使用阿里云主机搭建，一台阿里云模拟6个节点，3主3从。
下面开始搭建，不用动脑子，跟着复制粘贴即可

cd /opt
//创建集群目录
mkdir redis_cluster
//进入redis_cluster目录
cd redis_cluster
//下载redis安装包
wget http://download.redis.io/releases/redis-5.0.9.tar.gz
//解压redis安装包
tar -zxvf redis-5.0.9.tar.gz
cd redis-5.0.9
//编译redis
make && make install
//编译完成,修改目录名称
mv redis-5.0.9 7001
//清空redis.conf配置文件
cd 7001
cat /dev/null > redis.conf//编辑redis.conf文件,添加以下配置# 端口7001,7002,7003,7004,7005,7006 
port  7001
# 默认ip为127.0.0.1,如果用多台机器搭建集群，这个地方需要改成实际的ip
bind 127.0.0.1
# redis后台运行
daemonize yes
# pidfile文件对应7001,7002,7003,7004,7005,7006
pidfile /var/run/redis_7001.pid
# 开启集群  把注释#去掉
cluster-enabled  yes
# 集群的配置  配置文件首次启动自动生成7001,7002,7003,7004,7005,7006
cluster-config-file  nodes_7001.conf
# 请求超时  默认15秒，可自行设置
cluster-node-timeout  15000
# aof日志开启  有需要就开启，它会每次写操作都记录一条日志
appendonly  yes
# 错误日志,7001,7002,7003,7004,7005,7006。记得改
logfile /opt/redis_cluster/7001/redis_log.log

将7001，在当前目录复制5份，分别命名为7002,7003,7004,7005,7006
分别启动6台redis节点

//替换7001为7002,7003,7004,7005,7005
/opt/redis_cluster/7001/src/redis-server /opt/redis_cluster/7001/redis.conf

查看是否启动成功

ps -ef|grep redis

看到以下输出，说明6个节点全部启动成功

root      7796     1  0 22:15 ?        00:00:01 /opt/redis_cluster/7002/src/redis-server 127.0.0.1:7002 [cluster]
root      7825     1  0 22:15 ?        00:00:01 /opt/redis_cluster/7003/src/redis-server 127.0.0.1:7003 [cluster]
root      7854     1  0 22:16 ?        00:00:01 /opt/redis_cluster/7004/src/redis-server 127.0.0.1:7004 [cluster]
root      7883     1  0 22:16 ?        00:00:01 /opt/redis_cluster/7005/src/redis-server 127.0.0.1:7005 [cluster]
root      7912     1  0 22:16 ?        00:00:01 /opt/redis_cluster/7006/src/redis-server 127.0.0.1:7006 [cluster]
root      7996     1  0 22:16 ?        00:00:01 /opt/redis_cluster/7001/src/redis-server 127.0.0.1:7001 [cluster]

使用redis-cli命令创建集群

redis-cli --cluster create 127.0.0.1:7001 127.0.0.1:7002 127.0.0.1:7003 127.0.0.1:7004 127.0.0.1:7005 127.0.0.1:7006 --cluster-replicas 1

可能会报错，如下：

在这里插入代码片

该报错说明缺少ruby环境，redis集群的安装需要依赖ruby环境
redis脚本执行需要依赖ruby环境

yum -y install ruby ruby-devel rubygems rpm-build

看到如下日志输出，即为安装ruby成功

//省略大部分日志,只保留末尾的日志..
Installed:rpm-build.x86_64 0:4.11.3-48.el7_9   ruby.x86_64 0:2.0.0.648-39.el7_9   ruby-devel.x86_64 0:2.0.0.648-39.el7_9   rubygems.noarch 0:2.0.14.1-39.el7_9  Dependency Installed:bzip2.x86_64 0:1.0.6-13.el7                    elfutils.x86_64 0:0.176-5.el7                       gdb.x86_64 0:7.6.1-120.el7                         libyaml.x86_64 0:0.1.4-11.el7_0                perl-Thread-Queue.noarch 0:3.02-2.el7               ruby-irb.noarch 0:2.0.0.648-39.el7_9               ruby-libs.x86_64 0:2.0.0.648-39.el7_9          rubygem-bigdecimal.x86_64 0:1.2.0-39.el7_9          rubygem-io-console.x86_64 0:0.4.2-39.el7_9         rubygem-json.x86_64 0:1.7.7-39.el7_9           rubygem-psych.x86_64 0:2.0.0-39.el7_9               rubygem-rdoc.noarch 0:4.0.0-39.el7_9               unzip.x86_64 0:6.0-24.el7_9                   Complete!

继续执行redis-cli命令创建集群

redis-cli --cluster create 127.0.0.1:7001 127.0.0.1:7002 127.0.0.1:7003 127.0.0.1:7004 127.0.0.1:7005 127.0.0.1:7006 --cluster-replicas 1

看到以下输出，即为redis集群开始搭建

>>> Trying to optimize slaves allocation for anti-affinity
[WARNING] Some slaves are in the same host as their master
M: 28d9b2f458df1ab8e96ad5129b84069ea7481e45 127.0.0.1:7001slots:[0-5460] (5461 slots) master
M: 94dbde626faadff257bacdb83f2e12178bfba4f2 127.0.0.1:7002slots:[5461-10922] (5462 slots) master
M: 3d30f0bc0c1111b27ac417b76fbbe8a13aac67b8 127.0.0.1:7003slots:[10923-16383] (5461 slots) master
S: 1166dfccde9774bfd7d3ecfe027a192e33ffd22a 127.0.0.1:7004replicates 94dbde626faadff257bacdb83f2e12178bfba4f2
S: 11541027a13b57be07e34bcbb1261d29a70bec59 127.0.0.1:7005replicates 3d30f0bc0c1111b27ac417b76fbbe8a13aac67b8
S: c8fe97a667e8d999cb0976b8fc8608edf215f0fc 127.0.0.1:7006replicates 28d9b2f458df1ab8e96ad5129b84069ea7481e45
Can I set the above configuration? (type 'yes' to accept): yes

输入yes，开始创建集群
看到如下日志，说明redis集群搭建成功

[OK] All nodes agree about slots configuration.
>>> Check for open slots...
>>> Check slots coverage...
[OK] All 16384 slots covered.

连接redis集群看看效果，登录7001节点

//-c : 连接redis集群
redis-cli -h 127.0.0.1 -c -p 7001

设置一个String键值对

127.0.0.1:7001> set testKey testValue
-> Redirected to slot [11136] located at 127.0.0.1:7003
OK
127.0.0.1:7003> 

可以看到我们从7001节点上执行的set命令，redis集群给我们重定向到了7003节点上。这个原因是：redis集群是用哈希槽存储数据的，一共16384个哈希槽，分布在6个节点上。每次set数据，redis会使用crc16算法计算key应该被分配到哪个哈希槽上，然后会直接重定向到哈希槽对应的节点上