在CentOS7上安装和使用ZooKeeper最新版本（V3.4.11）

0.ZooKeeper文档 http://zookeeper.apache.org/doc/r3.4.11/zookeeperOver.html
1.准备
在CentOS7上安装zookeeper时，如下工具必须要有：wget
如果没有，则进行安装：yum -y install wget
2.下载安装下载到本地cd /usr/local/src
wget http://mirrors.hust.edu.cn/apache/zookeeper/zookeeper-3.4.11/zookeeper-3.4.11.tar.gz解压tar -xzvf zookeeper-3.4.11.tar.gz创建的安装目录，并移动解压后的目录到其下mkdir -p ../zookeeper
mv zookeeper-3.4.11/ ../zookeeper创建数据目录，用于存放数据mkdir -p /var/lib/zookeeper
创建配置cd ../zookeeper/zookeeper-3.4.11/conf
cp zoo_sample.cfg zoo.cfg修改其中配置dataDir：vi zoo.cfg

dataDir=/var/lib/zookeeper

3.启动服务cd ..
./bin/zkServer.sh start输出如下信息，表示启动成功Connecting to 127.0.0.1:2181
2018-02-09 14:56:10,914 [myid:] - INFO [main:Environment@100] - Client environment:zookeeper.version=3.4.11-37e277162d567b55a07d1755f0b31c32e93c01a0, built on 11/01/2017 18:06 GMT
2018-02-09 14:56:10,922 [myid:] - INFO [main:Environment@100] - Client environment:host.name=jiaodacailei-thinkpad-centos7
2018-02-09 14:56:10,922 [myid:] - INFO [main:Environment@100] - Client environment:java.version=1.8.0_161
2018-02-09 14:56:10,927 [myid:] - INFO [main:Environment@100] - Client environment:java.vendor=Oracle Corporation
2018-02-09 14:56:10,927 [myid:] - INFO [main:Environment@100] - Client environment:java.home=/usr/local/jdk/jdk1.8.0_161/jre
2018-02-09 14:56:10,927 [myid:] - INFO [main:Environment@100] - Client environment:java.class.path=/usr/local/zookeeper/zookeeper-3.4.11/bin/../build/classes:/usr/local/zookeeper/zookeeper-3.4.11/bin/../build/lib/*.jar:/usr/local/zookeeper/zookeeper-3.4.11/bin/../lib/slf4j-log4j12-1.6.1.jar:/usr/local/zookeeper/zookeeper-3.4.11/bin/../lib/slf4j-api-1.6.1.jar:/usr/local/zookeeper/zookeeper-3.4.11/bin/../lib/netty-3.10.5.Final.jar:/usr/local/zookeeper/zookeeper-3.4.11/bin/../lib/log4j-1.2.16.jar:/usr/local/zookeeper/zookeeper-3.4.11/bin/../lib/jline-0.9.94.jar:/usr/local/zookeeper/zookeeper-3.4.11/bin/../lib/audience-annotations-0.5.0.jar:/usr/local/zookeeper/zookeeper-3.4.11/bin/../zookeeper-3.4.11.jar:/usr/local/zookeeper/zookeeper-3.4.11/bin/../src/java/lib/*.jar:/usr/local/zookeeper/zookeeper-3.4.11/bin/../conf::/usr/local/jdk/jdk1.8.0_161/lib/dt.jar:/usr/local/jdk/jdk1.8.0_161/lib/tools.jar:/usr/local/jdk/jdk1.8.0_161/jre/lib/dt.jar
2018-02-09 14:56:10,927 [myid:] - INFO [main:Environment@100] - Client environment:java.library.path=/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib
2018-02-09 14:56:10,928 [myid:] - INFO [main:Environment@100] - Client environment:java.io.tmpdir=/tmp
2018-02-09 14:56:10,928 [myid:] - INFO [main:Environment@100] - Client environment:java.compiler=<NA>
2018-02-09 14:56:10,928 [myid:] - INFO [main:Environment@100] - Client environment:os.name=Linux
2018-02-09 14:56:10,928 [myid:] - INFO [main:Environment@100] - Client environment:os.arch=amd64
2018-02-09 14:56:10,928 [myid:] - INFO [main:Environment@100] - Client environment:os.version=3.10.0-693.el7.x86_64
2018-02-09 14:56:10,929 [myid:] - INFO [main:Environment@100] - Client environment:user.name=root
2018-02-09 14:56:10,929 [myid:] - INFO [main:Environment@100] - Client environment:user.home=/root
2018-02-09 14:56:10,929 [myid:] - INFO [main:Environment@100] - Client environment:user.dir=/usr/local/zookeeper/zookeeper-3.4.11
2018-02-09 14:56:10,932 [myid:] - INFO [main:ZooKeeper@441] - Initiating client connection, connectString=127.0.0.1:2181 sessionTimeout=30000 watcher=org.apache.zookeeper.ZooKeeperMain$MyWatcher@579bb367
Welcome to ZooKeeper!
2018-02-09 14:56:10,983 [myid:] - INFO [main-SendThread(127.0.0.1:2181):ClientCnxn$SendThread@1035] - Opening socket connection to server 127.0.0.1/127.0.0.1:2181. Will not attempt to authenticate using SASL (unknown error)
JLine support is enabled
2018-02-09 14:56:11,141 [myid:] - INFO [main-SendThread(127.0.0.1:2181):ClientCnxn$SendThread@877] - Socket connection established to 127.0.0.1/127.0.0.1:2181, initiating session
[zk: 127.0.0.1:2181(CONNECTING) 0] 2018-02-09 14:56:11,242 [myid:] - INFO [main-SendThread(127.0.0.1:2181):ClientCnxn$SendThread@1302] - Session establishment complete on server 127.0.0.1/127.0.0.1:2181, sessionid = 0x1000150f9ff0000, negotiated timeout = 30000

