探索云原生技术之基石-Docker容器高级篇(1)

2年前 (2022) 程序员胖胖胖虎阿

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❤️作者简介：2022新星计划第三季云原生与云计算赛道Top5🏅、华为云享专家🏅、云原生领域潜力新星🏅

💛博客首页：C站个人主页🌞

💗作者目的：如有错误请指正，将来会不断的完善笔记，帮助更多的Java爱好者入门，共同进步！

文章目录

- 探索云原生技术之基石-Docker容器高级篇(1)
- - 什么是云原生
  - 什么是Docker
  - MySQL主从复制（1主1从）
  - - Master节点配置
    - Slave节点配置
    - 测试主从同步
    - 主从同步失败问题（Slave_SQL_Running:No）
    - - Slave_SQL_Running:No的解决办法
  - Redis集群（3主6从）
  - - 10亿条数据怎么进行缓存
    - - 哈希取余算法（小厂采用）
      - 一致性hash算法（中大厂采用）
      - hash槽算法（大厂采用、和Redis集群也是采用这种）
    - 快速搭建Redis Cluster（3主6从）
    - - 快速生成9个容器实例
      - 查看容器实例是否全部启动
      - 配置主从
      - 以集群的方式进入Redis客户端
      - 操作set命令
      - 查看集群节点信息
      - 查看集群状态
    - 主从切换
    - 主从扩容
    - 主从缩容

探索云原生技术之基石-Docker容器高级篇(1)

本博文一共有6篇，如下

探索云原生技术之基石-Docker容器入门篇(1)
探索云原生技术之基石-Docker容器入门篇(2)
探索云原生技术之基石-Docker容器入门篇(3)
探索云原生技术之基石-Docker容器入门篇(4)，=>由于篇幅过长，所以另起一篇

等你对Docker有一定理解的时候可以看高级篇，不过不太建议。

探索云原生技术之基石-Docker容器高级篇(1)
探索云原生技术之基石-Docker容器高级篇(2)

剧透：未来将出云原生技术-Kubernetes（k8s），此时的你可以对Docker进行统一管理、动态扩缩容等等。

看完之后你会对Docker有一定的理解，并能熟练的使用Docker进行容器化开发、以及Docker部署微服务、Docker网络等等。干起来！

什么是云原生

Pivotal公司的Matt Stine于2013年首次提出云原生（Cloud-Native）的概念；2015年，云原生刚推广时，Matt Stine在《迁移到云原生架构》一书中定义了符合云原生架构的几个特征：12因素、微服务、自敏捷架构、基于API协作、扛脆弱性；到了2017年，Matt Stine在接受InfoQ采访时又改了口风，将云原生架构归纳为模块化、可观察、可部署、可测试、可替换、可处理6特质；而Pivotal最新官网对云原生概括为4个要点：DevOps+持续交付+微服务+容器。

总而言之，符合云原生架构的应用程序应该是：采用开源堆栈（K8S+Docker）进行容器化，基于微服务架构提高灵活性和可维护性，借助敏捷方法、DevOps支持持续迭代和运维自动化，利用云平台设施实现弹性伸缩、动态调度、优化资源利用率。

（此处摘选自《知乎-华为云官方帐号》）

探索云原生技术之基石-Docker容器高级篇(1)

什么是Docker

Docker 是一个开源的应用容器引擎，基于Go语言开发。
Docker 可以让开发者打包他们的应用以及依赖包到一个轻量级、可移植的容器中，然后发布到任何流行的 Linux 机器上，也可以实现虚拟化。
容器是完全使用沙箱机制（容器实例相互隔离），容器性能开销极低（高性能）。

总而言之：

Docker是一个高性能的容器引擎；

可以把本地源代码、配置文件、依赖、环境通通打包成一个容器即可以到处运行；

使用Docker安装软件十分方便，而且安装的软件十分精简，方便扩展。

MySQL主从复制（1主1从）

Master节点配置

运行一个mysql容器实例。作为Master节点

docker run -p 3307:3306 \
-v /my-sql/mysql-master/log:/var/log/mysql \
-v /my-sql/mysql-master/data:/var/lib/mysql \
-v /my-sql/mysql-master/conf:/etc/mysql \
-e MYSQL_ROOT_PASSWORD=123456 \
--name mysql-master \
-d mysql:5.7

创建my.cnf文件（也就是mysql的配置文件）

vim /my-sql/mysql-master/conf/my.cnf

将内容粘贴进my.cnf文件

[client]
# 指定编码格式为utf8,默认的MySQL会有中文乱码问题
default_character_set=utf8
[mysqld]
collation_server=utf8_general_ci
character_set_server=utf8

# 全局唯一id（不允许有相同的）
server_id=200
binlog-ignore-db=mysql
# 指定MySQL二进制日志
log-bin=order-mysql-bin
# binlog最大容量
binlog_cache_size=1M
# 二进制日志格式（这里指定的是混合日志）
binlog_format=mixed
# binlog的有效期（单位：天）
expire_logs_days=7
slave_skip_errors=1062

重启该mysql容器实例

docker restart mysql-master

进入容器内部，并登陆mysql

$ docker exec -it mysql-master /bin/bash
$ mysql -uroot -p

在Master节点的MySQL中创建用户和分配权限

在主数据库创建的该帐号密码只是用来进行同步数据。

create user 'slave'@'%' identified by '123456';

grant replication slave, replication client on *.* to 'slave'@'%';

Slave节点配置

运行一个MySQL容器实例，作为slave节点（从节点）

docker run -p 3308:3306 \
-v /my-sql/mysql-slave/log:/var/log/mysql \
-v /my-sql/mysql-slave/data:/var/lib/mysql \
-v /my-sql/mysql-slave/conf:/etc/mysql \
-e MYSQL_ROOT_PASSWORD=123456  \
--name mysql-slave \
-d mysql:5.7

创建my.cnf文件（也就是mysql的配置文件）

vim /my-sql/mysql-slave/conf/my.cnf

将内容粘贴进my.cnf文件

[client]
# 指定编码格式为utf8,默认的MySQL会有中文乱码问题
default_character_set=utf8
[mysqld]
collation_server=utf8_general_ci
character_set_server=utf8

