一.功能简述

Apache ZooKeeper是一种用于分布式应用程序的分布式开源协调服务；提供了命名服务、配置管理、集群管理、分布式锁、队列管理等一系列的功能

Ⅰ).角色功能

ZooKeeper主要包括leader、learner和client三大类角色，其中learner又分为follower和observer

功能描述

a).leader

负责进行投票的发起和决议，更新系统状态

b).learner

1).follower

用于接受客户端请求并想客户端返回结果，在选主过程中参与投票

2).observer

可以接受客户端连接，将写请求转发给leader，但observer不参加投票过程，只同步leader的状态，observer的目的是为了扩展系统，提高读取速度

c).client

请求发起方

Ⅱ).数据模型和分层命名空间

ZooKeeper提供的namespace非常类似于标准文件系统。名称是由斜杠（/）分隔的路径元素序列。ZooKeeper名称空间中的每个节点都由路径标识

层次化的目录结构，命名符合常规文件系统规范
每一个zookeeper节点一个znode,并且具有一个唯一的路径标识
节点Znode可以包含数据和子节点，但是EPHEMERAL类型的节点不能有子节点
Znode中的数据可以有多个版本，查询需要带版本号
客户端应用可以在节点上设置监视器
ZK节点只支持一次性完整读写

Ⅲ).Znode类型

Znode的类型在创建时确定并且之后不能再修改
持久znode不依赖于客户端会话，只有当客户端明确要删除该持久znode时才会被删除
短暂znode的客户端会话结束时，zookeeper会将该短暂znode删除，短暂znode不可以有子节点

PERSISTENT: 持久的
EPHEMERAL: 暂时的
PERSISTENT_SEQUENTIAL: 持久化顺序编号目录节点
EPHEMERAL_SEQUENTIAL: 暂时化顺序编号目录节点

二.安装部署

Ⅰ).下载

zookeeper-3.4.14
zookeeper-3.5.5

Ⅱ).配置

a).tickTime

CS通信心跳时间，单位是毫秒，系统默认是2000毫秒

客户端与服务器或者服务器与服务器之间维持心跳，也就是每个tickTime时间就会发送一次心跳。通过心跳不仅能够用来监听机器的工作状态，还可以通过心跳来控制Flower跟Leader的通信时间，默认情况下FL的会话时常是心跳间隔的两倍

b).initLimit

集群中的follower服务器(F)与leader服务器(L)之间初始连接时能容忍的最多心跳数（tickTime的数量）

c).syncLimit

集群中flower服务器（F）跟leader（L）服务器之间的请求和答应最多能容忍的心跳数

d).dataDir

存放myid信息跟一些版本，日志，跟服务器唯一的ID信息等

e).clientPort

客户端连接zookeeper服务器的端口，默认是2181

## 查看端口情况
netstat -tan

f).集群信息的配置

配置集群信息是存在一定的格式：service.N =YYY:A:B

N：代表服务器编号（也就是myid里面的值）
YYY：服务器地址
A：表示 Flower 跟 Leader的通信端口，简称服务端内部通信的端口（默认2888）
B：表示是选举端口（默认是3888）

