从zookeeper的下载安装到环境配置，轻松入门zookeeper！

r囧r小猫 2022-11-12 04:29 171阅读 0赞

# Zookeeper技术介绍 #

关于ZooKeeper的知识点总结了一个思维导图分享给大家

![zookeeper脑图.png][zookeeper_.png]  
ZooKeeper的目标就是封装好复杂易出错的关键服务，将简单易用的接口和性能高效、功能稳定的系统提供给用户。

ZooKeeper包含一个简单的原语集提供Java和C的接口。[2021面试题整理][2021]

ZooKeeper代码版本中，提供了分布式独享锁、选举、队列的接口，代码在zookeeper-3.4.3\\src\\recipes。其中分布锁和队列有Java和C两个版本，选举只有Java版本。

主要作用是用来解决分布式应用中经常遇到的一些数据管理问题，如集群管理、统一命名管理、分布式配置管理、分布式消息队列、分布式锁、分布式通知协调

官方网站：https://zookeeper.apache.org/

# zookeeper体系结构 #

zk的集群中有一个Leader，有一个或多个follower，它们之间是相互通信的，然后还存在一个客户端用来访问zk服务器。

服务器端具有fast fail特性，一旦主故障后，会选举从成为新的主，主从模式是目前最常见的模式。

![image.png][]

zookeeper名字空间由节点NODE构成,类似于文件系统,其中各个节点相当于目录和文件,通过路径作为唯一标识,与文件系统不同的是,每个节点具有与之对应的数据内容,同时也可以具有子节点,它用来存储协调数据,如状态、配置、位置信息、每个节点存储的数据量很小，KB级别.

## watches介绍 ##

zk对节点的增、删、改、查都可以触发监听

watch事件是一次性触发器，当它监视的数据发生变化时，通知设置了该客户端

# Zookeeper安装布署 #

**四台服务器**

> zk-001 10.0.0.8
> 
> zk-002 10.0.0.9
> 
> zk-003 10.0.0.10
> 
> zk-client 10.0.0.100

![image.png][image.png 1]

**下载安装JDK环境**

> tar zxf jdk-8u60-linux-x64.tar.gz
> 
> mv jdk1.8.0\_60 /usr/local/jdk
> 
> export JAVA\_HOME=/usr/local/jdk
> 
> export CLASSPATH=.: J A V A H O M E / l i b / d t . j a r : JAVA\_HOME/lib/dt.jar: JAVAHOME/lib/dt.jar:JAVA\_HOME/lib/tools.jar
> 
> export PATH= J A V A H O M E / b i n : JAVA\_HOME/bin: JAVAHOME/bin:PATH
> 
> source /etc/profile
> 
> java -version
> 
> \[root@zk-001 ~\]\# java -version
> 
> java version “1.8.0\_60”
> 
> Java™ SE Runtime Environment (build 1.8.0\_60-b27)
> 
> Java HotSpot™ 64-Bit Server VM (build 25.60-b23, mixed mode)

**下载安装zookeeper**

> wget http://www.apache.org/dist/zookeeper/zookeeper-3.4.6/zookeeper-3.4.6.tar.gz
> 
> tar zxf zookeeper-3.4.6.tar.gz
> 
> mv zookeeper-3.4.6 /usr/local/zookeeper
> 
> \[root@zk-001 ~\]\# cd /usr/local/zookeeper/

**配置环境变量**

> export ZOOKEEPER\_HOME=/usr/local/zookeeper
> 
> export PATH= Z O O K E E P E R H O M E / b i n : ZOOKEEPER\_HOME/bin: ZOOKEEPERHOME/bin:PATH
> 
> source /etc/profile