# 全局唯一id（不允许有相同的）
server_id=201
binlog-ignore-db=mysql
# 指定MySQL二进制日志
log-bin=order-mysql-bin
# binlog最大容量
binlog_cache_size=1M
# 二进制日志格式（这里指定的是混合日志）
binlog_format=mixed
# binlog的有效期（单位：天）
expire_logs_days=7
slave_skip_errors=1062
# 表示slave将复制事件写进自己的二进制日志
log_slave_updates=1
# 表示从机只能读
read_only=1

重启该mysql容器实例

docker restart mysql-slave

查看容器实例是否都是up

[root@aubin ~]# docker ps
CONTAINER ID   IMAGE       COMMAND                  CREATED         STATUS         PORTS                                                  NAMES
2c4136668536   mysql:5.7   "docker-entrypoint.s…"   3 minutes ago   Up 9 seconds   33060/tcp, 0.0.0.0:3308->3306/tcp, :::3308->3306/tcp   mysql-slave
20fc7174d1a7   mysql:5.7   "docker-entrypoint.s…"   15 hours ago    Up 8 minutes   33060/tcp, 0.0.0.0:3307->3306/tcp, :::3307->3306/tcp   mysql-master

进入Master节点查看主从同步状态

mysql> show master status;
+------------------------+----------+--------------+------------------+-------------------+
| File                   | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------------+----------+--------------+------------------+-------------------+
| order-mysql-bin.000001 |      617 |              | mysql            |                   |
+------------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)

进入从机MySQL

$ docker exec -it mysql-slave /bin/bash
$ mysql -uroot -p

在从数据库（slave）配置主从同步（重点）

在Master节点中找到ens33的ip地址并放到下面的master_host中（记住这个ip是Master数据库的服务器ip，不是从数据库的）：

[root@aubin ~]# ifconfig
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.184.132  netmask 255.255.255.0  broadcast 192.168.184.255
        inet6 fe80::5c87:5037:8d1d:7650  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:23:28:59  txqueuelen 1000  (Ethernet)
        RX packets 4186  bytes 443992 (433.5 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 3146  bytes 428816 (418.7 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

记住下面这个命令要在从（slave）数据库执行：

change master to master_host='192.168.184.132',master_user='slave',master_password='123456',master_port=3307,master_log_file='order-mysql-bin.000001',master_log_pos=617,master_connect_retry=30;

配置参数解析

master_host：主数据库（Master）的 ip 地址
master_user：在Master数据库中创建的用来进行同步的帐号
master_password：在Master数据库中创建的用来进行同步的帐号的密码
master_port：Master数据库的 MySQL端口号，这里是3307
master_log_file：MySQL的 binlog文件名
master_log_pos：binlog读取位置

在从数据库（slave）查看主从同步状态：

mysql> show slave status \G;
*************************** 1. row ***************************
               Slave_IO_State: 
                  Master_Host: 192.168.184.132
                  Master_User: slave
                  Master_Port: 3307
                Connect_Retry: 30
              Master_Log_File: order-mysql-bin.000001
          Read_Master_Log_Pos: 617
               Relay_Log_File: 2c4136668536-relay-bin.000001
                Relay_Log_Pos: 4
        Relay_Master_Log_File: order-mysql-bin.000001
             Slave_IO_Running: No
            Slave_SQL_Running: No
              Replicate_Do_DB: 
          Replicate_Ignore_DB: 
           Replicate_Do_Table: 
       Replicate_Ignore_Table: 
      Replicate_Wild_Do_Table: 
  Replicate_Wild_Ignore_Table: 
                   Last_Errno: 0
                   Last_Error: 
                 Skip_Counter: 0
          Exec_Master_Log_Pos: 617
              Relay_Log_Space: 154
              Until_Condition: None
               Until_Log_File: 
                Until_Log_Pos: 0
           Master_SSL_Allowed: No
           Master_SSL_CA_File: 
           Master_SSL_CA_Path: 
              Master_SSL_Cert: 
            Master_SSL_Cipher: 
               Master_SSL_Key: 
        Seconds_Behind_Master: NULL
Master_SSL_Verify_Server_Cert: No
                Last_IO_Errno: 0
                Last_IO_Error: 
               Last_SQL_Errno: 0
               Last_SQL_Error: 
  Replicate_Ignore_Server_Ids: 
             Master_Server_Id: 0
                  Master_UUID: 
             Master_Info_File: /var/lib/mysql/master.info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: 
           Master_Retry_Count: 86400
                  Master_Bind: 
      Last_IO_Error_Timestamp: 
     Last_SQL_Error_Timestamp: 
               Master_SSL_Crl: 
           Master_SSL_Crlpath: 
           Retrieved_Gtid_Set: 
            Executed_Gtid_Set: 
                Auto_Position: 0
         Replicate_Rewrite_DB: 
                 Channel_Name: 
           Master_TLS_Version: 
1 row in set (0.00 sec)

我们找到里面的Slave_IO_Running: No，Slave_SQL_Running: No属性，发现都是No的状态，证明主从同步还没有开始。。。

在从数据库（slave）正式开启主从同步

start slave;

再次在从数据库中查看主从同步状态

mysql> show slave status \G;
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.184.132
                  Master_User: slave
                  Master_Port: 3307
                Connect_Retry: 30
              Master_Log_File: order-mysql-bin.000001
          Read_Master_Log_Pos: 617
               Relay_Log_File: 2c4136668536-relay-bin.000002
                Relay_Log_Pos: 326
        Relay_Master_Log_File: order-mysql-bin.000001
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
.......

