Redis5.0发布了，其中更新了一个新的特性，把Redis的集群管理从Ruby(redis-trib.rb)移植到了C语言代码，直接使用redis-cli就可以管理集群，今天我们就尝试一下。

1、直接从官网下载最新的Redis5.0包，下载地址 Redis 5.0.0 is the latest stable version.，然后编译安装下。

2、创建三个文件夹
mkdir -p /data/redis/cluster/7000
mkdir -p /data/redis/cluster/7001
mkdir -p /data/redis/cluster/7002
把第一步编译好的文件，为了简单只需要把 redis.conf,redis-server,redis-cli 这三个文件copy到7000，7001，7002文件夹中。同时编辑各自的redis.conf文件，修改对应端口。 这些就作为cluster的三个节点。由于我们是为了演示使用redis-cli创建集群的过程，就直接三个master节点，不用对应的slave的节点了。

3、分别启动7000、7001、7002三个节点
cd /data/redis/cluster/7000
./redis-server redis.conf

cd /data/redis/cluster/7001
./redis-server redis.conf

cd /data/redis/cluster/7002
./redis-server redis.conf

然后确认redis节点是否正常启动
[root@shdreams cluster]# ps -ef|grep redis
root 30248 1 0 03:16 ? 00:00:00 ./redis-server 127.0.0.1:7000 [cluster]
root 30255 1 0 03:18 ? 00:00:00 ./redis-server 127.0.0.1:7001 [cluster]
root 30260 1 0 03:18 ? 00:00:00 ./redis-server 127.0.0.1:7002 [cluster]

4、接下来就是创建集群了，首先我们先看下 redis-cli 都提供了哪些操作集群的命令
[root@shdreams 7000]# ./redis-cli –cluster help
Cluster Manager Commands:
create host1:port1 … hostN:portN
–cluster-replicas
check host:port
info host:port
fix host:port
reshard host:port
–cluster-from
–cluster-to
–cluster-slots
–cluster-yes
–cluster-timeout
–cluster-pipeline
rebalance host:port
–cluster-weight <node1=w1…nodeN=wN>
–cluster-use-empty-masters
–cluster-timeout
–cluster-simulate
–cluster-pipeline
–cluster-threshold
add-node new_host:new_port existing_host:existing_port
–cluster-slave
–cluster-master-id
del-node host:port node_id
call host:port command arg arg .. arg
set-timeout host:port milliseconds
import host:port
–cluster-from
–cluster-copy
–cluster-replace
help

For check, fix, reshard, del-node, set-timeout you can specify the host and port of any working node in the cluster.

OK，我们就创建集群吧~
我们键入命令 ./redis-cli –cluster create 127.0.0.1:7000 127.0.0.1:7001 127.0.0.1:7002 回车就会出现如下信息

Performing hash slots allocation on 3 nodes…
Master[0] -> Slots 0 - 5460
Master[1] -> Slots 5461 - 10922
Master[2] -> Slots 10923 - 16383
M: a7b511330bffe28357cd21d6ee543e59f0a38dea 127.0.0.1:7000
slots:[0-5460](5461 slots) master
M: a7ab1aa24c9030d1fb42bbac3ad72c15bf683ef4 127.0.0.1:7001
slots:[5461-10922](5462 slots) master
M: 91d2903fa575b83b6dc9e6b7dac74c923e2882e9 127.0.0.1:7002
slots:[10923-16383](5461 slots) master
Can I set the above configuration? (type ‘yes’ to accept):

这里是提示我们确认节点相关信息。
M表示master；后面一长字符串是节点的RunID，在一个redis集群中RunID是唯一的，启动的时候系统自动创建的，不需要人工干预；slots表示此节点分配的hash槽
这里，就直接键入 yes 就会创建集群了。

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 127.0.0.1:7000)
M: a7b511330bffe28357cd21d6ee543e59f0a38dea 127.0.0.1:7000
slots:[0-5460](5461 slots) master
M: 91d2903fa575b83b6dc9e6b7dac74c923e2882e9 127.0.0.1:7002
slots:[10923-16383](5461 slots) master
M: a7ab1aa24c9030d1fb42bbac3ad72c15bf683ef4 127.0.0.1:7001
slots:[5461-10922](5462 slots) master
[OK] All nodes agree about slots configuration.
Check for open slots…
Check slots coverage…
[OK] All 16384 slots covered.

