Zookeeper系列一：Zookeeper基础命令操作

前言

由于公司年底要更换办公地点，所以最近投了一下简历，发现面试官现在很喜欢问dubbo、zookeeper和高并发等。由于公司没有使用dubbo，只知道dubbo是一个远程服务调用的分布式框架，zookeeper为分布式应用程序协调服务。因此，本周查阅资料整理下zookeeper学习笔记。

安装zookeeper

安装参考链接https://blog.csdn.net/qiunian144084/article/details/79192819

基础命令操作

启动zk服务

./zkServer.sh start

[root@localhost bin]# ./zkServer.sh

ZooKeeper JMX enabled by default

Using config: /usr/home/zookeeper-3.4.11/bin/../conf/zoo.cfg

Usage: ./zkServer.sh {start|start-foreground|stop|restart|status|upgrade|print-cmd}

# 提示要以./zkCli.sh start 启动zk

./zkCli.sh start 

查看zk的运行状态

./zkServer.sh status 由于我已经配置了zk的集群，所以此处显示状态为leader

[root@localhost bin]# ./zkServer.sh status

ZooKeeper JMX enabled by default

Using config: /usr/home/zookeeper-3.4.11/bin/../conf/zoo.cfg

Mode: leader

客户端链接zk

[root@localhost bin]# ./zkCli.sh 

......

WatchedEvent state:SyncConnected type:None path:null

[zk: localhost:2181(CONNECTED) 0]

help 查看客户端帮助命令

help

[zk: localhost:2181(CONNECTED) 0] help

ZooKeeper -server host:port cmd args

    stat path [watch]

    set path data [version]

    ls path [watch]

    delquota [-n|-b] path

    ls2 path [watch]

    setAcl path acl

    setquota -n|-b val path

    history 

    redo cmdno

    printwatches on|off

    delete path [version]

    sync path

    listquota path

    rmr path

    get path [watch]

    create [-s] [-e] path data acl

    addauth scheme auth

    quit 

    getAcl path

    close 

    connect host:port

[zk: localhost:2181(CONNECTED) 1] 

ls 查看

ls 查看命令(niocoder是我测试集群创建的节点，默认只有zookeeper一个节点)

[zk: localhost:2181(CONNECTED) 1] ls /

[niocoder, zookeeper]

[zk: localhost:2181(CONNECTED) 2] ls /zookeeper 

[quota]

[zk: localhost:2181(CONNECTED) 4] ls /zookeeper/quota

[]

get 获取节点数据和更新信息

get内容为空

cZxid ：创建节点的id

ctime ： 节点的创建时间

mZxid ：修改节点的id

mtime ：修改节点的时间

pZxid ：子节点的id

cversion : 子节点的版本

dataVersion ： 当前节点数据的版本

aclVersion ：权限的版本

ephemeralOwner ：判断是否是临时节点

dataLength ： 数据的长度

numChildren ：子节点的数量

[zk: localhost:2181(CONNECTED) 7] get /zookeeper #下面空行说明节点内容为空

cZxid = 0x0

ctime = Thu Jan 01 00:00:00 UTC 1970

mZxid = 0x0

mtime = Thu Jan 01 00:00:00 UTC 1970

pZxid = 0x0

cversion = -1

dataVersion = 0

aclVersion = 0

ephemeralOwner = 0x0

dataLength = 0

numChildren = 1

[zk: localhost:2181(CONNECTED) 8]

stat 获得节点的更新信息

stat

[zk: localhost:2181(CONNECTED) 8] stat /zookeeper

cZxid = 0x0

ctime = Thu Jan 01 00:00:00 UTC 1970

mZxid = 0x0

mtime = Thu Jan 01 00:00:00 UTC 1970

pZxid = 0x0

cversion = -1

dataVersion = 0

aclVersion = 0

ephemeralOwner = 0x0

dataLength = 0

numChildren = 1

ls2 ls命令和stat命令的整合

ls2

[zk: localhost:2181(CONNECTED) 10] ls2 /zookeeper

[quota]

