zookeeper的客户端常用操作

一，查看当前zookeeper的版本:

[root@localhost conf]# echo stat|nc 127.0.0.1 2181
Zookeeper version: 3.5.6-c11b7e26bc554b8523dc929761dd28808913f091, built on 10/08/2019 20:18 GMT

说明：架构森林是一个专注架构的博客，地址：https://www.cnblogs.com/architectforest

         对应的源码可以访问这里获取： https://github.com/liuhongdi/

 说明：作者:刘宏缔 邮箱: 371125307@qq.com

二，启动zookeeper客户端

[root@localhost conf]# zkCli.sh 

三，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]

四，创建一个新的 znode 

[zk: localhost:2181(CONNECTED) 1] create /lockdemo 'demo content'
Created /lockdemo
[zk: localhost:2181(CONNECTED) 2] ls /
[lockdemo, zookeeper]

五，获取一个znode的value

[zk: localhost:2181(CONNECTED) 3] get /lockdemo
demo content

六，设置一个znode的 value

[zk: localhost:2181(CONNECTED) 22] set /lockdemo 'demo content2'

六，删除一个znode

说明：使用delete命令

[zk: localhost:2181(CONNECTED) 4] create /lockdemo2
Created /lockdemo2
[zk: localhost:2181(CONNECTED) 5] ls /
[lockdemo, lockdemo2, zookeeper]
[zk: localhost:2181(CONNECTED) 6] delete /lockdemo2
[zk: localhost:2181(CONNECTED) 7] ls /
[lockdemo, zookeeper]

七，列出zkCli上执行过的命令

[zk: localhost:2181(CONNECTED) 8] history

八，创建一个子节点

[zk: localhost:2181(CONNECTED) 10] create /lockdemo/son
Created /lockdemo/son
[zk: localhost:2181(CONNECTED) 11] ls /
[lockdemo, zookeeper]

九，列出节点时，附带上统计信息

  给ls 加上 s参数即可

[zk: localhost:2181(CONNECTED) 12] ls -s /lockdemo
[son]cZxid = 0x2
ctime = Tue Feb 18 21:44:25 CST 2020
mZxid = 0x2
mtime = Tue Feb 18 21:44:25 CST 2020
pZxid = 0x5
cversion = 1
dataVersion = 0
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 12
numChildren = 1

十，统计节点的信息

[zk: localhost:2181(CONNECTED) 14] stat /lockdemo/son
cZxid = 0x5
ctime = Tue Feb 18 21:51:09 CST 2020
mZxid = 0x5
mtime = Tue Feb 18 21:51:09 CST 2020
pZxid = 0x5
cversion = 0
dataVersion = 0
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 0
numChildren = 0

说明：各个字段的含义是什么

cZxid：节点创建时的zxid
ctime：节点创建时间
mZxid：节点最近一次更新时的zxid
mtime：节点最近一次更新的时间
cversion：子节点数据更新次数
dataVersion：本节点数据更新次数
aclVersion：节点ACL(授权信息)的更新次数
ephemeralOwner：如果该节点为临时节点,ephemeralOwner值表示与该节点绑定的session id. 
如果该节点不是临时节点,ephemeralOwner值为0
dataLength：节点数据长度，本例中为根节点/的长度
numChildren：子节点个数 

十一，删除带子节点的节点

节点如果带有子节点时，不能直接使用delete做删除

[zk: localhost:2181(CONNECTED) 15] delete /lockdemo
Node not empty: /lockdemo
[zk: localhost:2181(CONNECTED) 16] deleteall /lockdemo
[zk: localhost:2181(CONNECTED) 17] ls /
[zookeeper]

十二，watch一个节点的value变化

在终端一上操作:

[zk: localhost:2181(CONNECTED) 27] set /lockdemo 'demo content2'
WATCHER::
WatchedEvent state:SyncConnected type:NodeDataChanged path:/lockdemo
[zk: localhost:2181(CONNECTED) 28] get -w /lockdemo
demo content2

说明： get -w 给当前的key添加了watcher

在终端二上操作

[zk: localhost:2181(CONNECTED) 4] set /lockdemo 'change2'

此时回到终端一查看

[zk: localhost:2181(CONNECTED) 29] 
WATCHER::
WatchedEvent state:SyncConnected type:NodeDataChanged path:/lockdemo

watcher提示: 有NodeDataChanged发生

十三，watch一个节点的node变化

        说明：这种主要是子节点的变化，不包括value的变化

在终端一操作:

[zk: localhost:2181(CONNECTED) 32] ls -w /lockdemo
[]

在终端二操作：

[zk: localhost:2181(CONNECTED) 7] create /lockdemo/son 'son value'
Created /lockdemo/son

回到终端一查看

[zk: localhost:2181(CONNECTED) 33] 
WATCHER::

WatchedEvent state:SyncConnected type:NodeChildrenChanged path:/lockdemo

说明：可以看到watcher提示的事件是:NodeChildrenChanged

十四，退出zkcli

[zk: localhost:2181(CONNECTED) 9] quit