zookeeper学习(六)

     下面列举一些，ZooKeeper的命令操作实例:

 

连接server

bin/zkCli.sh -server 10.1.39.43:4180

列出指定node的子node

[zk: 10.1.39.43:4180(CONNECTED) 9] ls /
[hello, filesync, zookeeper, xing, server, group, log]
[zk: 10.1.39.43:4180(CONNECTED) 10] ls /hello
[]

创建znode节点, 并指定关联数据

create /hello world

创建节点/hello, 并将字符串"world"关联到该节点中.

获取znode的数据和状态信息

[zk: 10.1.39.43:4180(CONNECTED) 7] get /hello
world
cZxid = 0x10000042c
ctime = Fri May 17 17:57:33 CST 2013
mZxid = 0x10000042c
mtime = Fri May 17 17:57:33 CST 2013
pZxid = 0x10000042c
cversion = 0
dataVersion = 0
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 5
numChildren = 0

删除znode

[zk: localhost:4180(CONNECTED) 13] delete /xing/item0000000001
[zk: localhost:4180(CONNECTED) 14] delete /xing
Node not empty: /xing

使用delete命令可以删除指定znode. 当该znode拥有子znode时, 必须先删除其所有子znode, 否则操作将失败. rmr命令可用于代替delete命令, rmr是一个递归删除命令, 如果发生指定节点拥有子节点时, rmr命令会首先删除子节点.

 

 使用-e参数指定创建ephemeral节点.

[zk: localhost:4180(CONNECTED) 4] create -e /xing/ei world
Created /xing/ei

使用-s参数指定创建sequence节点.

[zk: localhost:4180(CONNECTED) 0] create -s /xing/item world
Created /xing/item0000000001
[zk: localhost:4180(CONNECTED) 1] create -s /xing/item world
Created /xing/item0000000002
[zk: localhost:4180(CONNECTED) 2] create -s /xing/item world
Created /xing/item0000000003
[zk: localhost:4180(CONNECTED) 3] create -s /xing/item world
Created /xing/item0000000004

 ls命令. ls命令的第一个参数指定znode, 第二个参数如果为true, 则说明监听该znode的子节点的增减, 以及该znode本身的删除事件.

[zk: localhost:4180(CONNECTED) 21] ls /xing true
[]
[zk: localhost:4180(CONNECTED) 22] create /xing/item item000

WATCHER::

WatchedEvent state:SyncConnected type:NodeChildrenChanged path:/xing
Created /xing/item

get命令. get命令的第一个参数指定znode, 第二个参数如果为true, 则说明监听该znode的更新和删除事件.

[zk: localhost:4180(CONNECTED) 39] get /xing true
world
cZxid = 0x100000066
ctime = Fri May 17 22:30:01 CST 2013
mZxid = 0x100000066
mtime = Fri May 17 22:30:01 CST 2013
pZxid = 0x100000066
cversion = 0
dataVersion = 0
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 5
numChildren = 0
[zk: localhost:4180(CONNECTED) 40] create /xing/item item000
Created /xing/item
[zk: localhost:4180(CONNECTED) 41] rmr /xing

WATCHER::

WatchedEvent state:SyncConnected type:NodeDeleted path:/xing

stat命令. stat命令用于获取znode的状态信息. 第一个参数指定znode, 如果第二个参数为true, 则监听该node的更新和删除事件.

 

ps：注意上面这个例子，在/xing下建立子节点的时候，/xing/item，watch并没有触发。因为getData对于子节点创建这种事件是不会触发的，详见：

http://wjy320.iteye.com/blog/2078655