Redis系列之Redis集群(三)

痛定思痛。 2022-07-14 04:24 220阅读 0赞

在前面的文章中，已经实现了多节点的Master-Slave，其实也可以称作为集群，但是是以命令的方式实现的，不怎么方便，现在以配置的方式，实现Redis集群  
1、首页在redis路径下创建redis-cluster文件夹，再到redis-cluster目录下创建三个目录，分别为9001，9002，9003，文件名分别代表每个实例的端口号

longwentaodeMacBook-Pro:redis-cluster longwentao$ cd ~/java/redis-3.2.5/
    longwentaodeMacBook-Pro:redis-3.2.5 longwentao$ mkdir redis-cluster
    longwentaodeMacBook-Pro:redis-3.2.5 longwentao$ cd redis-cluster/
    longwentaodeMacBook-Pro:redis-cluster longwentao$ mkdir 9001
    longwentaodeMacBook-Pro:redis-cluster longwentao$ mkdir 9002
    longwentaodeMacBook-Pro:redis-cluster longwentao$ mkdir 9003
    longwentaodeMacBook-Pro:redis-cluster longwentao$ ls
    9001    9002    9003

2、将redis-server，redis.conf文件复制到9001,9002,9003目录下

longwentaodeMacBook-Pro:redis-3.2.5 longwentao$ cp redis.conf redis-cluster/9001
    longwentaodeMacBook-Pro:redis-3.2.5 longwentao$ cp redis.conf redis-cluster/9002
    longwentaodeMacBook-Pro:redis-3.2.5 longwentao$ cp redis.conf redis-cluster/9003
    longwentaodeMacBook-Pro:redis-3.2.5 longwentao$ cp src/redis-server redis-cluster/9001
    longwentaodeMacBook-Pro:redis-3.2.5 longwentao$ cp src/redis-server redis-cluster/9002
    longwentaodeMacBook-Pro:redis-3.2.5 longwentao$ cp src/redis-server redis-cluster/9003
    longwentaodeMacBook-Pro:redis-3.2.5 longwentao$ ls redis-cluster/9001
    redis-server    redis.conf
    longwentaodeMacBook-Pro:redis-3.2.5 longwentao$

3、分别修改9001，9002，9003目录下的redis.conf文件的配置，注意端口号要和文件夹名称保持一致，几个配置项修改如下

#启动守护进程
    demonize yes
    #端口号，与文件夹名保持一致
    port 9001
    #启用redis集群
    cluster-enabled yes
    #还不清楚这是干嘛用的
    #cluster-config-file nodes.conf
    #超时时间
    cluster-node-timeout 5000
    #开始append only模式，redis 将每一次写操作请求都追加到appendonly.aof 文件中，redis重新启动时,会从该文件恢复出之前的状态
    appendonly yes

4、启动这三个实例

longwentaodeMacBook-Pro:9001 longwentao$ ./redis-server ./redis.conf 
    longwentaodeMacBook-Pro:9001 longwentao$ cd ../9002
    longwentaodeMacBook-Pro:9002 longwentao$ ./redis-server ./redis.conf 
    longwentaodeMacBook-Pro:9002 longwentao$ cd ../9003
    longwentaodeMacBook-Pro:9003 longwentao$ ./redis-server ./redis.conf 
    longwentaodeMacBook-Pro:9003 longwentao$

5、进入到redis的src目录，运行redis-trib.rb文件，创建集群，让这三个实例间相互通信

longwentaodeMacBook-Pro:src longwentao$ cd ~/java/redis-3.2.5/src
    longwentaodeMacBook-Pro:src longwentao$ ./redis-trib.rb create --replicas 0 127.0.0.1:9001 127.0.0.1:9002 127.0.0.1:9003
    /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require': cannot load such file -- redis (LoadError)
        from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require'
        from ./redis-trib.rb:25:in `<main>'

