryProperties.ZOOKEEPER_URL.key(), "{ip-address-of-zookeeper}:{port-of-zookeeper}")
  .addProperty(ZookeeperDiscoveryProperties.ZOOKEEPER_PATH.key(), "{path-on-zookeeper}")
  .addProperty(ZookeeperDiscoveryProperties.GROUP.key(), "{clusterId}");
config.getNetworkConfig().getDiscoveryConfig().addDiscoveryStrategyConfig(discoveryStrategyConfig);

HazelcastClient.newHazelcastClient(config);

Configuration via Maven

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
      
    ...  
    <dependencies>
        <dependency>
            <groupId>org.apache.curator</groupId>
            <artifactId>curator-x-discovery</artifactId>
            <version>${curator.version}</version>
        </dependency>
        <dependency>
            <groupId>com.hazelcast</groupId>
            <artifactId>hazelcast-zookeeper</artifactId>
            <version>${hazelcast-zookeeper.version}</version>
        </dependency>
        <dependency>
            <groupId>com.hazelcast</groupId>
            <artifactId>hazelcast</artifactId>
            <version>${hazelcast.version}</version>
        </dependency>
    </dependencies>
...
</project>

Compatibilities

3.6.3 has been tested with Curator 2.9.0 and Zookeeper 3.4.6
4.0.1 has been tested with Curator 4.0.1 and Zookeeper 3.5.7

Known Issues

There is an issue between Zookeeper and curator client in some versions. You may get Received packet at server of unknown type 15 error.

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hazelcast / hazelcast-zookeeper

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