# The number of milliseconds of each tick
tickTime=2000

# The number of ticks that the initial
# synchronization phase can take
initLimit=10

# The number of ticks that can pass between
# sending a request and getting an acknowledgement
syncLimit=5

# the directory where the snapshot is stored.
dataDir=/home/bigdata/zookeeper-3.4.14/data

# the port at which the clients will connect
clientPort=2181

# the maximum number of client connections.
#maxClientCnxns=60

# The number of snapshots to retain in dataDir
#autopurge.snapRetainCount=3

# Purge task interval in hours
# Set to "0" to disable auto purge feature
#autopurge.purgeInterval=1

# 集群信息的配置
server.1=hostname1:2888:3888
server.2=hostname2:2888:3888
server.3=hostname3:2888:3888

Ⅲ).安装

a).解压

tar -zxvf zookeeper-3.4.14.tar.gz

b).修改配置

默认集群模式配置

1).修改存储路径

dataDir=/home/bigdata/zookeeper-3.4.14/data

2).修改myid

## 分别在每个节点的dataDir配置目录中，创建myid
vi myid

## 内容，代表服务器编号
1

3).增加集群配置

## 集群信息的配置
server.1=hostname1:2888:3888
server.2=hostname2:2888:3888
server.3=hostname3:2888:3888

c).启停服务

## 启动服务
./bin/zkServer.sh start ./conf/zoo.cfg

## 停止服务
./bin/zkServer.sh stop ./conf/zoo.cfg

三.常用命令

Ⅰ).查看状态

## 命令
./bin/zkServer.sh status

## 结果
## 可查看ZK工作模式，使用的配置文件等信息
ZooKeeper JMX enabled by default
Using config: /home/bigdata/zookeeper-3.4.14/bin/../conf/zoo.cfg
Mode: standalone

Ⅱ).客户端连接Zookeeper

./bin/zkCli.sh

Ⅲ).ls 查看

WatchedEvent state:SyncConnected type:None path:null
[zk: localhost:2181(CONNECTED) 0] ls /
[zookeeper]
[zk: localhost:2181(CONNECTED) 1] ls /zookeeper
[quota]
[zk: localhost:2181(CONNECTED) 2]

Ⅳ).get 获取节点数据和更新信息

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: 是否是临时节点标识
dataLength: 数据的长度
numChildren: 子节点的数量

[zk: localhost:2181(CONNECTED) 2] get /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

Ⅴ).stat 获得节点的更新信息

[zk: localhost:2181(CONNECTED) 4] stat /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

Ⅵ).ls2 查看

ls2是ls命令和stat命令的整合

[zk: localhost:2181(CONNECTED) 5] ls2 /zookeeper
[quota]
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

Ⅶ).create 创建节点

命令：create [-s] [-e] path data acl

[-s]：创建顺序节点，自动累加
[-e]：创建临时节点

## 创建dremio节点
[zk: localhost:2181(CONNECTED) 6] create /dremio dremio_data
Created /dremio

## 获得dremio节点内容
[zk: localhost:2181(CONNECTED) 7] get /dremio
dremio_data
cZxid = 0x2
ctime = Thu Aug 22 23:15:59 CST 2019
mZxid = 0x2
mtime = Thu Aug 22 23:15:59 CST 2019
pZxid = 0x2
cversion = 0
dataVersion = 0
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 11
numChildren = 0

Ⅷ).set 修改节点

命令： set path data [version]

1).数据修改

## 修改dremio节点数据
[zk: localhost:2181(CONNECTED) 8] set /dremio dremio_data_update
cZxid = 0x2
ctime = Thu Aug 22 23:15:59 CST 2019
mZxid = 0x3
mtime = Thu Aug 22 23:19:58 CST 2019
pZxid = 0x2
cversion = 0
dataVersion = 1
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 18
numChildren = 0

## 获得dremio节点内容
[zk: localhost:2181(CONNECTED) 9] get /dremio
dremio_data_update
cZxid = 0x2
ctime = Thu Aug 22 23:15:59 CST 2019
mZxid = 0x3
mtime = Thu Aug 22 23:19:58 CST 2019
pZxid = 0x2
cversion = 0
dataVersion = 1
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 18
numChildren = 0

2).根据版本号修改

## 获得dremio节点内容，此时dataVersion = 2
[zk: localhost:2181(CONNECTED) 11] get /dremio                   
dremio_data_update
cZxid = 0x2
ctime = Thu Aug 22 23:15:59 CST 2019
mZxid = 0x4
mtime = Thu Aug 22 23:22:08 CST 2019
pZxid = 0x2
cversion = 0
dataVersion = 2
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 18
numChildren = 0

## 根据版本号更新dataVersion乐观锁
### 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) 12] set /dremio dremio_data_update 1
version No is not valid : /dremio

