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手把手教你:5分钟搞定Zookeeper安装及应用，详细教程

2024-12-22 18:28 huorong 精选文章 4 ℃ 0 评论

下载

下载zookeeper-3.4.12.tar.gz，在目录“/opt”创建文件夹“zookeeper”，将下载的文件放入其中并解压缩，最后文件的路径为：

/opt/zookeeper/zookeeper-3.4.12

再创建一个文件夹：

/opt/zookeeper/zookeeper-3.4.12_dataDir

单机模式安装

1.配置

conf/zoo_sample.cfg

并重命名为：

conf/zoo.cfg

配置该文件，在里面添加内容：

tickTime=2000
dataDir=dataDir=/opt/zookeeper/zookeeper-3.4.12_dataDir	
clientPort=2181

2.启动

运行：

./bin/zkServer.sh  start

结果：

./bin/zkServer.sh  start
ZooKeeper JMX enabled by default
Using config: /opt/zookeeper/zookeeper-3.4.12/bin/../conf/zoo.cfg
Starting zookeeper ... STARTED

3.查看状态

运行：

./bin/zkServer.sh  status

结果：

./bin/zkServer.sh  status
ZooKeeper JMX enabled by default
Using config: /opt/zookeeper/zookeeper-3.4.12/bin/../conf/zoo.cfg
Mode: standalone

根据状态能看出是单机运行。

4.测试连接

运行：

./bin/zkCli.sh

结果：

./bin/zkCli.sh
Connecting to localhost:2181
2018-08-02 14:23:10,984 [myid:] - INFO  [main:Environment@100] - Client environment:zookeeper.version=3.4.12-e5259e437540f349646870ea94dc2658c4e44b3b, built on 03/27/2018 03:55 GMT
2018-08-02 14:23:10,988 [myid:] - INFO  [main:Environment@100] - Client environment:host.name=<NA>
2018-08-02 14:23:10,988 [myid:] - INFO  [main:Environment@100] - Client environment:java.version=1.8.0_162
2018-08-02 14:23:10,990 [myid:] - INFO  [main:Environment@100] - Client environment:java.vendor=Oracle Corporation
2018-08-02 14:23:10,990 [myid:] - INFO  [main:Environment@100] - Client environment:java.home=/opt/java/jdk1.8.0_162/jre
2018-08-02 14:23:10,990 [myid:] - INFO  [main:Environment@100] - Client environment:java.class.path=/opt/zookeeper/zookeeper-3.4.12/bin/../build/classes:/opt/zookeeper/zookeeper-3.4.12/bin/../build/lib/*.jar:/opt/zookeeper/zookeeper-3.4.12/bin/../lib/slf4j-log4j12-1.7.25.jar:/opt/zookeeper/zookeeper-3.4.12/bin/../lib/slf4j-api-1.7.25.jar:/opt/zookeeper/zookeeper-3.4.12/bin/../lib/netty-3.10.6.Final.jar:/opt/zookeeper/zookeeper-3.4.12/bin/../lib/log4j-1.2.17.jar:/opt/zookeeper/zookeeper-3.4.12/bin/../lib/jline-0.9.94.jar:/opt/zookeeper/zookeeper-3.4.12/bin/../lib/audience-annotations-0.5.0.jar:/opt/zookeeper/zookeeper-3.4.12/bin/../zookeeper-3.4.12.jar:/opt/zookeeper/zookeeper-3.4.12/bin/../src/java/lib/*.jar:/opt/zookeeper/zookeeper-3.4.12/bin/../conf:.:/opt/java/jdk1.8.0_162/bin/dt.jar:/opt/java/jdk1.8.0_162/lib/tools.jar
2018-08-02 14:23:10,990 [myid:] - INFO  [main:Environment@100] - Client environment:java.library.path=/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib
2018-08-02 14:23:10,990 [myid:] - INFO  [main:Environment@100] - Client environment:java.io.tmpdir=/tmp
2018-08-02 14:23:10,990 [myid:] - INFO  [main:Environment@100] - Client environment:java.compiler=<NA>
2018-08-02 14:23:10,991 [myid:] - INFO  [main:Environment@100] - Client environment:os.name=Linux
2018-08-02 14:23:10,991 [myid:] - INFO  [main:Environment@100] - Client environment:os.arch=amd64
2018-08-02 14:23:10,991 [myid:] - INFO  [main:Environment@100] - Client environment:os.version=4.4.0-93-generic
2018-08-02 14:23:10,991 [myid:] - INFO  [main:Environment@100] - Client environment:user.name=root
2018-08-02 14:23:10,991 [myid:] - INFO  [main:Environment@100] - Client environment:user.home=/root
2018-08-02 14:23:10,991 [myid:] - INFO  [main:Environment@100] - Client environment:user.dir=/opt/zookeeper/zookeeper-3.4.12
2018-08-02 14:23:10,993 [myid:] - INFO  [main:ZooKeeper@441] - Initiating client connection, connectString=localhost:2181 sessionTimeout=30000 watcher=org.apache.zookeeper.ZooKeeperMain$MyWatcher@277050dc
Welcome to ZooKeeper!
2018-08-02 14:23:11,016 [myid:] - INFO  [main-SendThread(localhost:2181):ClientCnxn$SendThread@1028] - Opening socket connection to server localhost/127.0.0.1:2181. Will not attempt to authenticate using SASL (unknown error)
JLine support is enabled
2018-08-02 14:23:11,134 [myid:] - INFO  [main-SendThread(localhost:2181):ClientCnxn$SendThread@878] - Socket connection established to localhost/127.0.0.1:2181, initiating session
2018-08-02 14:23:11,146 [myid:] - INFO  [main-SendThread(localhost:2181):ClientCnxn$SendThread@1302] - Session establishment complete on server localhost/127.0.0.1:2181, sessionid = 0x10008fcefa30001, negotiated timeout = 30000
WATCHER::
WatchedEvent state:SyncConnected type:None path:null
[zk: localhost:2181(CONNECTED) 0]

