Zookeeper 实战 分布式安装部署 （开发重点）

（一）分布式安装部署

1．集群规划

在hadoop102、hadoop103和hadoop104三个节点上部署Zookeeper。

2．解压安装

（1）解压Zookeeper安装包到/opt/module/目录下
[test@hadoop102 software]$ tar -zxvf zookeeper-3.4.10.tar.gz -C /opt/module/
（2）同步/opt/module/zookeeper-3.4.10目录内容到hadoop103、hadoop104
[test@hadoop102 module]$ xsync zookeeper-3.4.10/

3．配置服务器编号

（1）在/opt/module/zookeeper-3.4.10/这个目录下创建zkData
[test@hadoop102 zookeeper-3.4.10]$ mkdir -p zkData
（2）在/opt/module/zookeeper-3.4.10/zkData目录下创建一个myid的文件
[test@hadoop102 zkData]$ touch myid
添加myid文件，注意一定要在linux里面创建，在notepad++里面很可能乱码
（3）编辑myid文件
[test@hadoop102 zkData]$ vi myid
    在文件中添加与server对应的编号：2
（4）拷贝配置好的zookeeper到其他机器上
[test@hadoop102 zkData]$ xsync myid
并分别在hadoop103、hadoop104上修改myid文件中内容为3、4

4．配置zoo.cfg文件

（1）重命名/opt/module/zookeeper-3.4.10/conf这个目录下的zoo_sample.cfg为zoo.cfg
[test@hadoop102 conf]$ mv zoo_sample.cfg zoo.cfg
（2）打开zoo.cfg文件
[test@hadoop102 conf]$ vim zoo.cfg
修改数据存储路径配置
dataDir=/opt/module/zookeeper-3.4.10/zkData
增加如下配置
#######################cluster##########################
server.2=hadoop102:2888:3888
server.3=hadoop103:2888:3888
server.4=hadoop104:2888:3888
（3）同步zoo.cfg配置文件
[test@hadoop102 conf]$ xsync zoo.cfg
（4）配置参数解读
server.A=B:C:D。
A是一个数字，表示这个是第几号服务器；
集群模式下配置一个文件myid，这个文件在dataDir目录下，这个文件里面有一个数据就是A的值，Zookeeper启动时读取此文件，拿到里面的数据与zoo.cfg里面的配置信息比较从而判断到底是哪个server。
B是这个服务器的地址；
C是这个服务器Follower与集群中的Leader服务器交换信息的端口；
D是万一集群中的Leader服务器挂了，需要一个端口来重新进行选举，选出一个新的Leader，而这个端口就是用来执行选举时服务器相互通信的端口。

5．集群操作

（1）分别启动Zookeeper
[test@hadoop102 zookeeper-3.4.10]$ bin/zkServer.sh start
[test@hadoop103 zookeeper-3.4.10]$ bin/zkServer.sh start
[test@hadoop104 zookeeper-3.4.10]$ bin/zkServer.sh start
（2）查看状态
[test@hadoop102 zookeeper-3.4.10]# bin/zkServer.sh status
JMX enabled by default
Using config: /opt/module/zookeeper-3.4.10/bin/../conf/zoo.cfg
Mode: follower
[test@hadoop103 zookeeper-3.4.10]# bin/zkServer.sh status
JMX enabled by default
Using config: /opt/module/zookeeper-3.4.10/bin/../conf/zoo.cfg
Mode: leader
[test@hadoop104 zookeeper-3.4.5]# bin/zkServer.sh status
JMX enabled by default
Using config: /opt/module/zookeeper-3.4.10/bin/../conf/zoo.cfg
Mode: follower
 

 

（二）客户端命令行操作

       

命令基本语法	功能描述
help	显示所有操作命令
ls path [watch]	使用 ls 命令来查看当前znode中所包含的内容
ls2 path [watch]	查看当前节点数据并能看到更新次数等数据
create	普通创建 -s  含有序列 -e  临时（重启或者超时消失）
get path [watch]	获得节点的值
set	设置节点的具体值
stat	查看节点状态
delete	删除节点
rmr	递归删除节点

 1．启动客户端

[test@hadoop103 zookeeper-3.4.10]$ bin/zkCli.sh

2．显示所有操作命令

[zk: localhost:2181(CONNECTED) 1] help

3．查看当前znode中所包含的内容

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

4．查看当前节点详细数据

[zk: localhost:2181(CONNECTED) 1] ls2 /
[zookeeper]
cZxid = 0x0
ctime = Thu Jan 01 08:00:00 CST 1970
mZxid = 0x0
mtime = Thu Jan 01 08:00:00 CST 1970
pZxid = 0x0
cversion = -1
dataVersion = 0
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 0
numChildren = 1