# Zookeeper的配置 #

**三种配置模式**

> 1、伪分布模式
> 
> 2、完全分布式
> 
> 3、独立模式

**独立模式配置**

> \[root@zk-001 zookeeper\]\# cd conf/
> 
> \[root@zk-001 conf\]\# ll
> 
> total 12
> 
> \-rw-rw-r-- 1 1000 1000 535 Feb 20 2014 configuration.xsl
> 
> \-rw-rw-r-- 1 1000 1000 2161 Feb 20 2014 log4j.properties
> 
> \-rw-rw-r-- 1 1000 1000 922 Feb 20 2014 zoo\_sample.cfg
> 
> \[root@zk-001 conf\]\# cp zoo\_sample.cfg zoo.cfg
> 
> \[root@zk-001 conf\]\#vim zoo.cfg
> 
> The number of milliseconds of each tick
> 
> tickTime=2000 \#心跳检查周期（单位毫秒）
> 
> the directory where the snapshot is stored.
> 
> do not use /tmp for storage, /tmp here is just
> 
> example sakes.
> 
> dataDir=/tmp/zookeeper \#存放数据目录
> 
> the port at which the clients will connect
> 
> clientPort=2181 \#供客户端连接的端口

**集群模式配置**

> tickTime=2000
> 
> initLimit=10
> 
> syncLimit=5
> 
> //server.n=host:port1:port2
> 
> 数字N必须是myid中的值，Myid文件位于dataDIR目录下，只能是一个n值
> 
> //port1:leader端口，作为leader时，供follower连接的端口
> 
> //port2:选举端口，选举leader时，供follower连接的端口
> 
> server.1=s1:2888:3888
> 
> server.2=s2:2888:3888
> 
> server.3=s3:2888:3888
> 
> zk处理集群故障的算法是2n+1,最好在奇数机器数布署，如果同台服务器配置多实例就要注意端口冲突问题，可以写成如下
> 
> server.1=s1:2888:3888
> 
> server.2=s2:2889:3889
> 
> server.3=s3:2887:3887

**配置过程如下**

> 配置hosts文件
> 
> vim /etc/hosts
> 
> 10.0.0.8 zk-001
> 
> 10.0.0.9 zk-002
> 
> 10.0.0.10 zk-003
> 
> 配置各服务器配置文件
> 
> \[root@zk-001 conf\]\# mkdir /tmp/zookeeper
> 
> \[root@zk-001 conf\]\# cd /tmp/zookeeper/
> 
> \[root@zk-001 zookeeper\]\# echo 8 >myid
> 
> \[root@zk-001 conf\]\# egrep -v “\#|$” zoo.cfg
> 
> tickTime=2000
> 
> initLimit=10
> 
> syncLimit=5
> 
> dataDir=/tmp/zookeeper
> 
> clientPort=2181
> 
> server.8=zk-001:2888:3888
> 
> server.9=zk-002:2888:3888
> 
> server.10=zk-003:2888:3888
> 
> \[root@zk-002 ~\]\# mkdir /tmp/zookeeper
> 
> \[root@zk-002 ~\]\# cd /tmp/zookeeper/
> 
> \[root@zk-002 zookeeper\]\# echo 9 >myid
> 
> \[root@zk-002 zookeeper\]\# ll
> 
> total 4
> 
> \-rw-r–r-- 1 root root 2 May 13 15:51 myid
> 
> \[root@zk-002 zookeeper\]\# cd /usr/local/zookeeper/conf/
> 
> \[root@zk-002 conf\]\# cp zoo\_sample.cfg zoo.cfg
> 
> \[root@zk-002 conf\]\# vim zoo.cfg
> 
> tickTime=2000
> 
> initLimit=10
> 
> syncLimit=5
> 
> dataDir=/tmp/zookeeper
> 
> clientPort=2181
> 
> server.8=zk-001:2888:3888
> 
> server.9=zk-002:2888:3888
> 
> server.10=zk-003:2888:3888
> 
> \[root@zk-003 ~\]\# mkdir /tmp/zookeeper
> 
> \[root@zk-003 ~\]\# cd /tmp/zookeeper/
> 
> \[root@zk-003 zookeeper\]\# echo 10 >myid
> 
> \[root@zk-003 zookeeper\]\# cd /usr/local/zookeeper/conf/
> 
> \[root@zk-003 conf\]\# cp zoo\_sample.cfg zoo.cfg
> 
> \[root@zk-003 conf\]\# vim zoo.cfg
> 
> tickTime=2000
> 
> initLimit=10
> 
> syncLimit=5
> 
> dataDir=/tmp/zookeeper
> 
> clientPort=2181
> 
> server.8=zk-001:2888:3888
> 
> server.9=zk-002:2888:3888
> 
> server.10=zk-003:2888:3888