如果出现以上信息就表示集群创建OK了

5、验证下集群信息
我们进入集群 ./redis-cli -h 127.0.0.1 -p 7000 -c

127.0.0.1:7000> cluster info
cluster_state:ok
cluster_slots_assigned:16384
cluster_slots_ok:16384
cluster_slots_pfail:0
cluster_slots_fail:0
cluster_known_nodes:3
cluster_size:3
cluster_current_epoch:3
cluster_my_epoch:1
cluster_stats_messages_ping_sent:254
cluster_stats_messages_pong_sent:286
cluster_stats_messages_sent:540
cluster_stats_messages_ping_received:284
cluster_stats_messages_pong_received:254
cluster_stats_messages_meet_received:2
cluster_stats_messages_received:540

127.0.0.1:7000> cluster nodes
91d2903fa575b83b6dc9e6b7dac74c923e2882e9 127.0.0.1:7002@17002 master - 0 1539934393000 3 connected 10923-16383
a7ab1aa24c9030d1fb42bbac3ad72c15bf683ef4 127.0.0.1:7001@17001 master - 0 1539934393933 2 connected 5461-10922
a7b511330bffe28357cd21d6ee543e59f0a38dea 127.0.0.1:7000@17000 myself,master - 0 1539934390000 1 connected 0-5460

通过以上信息，确认目前reids集群是正常的。

6、尝试下redis-cli cluster的其他命令

把7000节点的10个slots移到7001节点上，键入命令如下，
./redis-cli –cluster reshard 127.0.0.1:7000 –cluster-from a7b511330bffe28357cd21d6ee543e59f0a38dea –cluster-to a7ab1aa24c9030d1fb42bbac3ad72c15bf683ef4 –cluster-slots 10 –cluster-yes

Performing Cluster Check (using node 127.0.0.1:7000)
M: a7b511330bffe28357cd21d6ee543e59f0a38dea 127.0.0.1:7000
slots:[0-5460](5461 slots) master
M: 91d2903fa575b83b6dc9e6b7dac74c923e2882e9 127.0.0.1:7002
slots:[10923-16383](5461 slots) master
M: a7ab1aa24c9030d1fb42bbac3ad72c15bf683ef4 127.0.0.1:7001
slots:[5461-10922](5462 slots) master
[OK] All nodes agree about slots configuration.
Check for open slots…
Check slots coverage…
[OK] All 16384 slots covered.

Ready to move 10 slots.
Source nodes:
M: a7b511330bffe28357cd21d6ee543e59f0a38dea 127.0.0.1:7000
slots:[0-5460](5461 slots) master
Destination node:
M: a7ab1aa24c9030d1fb42bbac3ad72c15bf683ef4 127.0.0.1:7001
slots:[5461-10922](5462 slots) master
Resharding plan:
Moving slot 0 from a7b511330bffe28357cd21d6ee543e59f0a38dea
Moving slot 1 from a7b511330bffe28357cd21d6ee543e59f0a38dea
Moving slot 2 from a7b511330bffe28357cd21d6ee543e59f0a38dea
Moving slot 3 from a7b511330bffe28357cd21d6ee543e59f0a38dea
Moving slot 4 from a7b511330bffe28357cd21d6ee543e59f0a38dea
Moving slot 5 from a7b511330bffe28357cd21d6ee543e59f0a38dea
Moving slot 6 from a7b511330bffe28357cd21d6ee543e59f0a38dea
Moving slot 7 from a7b511330bffe28357cd21d6ee543e59f0a38dea
Moving slot 8 from a7b511330bffe28357cd21d6ee543e59f0a38dea
Moving slot 9 from a7b511330bffe28357cd21d6ee543e59f0a38dea
Moving slot 0 from 127.0.0.1:7000 to 127.0.0.1:7001:
Moving slot 1 from 127.0.0.1:7000 to 127.0.0.1:7001:
Moving slot 2 from 127.0.0.1:7000 to 127.0.0.1:7001:
Moving slot 3 from 127.0.0.1:7000 to 127.0.0.1:7001:
Moving slot 4 from 127.0.0.1:7000 to 127.0.0.1:7001:
Moving slot 5 from 127.0.0.1:7000 to 127.0.0.1:7001:
Moving slot 6 from 127.0.0.1:7000 to 127.0.0.1:7001:
Moving slot 7 from 127.0.0.1:7000 to 127.0.0.1:7001:
Moving slot 8 from 127.0.0.1:7000 to 127.0.0.1:7001:
Moving slot 9 from 127.0.0.1:7000 to 127.0.0.1:7001:

以上显示已经移动成功了，我们可以再看下slots的分布情况
[root@shdreams 7000]# ./redis-cli -h 127.0.0.1 -p 7000 -c cluster nodes
91d2903fa575b83b6dc9e6b7dac74c923e2882e9 127.0.0.1:7002@17002 master - 0 1539934886013 3 connected 10923-16383
a7ab1aa24c9030d1fb42bbac3ad72c15bf683ef4 127.0.0.1:7001@17001 master - 0 1539934885011 4 connected 0-9 5461-10922
a7b511330bffe28357cd21d6ee543e59f0a38dea 127.0.0.1:7000@17000 myself,master - 0 1539934884000 1 connected 10-5460
发现slots已经转移了。

当然我们也可以添加节点，删除节点试验，这里就不做了。
通过以上尝试，发现通过redis-cli来操作redis集群确实方便多了。