/hazelcast-zookeeper

Hazelcast Discovery Plugin for Apache ZooKeeper

Primary LanguageJavaOtherNOASSERTION

Table of Contents

Hazelcast Discovery Plugin for Apache ZooKeeper

This plugin provides a service based discovery strategy 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-3.6.xsd"
           xmlns="http://www.hazelcast.com/schema/config">

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

    <network>
        <join>
            <multicast enabled="false"/>
            <tcp-ip enabled="false" />
            <aws enabled="false"/>
            <discovery-strategies>
                <discovery-strategy enabled="true" class="com.hazelcast.zookeeper.ZookeeperDiscoveryStrategy">
                    <properties>
                        <!--
                          Connection string to your ZooKeeper server.
                          Default: There is no default, this is a required property.
                          Example: 127.0.0.1:2181
                        -->
                        <property name="zookeeper_url">{ip-address-of-zookeeper}:{port-of-zookeeper}</property>
                        <!--Path in ZooKeeper Hazelcast will useDefault: /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-3.6.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"/>
        <smart-routing>true</smart-routing>
        <redo-operation>true</redo-operation>
        <discovery-strategies>
            <discovery-strategy enabled="true" class="com.hazelcast.zookeeper.ZookeeperDiscoveryStrategy">
                <properties>
                    <!--
                          Connection string to your ZooKeeper server.
                          Default: There is no default, this is a required property.
                          Example: 127.0.0.1:2181
                    -->
                    <property name="zookeeper_url">{ip-address-of-zookeeper}:{port-of-zookeeper}</property>
                    <!--Path in ZooKeeper Hazelcast will useDefault: /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

public static void main(String[] args) {

  String zookeeperURL = "{ip-address-of-zookeeper}:{port-of-zookeeper}";

  Config config = new Config();
  config.getNetworkConfig().getJoin().getMulticastConfig().setEnabled(false);
  config.setProperty(GroupProperty.DISCOVERY_SPI_ENABLED, "true");

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

  Hazelcast.newHazelcastInstance(config);
}

Client Programmatic Config

    ClientConfig config = new ClientConfig();
    config.getNetworkConfig().getAwsConfig().setEnabled(false);
    config.setProperty(GroupProperty.DISCOVERY_SPI_ENABLED, "true");

    DiscoveryStrategyConfig discoveryStrategyConfig = new DiscoveryStrategyConfig(new ZookeeperDiscoveryStrategyFactory());
    discoveryStrategyConfig.addProperty(ZookeeperDiscoveryProperties.ZOOKEEPER_URL.key(), "{ip-address-of-zookeeper}:{port-of-zookeeper}");
    discoveryStrategyConfig.addProperty(ZookeeperDiscoveryProperties.ZOOKEEPER_PATH.key(), "{path-on-zookeeper}");
    discoveryStrategyConfig.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-test</artifactId>
            <version>${curator.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.curator</groupId>
            <artifactId>curator-x-discovery</artifactId>
            <version>${curator.version}</version>
        </dependency>
        <dependency>
            <groupId>com.hazelcast</groupId>
            <artifactId>hazelcast-zookeeper</artifactId>
            <version>${hazelcast.version}</version>
        </dependency>
        <dependency>
            <groupId>com.hazelcast</groupId>
            <artifactId>hazelcast</artifactId>
            <version>${hazelcast.version}</version>
        </dependency>
        <dependency>
            <groupId>com.hazelcast</groupId>
            <artifactId>hazelcast-client</artifactId>
            <version>${hazelcast.version}</version>
      <dependency>
    </dependencies>
...
</project>

Compatibilities

In order for the hazelcast-zookeeper plugin to work for the Hazelcast Java client, you need to use Hazelcast Client 3.6.1 or higher.

hazelcast-zookeeper-3.6.3 has been tested with Curator 2.9.0 and Zookeeper 3.4.6

Current Snapshot version of hazelcast-zookeeper has been tested with Curator 4.0.1 and Zookeeper 3.5.3-beta

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.