**启动服务**

> \[root@zk-001 bin\]\# zkServer.sh start
> 
> JMX enabled by default
> 
> Using config: /usr/local/zookeeper/bin/…/conf/zoo.cfg
> 
> Starting zookeeper … STARTED
> 
> \[root@zk-002 bin\]\# zkServer.sh start
> 
> JMX enabled by default
> 
> Using config: /usr/local/zookeeper/bin/…/conf/zoo.cfg
> 
> Starting zookeeper … STARTED
> 
> \[root@zk-003 bin\]\# zkServer.sh start
> 
> JMX enabled by default
> 
> Using config: /usr/local/zookeeper/bin/…/conf/zoo.cfg
> 
> Starting zookeeper … STARTED

**查看状态**

\[root@zk-001 conf\]\# zkServer.sh status

> JMX enabled by default
> 
> Using config: /usr/local/zookeeper/bin/…/conf/zoo.cfg
> 
> Mode: follower
> 
> \[root@zk-002 conf\]\# zkServer.sh status
> 
> JMX enabled by default
> 
> Using config: /usr/local/zookeeper/bin/…/conf/zoo.cfg
> 
> Mode: follower
> 
> \[root@zk-003 conf\]\# zkServer.sh status
> 
> JMX enabled by default
> 
> Using config: /usr/local/zookeeper/bin/…/conf/zoo.cfg
> 
> Mode: leader
> 
> 可以看出已经选举leader出来了，表明配置是正确的

**测试leader故障后切换情况**

> \[root@zk-003 conf\]\# jps
> 
> 2694 Jps
> 
> 2430 QuorumPeerMain
> 
> \[root@zk-003 conf\]\# kill 2430
> 
> \[root@zk-003 conf\]\# jps
> 
> 2724 Jps
> 
> \[root@zk-002 conf\]\# zkServer.sh status
> 
> JMX enabled by default
> 
> Using config: /usr/local/zookeeper/bin/…/conf/zoo.cfg
> 
> Mode: follower
> 
> \[root@zk-001 conf\]\# zkServer.sh status
> 
> JMX enabled by default
> 
> Using config: /usr/local/zookeeper/bin/…/conf/zoo.cfg
> 
> Mode: leader
> 
> 可以看出zk-001这台服务器被选举成新的leader了

# Zookeeper客户端四字符指令 #

> conf 配置信息
> 
> cons 连接信息
> 
> dump 未处理会话节点
> 
> envi 环境信息
> 
> reqs 未处理请求
> 
> stat 统计信息
> 
> wchs 服务器watch的详细信息
> 
> wchp 列出指定路径下服务器信息