我们可以看到已经都为yes了，说明主从同步已经开启。

测试主从同步

在Master数据库执行：

创建数据库

create database mall;

使用数据库

use mall;

创建表（表是我从之前写的项目中拿的）

CREATE TABLE `order` (
  `id` bigint(20) NOT NULL,
  `imgUrl` varchar(255) NOT NULL,
  `goodsInfo` varchar(255) NOT NULL,
  `goodsParams` varchar(255) DEFAULT NULL,
  `goodsCount` int(20) NOT NULL,
  `singleGoodsMoney` decimal(10,2) NOT NULL,
  `realname` varchar(255) NOT NULL,
  `phone` varchar(255) NOT NULL,
  `address` text NOT NULL,
  `created` datetime DEFAULT NULL COMMENT '创建时间',
  `userid` bigint(20) NOT NULL,
  `productid` bigint(20) NOT NULL,
  `statusid` bigint(20) NOT NULL COMMENT '订单状态',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

插入数据

INSERT INTO `order` VALUES (3655575498130437, 'http://localhost/static/img/nav/max.jpg', '小米Max', '全网通 4GB内存+64GB容量 指纹识别 黑色 每月20G流量套餐', 2, 2998.00, '张三', '123123666', '广东省河源市源城区', '2021-11-26 16:40:57', 1, 1, 2);
INSERT INTO `order` VALUES (3655575610852357, 'http://localhost/static/img/nav/max.jpg', '小米Max', '全网通 4GB内存+64GB容量 指纹识别 黑色 每月20G流量套餐', 2, 2998.00, '张三', '123123666', '广东省河源市源城区', '2021-11-26 16:40:59', 1, 1, 6);
INSERT INTO `order` VALUES (3672761237177349, 'http://localhost/static/img/nav/max.jpg', '小米Max', '全网通 4GB内存+64GB容量 指纹识别 黑色 每月20G流量套餐', 2, 2998.00, '张三', '123123666', '广东省河源市源城区', '2021-11-29 17:31:31', 1, 1, 6);
INSERT INTO `order` VALUES (3678103231529989, 'http://localhost/static/img/nav/max.jpg', '小米Max', '全网通 4GB内存+64GB容量 指纹识别 黑色 每月20G流量套餐', 1, 1499.00, '张三', '123123666', '广东省河源市源城区', '2021-11-30 16:10:03', 1, 1, 6);
INSERT INTO `order` VALUES (3678347308893189, 'http://localhost/static/img/nav/mi5.jpg', '小米手机5', '标准版', 1, 1999.00, '张三', '123123666', '广东省河源市源城区', '2021-11-30 17:12:07', 1, 2, 4);

查询数据库表（在Master数据库执行）

mysql> select * from `order`;
+------------------+-----------------------------------------+-----------+-----------------+------------+------------------+----------+-----------+---------+---------------------+--------+-----------+----------+
| id               | imgUrl                                  | goodsInfo | goodsParams     | goodsCount | singleGoodsMoney | realname | phone     | address | created             | userid | productid | statusid |
+------------------+-----------------------------------------+-----------+-----------------+------------+------------------+----------+-----------+---------+---------------------+--------+-----------+----------+
| 3655575498130437 | http://localhost/static/img/nav/max.jpg | Max       |  4GB+64GB   20G |          2 |          2998.00 |          | 123123666 |         | 2021-11-26 16:40:57 |      1 |         1 |        2 |
| 3655575610852357 | http://localhost/static/img/nav/max.jpg | Max       |  4GB+64GB   20G |          2 |          2998.00 |          | 123123666 |         | 2021-11-26 16:40:59 |      1 |         1 |        6 |
| 3672761237177349 | http://localhost/static/img/nav/max.jpg | Max       |  4GB+64GB   20G |          2 |          2998.00 |          | 123123666 |         | 2021-11-29 17:31:31 |      1 |         1 |        6 |
| 3678103231529989 | http://localhost/static/img/nav/max.jpg | Max       |  4GB+64GB   20G |          1 |          1499.00 |          | 123123666 |         | 2021-11-30 16:10:03 |      1 |         1 |        6 |
| 3678347308893189 | http://localhost/static/img/nav/mi5.jpg | 5         |                 |          1 |          1999.00 |          | 123123666 |         | 2021-11-30 17:12:07 |      1 |         2 |        4 |
+------------------+-----------------------------------------+-----------+-----------------+------------+------------------+----------+-----------+---------+---------------------+--------+-----------+----------+
5 rows in set (0.00 sec)

切换从数据库机器（在slave数据库执行）

mysql> use mall;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed

查询数据库表（在slave数据库执行）

mysql> select * from `order`;
+------------------+-----------------------------------------+-----------+-----------------+------------+------------------+----------+-----------+---------+---------------------+--------+-----------+----------+
| id               | imgUrl                                  | goodsInfo | goodsParams     | goodsCount | singleGoodsMoney | realname | phone     | address | created             | userid | productid | statusid |
+------------------+-----------------------------------------+-----------+-----------------+------------+------------------+----------+-----------+---------+---------------------+--------+-----------+----------+
| 3655575498130437 | http://localhost/static/img/nav/max.jpg | Max       |  4GB+64GB   20G |          2 |          2998.00 |          | 123123666 |         | 2021-11-26 16:40:57 |      1 |         1 |        2 |
| 3655575610852357 | http://localhost/static/img/nav/max.jpg | Max       |  4GB+64GB   20G |          2 |          2998.00 |          | 123123666 |         | 2021-11-26 16:40:59 |      1 |         1 |        6 |
| 3672761237177349 | http://localhost/static/img/nav/max.jpg | Max       |  4GB+64GB   20G |          2 |          2998.00 |          | 123123666 |         | 2021-11-29 17:31:31 |      1 |         1 |        6 |
| 3678103231529989 | http://localhost/static/img/nav/max.jpg | Max       |  4GB+64GB   20G |          1 |          1499.00 |          | 123123666 |         | 2021-11-30 16:10:03 |      1 |         1 |        6 |
| 3678347308893189 | http://localhost/static/img/nav/mi5.jpg | 5         |                 |          1 |          1999.00 |          | 123123666 |         | 2021-11-30 17:12:07 |      1 |         2 |        4 |
+------------------+-----------------------------------------+-----------+-----------------+------------+------------------+----------+-----------+---------+---------------------+--------+-----------+----------+
5 rows in set (0.00 sec)

Docker+MySQL主从同步搞定！

也可以用Navicat去连接这两个数据库。如果Navicat出现连接不了docker的mysql，则可以：

方法一：关闭防火墙（测试环境用，生产环境不可以用）

sudo systemctl stop firewalld

方法二：开放防火墙对应端口，比如master数据库的3307和slave数据库的3308（生产环境用这个）

主从同步失败问题（Slave_SQL_Running:No）

mysql> show slave status \G;
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.184.132
                  Master_User: slave
                  Master_Port: 3307
                Connect_Retry: 30
              Master_Log_File: order-mysql-bin.000001
          Read_Master_Log_Pos: 3752
               Relay_Log_File: 2c4136668536-relay-bin.000002
                Relay_Log_Pos: 326
        Relay_Master_Log_File: order-mysql-bin.000001
             Slave_IO_Running: Yes
            Slave_SQL_Running: No
              Replicate_Do_DB: 
          Replicate_Ignore_DB: 
           Replicate_Do_Table: 
       Replicate_Ignore_Table: 
      Replicate_Wild_Do_Table: 
  Replicate_Wild_Ignore_Table: 
                   Last_Errno: 1007
                   Last_Error: Error 'Can't create database 'mall'; database exists' on query. Default database: 'mall'. Query: 'create database mall'