### 修改版本号为2的数据，版本号更新为3 
[zk: localhost:2181(CONNECTED) 13] set /dremio dremio_data_update 2
cZxid = 0x2
ctime = Thu Aug 22 23:15:59 CST 2019
mZxid = 0x6
mtime = Thu Aug 22 23:25:23 CST 2019
pZxid = 0x2
cversion = 0
dataVersion = 3
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 18
numChildren = 0

Ⅸ).delete删除节点

命令：delete path [version]

## 根据版本号删除
[zk: localhost:2181(CONNECTED) 14] delete /dremio 3

## 获得dremio节点内容
[zk: localhost:2181(CONNECTED) 15] get /dremio                     
Node does not exist: /dremio

Ⅹ).watcher通知机制

a).设置watch事件

命令：stat path [watch]

## 设置watch事件
[zk: localhost:2181(CONNECTED) 17] stat /hbase watch
Node does not exist: /hbase

## 触发watcher事件
[zk: localhost:2181(CONNECTED) 18] create /hbase hbase

WATCHER::

WatchedEvent state:SyncConnected type:NodeCreated path:/hbase
Created /hbase

b).查看watch事件

命令：get path [watch]

## 设置watch事件
[zk: localhost:2181(CONNECTED) 19] get /solr watch
Node does not exist: /solr

## 不存在的目录无法触发watcher事件
[zk: localhost:2181(CONNECTED) 20] create /solr solr
Created /solr

## 设置watch事件
[zk: localhost:2181(CONNECTED) 22] get /solr watch
solr_data
cZxid = 0xa
ctime = Thu Aug 22 23:34:54 CST 2019
mZxid = 0xb
mtime = Thu Aug 22 23:35:09 CST 2019
pZxid = 0xa
cversion = 0
dataVersion = 1
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 9
numChildren = 0

## 触发watcher事件
[zk: localhost:2181(CONNECTED) 23] set /solr solr_data_update

WATCHER::
cZxid = 0xa
WatchedEvent state:SyncConnected type:NodeDataChanged path:/solr

ctime = Thu Aug 22 23:34:54 CST 2019
mZxid = 0xc
mtime = Thu Aug 22 23:37:02 CST 2019
pZxid = 0xa
cversion = 0
dataVersion = 2
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 16
numChildren = 0

Ⅺ).ACL权限控制

Zookeeper有5种操作权限：CREATE、READ、WRITE、DELETE、ADMIN，即增、删、改、查、管理权限
赋权方式： [scheme:id:permissions]

scheme4种身份认证

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

a).获取acl权限信息

命令： getAcl /znode_path
默认: world:cdrwa任何人都可以访问

[zk: localhost:2181(CONNECTED) 24] getAcl /solr
'world,'anyone
: cdrwa

b).设置权限

命令： setAcl /znode_path [scheme:id:permissions]

## 默认权限
[zk: localhost:2181(CONNECTED) 24] getAcl /solr
'world,'anyone
: cdrwa

## 设置权限
[zk: localhost:2181(CONNECTED) 26] setAcl /solr world:anyone:rwa
cZxid = 0xa
ctime = Thu Aug 22 23:34:54 CST 2019
mZxid = 0xc
mtime = Thu Aug 22 23:37:02 CST 2019
pZxid = 0xa
cversion = 0
dataVersion = 2
aclVersion = 1
ephemeralOwner = 0x0
dataLength = 16
numChildren = 0

## 查看权限
[zk: localhost:2181(CONNECTED) 27] getAcl /solr                 
'world,'anyone
: rwa

c).密码明文设置

命令： setAcl /znode_path [scheme:username:password:permissions]

## 创建/hbase/data节点
[zk: localhost:2181(CONNECTED) 28] create /hbase/data hbase_test_data
Created /hbase/data

## 查看默认权限
[zk: localhost:2181(CONNECTED) 29] getAcl /hbase/data
'world,'anyone
: cdrwa

## 使用auth，密码明文设置
[zk: localhost:2181(CONNECTED) 30] setAcl /hbase/data auth:hbase:hbase:cdrwa
Acl is not valid : /hbase/data