> \[root@zk-003 ~\]\# echo conf | nc 10.0.0.8 2181
> 
> clientPort=2181
> 
> dataDir=/tmp/zookeeper/version-2
> 
> dataLogDir=/tmp/zookeeper/version-2
> 
> tickTime=2000
> 
> maxClientCnxns=60
> 
> minSessionTimeout=4000
> 
> maxSessionTimeout=40000
> 
> serverId=8
> 
> initLimit=10
> 
> syncLimit=5
> 
> electionAlg=3
> 
> electionPort=3888
> 
> quorumPort=2888
> 
> peerType=0
> 
> \[root@zk-003 ~\]\# echo envi | nc 10.0.0.8 2181
> 
> Environment:
> 
> zookeeper.version=3.4.6-1569965, built on 02/20/2014 09:09 GMT
> 
> host.name=zk-001
> 
> java.version=1.8.0\_121
> 
> java.vendor=Oracle Corporation
> 
> java.home=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.121-0.b13.el6\_8.x86\_64/jre
> 
> java.class.path=/usr/local/zookeeper/bin/…/build/classes:/usr/local/zookeeper/bin/…/build/lib/*.jar:/usr/local/zookeeper/bin/…/lib/slf4j-log4j12-1.6.1.jar:/usr/local/zookeeper/bin/…/lib/slf4j-api-1.6.1.jar:/usr/local/zookeeper/bin/…/lib/netty-3.7.0.Final.jar:/usr/local/zookeeper/bin/…/lib/log4j-1.2.16.jar:/usr/local/zookeeper/bin/…/lib/jline-0.9.94.jar:/usr/local/zookeeper/bin/…/zookeeper-3.4.6.jar:/usr/local/zookeeper/bin/…/src/java/lib/*.jar:/usr/local/zookeeper/bin/…/conf:
> 
> java.library.path=/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib
> 
> java.io.tmpdir=/tmp
> 
> java.compiler=
> 
> os.name=Linux
> 
> os.arch=amd64
> 
> os.version=2.6.32-504.el6.x86\_64
> 
> user.name=root
> 
> user.home=/root
> 
> user.dir=/usr/local/zookeeper/conf
> 
> \[root@zk-003 ~\]\# echo stat | nc 10.0.0.8 2181
> 
> Zookeeper version: 3.4.6-1569965, built on 02/20/2014 09:09 GMT
> 
> Clients:
> 
> /10.0.0.10:411920
> 
> Latency min/avg/max: 0/0/0
> 
> Received: 4
> 
> Sent: 3
> 
> Connections: 1
> 
> Outstanding: 0
> 
> Zxid: 0x200000000
> 
> Mode: leader
> 
> Node count: 4

# Zookeeper客户端命令 #

**通过zkCli.sh 连接服务器**

> zkCli.sh -server zk-001:2181
> 
>     -server 10.0.0.9:2181
> 
> \[root@zk-001 ~\]\# zkCli.sh -server zk-002:2181
> 
> Connecting to zk-002:2181
> 
> WATCHER::
> 
> WatchedEvent state:SyncConnected type:None path:null
> 
> \[zk: zk-002:2181(CONNECTED) 0\] h \#\#帮助命令
> 
> 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
> 
> \[zk: zk-002:2181(CONNECTED) 1\] ls /

**列出目录下内容**

> \[zookeeper\]
> 
> \[zk: zk-002:2181(CONNECTED) 2\] ls /zookeeper
> 
> \[quota\]
> 
> \[zk: zk-002:2181(CONNECTED) 3\] ls /zookeeper/quota
> 
> \[\]
> 
> \[zk: zk-002:2181(CONNECTED) 4\] create /root testfile

**创建目录及数据**

> Created /root
> 
> \[zk: zk-002:2181(CONNECTED)5\]get /root \#获取数据
> 
> testfile
> 
> cZxid = 0x200000002
> 
> ctime = Sat May 13 20:09:52 CST 2017
> 
> mZxid = 0x200000002
> 
> mtime = Sat May 13 20:09:52 CST 2017
> 
> pZxid = 0x200000002
> 
> cversion = 0
> 
> dataVersion = 0
> 
> aclVersion = 0
> 
> ephemeralOwner = 0x0
> 
> dataLength = 8
> 
> numChildren = 0
> 
> \[zk: zk-002:2181(CONNECTED) 6\] set /root testfile-001
> 
> cZxid = 0x200000002
> 
> ctime = Sat May 13 20:09:52 CST 2017
> 
> mZxid = 0x200000003
> 
> mtime = Sat May 13 21:04:17 CST 2017
> 
> pZxid = 0x200000002
> 
> cversion = 0
> 
> dataVersion = 1
> 
> aclVersion = 0
> 
> ephemeralOwner = 0x0
> 
> dataLength = 12
> 
> numChildren = 0