Slave_SQL_Running为No的状态，那么这是为什么呢？
可以看到Last_Error: Error ‘Can’t create database ‘mall’; database exists’ on query. Default database: ‘mall’. Query: ‘create database mall’
原因是主数据库（Master）和从数据库（slave）不一致造成的，我在从数据库执行了命令导致数据不一致，最终导致主从复制失败。

Slave_SQL_Running:No的解决办法

1：把主数据库和从数据库变成一模一样，也就是把多余的数据库和表删除掉，变成默认的mysql状态。（切记生产环境下要做好数据备份！！！）

2：结束同步：

stop slave;

3：再次开启同步：

start slave;

4：搞定！

mysql> show slave status \G;
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.184.132
                  Master_User: slave
                  Master_Port: 3307
                Connect_Retry: 30
              Master_Log_File: order-mysql-bin.000001
          Read_Master_Log_Pos: 3752
               Relay_Log_File: 2c4136668536-relay-bin.000003
                Relay_Log_Pos: 326
        Relay_Master_Log_File: order-mysql-bin.000001
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes

Redis集群（3主6从）

10亿条数据怎么进行缓存

这么大量的数据放在一个Redis里面显然是不行的，所以我们必须进行搭建分布式的Redis集群进行存储。
那么我们如何确定每一条数据存放在哪一个Redis中呢？我们有如下三种方法。

哈希取余算法（小厂采用）

过程

1：假设一共有5台Redis服务器，编号分别为：0 1 2 3 4，服务器台数为count=5
2：先把key（关键字）进行哈希后产生一个哈希值为val，假设这个val为22
3：再用哈希取余算法公式：val%count，也就是22%5=2
4：那么就定位到3号（0为1号机器），那么该数据就插入3号Redis机器中

缺点：

1：Redis节点扩容十分麻烦，如果此时从5台机器变成10台，那么我们需要去修改哈希取余算法的公式，不利于扩展。
2：又或者是缩容也十分麻烦，如果有一台服务器宕机了，在线机器从5->4台，那么也需要去修改哈希取余算法公式。

一致性hash算法（中大厂采用）

图解：
先虚拟一个哈希环,记录我们机器的ip的hash对应到哈希环中：
探索云原生技术之基石-Docker容器高级篇(1)
将对象的关键字key进行hash，顺时针寻找我们的机器，如果机器还在线就插入：

过程

1：虚拟一个哈希环（类似于大小为2^32的数组arr），即0 ~ (2^32)-1的空间中。
2：对我们所有的Redis节点所在的服务器IP或者主机名进行hash，得到的这个hash值记录下来。
3：先把key（关键字）进行hash后产生一个hash值为val
4：把这个val当成数组的下标进行遍历（也就是从这个位置顺时针遍历哈希环）一旦遇到Redis节点的hash值则进行插入，如果该节点宕机了则插入失败，这个时候我们就会跳过这个Redis节点继续顺时针搜索合适的节点，直到插入成功或者遍历完整个哈希环（当然此时是最坏情况）。
5：如果有新增的节点就按照第2步操作即可
6：如果Redis节点被删除或者宕机了，就移除这个记录的节点即可。

优点：

方便扩容和缩容，不需要和哈希取余算法一样更改算法公式，扩展性很好。
是因为哈希环的大小是2^32，几乎涵盖了所有hash值的可能。

缺点：

缺点也是十分明显的，当我们的Redis节点过少时，会造成数据倾斜问题。这种问题也是十分致命的。
因此该算法小厂不适合用，中大厂在多节点的情况下采用效果会更好。

hash槽算法（大厂采用、和Redis集群也是采用这种）

1：由于一致性hash算法会导致数据倾斜问题，而hash槽可以避免这个问题。
2：Redis的hash槽大小固定为：16384个。
3：将hash槽均匀分配到各个Master节点上（注意：slave节点不会被分配）
4：假如有三个Redis节点，则会分配成5461：5462：5461
- Redis的1号节点：负责0-5460号槽位
- Redis的2号节点：负责5461-10922号槽位
- Redis的3号节点：负责10923-16383号槽位
5：将关键字（key）进行hash取值，并且映射到对应的hash槽位上。
6：如果需要扩容或者缩容，只需要重新分配槽位即可。

快速搭建Redis Cluster（3主6从）

搭建的集群为：3主6从。
其中内部是1个Master主节点对应2个slave从节点

快速生成9个容器实例

由于我们搭建3主6从，所以需要9个Redis容器实例。这里的Redis都是最新版，如果需要改变版本，只需要把下面的版本换成你需要指定的版本即可。

docker run -d \
--name redis-node-1 \
--net host \
--privileged=true \
-v /data/redis/share/redis-node-1:/data \
 redis:latest \
--cluster-enabled yes \
--appendonly yes \
--port 6381

docker run -d \
--name redis-node-2 \
--net host \
--privileged=true \
-v /data/redis/share/redis-node-2:/data \
 redis:latest \
--cluster-enabled yes \
--appendonly yes \
--port 6382

docker run -d \
--name redis-node-3 \
--net host \
--privileged=true \
-v /data/redis/share/redis-node-3:/data \
 redis:latest \
--cluster-enabled yes \
--appendonly yes \
--port 6383

docker run -d \
--name redis-node-4 \
--net host \
--privileged=true \
-v /data/redis/share/redis-node-4:/data \
 redis:latest \
--cluster-enabled yes \
--appendonly yes \
--port 6384

docker run -d \
--name redis-node-5 \
--net host \
--privileged=true \
-v /data/redis/share/redis-node-5:/data \
 redis:latest \
--cluster-enabled yes \
--appendonly yes \
--port 6385

docker run -d \
--name redis-node-6 \
--net host \
--privileged=true \
-v /data/redis/share/redis-node-6:/data \
 redis:latest \
--cluster-enabled yes \
--appendonly yes \
--port 6386

docker run -d \
--name redis-node-7 \
--net host \
--privileged=true \
-v /data/redis/share/redis-node-7:/data \
 redis:latest \
--cluster-enabled yes \
--appendonly yes \
--port 6387

docker run -d \
--name redis-node-8 \
--net host \
--privileged=true \
-v /data/redis/share/redis-node-8:/data \
 redis:latest \
--cluster-enabled yes \
--appendonly yes \
--port 6388

docker run -d \
--name redis-node-9 \
--net host \
--privileged=true \
-v /data/redis/share/redis-node-9:/data \
 redis:latest \
--cluster-enabled yes \
--appendonly yes \
--port 6389