说明连接成功，并且介入到了Zookeeper的文件系统中。

5.常用命令

5.1.使用 ls 命令来查看当前 ZooKeeper 中所包含的内容

[zk: localhost:2181(CONNECTED) 0] ls /
[zookeeper]

5.2.创建一个新的 znode ，使用 create /zkPro myData

[zk: localhost:2181(CONNECTED) 1] create /zkPro myData
Created /zkPro

5.3.再次使用 ls 命令来查看现在 zookeeper 中所包含的内容：

[zk: localhost:2181(CONNECTED) 2] ls /
[zookeeper, zkPro]

5.4.下面我们运行 get 命令来确认第二步中所创建的 znode 是否包含我们所创建的字符串：

[zk: localhost:2181(CONNECTED) 3] get /zkPro
myData
cZxid = 0xf
ctime = Thu Aug 02 14:32:01 CST 2018
mZxid = 0xf
mtime = Thu Aug 02 14:32:01 CST 2018
pZxid = 0xf
cversion = 0
dataVersion = 0
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 6
numChildren = 0

5.5.下面我们通过 set 命令来对 zk 所关联的字符串进行设置：

[zk: localhost:2181(CONNECTED) 4] set /zkPro myData2
cZxid = 0xf
ctime = Thu Aug 02 14:32:01 CST 2018
mZxid = 0x10
mtime = Thu Aug 02 14:38:40 CST 2018
pZxid = 0xf
cversion = 0
dataVersion = 1
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 7
numChildren = 0

5.6.使用 get 命令再次查看：

[zk: localhost:2181(CONNECTED) 5] get /zkPro
myData2
cZxid = 0xf
ctime = Thu Aug 02 14:32:01 CST 2018
mZxid = 0x10
mtime = Thu Aug 02 14:38:40 CST 2018
pZxid = 0xf
cversion = 0
dataVersion = 1
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 7
numChildren = 0

能够看到字符串“myData”被改为了“myData2”。

5.7.下面我们将刚才创建的 znode 删除

[zk: localhost:2181(CONNECTED) 6] delete /zkPro

5.8.再次使用 ls 命令查看

[zk: localhost:2181(CONNECTED) 7] ls /
[zookeeper]

能够看到名为“/zkPro”的znode被删除了。

6.使用Java API操作zookeeper

现在我们来做一个实验测试一下Zookeeper服务器的功能。

我们要做的是在zookeeper里增加一个znode目录节点，并且把配置信息存储在里面，接着写一段Java代码作为client来连接Zookeeper的server上，查看server目前的目录文件情况；然后再打开一个终端，连接到Zookeeper的server上，改变Zookeeper的目录文件情况，这时候Java代码作为client端会输出server端目录文件结构的改变。

6.1.创建一个znode，并且保存一个配置信息

[zk: localhost:2181(CONNECTED) 7] create /username dongdong
[zookeeper]