**需要注意的是ZK是不能一次创建多级节点的**

> \[zk: zk-002:2181(CONNECTED) 7\] create /root/s1/s1-1
> 
> \[zk: zk-002:2181(CONNECTED) 8\] ls /root \#提示是空
> 
> \[\]
> 
> \[zk: zk-002:2181(CONNECTED) 9\] create /root/s1 s1-data
> 
> Created /root/s1
> 
> \[zk: zk-002:2181(CONNECTED) 10\] create /root/s2 s2-data
> 
> Created /root/s2
> 
> \[zk: zk-002:2181(CONNECTED) 11\] create /root/s3 s3-data
> 
> Created /root/s3
> 
> \[zk: zk-002:2181(CONNECTED) 13\] ls /root
> 
> \[s3, s1, s2\]

**查看状态**

> \[zk: zk-002:2181(CONNECTED) 14\] stat /root
> 
> cZxid = 0x200000002
> 
> ctime = Sat May 13 20:09:52 CST 2017
> 
> mZxid = 0x200000003
> 
> mtime = Sat May 13 21:04:17 CST 2017
> 
> pZxid = 0x200000006
> 
> cversion = 3
> 
> dataVersion = 1
> 
> aclVersion = 0
> 
> ephemeralOwner = 0x0
> 
> dataLength = 12
> 
> numChildren = 3

**删除目录**

> \[zk: zk-002:2181(CONNECTED) 15\] delete /root/s3
> 
> \[zk: zk-002:2181(CONNECTED) 16\] ls /root
> 
> \[s1, s2\]

**断开连接**

\[zk: zk-002:2181(CONNECTED) 17\] close

2017-05-13 21:13:00,603 \[myid:\] - INFO\[main:ZooKeeper@684\] - Session: 0x95c0122efa50000 closed

2017-05-13 21:13:00,604 \[myid:\] - INFO\[main-EventThread:ClientCnxn$EventThread@512\] - EventThread shut down

**重新连接**

> 由于ZK服务器间的数据是一致的，因此这次我连接其它服务器
> 
> \[zk: zk-002:2181(CLOSED) 18\] connect zk-001:2181
> 
> \[zk: zk-001:2181(CONNECTED) 19\] get /root
> 
> testfile-001
> 
> cZxid = 0x200000002
> 
> ctime = Sat May 13 20:09:52 CST 2017
> 
> mZxid = 0x200000003
> 
> mtime = Sat May 13 21:04:17 CST 2017
> 
> pZxid = 0x200000007
> 
> cversion = 4
> 
> dataVersion = 1
> 
> aclVersion = 0
> 
> ephemeralOwner = 0x0
> 
> dataLength = 12
> 
> numChildren = 2
> 
> \[zk: zk-001:2181(CONNECTED) 20\] get /root/s1
> 
> s1-data
> 
> cZxid = 0x200000004
> 
> ctime = Sat May 13 21:07:42 CST 2017
> 
> mZxid = 0x200000004
> 
> mtime = Sat May 13 21:07:42 CST 2017
> 
> pZxid = 0x200000004
> 
> cversion = 0
> 
> dataVersion = 0
> 
> aclVersion = 0
> 
> ephemeralOwner = 0x0
> 
> dataLength = 7
> 
> numChildren = 0

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[zookeeper_.png]: /images/20221022/eb9abdbf9cdf4ae48fa1a25756a99141.png
[2021]: https://mp.weixin.qq.com/s?__biz=Mzg2ODUzMDg1OQ==&mid=2247483699&idx=1&sn=c0d55c9ecf68a17105134cd5b3d9cef0&chksm=ceabaef7f9dc27e13dc0d7ada9bee4baf1c3d559fda084c9d92ff09a98f9381e798d4520cbed&token=150888101&lang=zh_CN#rd
[image.png]: /images/20221022/98fc3c2d36144a9e911b7da95f732798.png
[image.png 1]: /images/20221022/873c41df60f4495095dfdf22bc4130b4.png