查看容器实例是否全部启动

[root@aubin ~]# docker ps
CONTAINER ID   IMAGE          COMMAND                  CREATED         STATUS         PORTS     NAMES
73caff0968f1   redis:latest   "docker-entrypoint.s…"   4 seconds ago   Up 4 seconds             redis-node-9
c8c5bd1034b4   redis:latest   "docker-entrypoint.s…"   5 seconds ago   Up 5 seconds             redis-node-8
c7cf3d764f65   redis:latest   "docker-entrypoint.s…"   6 seconds ago   Up 5 seconds             redis-node-7
98dcf5fd80d7   redis:latest   "docker-entrypoint.s…"   6 seconds ago   Up 5 seconds             redis-node-6
7035e4a73a83   redis:latest   "docker-entrypoint.s…"   6 seconds ago   Up 5 seconds             redis-node-5
7ae839c95a0c   redis:latest   "docker-entrypoint.s…"   6 seconds ago   Up 5 seconds             redis-node-4
87f841d136b9   redis:latest   "docker-entrypoint.s…"   6 seconds ago   Up 6 seconds             redis-node-3
98e605469e0e   redis:latest   "docker-entrypoint.s…"   6 seconds ago   Up 6 seconds             redis-node-2
69eec71b0835   redis:latest   "docker-entrypoint.s…"   7 seconds ago   Up 6 seconds             redis-node-1

配置主从

随便进入一个Redis容器（我们这里选择redis-node-2，其实都行），执行下面命令
- 下面的ip需要修改成Redis所在的服务器的ip。
- 如果需要输入内容，则输入：yes

docker exec -it redis-node-2 /bin/bash

redis-cli --cluster create 192.168.184.132:6381 192.168.184.132:6382 192.168.184.132:6383 192.168.184.132:6384 192.168.184.132:6385 192.168.184.132:6386 192.168.184.132:6387 192.168.184.132:6388 192.168.184.132:6389 --cluster-replicas 2

>>> Performing hash slots allocation on 9 nodes...
Master[0] -> Slots 0 - 5460
Master[1] -> Slots 5461 - 10922
Master[2] -> Slots 10923 - 16383
Adding replica 192.168.184.132:6385 to 192.168.184.132:6381
Adding replica 192.168.184.132:6386 to 192.168.184.132:6381
Adding replica 192.168.184.132:6387 to 192.168.184.132:6382
Adding replica 192.168.184.132:6388 to 192.168.184.132:6382
Adding replica 192.168.184.132:6389 to 192.168.184.132:6383
Adding replica 192.168.184.132:6384 to 192.168.184.132:6383
>>> Trying to optimize slaves allocation for anti-affinity
[WARNING] Some slaves are in the same host as their master
M: 888158ad30d9a173175b115974b9d1cc5b39736e 192.168.184.132:6381
   slots:[0-5460] (5461 slots) master
M: 1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e 192.168.184.132:6382
   slots:[5461-10922] (5462 slots) master
M: af28288480e3398b18402e4475c9ae52c39ea776 192.168.184.132:6383
   slots:[10923-16383] (5461 slots) master
S: a11993ddc7a726e3ad476858fb53bdc97d4834b8 192.168.184.132:6384
   replicates 1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e
S: c9d7f4ed642fa2fde013f2b060476b542b9af76e 192.168.184.132:6385
   replicates af28288480e3398b18402e4475c9ae52c39ea776
S: 29a79c9f9a007bf80fdfc2ffaaf1cf27d29396c2 192.168.184.132:6386
   replicates 888158ad30d9a173175b115974b9d1cc5b39736e
S: 5b20d04646f7f38eb57266b81749e565825ab6e5 192.168.184.132:6387
   replicates 1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e
S: 92d06bfb428a1358149c209c336152cae3304c66 192.168.184.132:6388
   replicates af28288480e3398b18402e4475c9ae52c39ea776
S: 9ef7a5bb156de64a969688eade8535399983dd00 192.168.184.132:6389
   replicates 888158ad30d9a173175b115974b9d1cc5b39736e
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 192.168.184.132:6381)
M: 888158ad30d9a173175b115974b9d1cc5b39736e 192.168.184.132:6381
   slots:[0-5460] (5461 slots) master
   2 additional replica(s)
S: 9ef7a5bb156de64a969688eade8535399983dd00 192.168.184.132:6389
   slots: (0 slots) slave
   replicates 888158ad30d9a173175b115974b9d1cc5b39736e
S: 92d06bfb428a1358149c209c336152cae3304c66 192.168.184.132:6388
   slots: (0 slots) slave
   replicates af28288480e3398b18402e4475c9ae52c39ea776
S: c9d7f4ed642fa2fde013f2b060476b542b9af76e 192.168.184.132:6385
   slots: (0 slots) slave
   replicates af28288480e3398b18402e4475c9ae52c39ea776
M: 1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e 192.168.184.132:6382
   slots:[5461-10922] (5462 slots) master
   2 additional replica(s)
S: a11993ddc7a726e3ad476858fb53bdc97d4834b8 192.168.184.132:6384
   slots: (0 slots) slave
   replicates 1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e
M: af28288480e3398b18402e4475c9ae52c39ea776 192.168.184.132:6383
   slots:[10923-16383] (5461 slots) master
   2 additional replica(s)
S: 29a79c9f9a007bf80fdfc2ffaaf1cf27d29396c2 192.168.184.132:6386
   slots: (0 slots) slave
   replicates 888158ad30d9a173175b115974b9d1cc5b39736e
S: 5b20d04646f7f38eb57266b81749e565825ab6e5 192.168.184.132:6387
   slots: (0 slots) slave
   replicates 1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e
[OK] All nodes agree about slots configuration.
>>> Check for open slots...
>>> Check slots coverage...
[OK] All 16384 slots covered.