WATCHER::

WatchedEvent state:SyncConnected type:None path:null4.启动客户端./bin/zkCli.sh -server 127.0.0.1:2181输入如下，等待用户输入命令：[zk: 127.0.0.1:2181(CONNECTED) 0]5.获取帮助
输入如下命令，可以获取帮助信息：help输出信息如下：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上面是所有可以使用的命令

6.ls命令ls /默认根节点下有一个zookeeper节点[zookeeper]7.创建节点
创建节点采用create命令，创建之后查看根路径，发现多了一个节点；
通过get命令，可以查询节点路径对应的数据[zk: 127.0.0.1:2181(CONNECTED) 4] create /zk_test test_data
Created /zk_test

[zk: 127.0.0.1:2181(CONNECTED) 6] ls /
[zookeeper, zk_test]

[zk: 127.0.0.1:2181(CONNECTED) 7] get /zk_test
test_data
cZxid = 0x2
ctime = Fri Feb 09 15:19:11 CST 2018
mZxid = 0x2
mtime = Fri Feb 09 15:19:11 CST 2018
pZxid = 0x2
cversion = 0
dataVersion = 0
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 9
numChildren = 0

8.修改节点数据
set命令可以修改路径对应的节点数据，修改后再通过get命令查看结果[zk: 127.0.0.1:2181(CONNECTED) 8] set /zk_test test_data_change

cZxid = 0x2
ctime = Fri Feb 09 15:19:11 CST 2018
mZxid = 0x3
mtime = Fri Feb 09 15:21:31 CST 2018
pZxid = 0x2
cversion = 0
dataVersion = 1
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 16
numChildren = 0

[zk: 127.0.0.1:2181(CONNECTED) 10] get /zk_test

test_data_change
cZxid = 0x2
ctime = Fri Feb 09 15:19:11 CST 2018
mZxid = 0x3
mtime = Fri Feb 09 15:21:31 CST 2018
pZxid = 0x2
cversion = 0
dataVersion = 1
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 16
numChildren = 0

9.删除节点
delete命令可以删除路径对应的节点，删除之后，通过ls命令查看其父路径，可以看到节点已经减少一个[zk: 127.0.0.1:2181(CONNECTED) 11] delete /zk_test
[zk: 127.0.0.1:2181(CONNECTED) 12] ls /
[zookeeper]10.退出客户端

quit

11.停止服务./bin/zkServer.sh stop