## 注册hbase:hbase账号密码
[zk: localhost:2181(CONNECTED) 31] addauth digest hbase:hbase

## 使用auth，密码明文设置
[zk: localhost:2181(CONNECTED) 32] setAcl /hbase/data auth:hbase:hbase:cdrwa
cZxid = 0xe
ctime = Thu Aug 22 23:55:44 CST 2019
mZxid = 0xe
mtime = Thu Aug 22 23:55:44 CST 2019
pZxid = 0xe
cversion = 0
dataVersion = 0
aclVersion = 1
ephemeralOwner = 0x0
dataLength = 15
numChildren = 0

## 查看权限，密码为密文格式
[zk: localhost:2181(CONNECTED) 33] getAcl /hbase/data
'digest,'hbase:zJ5u59GFXPgRIx4zWNFCOCbyBOs=
: cdrwa

d).密码密文设置

命令： setAcl /znode_path [scheme:username:password:permissions]

## 创建/kafka节点
[zk: localhost:2181(CONNECTED) 39] create /kafka kafka
Created /kafka

## 密码密文设置
[zk: localhost:2181(CONNECTED) 40] setAcl /kafka digest:hbase:zJ5u59GFXPgRIx4zWNFCOCbyBOs=:cdrwa
cZxid = 0x13
ctime = Fri Aug 23 00:10:59 CST 2019
mZxid = 0x13
mtime = Fri Aug 23 00:10:59 CST 2019
pZxid = 0x13
cversion = 0
dataVersion = 0
aclVersion = 1
ephemeralOwner = 0x0
dataLength = 5
numChildren = 0

## 查看权限，密码为密文格式
[zk: localhost:2181(CONNECTED) 41] getAcl /kafka
'digest,'hbase:zJ5u59GFXPgRIx4zWNFCOCbyBOs=
: cdrwa

e).ip 控制客户端

命令： setAcl /znode_path [ip:hostname:permissions]

## 设置ip控制的权限信息
[zk: localhost:2181(CONNECTED) 44] setAcl /kafka/ip ip:192.168.133.132:cdrwa
cZxid = 0x15
ctime = Fri Aug 23 00:12:58 CST 2019
mZxid = 0x15
mtime = Fri Aug 23 00:12:58 CST 2019
pZxid = 0x15
cversion = 0
dataVersion = 0
aclVersion = 1
ephemeralOwner = 0x0
dataLength = 2
numChildren = 0


[zk: localhost:2181(CONNECTED) 45] getAcl /kafka/ip
Authentication is not valid : /kafka/ip

f).super 超级管理员

命令如下：

"-Dzookeeper.DigestAuthenticationProvider.superDigest=username:password"
 nohup "$JAVA" "-Dzookeeper.log.dir=${ZOO_LOG_DIR}" "-Dzookeeper.root.logger=${ZOO_LOG4J_PROP}" "-Dzookeeper.DigestAuthenticationprovider.superDigest=username:password" \
    -cp "$CLASSPATH" $JVMFLAGS $ZOOMAIN "$ZOOCFG" > "$_ZOO_DAEMON_OUT" 2>&1 < /dev/null &

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

g).注册账号密码

命令： addauth digest username:password

## 注册hbase:hbase账号密码
[zk: localhost:2181(CONNECTED) 31] addauth digest hbase:hbase

Ⅻ).nc命令查看zookeeper信息

需安装nc： yum install nc

a).查看服务器配置

命令：echo conf|nc hostname 2181

[bigdata@carbondata data]$ echo conf|nc 192.168.133.132 2181
clientPort=2181
dataDir=/home/bigdata/zookeeper-3.4.14/data/version-2
dataLogDir=/home/bigdata/zookeeper-3.4.14/data/version-2
tickTime=2000
maxClientCnxns=60
minSessionTimeout=4000
maxSessionTimeout=40000
serverId=0

b).查看状态信息

命令：echo stat|nc hostname 2181

[bigdata@carbondata data]$ echo stat|nc 192.168.133.132 2181
Zookeeper version: 3.4.14-4c25d480e66aadd371de8bd2fd8da255ac140bcf, built on 03/06/2019 16:18 GMT
Clients:
 /127.0.0.1:59358[1](queued=0,recved=523,sent=525)
 /192.168.133.132:60578[0](queued=0,recved=1,sent=0)

