Zookeeper的安装和使用

1、  下载zookeeper安装文件，解压缩，放入固定目录中

下载地址：http://hadoop.apache.org/zookeeper/

下载文件：zookeeper-3.4.6.tar.gz，解压缩后，放入目录D:\ll\program\zookeeper-3.4.6

2、  修改zookeeper配置文件zoo-example.cfg改为zoo.cfg，zookeeper默认寻找zoo.cfg配置文件

Zoo.cfg在zookeeper安装文件的conf文件夹下

修改内容为：

# The number of milliseconds of each ticktickTime=2000# The number of ticks that the initial # synchronization phase can takeinitLimit=10# The number of ticks that can pass between # sending a request and getting an acknowledgementsyncLimit=5# the directory where the snapshot is stored.# do not use /tmp for storage, /tmp here is just # example sakes.#dataDir=/tmp/zookeeperdataDir=D:\\ll\\program\\zookeeper-3.4.6\\datadataLogDir=D:\\ll\\program\\zookeeper-3.4.6\\log# the port at which the clients will connectclientPort=2181# the maximum number of client connections.# increase this if you need to handle more clients#maxClientCnxns=60## Be sure to read the maintenance section of the # administrator guide before turning on autopurge.## http://zookeeper.apache.org/doc/current/zookeeperAdmin.html#sc_maintenance## The number of snapshots to retain in dataDir#autopurge.snapRetainCount=3# Purge task interval in hours# Set to "0" to disable auto purge feature#autopurge.purgeInterval=1

说明：

tickTime：这个时间是作为Zookeeper 服务器之间或客户端与服务器之间维持心跳的时间间隔，也就是每个 tickTime 时间就会发送一个心跳。

dataDir：顾名思义就是Zookeeper 保存数据的目录，默认情况下，Zookeeper 将写数据的日志文件也保存在这个目录里。

dataLogDir：顾名思义就是Zookeeper 保存日志文件的目录

clientPort：这个端口就是客户端连接Zookeeper 服务器的端口，Zookeeper 会监听这个端口，接受客户端的访问请求。

3、  启动zookeeper

Window下命令：进入bin目录 ->zkServer.cmd

Linux下命令：进入bin目录 -> zkServer.sh

示例：在windows的命令行下执行D:\ll\program\zookeeper-3.4.6\bin>zkServer.cmd
说明：头两次执行失败，修改路径后仍不成功，第三次手动添加data和log目录，运行，执行成功

4、检查zookeeper是否已经在服务，通过netstat – ano 命令查看是否有你配置的 clientPort 端口号在监听服务

示例：D:\ll\program\zookeeper-3.4.6\bin>netstat-ano

4、  Zookeeper启动成功后，编写java代码

需要两个jar包：zookeeper-3.4.6.jarslf4j-api-1.6.1.jar，在zookeeper-3.4.6.tar.gz中都可找到

package test;import java.io.IOException;import org.apache.zookeeper.CreateMode;import org.apache.zookeeper.KeeperException;import org.apache.zookeeper.WatchedEvent;import org.apache.zookeeper.Watcher;import org.apache.zookeeper.ZooKeeper;import org.apache.zookeeper.ZooDefs.Ids;public class ZookeeperTest {// 会话超时时间，设置为与系统默认时间一致private final static int SESSION_TIMEOUT = 30000;//创建zookeeper实例ZooKeeper zk;//创建watch实例Watcher wa = new Watcher(){public void process(WatchedEvent event){System.out.print(event.toString());}};//初始化zookeeper实例private void createZkInstance() throws IOException{zk = new ZooKeeper("localhost:2181",ZookeeperTest.SESSION_TIMEOUT , this.wa);}private void ZKOptions() throws KeeperException, InterruptedException{System.out.println("/n1. 创建 ZooKeeper 节点 (znode ： zoo2, 数据： myData2 ，权限：OPEN_ACL_UNSAFE ，节点类型： Persistent");zk.create("/zoo2","myData2".getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);System.out.println("/n2. 查看是否创建成功： ");System.out.println(new String(zk.getData("/zoo2",false,null)));System.out.println("/n3. 修改节点数据 ");zk.setData("/zoo2", "shenlan211314".getBytes(), -1);System.out.println("/n4. 查看是否修改成功： ");System.out.println(new String(zk.getData("/zoo2", false, null)));System.out.println("/n5. 删除节点 ");zk.delete("/zoo2", -1);System.out.println("/n6. 查看节点是否被删除： ");System.out.println(" 节点状态： ["+zk.exists("/zoo2", false)+"]");}private void ZKClose() throws InterruptedException{zk.close();}/** * @param args * @author ll * @throws IOException  * @throws InterruptedException  * @throws KeeperException  * @category zookeeper */public static void main(String[] args) throws IOException, KeeperException, InterruptedException {ZookeeperTest z = new ZookeeperTest();z.createZkInstance();z.ZKOptions();z.ZKClose();}}

启动java程序后，运行成功(前提需要zookeeper服务器启动)，控制台打印如下信息：