【Zookeeper】三，Zookeeper的安装与基本操作

安装Zookeeper

下载

官网下载Zookeeper，会得到一个tar包，如：apache-zookeeper-3.8.4-bin.tar.gz

解压

tar -xvf apache-zookeeper-3.8.4-bin.tar.gz -C /usr/local/bin/

-x：解压
-v：显示所有过程
-f：最后一个参数，且是必须的，代表文件名
-C：解压到指定目录下

解压后的目录结构

• bin目录：存放着启动Zookeeper的脚本。
• conf目录：保存配置文件。
• lib目录：包括Java的JAR文件，这些JAR是运行Zookeeper的第三方文件。

运行Zookeeper

在Zookeeper包的根目录下，复制一份配置文件

cp conf/zoo_sample.cfg conf/zoo.cfg

修改dataDir

dataDir=/usr/local/data/zookeeper

手动创建一下对应目录

mkdir xxx

启动Server

sh zkServer.sh start

输出结果

/usr/bin/java
ZooKeeper JMX enabled by default
Using config: /usr/local/bin/apache-zookeeper-3.8.4-bin/bin/../conf/zoo.cfg
Starting zookeeper ... STARTED

启动客户端

sh zkCli.sh

日志输出

2024-11-27 08:35:45,610 [myid:localhost:2181] - INFO  [main-SendThread(localhost:2181):o.a.z.ClientCnxn$SendThread@1013] - Socket connection established, initiating session, client: /0:0:0:0:0:0:0:1:55800, server: localhost/0:0:0:0:0:0:0:1:2181
2024-11-27 08:35:45,673 [myid:localhost:2181] - INFO  [main-SendThread(localhost:2181):o.a.z.ClientCnxn$SendThread@1453] - Session establishment complete on server localhost/0:0:0:0:0:0:0:1:2181, session id = 0x100001d014f0000, negotiated timeout = 30000

WATCHER::

WatchedEvent state:SyncConnected type:None path:null
[zk: localhost:2181(CONNECTED) 0] 
[zk: localhost:2181(CONNECTED) 0] 

连接过程

1. 客户端启动程序来建立一个会话
2. 客户端尝试连接到 localhost / 127.0.0.1:2181
3. 客户端连接成功，服务器开始初始化这个会话
4. 会话初始化完成
5. 服务器向客户端发送一个SyncConnected事件

基本操作

列出根下的所有znode

[zk: localhost:2181(CONNECTED) 0] ls /
[zookeeper]
[zk: localhost:2181(CONNECTED) 1] 

创建一个名为/workers的znode

[zk: localhost:2181(CONNECTED) 1] create /workers ""
Created /workers
[zk: localhost:2181(CONNECTED) 2] ls /
[workers, zookeeper]
[zk: localhost:2181(CONNECTED) 3]

删除znode

[zk: localhost:2181(CONNECTED) 3] delete /workers
[zk: localhost:2181(CONNECTED) 4] ls /
[zookeeper]
[zk: localhost:2181(CONNECTED) 5] 

设置数据、获取数据

[zk: localhost:2181(CONNECTED) 17] create /test
Created /test
[zk: localhost:2181(CONNECTED) 18] set /test "hello"
[zk: localhost:2181(CONNECTED) 19] get /test
hello
[zk: localhost:2181(CONNECTED) 20] 
[zk: localhost:2181(CONNECTED) 20] ls /
[test, workers, zookeeper]
[zk: localhost:2181(CONNECTED) 21]