cZxid = 0x0

ctime = Thu Jan 01 00:00:00 UTC 1970

mZxid = 0x0

mtime = Thu Jan 01 00:00:00 UTC 1970

pZxid = 0x0

cversion = -1

dataVersion = 0

aclVersion = 0

ephemeralOwner = 0x0

dataLength = 0

numChildren = 1

[zk: localhost:2181(CONNECTED) 11] 

create 创建节点

create [-s] [-e] path data acl 可以注意一下各个版本的变化

#创建merryyou节点，节点的内容为merryyou

[zk: localhost:2181(CONNECTED) 1] create /merryyou merryyou

Created /merryyou

#获得merryyou节点内容

[zk: localhost:2181(CONNECTED) 3] get /merryyou

merryyou

cZxid = 0x200000004

ctime = Sat Jun 02 14:20:06 UTC 2018

mZxid = 0x200000004

mtime = Sat Jun 02 14:20:06 UTC 2018

pZxid = 0x200000004

cversion = 0

dataVersion = 0

aclVersion = 0

ephemeralOwner = 0x0

dataLength = 8

numChildren = 0

create -e 创建临时节点

create -e

#创建临时节点

[zk: localhost:2181(CONNECTED) 4] create -e  /merryyou/temp merryyou

Created /merryyou/temp

[zk: localhost:2181(CONNECTED) 5] get /merryyou

merryyou

cZxid = 0x200000004

ctime = Sat Jun 02 14:20:06 UTC 2018

mZxid = 0x200000004

mtime = Sat Jun 02 14:20:06 UTC 2018

pZxid = 0x200000005

cversion = 1

dataVersion = 0

aclVersion = 0

ephemeralOwner = 0x0

dataLength = 8

numChildren = 1

[zk: localhost:2181(CONNECTED) 6] get /merryyou/temp

merryyou

cZxid = 0x200000005

ctime = Sat Jun 02 14:22:24 UTC 2018

mZxid = 0x200000005

mtime = Sat Jun 02 14:22:24 UTC 2018

pZxid = 0x200000005

cversion = 0

dataVersion = 0

aclVersion = 0

ephemeralOwner = 0x2000000d4500000

dataLength = 8

numChildren = 0

[zk: localhost:2181(CONNECTED) 7] 

#断开重连之后，临时节点自动消失

WATCHER::

WatchedEvent state:SyncConnected type:None path:null

#因为默认的心跳机制，此时查询临时节点还存在

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

[temp]

#再次查询，临时节点消失

[zk: localhost:2181(CONNECTED) 1] ls /merryyou

[]

[zk: localhost:2181(CONNECTED) 2] 

