一、redisz主从集群最少需要6个节点
首先我们既然要搭建集群，那么master节点至少要3个，slave节点也是3个，为什么呢？这是因为一个redis集群如果要对外提供可用的服务，那么集群中必须要有过半的master节点正常工作。基于这个特性，如果想搭建一个能够允许 n 个master节点挂掉的集群，那么就要搭建2n+1个master节点的集群。（感觉和Zookeeper的vote机制差不多）
如：
2个master节点，挂掉1个，则1不过半，则集群down掉，无法使用，容错率为0
3个master节点，挂掉1个，2>1，还可以正常运行，容错率为1
4个master节点，挂掉1个，3>1，还可以正常运行，但是当挂掉2个时，2=2，不过半，容错率依然为1
如果创建集群时设置slave为1个
--cluster-replicas 1
则当总节点少于6个时会有如下报错：
[root@wzy-cloud 7000]# redis-cli --cluster create 0.0.0.0:7000 0.0.0.0:7001 0.0.0.0:7002 --cluster-replicas 1 -a wzy123 Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe. *** ERROR: Invalid configuration for cluster creation. *** Redis Cluster requires at least 3 master nodes. *** This is not possible with 3 nodes and 1 replicas per node. *** At least 6 nodes are required.
所以集群搭建至少需要6个节点哦~
二、redis集群开始搭建
首先尼，由于条件限制，我只有一台服务器，所以节点ip都一致，只是端口不同，有条件的朋友可以多ip哦。
我们先在redis根目录下
mkdir redis_cluster
并在redis_cluster目录下分别创建7000、7001、7002、7003、7004、7005，并将redis.conf文件cp到这几个文件夹下
[root@wzy-cloud redis_cluster]# pwd /usr/local/redis/redis_cluster [root@wzy-cloud redis_cluster]# ll total 24 drwxr-xr-x 2 root root 4096 Jul 17 21:43 7000 drwxr-xr-x 2 root root 4096 Jul 17 16:36 7001 drwxr-xr-x 2 root root 4096 Jul 17 16:36 7002 drwxrwxr-x 2 root root 4096 Jul 17 16:37 7003 drwxrwxr-x 2 root root 4096 Jul 17 16:37 7004 drwxrwxr-x 2 root root 4096 Jul 17 16:38 7005
cp redis.conf redis_cluster/7000 cp redis.conf redis_cluster/7001 cp redis.conf redis_cluster/7002 cp redis.conf redis_cluster/7003 cp redis.conf redis_cluster/7004 cp redis.conf redis_cluster/7005
然后修改各个文件夹中的redis.conf
port 7000 //端口7000,7002,7003 bind 本机ip //默认ip为127.0.0.1 需要改为其他节点机器可访问的ip 否则创建集群时无法访问对应的端口，无法创建集群，我这里是注释掉了，不知道0.0.0.0行不行 daemonize yes //redis后台运行 pidfile /var/run/redis_7000.pid //pidfile文件对应7000,7001,7002 cluster-enabled yes //开启集群 把注释#去掉 cluster-config-file nodes_7000.conf //集群的配置 配置文件首次启动自动生成 7000,7001,7002 cluster-node-timeout 15000 //请求超时 默认15秒，可自行设置 appendonly yes //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
然后分别启动这6个节点，也可以写个shell一键搞定~
[root@wzy-cloud redis]# cat startRedis.sh redis-server /usr/local/redis/redis_cluster/7000/redis.conf redis-server /usr/local/redis/redis_cluster/7001/redis.conf redis-server /usr/local/redis/redis_cluster/7002/redis.conf redis-server /usr/local/redis/redis_cluster/7003/redis.conf redis-server /usr/local/redis/redis_cluster/7004/redis.conf redis-server /usr/local/redis/redis_cluster/7005/redis.conf [root@wzy-cloud redis]# ./startRedis.sh [root@wzy-cloud redis]# ps -ef|grep redis root 6304 1 0 21:44 ? 00:00:00 redis-server 0.0.0.0:7000 [cluster] root 6306 1 0 21:44 ? 00:00:00 redis-server 0.0.0.0:7001 [cluster] root 6308 1 0 21:44 ? 00:00:00 redis-server 0.0.0.0:7002 [cluster] root 6310 1 0 21:44 ? 00:00:00 redis-server 0.0.0.0:7003 [cluster] root 6318 1 0 21:44 ? 00:00:00 redis-server 0.0.0.0:7004 [cluster] root 6320 1 0 21:44 ? 00:00:00 redis-server 0.0.0.0:7005 [cluster] root 6345 4985 0 21:44 pts/0 00:00:00 grep --color=auto redi
所有节点启动好后，输入以下命令创建集群，注意ip哦，是你的本地ip
注意：如果输入命令后没有反应，那可能是防火墙的关系，关掉防火墙就好了
[root@wzy-cloud redis]# redis-cli --cluster create 114.116.35.252:7000 114.116.35.252:7001 114.116.35.252:7002 114.116.35.252:7003 114.116.35.252:7004 114.116.35.252:7005 --cluster-replicas 1
如果加了密码，那么创建集群时就需要加-a wzy123参数
[root@wzy-cloud redis]# redis-cli --cluster create 114.116.35.252:7000 114.116.35.252:7001 114.116.35.252:7002 114.116.35.252:7003 114.116.35.252:7004 114.116.35.252:7005 --cluster-replicas 1 -a wzy123
不然会报以下错误
[ERR] Node 114.116.35.252:7000 NOAUTH Authentication required.