执行 redis-trib.rb 命令需要 ruby 的支持，如果没有安装ruby，就会报如上错误，可以从官网( [https://rubygems.org/gems/redis][https_rubygems.org_gems_redis])下载，然后本地安装，这里使用使用gem命令直接在线安装

longwentaodeMacBook-Pro:src longwentao$ sudo gem install redis
    Fetching: redis-3.3.2.gem (100%)
    Successfully installed redis-3.3.2
    Parsing documentation for redis-3.3.2
    Installing ri documentation for redis-3.3.2
    1 gem installed
    longwentaodeMacBook-Pro:src longwentao$

再执行redis-trib.rb，创建集群

longwentaodeMacBook-Pro:src longwentao$ ./redis-trib.rb create --replicas 0 127.0.0.1:9001 127.0.0.1:9002 127.0.0.1:9003 >>> Creating cluster >>> Performing hash slots allocation on 3 nodes... Using 3 masters: 127.0.0.1:9001 127.0.0.1:9002 127.0.0.1:9003 M: e41c2776755aa86322582dc37a0f6904b05c0dd3 127.0.0.1:9001 slots:0-5460 (5461 slots) master M: dddc296b4a3e26a536db40004f3d36a1561d35d9 127.0.0.1:9002 slots:5461-10922 (5462 slots) master M: 8fdc274fc6c341ef4c74bfe53ac9ad4309029a4a 127.0.0.1:9003 slots:10923-16383 (5461 slots) master 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 127.0.0.1:9001) M: e41c2776755aa86322582dc37a0f6904b05c0dd3 127.0.0.1:9001 slots:0-5460 (5461 slots) master 0 additional replica(s) M: 8fdc274fc6c341ef4c74bfe53ac9ad4309029a4a 127.0.0.1:9003 slots:10923-16383 (5461 slots) master 0 additional replica(s) M: dddc296b4a3e26a536db40004f3d36a1561d35d9 127.0.0.1:9002 slots:5461-10922 (5462 slots) master 0 additional replica(s) [OK] All nodes agree about slots configuration. >>> Check for open slots... >>> Check slots coverage... [OK] All 16384 slots covered. longwentaodeMacBook-Pro:src longwentao$

–replicas 表示需要几个Slave  
现在redis集群就已经创建完成了，使用redis客户端redis-cli测试一下

longwentaodeMacBook-Pro:src longwentao$ ./redis-cli -c -p 9001
    127.0.0.1:9001> get foo
    -> Redirected to slot [12182] located at 127.0.0.1:9003
    (nil)
    127.0.0.1:9003> set foo testvalue
    OK
    127.0.0.1:9003> get foo
    "testvalue"
    127.0.0.1:9003>

127.0.0.1:9001> get foo
    -> Redirected to slot [12182] located at 127.0.0.1:9003
    "testvalue"
    127.0.0.1:9003>

127.0.0.1:9002> get foo
    -> Redirected to slot [12182] located at 127.0.0.1:9003
    "testvalue"
    127.0.0.1:9003>

可以看到，当我们在9001实例中获得foo的值时，自动重定向到9003的实例中，在9003实例上设置foo的值后，在9001，9002上get foo的值，会自动重定向到9003上，并输出foo的值

使用redis-trib.rb进行集群检查

longwentaodeMacBook-Pro:src longwentao$ ./redis-trib.rb check 127.0.0.1:9001
    >>> Performing Cluster Check (using node 127.0.0.1:9001)
    M: e41c2776755aa86322582dc37a0f6904b05c0dd3 127.0.0.1:9001
       slots:0-5460 (5461 slots) master
       0 additional replica(s)
    M: 8fdc274fc6c341ef4c74bfe53ac9ad4309029a4a 127.0.0.1:9003
       slots:10923-16383 (5461 slots) master
       0 additional replica(s)
    M: dddc296b4a3e26a536db40004f3d36a1561d35d9 127.0.0.1:9002
       slots:5461-10922 (5462 slots) master
       0 additional replica(s)
    [OK] All nodes agree about slots configuration.
    >>> Check for open slots...
    >>> Check slots coverage...
    [OK] All 16384 slots covered.
    longwentaodeMacBook-Pro:src longwentao$

[https_rubygems.org_gems_redis]: https://rubygems.org/gems/redis