create -s 创建顺序节点 自动累加

create -s

# 创建顺序节点，顺序节点会自动累加

[zk: localhost:2181(CONNECTED) 2] create -s /merryyou/sec seq

Created /merryyou/sec0000000001

[zk: localhost:2181(CONNECTED) 3] create -s /merryyou/sec seq

Created /merryyou/sec0000000002 

set path data [version] 修改节点

[zk: localhost:2181(CONNECTED) 6] get /merryyou

merryyou

cZxid = 0x200000004

ctime = Sat Jun 02 14:20:06 UTC 2018

mZxid = 0x200000004

mtime = Sat Jun 02 14:20:06 UTC 2018

pZxid = 0x200000009

cversion = 4

dataVersion = 0

aclVersion = 0

ephemeralOwner = 0x0

dataLength = 8

numChildren = 2

# 修改节点内容为new-merryyou

[zk: localhost:2181(CONNECTED) 7] set /merryyou new-merryyou

cZxid = 0x200000004

ctime = Sat Jun 02 14:20:06 UTC 2018

mZxid = 0x20000000a

mtime = Sat Jun 02 14:29:23 UTC 2018

pZxid = 0x200000009

cversion = 4

dataVersion = 1

aclVersion = 0

ephemeralOwner = 0x0

dataLength = 12

numChildren = 2

#再次查询，节点内容已经修改

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

new-merryyou

cZxid = 0x200000004

ctime = Sat Jun 02 14:20:06 UTC 2018

mZxid = 0x20000000a

mtime = Sat Jun 02 14:29:23 UTC 2018

pZxid = 0x200000009

cversion = 4

dataVersion = 1

aclVersion = 0

ephemeralOwner = 0x0

dataLength = 12

numChildren = 2

#set 根据版本号更新 dataVersion 乐观锁

[zk: localhost:2181(CONNECTED) 9] set /merryyou test-merryyou 1

cZxid = 0x200000004

ctime = Sat Jun 02 14:20:06 UTC 2018

mZxid = 0x20000000b

mtime = Sat Jun 02 14:31:30 UTC 2018

pZxid = 0x200000009

cversion = 4

dataVersion = 2

aclVersion = 0

ephemeralOwner = 0x0

dataLength = 13

numChildren = 2

#因为数据的版本号已经修改为2 再次使用版本号1修改节点提交错误

[zk: localhost:2181(CONNECTED) 10] set /merryyou test-merryyou 1

version No is not valid : /merryyou

delete path [version] 删除节点

[zk: localhost:2181(CONNECTED) 13] delete /merryyou/sec000000000

sec0000000001   sec0000000002

[zk: localhost:2181(CONNECTED) 13] delete /merryyou/sec0000000001

[zk: localhost:2181(CONNECTED) 14] ls /merryyou

[sec0000000002]

[zk: localhost:2181(CONNECTED) 15] 

#版本号操作与set类似 version

watcher通知机制

关于watcher机制大体的理解可以为，当每个节点发生变化，都会触发watcher事件，类似于mysql的触发器。zk中 watcher是一次性的，触发后立即销毁。可以参考https://blog.csdn.net/hohoo1990/article/details/78617336 

- stat path [watch] 设置watch事件 

- get path [watch]设置watch事件 

- 子节点创建和删除时触发watch事件，子节点修改不会触发该事件

stat path [watch] 设置watch事件

#添加watch 事件

[zk: localhost:2181(CONNECTED) 18] stat /longfei watch

Node does not exist: /longfei

#创建longfei节点时触发watcher事件

[zk: localhost:2181(CONNECTED) 19] create /longfei test

WATCHER::

WatchedEvent state:SyncConnected type:NodeCreated path:/longfei

Created /longfei

get path [watch] 设置watch事件

#使用get命令添加watch事件

[zk: localhost:2181(CONNECTED) 20] get /longfei watch

test

cZxid = 0x20000000e

ctime = Sat Jun 02 14:43:15 UTC 2018

mZxid = 0x20000000e

mtime = Sat Jun 02 14:43:15 UTC 2018

pZxid = 0x20000000e

cversion = 0

dataVersion = 0

aclVersion = 0

ephemeralOwner = 0x0

dataLength = 4

numChildren = 0

#修改节点触发watcher事件

[zk: localhost:2181(CONNECTED) 21] set /longfei new_test

WATCHER::

WatchedEvent state:SyncConnected type:NodeDataChanged path:/longfei

cZxid = 0x20000000e

ctime = Sat Jun 02 14:43:15 UTC 2018

mZxid = 0x20000000f

mtime = Sat Jun 02 14:45:06 UTC 2018

pZxid = 0x20000000e

cversion = 0

dataVersion = 1

aclVersion = 0

ephemeralOwner = 0x0

dataLength = 8

numChildren = 0

[zk: localhost:2181(CONNECTED) 22] 

#删除触发watcher事件

[zk: localhost:2181(CONNECTED) 23] get /longfei watch

new_test

cZxid = 0x20000000e

ctime = Sat Jun 02 14:43:15 UTC 2018

mZxid = 0x20000000f

mtime = Sat Jun 02 14:45:06 UTC 2018

pZxid = 0x20000000e

cversion = 0

dataVersion = 1

aclVersion = 0

ephemeralOwner = 0x0

dataLength = 8

numChildren = 0

[zk: localhost:2181(CONNECTED) 24] delete /longfei

WATCHER::