Latency min/avg/max: 0/0/17
Received: 526
Sent: 527
Connections: 2
Outstanding: 0
Zxid: 0x16
Mode: standalone
Node count: 10

c).查看zookeeper运行状态

命令：echo ruok|nc hostname 2181

[bigdata@carbondata data]$ echo ruok|nc 192.168.133.132 2181
imok
[bigdata@carbondata data]$

d).列出临时节点

命令：echo dump|nc hostname 2181

## 未创建临时节点
[bigdata@carbondata data]$ echo dump|nc 192.168.133.132 2181
SessionTracker dump:
Session Sets (3):
0 expire at Thu Jan 01 10:47:54 CST 1970:
0 expire at Thu Jan 01 10:48:04 CST 1970:
1 expire at Thu Jan 01 10:48:14 CST 1970:
        0x100002177b70000
ephemeral nodes dump:
Sessions with Ephemerals (0):

## 创建临时节点
[zk: localhost:2181(CONNECTED) 0] create -e /hbase/tmp test
Created /hbase/tmp

## 列出临时节点
[bigdata@carbondata data]$ echo dump|nc 192.168.133.132 2181
SessionTracker dump:
Session Sets (4):
0 expire at Thu Jan 01 10:55:34 CST 1970:
0 expire at Thu Jan 01 10:55:44 CST 1970:
0 expire at Thu Jan 01 10:55:54 CST 1970:
1 expire at Thu Jan 01 10:55:56 CST 1970:
        0x100002177b70003
ephemeral nodes dump:
Sessions with Ephemerals (1):
0x100002177b70003:
        /hbase/temp
        /hbase/tmp

e).显示连接到服务端的信息

命令：echo cons|nc hostname 2181

[bigdata@carbondata data]$ echo cons|nc 192.168.133.132 2181
 /192.168.133.132:60598[0](queued=0,recved=1,sent=0)
 /127.0.0.1:59376[1](queued=0,recved=21,sent=21,sid=0x100002177b70003,lop=PING,est=1566491558846,to=30000,lcxid=0x2,lzxid=0x21,lresp=10575010,llat=0,minlat=0,avglat=0,maxlat=3)

f).显示环境变量信息

命令：echo envi|nc hostname 2181

[bigdata@carbondata data]$ echo envi|nc 192.168.133.132 2181
Environment:
zookeeper.version=3.4.14-4c25d480e66aadd371de8bd2fd8da255ac140bcf, built on 03/06/2019 16:18 GMT
host.name=carbondata
java.version=1.8.0_211
java.vendor=Oracle Corporation
java.home=/usr/java/jdk1.8.0_211-amd64/jre
java.class.path=/home/bigdata/zookeeper-3.4.14/bin/../zookeeper-server/target/classes:/home/bigdata/zookeeper-3.4.14/bin/../build/classes:/home/bigdata/zookeeper-3.4.14/bin/../zookeeper-server/target/lib/*.jar:/home/bigdata/zookeeper-3.4.14/bin/../build/lib/*.jar:/home/bigdata/zookeeper-3.4.14/bin/../lib/slf4j-log4j12-1.7.25.jar:/home/bigdata/zookeeper-3.4.14/bin/../lib/slf4j-api-1.7.25.jar:/home/bigdata/zookeeper-3.4.14/bin/../lib/netty-3.10.6.Final.jar:/home/bigdata/zookeeper-3.4.14/bin/../lib/log4j-1.2.17.jar:/home/bigdata/zookeeper-3.4.14/bin/../lib/jline-0.9.94.jar:/home/bigdata/zookeeper-3.4.14/bin/../lib/audience-annotations-0.5.0.jar:/home/bigdata/zookeeper-3.4.14/bin/../zookeeper-3.4.14.jar:/home/bigdata/zookeeper-3.4.14/bin/../zookeeper-server/src/main/resources/lib/*.jar:/home/bigdata/zookeeper-3.4.14/bin/../conf:.:/usr/java/jdk1.8.0_211-amd64/lib/dt.jar:/usr/java/jdk1.8.0_211-amd64/lib/tools.jar
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=3.10.0-957.el7.x86_64
user.name=bigdata
user.home=/home/bigdata
user.dir=/home/bigdata/zookeeper-3.4.14