–cluster-replicas 2：意味着Master和slave是以1比2的形式生成。
- Redis集群至少需要3个Master节点，意味着每个Master对应replicas为2个slave节点。
- 如果–cluster-replicas 1，那么就是说1个Master节点对应1个slave节点。

以集群的方式进入Redis客户端

只需要多加一个-c即表示集群方式进入客户端。
别忘了指定端口号。因为Redis默认是6379端口！！！！！

redis-cli -p 6381 -c

如果搭建了Redis集群，而不使用Redis集群的方式进入客户端会怎样？
上面说过，Redis集群是通过hash槽进行存储kv键值对数据的，这种情况下，当我们进入1号Redis节点进行set值，如果刚好这个set的key的hash值刚好分配到我们当前所在的1号节点，那么就可以插入成功。
如果这个key的hash值分配到其他节点比如2，3号这些节点，则会插入失败。因为这个连接没有用集群的方式进入客户端。
只有我们使用集群的方式进入客户端才能随意插入数据，否则只能看缘分插入！！！！！！！！

操作set命令

192.168.184.132:6381> set k1 v1
-> Redirected to slot [12706] located at 192.168.184.132:6383
OK
192.168.184.132:6383> set k2 v2
-> Redirected to slot [449] located at 192.168.184.132:6381
OK
192.168.184.132:6381> set k3 v3
OK
192.168.184.132:6381> get k1
-> Redirected to slot [12706] located at 192.168.184.132:6383
"v1"
192.168.184.132:6383> get k2
-> Redirected to slot [449] located at 192.168.184.132:6381
"v2"
192.168.184.132:6381> get k3
"v3"

可以看到Redis集群底层都是通过hash槽算法分区。

查看集群节点信息

redis-cli -p 6381 -c

192.168.184.132:6381> cluster nodes
9ef7a5bb156de64a969688eade8535399983dd00 192.168.184.132:6389@16389 slave 888158ad30d9a173175b115974b9d1cc5b39736e 0 1651761707000 1 connected
888158ad30d9a173175b115974b9d1cc5b39736e 192.168.184.132:6381@16381 myself,master - 0 1651761703000 1 connected 0-5460
92d06bfb428a1358149c209c336152cae3304c66 192.168.184.132:6388@16388 slave af28288480e3398b18402e4475c9ae52c39ea776 0 1651761706000 3 connected
c9d7f4ed642fa2fde013f2b060476b542b9af76e 192.168.184.132:6385@16385 slave af28288480e3398b18402e4475c9ae52c39ea776 0 1651761708298 3 connected
1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e 192.168.184.132:6382@16382 master - 0 1651761704000 2 connected 5461-10922
a11993ddc7a726e3ad476858fb53bdc97d4834b8 192.168.184.132:6384@16384 slave 1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e 0 1651761708000 2 connected
af28288480e3398b18402e4475c9ae52c39ea776 192.168.184.132:6383@16383 master - 0 1651761708000 3 connected 10923-16383
29a79c9f9a007bf80fdfc2ffaaf1cf27d29396c2 192.168.184.132:6386@16386 slave 888158ad30d9a173175b115974b9d1cc5b39736e 0 1651761710336 1 connected
5b20d04646f7f38eb57266b81749e565825ab6e5 192.168.184.132:6387@16387 slave 1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e 0 1651761709314 2 connected

查看集群状态

root@aubin:/data# redis-cli --cluster check 192.168.184.132:6381
192.168.184.132:6381 (888158ad...) -> 2 keys | 5461 slots | 2 slaves.
192.168.184.132:6382 (1ff5a2a1...) -> 0 keys | 5462 slots | 2 slaves.
192.168.184.132:6383 (af282884...) -> 1 keys | 5461 slots | 2 slaves.
[OK] 3 keys in 3 masters.
0.00 keys per slot on average.
>>> Performing Cluster Check (using node 192.168.184.132:6381)
M: 888158ad30d9a173175b115974b9d1cc5b39736e 192.168.184.132:6381
   slots:[0-5460] (5461 slots) master
   2 additional replica(s)
S: 9ef7a5bb156de64a969688eade8535399983dd00 192.168.184.132:6389
   slots: (0 slots) slave
   replicates 888158ad30d9a173175b115974b9d1cc5b39736e
S: 92d06bfb428a1358149c209c336152cae3304c66 192.168.184.132:6388
   slots: (0 slots) slave
   replicates af28288480e3398b18402e4475c9ae52c39ea776
S: c9d7f4ed642fa2fde013f2b060476b542b9af76e 192.168.184.132:6385
   slots: (0 slots) slave
   replicates af28288480e3398b18402e4475c9ae52c39ea776
M: 1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e 192.168.184.132:6382
   slots:[5461-10922] (5462 slots) master
   2 additional replica(s)
S: a11993ddc7a726e3ad476858fb53bdc97d4834b8 192.168.184.132:6384
   slots: (0 slots) slave
   replicates 1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e
M: af28288480e3398b18402e4475c9ae52c39ea776 192.168.184.132:6383
   slots:[10923-16383] (5461 slots) master
   2 additional replica(s)
S: 29a79c9f9a007bf80fdfc2ffaaf1cf27d29396c2 192.168.184.132:6386
   slots: (0 slots) slave
   replicates 888158ad30d9a173175b115974b9d1cc5b39736e
S: 5b20d04646f7f38eb57266b81749e565825ab6e5 192.168.184.132:6387
   slots: (0 slots) slave
   replicates 1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e
[OK] All nodes agree about slots configuration.
>>> Check for open slots...
>>> Check slots coverage...
[OK] All 16384 slots covered.