WatchedEvent state:SyncConnected type:NodeDeleted path:/longfei

[zk: localhost:2181(CONNECTED) 25] 

ACL权限控制

ZK的节点有5种操作权限：CREATE、READ、WRITE、DELETE、ADMIN 也就是 增、删、改、查、管理权限，这5种权限简写为crwda(即：每个单词的首字符缩写)。 

注：这5种权限中，delete是指对子节点的删除权限，其它4种权限指对自身节点的操作权限

身份的认证有4种方式： 

- world：默认方式，相当于全世界都能访问 

- auth：代表已经认证通过的用户(cli中可以通过addauth digest user:pwd 来添加当前上下文中的授权用户) 

- digest：即用户名:密码这种方式认证，这也是业务系统中最常用的 

- ip：使用Ip地址认证

使用[scheme:id:permissions]来表示acl权限

getAcl:获取某个节点的acl权限信息

#获取节点权限信息默认为 world:cdrwa任何人都可以访问

[zk: localhost:2181(CONNECTED) 34] getAcl /merryyou

'world,'anyone

: cdrwa

[zk: localhost:2181(CONNECTED) 35] 

setAcl 设置权限

[zk: localhost:2181(CONNECTED) 35] create /merryyou/test test

Created /merryyou/test

[zk: localhost:2181(CONNECTED) 36] getAcl /merryyou/test

'world,'anyone

: cdrwa

#设置节点权限 crwa 不允许删除

[zk: localhost:2181(CONNECTED) 37] setAcl /merryyou/test world:anyone:crwa

cZxid = 0x200000018

ctime = Sat Jun 02 16:18:18 UTC 2018

mZxid = 0x200000018

mtime = Sat Jun 02 16:18:18 UTC 2018

pZxid = 0x200000018

cversion = 0

dataVersion = 0

aclVersion = 1

ephemeralOwner = 0x0

dataLength = 4

numChildren = 0

#查询刚才设置的acl权限信息 crwa 没有删除权限

[zk: localhost:2181(CONNECTED) 38] getAcl /merryyou/test

'world,'anyone

: crwa

[zk: localhost:2181(CONNECTED) 39] 

[zk: localhost:2181(CONNECTED) 39] create /merryyou/test/abc abc

Created /merryyou/test/abc

#删除子节点的时候提交权限不足

[zk: localhost:2181(CONNECTED) 40] delete /merryyou/test/abc

Authentication is not valid : /merryyou/test/abc

#设置节点的权限信息为rda

[zk: localhost:2181(CONNECTED) 41] setAcl /merryyou/test world:anyone:rda 

cZxid = 0x200000018

ctime = Sat Jun 02 16:18:18 UTC 2018

mZxid = 0x200000018

mtime = Sat Jun 02 16:18:18 UTC 2018

pZxid = 0x20000001a

cversion = 1

dataVersion = 0

aclVersion = 2

ephemeralOwner = 0x0

dataLength = 4

numChildren = 1

[zk: localhost:2181(CONNECTED) 42] getAcl /merryyou/test

'world,'anyone

: dra

#可以成功删除

[zk: localhost:2181(CONNECTED) 43] delete /merryyou/test/abc             

[zk: localhost:2181(CONNECTED) 46] ls /merryyou/test

[]

[zk: localhost:2181(CONNECTED) 47] 