然后查看“/username”的配置信息：

[zk: localhost:2181(CONNECTED) 7] ls /
[zookeeper]

6.2.使用Java制作一个client

6.2.1.Maven部分

client端创建一个maven项目：

<!-- https://mvnrepository.com/artifact/org.apache.zookeeper/zookeeper -->
<dependency>
	<groupId>org.apache.zookeeper</groupId>
	<artifactId>zookeeper</artifactId>
	<version>3.4.12</version>
	<!-- <type>pom</type> -->
</dependency>

这里注意，在maven库中复制的结构里面有：

<type>pom</type>

部分，这里要将其注释掉，否则项目中不会加入：

zookeeper-3.4.12.jar

这个jar包，代码中的类也就无法继承：

org.apache.zookeeper.Watcher

这个监听器的接口。

6.2.2.Java代码部分

使用Java代码制作的client端如下：

package com.yhd.project.zookeepertest;
import java.util.concurrent.CountDownLatch;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.Watcher.Event.EventType;
import org.apache.zookeeper.Watcher.Event.KeeperState;
import org.apache.zookeeper.data.Stat;
import org.apache.zookeeper.ZooKeeper;
/**
 * 分布式配置中心demo
 * 
 * @author admin
 *
 */
public class ZooKeeperProSync implements Watcher {
	private static CountDownLatch connectedSemaphore = new CountDownLatch(1);
	private static ZooKeeper zk = null;
	private static Stat stat = new Stat();
	
	public static void main(String[] args) throws Exception {
		//Zookeeper配置数据存放路径
		String path = "/username";
		//连接Zookeeper并且注册一个默认的监听器，注明服务器的IP和端口
		zk = new ZooKeeper("*.*.*.*:2181", 5000, new ZooKeeperProSync());
		
		//等待zk连接成功的通知
		connectedSemaphore.await();
		//获取path目录节点的配置数据，并注册默认的监听器
		System.out.println(new String(zk.getData(path, true, stat)));
		
		Thread.sleep(Integer.MAX_VALUE);
	}
	
	public void process(WatchedEvent event) {
				if (KeeperState.SyncConnected == event.getState()) {	//zk连接成功通知事件
			if ( EventType.None == event.getType() && null == event.getPath() ) {
				connectedSemaphore.countDown();
			} else if (event.getType() == EventType.NodeDataChanged) {	//zk目录节点数据变化通知事件
				try {
					System.out.println("配置已修改，新值为：" + 
							new String(zk.getData(event.getPath(), true, stat)));
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		} else {
		}
	}
}

6.3.运行Java制作的client

运行java，结果如下：

log4j:WARN No appenders could be found for logger (org.apache.zookeeper.ZooKeeper).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
dongdong

因为之前在：

/username

这个znode下创建了：

dongdong

这个字符串，此处运行client，输出了这个字符串。

6.4.使用终端连接Zookeeper的server，改变znode的配置

1.连接server

使用终端连接server，可以在Zookeeper的服务器上使用终端输入：

./bin/zkCli.sh

来连接server。

先查看一下现有结构：

[zk: localhost:2181(CONNECTED) 0] ls /
[zookeeper, username]

然后将原有的字符串“dongdong”修改为“dongdong123”。

[zk: localhost:2181(CONNECTED) 1] set /username dongdong123		//修改
cZxid = 0x14
ctime = Thu Aug 02 14:56:38 CST 2018
mZxid = 0x1c
mtime = Thu Aug 02 22:01:10 CST 2018
pZxid = 0x14
cversion = 0
dataVersion = 1
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 11
numChildren = 0
[zk: localhost:2181(CONNECTED) 2]

3.在client上查看变化

现在是有2个client：Java代码制作的client，终端命令行的client。

在之前将“dongdong”修改为“dongdong123”的同时，Java代码的client端就会输出：

log4j:WARN No appenders could be found for logger (org.apache.zookeeper.ZooKeeper).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
dongdong
配置已修改，新值为：dongdong123

说明我们设置的监听器是生效了的。另外在终端命令行查看一下znode的信息：

[zk: localhost:2181(CONNECTED) 2] get /username
dongdong123
cZxid = 0x14
ctime = Thu Aug 02 14:56:38 CST 2018
mZxid = 0x1c
mtime = Thu Aug 02 22:01:10 CST 2018
pZxid = 0x14
cversion = 0
dataVersion = 1
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 11
numChildren = 0

也能够看出信息变为“dongdong123”了，说明测试成功！

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