主从切换

我们可以看到6381、6382、6383是Master节点。

127.0.0.1:6382> CLUSTER NODES
29a79c9f9a007bf80fdfc2ffaaf1cf27d29396c2 192.168.184.132:6386@16386 slave 888158ad30d9a173175b115974b9d1cc5b39736e 0 1651766520602 1 connected
a11993ddc7a726e3ad476858fb53bdc97d4834b8 192.168.184.132:6384@16384 slave 1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e 0 1651766520000 2 connected
c9d7f4ed642fa2fde013f2b060476b542b9af76e 192.168.184.132:6385@16385 slave af28288480e3398b18402e4475c9ae52c39ea776 0 1651766521621 3 connected
9ef7a5bb156de64a969688eade8535399983dd00 192.168.184.132:6389@16389 slave 888158ad30d9a173175b115974b9d1cc5b39736e 0 1651766516521 1 connected
92d06bfb428a1358149c209c336152cae3304c66 192.168.184.132:6388@16388 slave af28288480e3398b18402e4475c9ae52c39ea776 0 1651766522638 3 connected
5b20d04646f7f38eb57266b81749e565825ab6e5 192.168.184.132:6387@16387 slave 1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e 0 1651766519000 2 connected
af28288480e3398b18402e4475c9ae52c39ea776 192.168.184.132:6383@16383 master - 0 1651766521000 3 connected 10923-16383
1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e 192.168.184.132:6382@16382 myself,master - 0 1651766519000 2 connected 5461-10922
888158ad30d9a173175b115974b9d1cc5b39736e 192.168.184.132:6381@16381 master - 0 1651766518571 1 connected 0-5460

可以看出6381的从节点是：6389、6386
把6381的容器实例给stop掉。

docker stop redis-node-1

先过一会，再次查看集群节点

192.168.184.132:6383> CLUSTER NODES
c9d7f4ed642fa2fde013f2b060476b542b9af76e 192.168.184.132:6385@16385 slave af28288480e3398b18402e4475c9ae52c39ea776 0 1651767445299 3 connected
9ef7a5bb156de64a969688eade8535399983dd00 192.168.184.132:6389@16389 slave 29a79c9f9a007bf80fdfc2ffaaf1cf27d29396c2 0 1651767443000 10 connected
888158ad30d9a173175b115974b9d1cc5b39736e 192.168.184.132:6381@16381 master,fail - 1651767320800 1651767314000 1 disconnected
1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e 192.168.184.132:6382@16382 master - 0 1651767444000 2 connected 5461-10922
29a79c9f9a007bf80fdfc2ffaaf1cf27d29396c2 192.168.184.132:6386@16386 master - 0 1651767444000 10 connected 0-5460
92d06bfb428a1358149c209c336152cae3304c66 192.168.184.132:6388@16388 slave af28288480e3398b18402e4475c9ae52c39ea776 0 1651767443000 3 connected
af28288480e3398b18402e4475c9ae52c39ea776 192.168.184.132:6383@16383 myself,master - 0 1651767443000 3 connected 10923-16383
5b20d04646f7f38eb57266b81749e565825ab6e5 192.168.184.132:6387@16387 slave 1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e 0 1651767444284 2 connected
a11993ddc7a726e3ad476858fb53bdc97d4834b8 192.168.184.132:6384@16384 slave 1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e 0 1651767446319 2 connected

我们可以看到以前6381的从节点6386变成了Master节点。说明已经进行主从切换了。

如果此时重新启动6381的容器

docker start redis-node-1

192.168.184.132:6383> CLUSTER NODES
c9d7f4ed642fa2fde013f2b060476b542b9af76e 192.168.184.132:6385@16385 slave af28288480e3398b18402e4475c9ae52c39ea776 0 1651767586000 3 connected
9ef7a5bb156de64a969688eade8535399983dd00 192.168.184.132:6389@16389 slave 29a79c9f9a007bf80fdfc2ffaaf1cf27d29396c2 0 1651767586183 10 connected
888158ad30d9a173175b115974b9d1cc5b39736e 192.168.184.132:6381@16381 slave 29a79c9f9a007bf80fdfc2ffaaf1cf27d29396c2 0 1651767582247 10 connected
1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e 192.168.184.132:6382@16382 master - 0 1651767586000 2 connected 5461-10922
29a79c9f9a007bf80fdfc2ffaaf1cf27d29396c2 192.168.184.132:6386@16386 master - 0 1651767588204 10 connected 0-5460
92d06bfb428a1358149c209c336152cae3304c66 192.168.184.132:6388@16388 slave af28288480e3398b18402e4475c9ae52c39ea776 0 1651767586000 3 connected
af28288480e3398b18402e4475c9ae52c39ea776 192.168.184.132:6383@16383 myself,master - 0 1651767587000 3 connected 10923-16383
5b20d04646f7f38eb57266b81749e565825ab6e5 192.168.184.132:6387@16387 slave 1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e 0 1651767585000 2 connected
a11993ddc7a726e3ad476858fb53bdc97d4834b8 192.168.184.132:6384@16384 slave 1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e 0 1651767587192 2 connected

我们可以看到6381变成了从节点（slave），主节点（Master）是6386。

主从扩容

启动三个Redis容器实例，分别为6390、6391、6392
目的是配置6390为Master节点加入集群，6391和6392为6390的Slave节点

docker run -d \
--name redis-node-10 \
--net host \
--privileged=true \
-v /data/redis/share/redis-node-10:/data \
 redis:latest \
--cluster-enabled yes \
--appendonly yes \
--port 6390

docker run -d \
--name redis-node-11 \
--net host \
--privileged=true \
-v /data/redis/share/redis-node-11:/data \
 redis:latest \
--cluster-enabled yes \
--appendonly yes \
--port 6391

docker run -d \
--name redis-node-12 \
--net host \
--privileged=true \
-v /data/redis/share/redis-node-12:/data \
 redis:latest \
--cluster-enabled yes \
--appendonly yes \
--port 6392