#设置节点信息为a admin

[zk: localhost:2181(CONNECTED) 47] setAcl /merryyou/test world:anyone:a  

cZxid = 0x200000018

ctime = Sat Jun 02 16:18:18 UTC 2018

mZxid = 0x200000018

mtime = Sat Jun 02 16:18:18 UTC 2018

pZxid = 0x20000001d

cversion = 2

dataVersion = 0

aclVersion = 3

ephemeralOwner = 0x0

dataLength = 4

numChildren = 0

#获取 设置都提示权限不足

[zk: localhost:2181(CONNECTED) 49] get /merryyou/test

Authentication is not valid : /merryyou/test

[zk: localhost:2181(CONNECTED) 50] set /merryyou/test 123

Authentication is not valid : /merryyou/test

[zk: localhost:2181(CONNECTED) 51] 

acl Auth 密码明文设置

[zk: localhost:2181(CONNECTED) 53] create /niocoder/merryyou merryyou

Created /niocoder/merryyou

#查询默认节点权限信息

[zk: localhost:2181(CONNECTED) 54] getAcl /niocoder/merryyou

'world,'anyone

: cdrwa

[zk: localhost:2181(CONNECTED) 55] 

#使用auth设置节点权限信息

[zk: localhost:2181(CONNECTED) 2] setAcl /niocoder/merryyou auth:test:test:cdrwa  

Acl is not valid : /niocoder/merryyou

# 注册test:test 账号密码

[zk: localhost:2181(CONNECTED) 3] addauth digest test:test

[zk: localhost:2181(CONNECTED) 4] setAcl /niocoder/merryyou auth:test:test:cdrwa

cZxid = 0x200000020

ctime = Sat Jun 02 16:32:08 UTC 2018

mZxid = 0x200000020

mtime = Sat Jun 02 16:32:08 UTC 2018

pZxid = 0x200000020

cversion = 0

dataVersion = 0

aclVersion = 1

ephemeralOwner = 0x0

dataLength = 8

numChildren = 0

#查询节点权限信息 密码为密文格式

[zk: localhost:2181(CONNECTED) 5] getAcl /niocoder/merryyou

'digest,'test:V28q/NynI4JI3Rk54h0r8O5kMug=

: cdrwa

[zk: localhost:2181(CONNECTED) 6] 

acl digest 密码密文设置

[zk: localhost:2181(CONNECTED) 13] create /names test

Created /names

[zk: localhost:2181(CONNECTED) 14] getAcl /names

'world,'anyone

: cdrwa

#使用digest设置节点的权限信息 密码为test密文

[zk: localhost:2181(CONNECTED) 15] setAcl /names digest:test:V28q/NynI4JI3Rk54h0r8O5kMug=:cdra

cZxid = 0x400000006

ctime = Sun Jun 03 01:01:17 UTC 2018

mZxid = 0x400000006

mtime = Sun Jun 03 01:01:17 UTC 2018

pZxid = 0x400000006

cversion = 0

dataVersion = 0

aclVersion = 1

ephemeralOwner = 0x0

dataLength = 4

numChildren = 0

#查询节点权限信息

[zk: localhost:2181(CONNECTED) 16] getAcl /names

'digest,'test:V28q/NynI4JI3Rk54h0r8O5kMug=

: cdra

#获取节点信息提示权限不足

[zk: localhost:2181(CONNECTED) 5] get /names

Authentication is not valid : /names

# 注册账户

[zk: localhost:2181(CONNECTED) 4] addauth digest test:test

# 可以正常获取

[zk: localhost:2181(CONNECTED) 17] get /names          

test

cZxid = 0x400000006

ctime = Sun Jun 03 01:01:17 UTC 2018

mZxid = 0x400000006

mtime = Sun Jun 03 01:01:17 UTC 2018

pZxid = 0x400000006

cversion = 0

dataVersion = 0

aclVersion = 1

ephemeralOwner = 0x0

dataLength = 4

numChildren = 0

#由于没有设置写权限不能修改节点 w

[zk: localhost:2181(CONNECTED) 18] set /names 111

Authentication is not valid : /names

[zk: localhost:2181(CONNECTED) 19] delete /names

[zk: localhost:2181(CONNECTED) 20] 