输入创建集群的命令后会出现以下提示，注意Can I set the above configuration? (type 'yes' to accept): yes，该处请输入yes，不然好像分配不了哈希槽（别人说的，没试）
[root@wzy-cloud redis_cluster]# redis-cli --cluster create 114.116.35.252:7000 114.116.35.252:7001 114.116.35.252:7002 114.116.35.252:7003 114.116.35.252:7004 114.116.35.252:7005 --cluster-replicas 1 -a wzy123 Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe. >>> Performing hash slots allocation on 6 nodes... Master[0] -> Slots 0 - 5460 Master[1] -> Slots 5461 - 10922 Master[2] -> Slots 10923 - 16383 Adding replica 114.116.35.252:7003 to 114.116.35.252:7000 Adding replica 114.116.35.252:7004 to 114.116.35.252:7001 Adding replica 114.116.35.252:7005 to 114.116.35.252:7002 >>> Trying to optimize slaves allocation for anti-affinity [WARNING] Some slaves are in the same host as their master M: 4e571c020d1f2cca020132a9adfdea2a367da21d 114.116.35.252:7000 slots:[0-5460] (5461 slots) master M: 838382153a78260e274c1d2d11a105dd3986a223 114.116.35.252:7001 slots:[5461-10922] (5462 slots) master M: e86d01e92214015304461a104a9f14e3cedc7829 114.116.35.252:7002 slots:[10923-16383] (5461 slots) master S: 22b1f3d83f068973c6e8a5d0b9e87c0c1b950594 114.116.35.252:7003 replicates 838382153a78260e274c1d2d11a105dd3986a223 S: 5248474e122d745b7e929a2705da210d3d150b4c 114.116.35.252:7004 replicates e86d01e92214015304461a104a9f14e3cedc7829 S: b3d20a419df22b4c9f4fe14c1fda22c2920c5c11 114.116.35.252:7005 replicates 4e571c020d1f2cca020132a9adfdea2a367da21d Can I set the above configuration? (type 'yes' to accept): yes
输完yes后，会出现如下提示，[OK] All 16384 slots covered.说明成功啦
Can I set the above configuration? (type 'yes' to accept): yes >>> Nodes configuration updated >>> Assign a different config epoch to each node >>> Sending CLUSTER MEET messages to join the cluster Waiting for the cluster to join ..... >>> Performing Cluster Check (using node 0.0.0.0:7000) M: 4e571c020d1f2cca020132a9adfdea2a367da21d 114.116.35.252:7000 slots:[0-5460] (5461 slots) master 1 additional replica(s) S: b3d20a419df22b4c9f4fe14c1fda22c2920c5c11 114.116.35.252:7005 slots: (0 slots) slave replicates 4e571c020d1f2cca020132a9adfdea2a367da21d M: e86d01e92214015304461a104a9f14e3cedc7829 114.116.35.252:7002 slots:[10923-16383] (5461 slots) master 1 additional replica(s) S: 22b1f3d83f068973c6e8a5d0b9e87c0c1b950594 114.116.35.252:7003 slots: (0 slots) slave replicates 838382153a78260e274c1d2d11a105dd3986a223 M: 838382153a78260e274c1d2d11a105dd3986a223 114.116.35.252:7001 slots:[5461-10922] (5462 slots) master 1 additional replica(s) S: 5248474e122d745b7e929a2705da210d3d150b4c 114.116.35.252:7004 slots: (0 slots) slave replicates e86d01e92214015304461a104a9f14e3cedc7829 [OK] All nodes agree about slots configuration. >>> Check for open slots... >>> Check slots coverage... [OK] All 16384 slots covered.
验证一下
[root@wzy-cloud redis_cluster]# redis-cli -c -p 7000 127.0.0.1:7000> auth wzy123 OK 127.0.0.1:7000> cluster nodes b3d20a419df22b4c9f4fe14c1fda22c2920c5c11 114.116.35.252:7005@17005 slave 4e571c020d1f2cca020132a9adfdea2a367da21d 0 1563378113000 6 connected e86d01e92214015304461a104a9f14e3cedc7829 114.116.35.252:7002@17002 master - 0 1563378115000 3 connected 10923-16383 22b1f3d83f068973c6e8a5d0b9e87c0c1b950594 114.116.35.252:7003@17003 slave 838382153a78260e274c1d2d11a105dd3986a223 0 1563378116490 4 connected 838382153a78260e274c1d2d11a105dd3986a223 114.116.35.252:7001@17001 master - 0 1563378114486 2 connected 5461-10922 5248474e122d745b7e929a2705da210d3d150b4c 114.116.35.252:7004@17004 slave e86d01e92214015304461a104a9f14e3cedc7829 0 1563378115488 5 connected 4e571c020d1f2cca020132a9adfdea2a367da21d 114.116.35.252:7000@17000 myself,master - 0 1563378114000 1 connected 0-5460 114.116.35.252:7000> set qwe 111 OK 114.116.35.252:7000>exit [root@wzy-cloud 7000]# redis-cli -c -p 7003 114.116.35.252:7003> auth wzy123 OK 114.116.35.252:7003> get qwe -> Redirected to slot [757] located at 127.0.0.1:7000 (error) NOAUTH Authentication required. 114.116.35.252:7000> auth wzy123 OK 127.0.0.1:7000> get qwe "111" 127.0.0.1:7000>
亲测可用！
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原文链接：https://blog.csdn.net/aloneno/java/article/details/96370167