g).查看zookeeper的健康信息

命令：echo mntr|nc hostname 2181

[bigdata@carbondata data]$ echo mntr|nc 192.168.133.132 2181
zk_version      3.4.14-4c25d480e66aadd371de8bd2fd8da255ac140bcf, built on 03/06/2019 16:18 GMT
zk_avg_latency  0
zk_max_latency  17
zk_min_latency  0
zk_packets_received     621
zk_packets_sent 622
zk_num_alive_connections        2
zk_outstanding_requests 0
zk_server_state standalone
zk_znode_count  12
zk_watch_count  0
zk_ephemerals_count     2
zk_approximate_data_size        154
zk_open_file_descriptor_count   30
zk_max_file_descriptor_count    4096
zk_fsync_threshold_exceed_count 0

h).展示watch的信息

命令：echo wchs|nc hostname 2181

## 未添加watch前
[bigdata@carbondata data]$ echo wchs|nc 192.168.133.132 2181
0 connections watching 0 paths
Total watches:0

## 添加watch
[zk: localhost:2181(CONNECTED) 3] stat /hbase/tmp watch
cZxid = 0x20
ctime = Fri Aug 23 00:33:42 CST 2019
mZxid = 0x20
mtime = Fri Aug 23 00:33:42 CST 2019
pZxid = 0x20
cversion = 0
dataVersion = 0
aclVersion = 0
ephemeralOwner = 0x100002177b70003
dataLength = 4
numChildren = 0
[zk: localhost:2181(CONNECTED) 4] get /hbase/temp watch
test
cZxid = 0x21
ctime = Fri Aug 23 00:34:54 CST 2019
mZxid = 0x21
mtime = Fri Aug 23 00:34:54 CST 2019
pZxid = 0x21
cversion = 0
dataVersion = 0
aclVersion = 0
ephemeralOwner = 0x100002177b70003
dataLength = 4
numChildren = 0

## 展示watch的信息
[bigdata@carbondata data]$ echo wchs|nc 192.168.133.132 2181
1 connections watching 2 paths
Total watches:2

i).显示session的watch信息

命令：echo wchc|nc hostname 2181

[bigdata@carbondata data]$ echo wchc|nc 192.168.133.132 2181
wchc is not executed because it is not in the whitelist.

[bigdata@carbondata zookeeper-3.4.14]$ echo wchc|nc 192.168.133.132 2181
0x100002177b70003
        /hbase/temp
        /hbase/tmp

i).显示path的watch信息

命令：echo wchp|nc hostname 2181

[bigdata@carbondata zookeeper-3.4.14]$ echo wchp|nc 192.168.133.132 2181
wchp is not executed because it is not in the whitelist.

[bigdata@carbondata zookeeper-3.4.14]$ echo wchp|nc 192.168.133.132 2181
/hbase/temp
        0x100002177b70003
/hbase/tmp
        0x100002177b70003

三.问题

问题描述

在查看session和path的watch信息时出现

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

解决办法

需修改配置文件，然后重启Zookeeper，查看

## zoo.cfg配置文件中添加
4lw.commands.whitelist=*

## 重启zookeeper
./bin/zkServer.sh restart ./conf/zoo.cfg 

## 显示session的watch信息
[bigdata@carbondata zookeeper-3.4.14]$ echo wchc|nc 192.168.133.132 2181
0x100002177b70003
        /hbase/temp
        /hbase/tmp

## 显示path的watch信息
[bigdata@carbondata zookeeper-3.4.14]$ echo wchp|nc 192.168.133.132 2181
/hbase/temp
        0x100002177b70003
/hbase/tmp
        0x100002177b70003

Apache Zookeeper常用命令