acl ip 控制客户端

[zk: localhost:2181(CONNECTED) 22] create /niocoder/ip aa

Created /niocoder/ip

[zk: localhost:2181(CONNECTED) 23] get /niocoder/ip

aa

cZxid = 0x40000000a

ctime = Sun Jun 03 01:06:47 UTC 2018

mZxid = 0x40000000a

mtime = Sun Jun 03 01:06:47 UTC 2018

pZxid = 0x40000000a

cversion = 0

dataVersion = 0

aclVersion = 0

ephemeralOwner = 0x0

dataLength = 2

numChildren = 0

# 添加ip控制的权限信息

[zk: localhost:2181(CONNECTED) 24] setAcl /niocoder/ip ip:192.168.0.68:cdrwa

cZxid = 0x40000000a

ctime = Sun Jun 03 01:06:47 UTC 2018

mZxid = 0x40000000a

mtime = Sun Jun 03 01:06:47 UTC 2018

pZxid = 0x40000000a

cversion = 0

dataVersion = 0

aclVersion = 1

ephemeralOwner = 0x0

dataLength = 2

numChildren = 0

[zk: localhost:2181(CONNECTED) 25] getAcl /niocoder/ip

'ip,'192.168.0.68

: cdrwa

[zk: localhost:2181(CONNECTED) 26] 

acl super超级管理员

使用super权限需要修改zkServer.sh，添加super管理员，重启zkServer.sh

"-Dzookeeper.DigestAuthenticationProvider.superDigest=test:V28q/NynI4JI3Rk54h0r8O5kMug="

 nohup "$JAVA" "-Dzookeeper.log.dir=${ZOO_LOG_DIR}" "-Dzookeeper.root.logger=${ZOO_LOG4J_PROP}" "-Dzookeeper.DigestAuthenticationprovider.superDigest=test:V28q/NynI4JI3Rk54h0r8O5kMug=" \

    -cp "$CLASSPATH" $JVMFLAGS $ZOOMAIN "$ZOOCFG" > "$_ZOO_DAEMON_OUT" 2>&1 < /dev/null &

#重启进入zkCli

#由于之前设置ip权限，所以不允许访问

[zk: localhost:2181(CONNECTED) 2] ls /niocoder/ip

Authentication is not valid : /niocoder/ip

#登录账号信息，即为管理员账号

[zk: localhost:2181(CONNECTED) 3] addauth digest test:test

#正常访问，节点内容为空

[zk: localhost:2181(CONNECTED) 4] ls /niocoder/ip

[]

[zk: localhost:2181(CONNECTED) 5] get /niocoder/ip

aa

cZxid = 0x40000000a

ctime = Sun Jun 03 01:06:47 UTC 2018

mZxid = 0x40000000a

mtime = Sun Jun 03 01:06:47 UTC 2018

pZxid = 0x40000000a

cversion = 0

dataVersion = 0

aclVersion = 1

ephemeralOwner = 0x0

dataLength = 2

numChildren = 0

[zk: localhost:2181(CONNECTED) 6] 

四字命令Four Letter Words

使用四字命令需要安装nc命令,(yum install nc)

stat 查看状态信息

[root@localhost bin]# echo stat | nc 192.168.0.68 2181

Zookeeper version: 3.4.11-37e277162d567b55a07d1755f0b31c32e93c01a0, built on 11/01/2017 18:06 GMT

Clients:

 /192.168.0.68:49346[0](queued=0,recved=1,sent=0)

Latency min/avg/max: 0/0/4

Received: 62

Sent: 61

Connections: 1

Outstanding: 0

Zxid: 0x50000000a

Mode: follower

Node count: 10

[root@localhost bin]# 

ruok 查看zookeeper是否启动

[root@localhost bin]# echo ruok | nc 192.168.0.68 2181

imok[root@localhost bin]# 

dump 列出没有处理的节点，临时节点

imok[root@localhost bin]# echo dump | nc 192.168.0.68 2181

SessionTracker dump:

org.apache.zookeeper.server.quorum.LearnerSessionTracker@29805957

ephemeral nodes dump:

Sessions with Ephemerals (0):