5．分别创建2个普通节点

[zk: localhost:2181(CONNECTED) 3] create /sanguo "jinlian"
Created /sanguo
[zk: localhost:2181(CONNECTED) 4] create /sanguo/shuguo "liubei"
Created /sanguo/shuguo

6．获得节点的值

[zk: localhost:2181(CONNECTED) 5] get /sanguo
jinlian
cZxid = 0x100000003
ctime = Wed Aug 29 00:03:23 CST 2018
mZxid = 0x100000003
mtime = Wed Aug 29 00:03:23 CST 2018
pZxid = 0x100000004
cversion = 1
dataVersion = 0
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 7
numChildren = 1
[zk: localhost:2181(CONNECTED) 6]
[zk: localhost:2181(CONNECTED) 6] get /sanguo/shuguo
liubei
cZxid = 0x100000004
ctime = Wed Aug 29 00:04:35 CST 2018
mZxid = 0x100000004
mtime = Wed Aug 29 00:04:35 CST 2018
pZxid = 0x100000004
cversion = 0
dataVersion = 0
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 6
numChildren = 0

7．创建短暂节点

[zk: localhost:2181(CONNECTED) 7] create -e /sanguo/wuguo "zhouyu"
Created /sanguo/wuguo

（1）在当前客户端是能查看到的

[zk: localhost:2181(CONNECTED) 3] ls /sanguo 
[wuguo, shuguo]

（2）退出当前客户端然后再重启客户端

[zk: localhost:2181(CONNECTED) 12] quit
[test@hadoop104 zookeeper-3.4.10]$ bin/zkCli.sh

（3）再次查看根目录下短暂节点已经删除

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

8．创建带序号的节点
    （1）先创建一个普通的根节点/sanguo/weiguo

[zk: localhost:2181(CONNECTED) 1] create /sanguo/weiguo "caocao"
Created /sanguo/weiguo

    （2）创建带序号的节点

[zk: localhost:2181(CONNECTED) 2] create -s /sanguo/weiguo/xiaoqiao "jinlian"
Created /sanguo/weiguo/xiaoqiao0000000000
[zk: localhost:2181(CONNECTED) 3] create -s /sanguo/weiguo/daqiao "jinlian"
Created /sanguo/weiguo/daqiao0000000001
[zk: localhost:2181(CONNECTED) 4] create -s /sanguo/weiguo/diaocan "jinlian"
Created /sanguo/weiguo/diaocan0000000002

如果原来没有序号节点，序号从0开始依次递增。如果原节点下已有2个节点，则再排序时从2开始，以此类推。

9．修改节点数据值

[zk: localhost:2181(CONNECTED) 6] set /sanguo/weiguo "simayi"

10．节点的值变化监听
    （1）在hadoop104主机上注册监听/sanguo节点数据变化

[zk: localhost:2181(CONNECTED) 8] get /sanguo watch

    （2）在hadoop103主机上修改/sanguo节点的数据

[zk: localhost:2181(CONNECTED) 1] set /sanguo "xisi"

    （3）观察hadoop104主机收到数据变化的监听

WATCHER::
WatchedEvent state:SyncConnected type:NodeDataChanged path:/sanguo

11．节点的子节点变化监听（路径变化）
    （1）在hadoop104主机上注册监听/sanguo节点的子节点变化

[zk: localhost:2181(CONNECTED) 1] ls /sanguo watch
[aa0000000001, server101]

    （2）在hadoop103主机/sanguo节点上创建子节点

[zk: localhost:2181(CONNECTED) 2] create /sanguo/jin "simayi"
Created /sanguo/jin

    （3）观察hadoop104主机收到子节点变化的监听

WATCHER::
WatchedEvent state:SyncConnected type:NodeChildrenChanged path:/sanguo

12．删除节点

[zk: localhost:2181(CONNECTED) 4] delete /sanguo/jin

13．递归删除节点

[zk: localhost:2181(CONNECTED) 15] rmr /sanguo/shuguo

14．查看节点状态
 

[zk: localhost:2181(CONNECTED) 17] stat /sanguo
cZxid = 0x100000003
ctime = Wed Aug 29 00:03:23 CST 2018
mZxid = 0x100000011
mtime = Wed Aug 29 00:21:23 CST 2018
pZxid = 0x100000014
cversion = 9
dataVersion = 1
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 4
numChildren = 1