Zookeeper (5) - Zookeeper common commands

Zookeeper server commands

First enter the zk installation directory: cd /usr/local/zookeeper-3.4.10

bin/zkServer.sh start - start the zk server

bin/zkServer.sh status - View zk server status

# 查看状态（本地模式会显示standalone，如果是集群模式会显示leader或者follower）
bin/zkServer.sh status
ZooKeeper JMX enabled by default
Using config: /usr/local/zookeeper-3.4.10/bin/../conf/zoo.cfg
Mode: standalone

bin/zkServer.sh stop - stop zk server

Client Command Line Operations

command basic syntax	Functional description
help	show all action commands
ls path [watch]	Use the ls command to view the content contained in the current znode
ls2 path [watch]	View the current node data and see data such as the number of updates
create	Normal creation (permanent node); -s contains sequence; -e temporary (restart or timeout disappears)
get path [watch]	get the value of the node
set	Set the specific value of the node
stat	View node status
delete	delete node
rmr	delete node recursively

bin/zkCli.sh - start zk client

quit - quit the zk client

# 退出客户端
[zk: localhost:2181(CONNECTED) 0] quit

help - display all operation commands

# 显示所有操作命令
[zk: localhost:2181(CONNECTED) 1] help

ls - view the content contained in the current ZNode

# 查看当前znode中所包含的内容
[zk: localhost:2181(CONNECTED) 0] ls /
[zookeeper]

ls / watch - watch for path changes

# 节点的子节点变化监听（路径变化）
# 命令里监听是一次性的，可以通过代码循环监听
# 在104主机上注册监听/app1节点的子节点变化
[zk: localhost:2181(CONNECTED) 1] ls /app1 watch
[aa0000000001, server101]
# 在103主机/app1节点上创建子节点
[zk: localhost:2181(CONNECTED) 6] create /app1/bb 666
Created /app1/bb
# 观察104主机收到子节点变化的监听
WATCHER::
WatchedEvent state:SyncConnected type:NodeChildrenChanged path:/app1

ls2 - view the current node data and can see data such as the number of updates

# 查看当前节点数据并能看到更新次数等数据
[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

create - create a normal node

# 创建普通节点
[zk: localhost:2181(CONNECTED) 2] create /app1 "hello app1"
Created /app1
[zk: localhost:2181(CONNECTED) 4] create /app1/server101 "192.168.1.101"
Created /app1/server101

create -e - create an ephemeral node

# 创建短暂节点
[zk: localhost:2181(CONNECTED) 9] create -e /app-emphemeral 8888
# 在当前客户端是能查看到的
[zk: localhost:2181(CONNECTED) 10] ls /
[app1, app-emphemeral, zookeeper]
# 退出当前客户端然后再重启客户端
[zk: localhost:2181(CONNECTED) 12] quit
bin/zkCli.sh
# 再次查看根目录下短暂节点已经删除
[zk: localhost:2181(CONNECTED) 0] ls /
[app1, zookeeper]

create -s - create a node with a sequence number

# 创建带序号的节点
# 先创建一个普通的根节点app2
[zk: localhost:2181(CONNECTED) 11] create /app2 "app2"
# 创建带序号的节点
[zk: localhost:2181(CONNECTED) 13] create -s /app2/aa 888
Created /app2/aa0000000000
[zk: localhost:2181(CONNECTED) 14] create -s /app2/bb 888
Created /app2/bb0000000001
[zk: localhost:2181(CONNECTED) 15] create -s /app2/cc 888
Created /app2/cc0000000002
# 如果原节点下有1个节点，则再排序时从1开始，以此类推。
[zk: localhost:2181(CONNECTED) 16] create -s /app1/aa 888
Created /app1/aa0000000001

get - get the value of the node

[zk: localhost:2181(CONNECTED) 8] get /app1/server101
192.168.1.101
cZxid = 0x20000000b
ctime = Mon Jul 17 16:11:04 CST 2017
mZxid = 0x20000000b
mtime = Mon Jul 17 16:11:04 CST 2017
pZxid = 0x20000000b
cversion = 0
dataVersion = 0
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 13
numChildren = 0

get / watch - watch the value of the node

# 节点的值变化监听
# 在104主机上注册监听/app1节点数据变化
[zk: localhost:2181(CONNECTED) 26] get /app1 watch
# 在103主机上修改/app1节点的数据
[zk: localhost:2181(CONNECTED) 5] set /app1  777
# 观察104主机收到数据变化的监听
WATCHER::
WatchedEvent state:SyncConnected type:NodeDataChanged path:/app1

set - modify the value of the node

# 修改节点数据值
[zk: localhost:2181(CONNECTED) 2] set /app1 999

stat - view node status

# 查看节点状态
[zk: localhost:2181(CONNECTED) 12] stat /app1
cZxid = 0x20000000a
ctime = Mon Jul 17 16:08:35 CST 2017
mZxid = 0x200000018
mtime = Mon Jul 17 16:54:38 CST 2017
pZxid = 0x20000001c
cversion = 4
dataVersion = 2
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 3
numChildren = 2

delete - delete a node

# 删除节点
[zk: localhost:2181(CONNECTED) 4] delete /app1/bb

rmr - remove nodes recursively

# 递归删除节点
[zk: localhost:2181(CONNECTED) 7] rmr /app2