[root@localhost bin]# 

conf 查看服务器配置

[root@localhost bin]# echo conf | nc 192.168.0.68 2181

clientPort=2181

dataDir=/usr/home/zookeeper-3.4.11/data/version-2

dataLogDir=/usr/home/zookeeper-3.4.11/data/version-2

tickTime=2000

maxClientCnxns=60

minSessionTimeout=4000

maxSessionTimeout=40000

serverId=2

initLimit=10

syncLimit=5

electionAlg=3

electionPort=3888

quorumPort=2888

peerType=0

[root@localhost bin]# 

cons 显示连接到服务端的信息

[root@localhost bin]# echo cons | nc 192.168.0.68 2181

 /192.168.0.68:49354[0](queued=0,recved=1,sent=0)

[root@localhost bin]# 

envi 显示环境变量信息

[root@localhost bin]# echo envi | nc 192.168.0.68 2181

Environment:

zookeeper.version=3.4.11-37e277162d567b55a07d1755f0b31c32e93c01a0, built on 11/01/2017 18:06 GMT

host.name=localhost

java.version=1.8.0_111

java.vendor=Oracle Corporation

java.home=/usr/local/jdk1.8.0_111/jre

java.class.path=/usr/home/zookeeper-3.4.11/bin/../build/classes:/usr/home/zookeeper-3.4.11/bin/../build/lib/*.jar:/usr/home/zookeeper-3.4.11/bin/../lib/slf4j-log4j12-1.6.1.jar:/usr/home/zookeeper-3.4.11/bin/../lib/slf4j-api-1.6.1.jar:/usr/home/zookeeper-3.4.11/bin/../lib/netty-3.10.5.Final.jar:/usr/home/zookeeper-3.4.11/bin/../lib/log4j-1.2.16.jar:/usr/home/zookeeper-3.4.11/bin/../lib/jline-0.9.94.jar:/usr/home/zookeeper-3.4.11/bin/../lib/audience-annotations-0.5.0.jar:/usr/home/zookeeper-3.4.11/bin/../zookeeper-3.4.11.jar:/usr/home/zookeeper-3.4.11/bin/../src/java/lib/*.jar:/usr/home/zookeeper-3.4.11/bin/../conf:

java.library.path=/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib

java.io.tmpdir=/tmp

java.compiler=<NA>

os.name=Linux

os.arch=amd64

os.version=3.10.0-514.10.2.el7.x86_64

user.name=root

user.home=/root

user.dir=/usr/home/zookeeper-3.4.11/bin

[root@localhost bin]#

mntr 查看zk的健康信息

[root@localhost bin]# echo mntr | nc 192.168.0.68 2181

zk_version  3.4.11-37e277162d567b55a07d1755f0b31c32e93c01a0, built on 11/01/2017 18:06 GMT

zk_avg_latency  0

zk_max_latency  4

zk_min_latency  0

zk_packets_received 68

zk_packets_sent 67

zk_num_alive_connections    1

zk_outstanding_requests 0

zk_server_state follower

zk_znode_count  10

zk_watch_count  0

zk_ephemerals_count 0

zk_approximate_data_size    124

zk_open_file_descriptor_count   32

zk_max_file_descriptor_count    4096

[root@localhost bin]# 

wchs 展示watch的信息

[root@localhost bin]# echo wchs | nc 192.168.0.68 2181

0 connections watching 0 paths

Total watches:0

[root@localhost bin]# 

wchc和wchp 显示session的watch信息 path的watch信息

需要在 配置zoo.cfg文件中添加 4lw.commands.whitelist=*

[root@localhost bin]# echo wchc | nc 192.168.0.68 2181

wchc is not executed because it is not in the whitelist.

[root@localhost bin]# echo wchp | nc 192.168.0.68 2181

wchp is not executed because it is not in the whitelist.

总结

熟悉zookeeper基础命令操作后，再使用zookeeper提供的api或者第三方封装的api,会感觉一目了然。

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原文：https://blog.csdn.net/dandandeshangni/article/details/80558383