ZK的基本使用

3888端口，用于leader选举的端口

命令行使用

创建

create [-s | -e ] path data acl

其中 -s 表示顺序节点，

-e 表示 临时节点

不加的话，默认是持久化节点

acl是权限，默认不加权限限制

sh $ZK_HOME/bin/zkCli.sh

[zk: localhost:2181(CONNECTED) 0] create /zk-jsy-book 122jin
Created /zk-jsy-book

通过执行以上命令，可以在根目录下创建一个 zk-jsy-book的节点，其值是 122jin

读取

ls path

类似于linux下的ls命令，可以列举出path下所有的一级子节点

[zk: localhost:2181(CONNECTED) 2] ls /
[zk-jsy-book, zookeeper]
[zk: localhost:2181(CONNECTED) 3] ls /zk-jsy-book
[]

get path

可以获取某个节点的值及其对应属性

[zk: localhost:2181(CONNECTED) 5] create /zk-jsy-book/book1 111  --- 再创建一个子节点
Created /zk-jsy-book/book1
[zk: localhost:2181(CONNECTED) 6] ls /zk-jsy-book    --- ls查看
[book1]
[zk: localhost:2181(CONNECTED) 7] get /zk-jsy-book   --- get获取节点值及属性信息
122jin
cZxid = 0x2d
ctime = Tue Jul 24 12:47:37 GMT 2018
mZxid = 0x2d
mtime = Tue Jul 24 12:47:37 GMT 2018
pZxid = 0x2e
cversion = 1
dataVersion = 0
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 6
numChildren = 1
[zk: localhost:2181(CONNECTED) 8] get /zk-jsy-book/book1  --- 获取子节点值及属性信息
111
cZxid = 0x2e
ctime = Tue Jul 24 13:21:01 GMT 2018
mZxid = 0x2e
mtime = Tue Jul 24 13:21:01 GMT 2018
pZxid = 0x2e
cversion = 0
dataVersion = 0
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 3
numChildren = 0

更新

set path data [version]

[zk: localhost:2181(CONNECTED) 9] set /zk-jsy-book test
cZxid = 0x2d
ctime = Tue Jul 24 12:47:37 GMT 2018
mZxid = 0x2f
mtime = Tue Jul 24 13:39:13 GMT 2018
pZxid = 0x2e
cversion = 1
dataVersion = 1
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 4
numChildren = 1
[zk: localhost:2181(CONNECTED) 10] get /zk-jsy-book
test
cZxid = 0x2d
ctime = Tue Jul 24 12:47:37 GMT 2018
mZxid = 0x2f
mtime = Tue Jul 24 13:39:13 GMT 2018
pZxid = 0x2e
cversion = 1
dataVersion = 1
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 4
numChildren = 1
[zk: localhost:2181(CONNECTED) 11]

可以看到，dataVersion变成了1

删除

delete path

[zk: localhost:2181(CONNECTED) 11] ls /
[zk-jsy-book, zookeeper]
[zk: localhost:2181(CONNECTED) 12] delete /zk-jsy-book
Node not empty: /zk-jsy-book
[zk: localhost:2181(CONNECTED) 13] delete /zk-jsy-book/book1
[zk: localhost:2181(CONNECTED) 14] get /zk-jsy-book/book1
Node does not exist: /zk-jsy-book/book1
[zk: localhost:2181(CONNECTED) 15] delete /zk-jsy-book
[zk: localhost:2181(CONNECTED) 16] ls /
[zookeeper]
[zk: localhost:2181(CONNECTED) 17]

注意，无法删除一个有子节点的节点，如上所示。