【Zookeeper】Re03 集群搭建

我这里采用的是模拟真实情况：

部署三台虚拟机Centos7

192.168.242.101
192.168.242.102
192.168.242.103

每台机器都安装Zookeeper且一致：

/usr/local/apache-zookeeper-3.7.0-bin/

要三台机器上的Zookeeper相互通信，设置比较简单

1、找到ZK配置的dataDir路径，配置myid文件，内容即服务编号

[root@localhost ~]# cat /usr/local/apache-zookeeper-3.7.0-bin/conf/zoo.cfg
# 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.
# do not use /tmp for storage, /tmp here is just
# example sakes.
dataDir=/tmp/zookeeper
# the port at which the clients will connect
clientPort=2181
# the maximum number of client connections.
# increase this if you need to handle more clients
#maxClientCnxns=60
#
# Be sure to read the maintenance section of the
# administrator guide before turning on autopurge.
#
# http://zookeeper.apache.org/doc/current/zookeeperAdmin.html#sc_maintenance
#
# 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

## Metrics Providers
#
# https://prometheus.io Metrics Exporter
#metricsProvider.className=org.apache.zookeeper.metrics.prometheus.PrometheusMetricsProvider
#metricsProvider.httpPort=7000
#metricsProvider.exportJvmInfo=true

server.1 = 192.168.242.101:2182:3888
server.2 = 192.168.242.102:2182:3888
server.3 = 192.168.242.103:2182:3888

[root@localhost ~]# 

zoo.cfg默认是找zoo_sample.cfg复制粘贴的

可以看到dataDir默认是配置在  /tmp/zookeeper

然后配置myid文件：

[root@192.168.242.101 ~]# echo 1 > /tmp/zookeeper/myid

[root@192.168.242.102 ~]# echo 2 > /tmp/zookeeper/myid

[root@192.168.242.103 ~]# echo 3 > /tmp/zookeeper/myid

然后回到zoo.cfg，把所有Zookeeper都注册一遍：

vim /usr/local/apache-zookeeper-3.7.0-bin/conf/zoo.cfg

格式： server.[myid编号] = ZK服务IP:ZK服务端口:选举端口

在最底下空行处追加

server.1 = 192.168.242.101:2182:3888
server.2 = 192.168.242.102:2182:3888
server.3 = 192.168.242.103:2182:3888

这里要注意，不能再使用单例模式的2181端口，否则ZK报错启动失败，端口已被占用

选举端口在黑马的教程中是使用3881端口，尚硅谷则使用3888，应该是都可以使用的

下一步是开放防火墙端口，也可以直接选择关闭防火墙：

systemctl start firewalld
firewall-cmd --zone=public --add-port=2182/tcp --permanent
firewall-cmd --zone=public --add-port=3888/tcp --permanent
firewall-cmd --reload

然后依次启动Zookeeper：

/usr/local/apache-zookeeper-3.7.0-bin/bin/zkServer.sh start

启动之后检查一下各个ZK的状态是否正常

1号机ZK：

[root@localhost ~]# /usr/local/apache-zookeeper-3.7.0-bin/bin/zkServer.sh status
/usr/bin/java
ZooKeeper JMX enabled by default
Using config: /usr/local/apache-zookeeper-3.7.0-bin/bin/../conf/zoo.cfg
Client port found: 2181. Client address: localhost. Client SSL: false.
Mode: leader
[root@localhost ~]# 

2号机ZK：

[root@localhost ~]# /usr/local/apache-zookeeper-3.7.0-bin/bin/zkServer.sh status
/usr/bin/java
ZooKeeper JMX enabled by default
Using config: /usr/local/apache-zookeeper-3.7.0-bin/bin/../conf/zoo.cfg
Client port found: 2181. Client address: localhost. Client SSL: false.
Mode: follower
[root@localhost ~]# 

3号机ZK：

[root@localhost ~]# /usr/local/apache-zookeeper-3.7.0-bin/bin/zkServer.sh status
/usr/bin/java
ZooKeeper JMX enabled by default
Using config: /usr/local/apache-zookeeper-3.7.0-bin/bin/../conf/zoo.cfg
Client port found: 2181. Client address: localhost. Client SSL: false.
Mode: follower
[root@localhost ~]# 

可以看到模式发生变化了，选举机制将1号机ZK任命为Leader，2和3号机ZK则任命为Follower

说明集群部署成功

这里补充一个尚硅谷的集群控制脚本，非常实用

# 集群控制脚本
vim /usr/bin/zk-cluster
######################################################################
#!/bin/bash
case $1 in
"start"){
for i in 192.168.242.131 192.168.242.132 192.168.242.133
do
 echo ---------- zookeeper $i 启动 ------------
ssh $i "/opt/module/apache-zookeeper-3.7.0/bin/zkServer.sh start"
done
};;
"stop"){
for i in 192.168.242.131 192.168.242.132 192.168.242.133
do
 echo ---------- zookeeper $i 停止 ------------
ssh $i "/opt/module/apache-zookeeper-3.7.0/bin/zkServer.sh stop"
done
};;
"status"){
for i in 192.168.242.131 192.168.242.132 192.168.242.133
do
 echo ---------- zookeeper $i 状态 ------------
ssh $i "/opt/module/apache-zookeeper-3.7.0/bin/zkServer.sh status"
done
};;
esac
######################################################################

# 可执行权限赋予
chmod +x /usr/bin/zk-cluster

# 集群操作
zk-cluster start
zk-cluster stop
zk-cluster status