《云计算》Zookeeper基础：Zookeeper安装详解
1 案例1：Zookeeper安装
1.1 问题
本案例要求：
搭建Zookeeper集群并查看各服务器的角色
停止Leader并查看各服务器的角色
1.2 步骤
实现此案例需要按照如下步骤进行。
2 步骤一：安装Zookeeper
1）编辑/etc/hosts ,所有集群主机可以相互 ping 通（在nn01上面配置，同步到node1，node2，node3）
[root@nn01 hadoop]# vim /etc/hosts
192.168.1.21 nn01
192.168.1.22 node1
192.168.1.23 node2
192.168.1.24 node3
192.168.1.25 node4
[root@nn01 hadoop]# for i in {22..24} \
do \
scp /etc/hosts 192.168.1.$i:/etc/ \
done //同步配置
hosts 100% 253 639.2KB/s 00:00
hosts 100% 253 497.7KB/s 00:00
hosts 100% 253 662.2KB/s 00:00
2）安装 java-1.8.0-openjdk-devel,由于之前的hadoop上面已经安装过，这里不再安装，若是新机器要安装
3）zookeeper 解压拷贝到 /usr/local/zookeeper
[root@nn01 ~]# tar -xf zookeeper-3.4.10.tar.gz
[root@nn01 ~]# mv zookeeper-3.4.10 /usr/local/zookeeper
4）配置文件改名，并在最后添加配置
[root@nn01 ~]# cd /usr/local/zookeeper/conf/
[root@nn01 conf]# ls
configuration.xsl log4j.properties zoo_sample.cfg
[root@nn01 conf]# mv zoo_sample.cfg zoo.cfg
[root@nn01 conf]# chown root.root zoo.cfg
[root@nn01 conf]# vim zoo.cfg
server.1=node1:2888:3888
server.2=node2:2888:3888
server.3=node3:2888:3888
server.4=nn01:2888:3888:observer
5）拷贝 /usr/local/zookeeper 到其他集群主机
[root@nn01 conf]# for i in {22..24}; do rsync -aSH --delete /usr/local/zookeeper/ 192.168.1.$i:/usr/local/zookeeper -e 'ssh' & done
[4] 4956
[5] 4957
[6] 4958
6）创建 mkdir /tmp/zookeeper，每一台都要
[root@nn01 conf]# mkdir /tmp/zookeeper
[root@nn01 conf]# ssh node1 mkdir /tmp/zookeeper
[root@nn01 conf]# ssh node2 mkdir /tmp/zookeeper
[root@nn01 conf]# ssh node3 mkdir /tmp/zookeeper
7）创建 myid 文件，id 必须与配置文件里主机名对应的 server.(id) 一致
[root@nn01 conf]# echo 4 >/tmp/zookeeper/myid
[root@nn01 conf]# ssh node1 'echo 1 >/tmp/zookeeper/myid'
[root@nn01 conf]# ssh node2 'echo 2 >/tmp/zookeeper/myid'
[root@nn01 conf]# ssh node3 'echo 3 >/tmp/zookeeper/myid'
8）启动服务，单启动一台无法查看状态，需要启动全部集群以后才能查看状态，每一台上面都要手工启动（以nn01为例子）
[root@nn01 conf]# /usr/local/zookeeper/bin/zkServer.sh start
ZooKeeper JMX enabled by default
Using config: /usr/local/zookeeper/bin/../conf/zoo.cfg
Starting zookeeper ... STARTED
注意：刚启动zookeeper查看状态的时候报错，启动的数量要保证半数以上，这时再去看就成功了
9）查看状态
[root@nn01 conf]# /usr/local/zookeeper/bin/zkServer.sh status
ZooKeeper JMX enabled by default
Using config: /usr/local/zookeeper/bin/../conf/zoo.cfg
Mode: observe
[root@nn01 conf]# /usr/local/zookeeper/bin/zkServer.sh stop
//关闭之后查看状态其他服务器的角色
ZooKeeper JMX enabled by default
Using config: /usr/local/zookeeper/bin/../conf/zoo.cfg
Stopping zookeeper ... STOPPED
[root@nn01 conf]# yum -y install telnet
[root@nn01 conf]# telnet node3 2181
Trying 192.168.1.24...
Connected to node3.
Escape character is '^]'.
ruok //发送
imokConnection closed by foreign host. //imok回应的结果
10）利用 api 查看状态（nn01上面操作）
[root@nn01 conf]# /usr/local/zookeeper/bin/zkServer.sh start
[root@nn01 conf]# vim api.sh
#!/bin/bash
function getstatus(){
exec 9<>/dev/tcp/$1/2181 2>/dev/null
echo stat >&9
MODE=$(cat <&9 |grep -Po "(?<=Mode:).*")
exec 9<&-
echo ${MODE:-NULL}
}
for i in node{1..3} nn01;do
echo -ne "${i}\t"
getstatus ${i}
done
[root@nn01 conf]# chmod 755 api.sh
[root@nn01 conf]# ./api.sh
node1 follower
node2 leader
node3 follower
nn01 observer