查看docker实例是否全部启动

[root@aubin ~]# docker ps
CONTAINER ID   IMAGE          COMMAND                  CREATED          STATUS          PORTS     NAMES
2d51b83798fc   redis:latest   "docker-entrypoint.s…"   7 seconds ago    Up 6 seconds              redis-node-12
7155d53bda8f   redis:latest   "docker-entrypoint.s…"   8 seconds ago    Up 7 seconds              redis-node-11
80f3006ff904   redis:latest   "docker-entrypoint.s…"   8 seconds ago    Up 7 seconds              redis-node-10
79af920ed704   redis:latest   "docker-entrypoint.s…"   13 seconds ago   Up 12 seconds             redis-node-9
8476f6db25f1   redis:latest   "docker-entrypoint.s…"   14 seconds ago   Up 13 seconds             redis-node-8
dbcee539c3d4   redis:latest   "docker-entrypoint.s…"   14 seconds ago   Up 13 seconds             redis-node-7
3883016c4225   redis:latest   "docker-entrypoint.s…"   14 seconds ago   Up 13 seconds             redis-node-6
073b551c8366   redis:latest   "docker-entrypoint.s…"   14 seconds ago   Up 14 seconds             redis-node-5
0114f11f42ae   redis:latest   "docker-entrypoint.s…"   14 seconds ago   Up 14 seconds             redis-node-4
bd9b8fd9aa8b   redis:latest   "docker-entrypoint.s…"   15 seconds ago   Up 14 seconds             redis-node-3
f1e90ded9cb3   redis:latest   "docker-entrypoint.s…"   15 seconds ago   Up 14 seconds             redis-node-2
f9c61333faae   redis:latest   "docker-entrypoint.s…"   15 seconds ago   Up 15 seconds             redis-node-1

docker exec -it redis-node-10 /bin/bash

首先将主节点6390（Master）添加进集群中。
192.168.184.132:6390：是你想要加入的Redis节点ip+端口号
192.168.184.132:6383：随便一个集群中的Master节点的ip+端口（这个Master代表着整个集群，必须得是Master节点）

redis-cli --cluster add-node 192.168.184.132:6390 192.168.184.132:6383

检查一下集群

root@aubin:/data# redis-cli --cluster check 192.168.184.132:6383
192.168.184.132:6383 (af282884...) -> 2 keys | 5461 slots | 2 slaves.
192.168.184.132:6382 (1ff5a2a1...) -> 0 keys | 5462 slots | 2 slaves.
192.168.184.132:6386 (29a79c9f...) -> 3 keys | 5461 slots | 2 slaves.
192.168.184.132:6390 (a25da2e5...) -> 0 keys | 0 slots | 0 slaves.
[OK] 5 keys in 4 masters.
0.00 keys per slot on average.
>>> Performing Cluster Check (using node 192.168.184.132:6383)
M: af28288480e3398b18402e4475c9ae52c39ea776 192.168.184.132:6383
   slots:[10923-16383] (5461 slots) master
   2 additional replica(s)
S: a11993ddc7a726e3ad476858fb53bdc97d4834b8 192.168.184.132:6384
   slots: (0 slots) slave
   replicates 1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e
S: 888158ad30d9a173175b115974b9d1cc5b39736e 192.168.184.132:6381
   slots: (0 slots) slave
   replicates 29a79c9f9a007bf80fdfc2ffaaf1cf27d29396c2
S: 5b20d04646f7f38eb57266b81749e565825ab6e5 192.168.184.132:6387
   slots: (0 slots) slave
   replicates 1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e
S: c9d7f4ed642fa2fde013f2b060476b542b9af76e 192.168.184.132:6385
   slots: (0 slots) slave
   replicates af28288480e3398b18402e4475c9ae52c39ea776
S: 92d06bfb428a1358149c209c336152cae3304c66 192.168.184.132:6388
   slots: (0 slots) slave
   replicates af28288480e3398b18402e4475c9ae52c39ea776
M: 1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e 192.168.184.132:6382
   slots:[5461-10922] (5462 slots) master
   2 additional replica(s)
M: 29a79c9f9a007bf80fdfc2ffaaf1cf27d29396c2 192.168.184.132:6386
   slots:[0-5460] (5461 slots) master
   2 additional replica(s)
S: 9ef7a5bb156de64a969688eade8535399983dd00 192.168.184.132:6389
   slots: (0 slots) slave
   replicates 29a79c9f9a007bf80fdfc2ffaaf1cf27d29396c2
M: a25da2e5be0487b3109b23e807b2d4c9c23e5a1a 192.168.184.132:6390
   slots: (0 slots) master
[OK] All nodes agree about slots configuration.
>>> Check for open slots...
>>> Check slots coverage...
[OK] All 16384 slots covered.

发现6390已经成功加入到集群，并且是Master节点，但是没有被分配槽位，slots为0。需要分配槽位才有用

重新分配槽位，下面的6386也是Master节点，哪个Master节点都行

redis-cli --cluster reshard 192.168.184.132:6386

提示：How many slots do you want to move (from 1 to 16384)?

因为我们是4个Master节点，所以是16384/4=4096，所以输入：4096
再输入新加入的6390Master节点的容器id，输入：a25da2e5be0487b3109b23e807b2d4c9c23e5a1a
再输入：all ，回车
输入：yes
检查一下集群：

root@aubin:/data# redis-cli --cluster check 192.168.184.132:6390
192.168.184.132:6390 (a25da2e5...) -> 1 keys | 4096 slots | 1 slaves.
192.168.184.132:6386 (29a79c9f...) -> 2 keys | 4096 slots | 2 slaves.
192.168.184.132:6382 (1ff5a2a1...) -> 0 keys | 4096 slots | 1 slaves.
192.168.184.132:6383 (af282884...) -> 2 keys | 4096 slots | 2 slaves.
[OK] 5 keys in 4 masters.
0.00 keys per slot on average.
>>> Performing Cluster Check (using node 192.168.184.132:6390)
M: a25da2e5be0487b3109b23e807b2d4c9c23e5a1a 192.168.184.132:6390
   slots:[0-1364],[5461-6826],[10923-12287] (4096 slots) master
   1 additional replica(s)
M: 29a79c9f9a007bf80fdfc2ffaaf1cf27d29396c2 192.168.184.132:6386
   slots:[1365-5460] (4096 slots) master
   2 additional replica(s)
S: 92d06bfb428a1358149c209c336152cae3304c66 192.168.184.132:6388
   slots: (0 slots) slave
   replicates af28288480e3398b18402e4475c9ae52c39ea776
M: 1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e 192.168.184.132:6382
   slots:[6827-10922] (4096 slots) master
   1 additional replica(s)
M: af28288480e3398b18402e4475c9ae52c39ea776 192.168.184.132:6383
   slots:[12288-16383] (4096 slots) master
   2 additional replica(s)
S: c9d7f4ed642fa2fde013f2b060476b542b9af76e 192.168.184.132:6385
   slots: (0 slots) slave
   replicates af28288480e3398b18402e4475c9ae52c39ea776
S: 5b20d04646f7f38eb57266b81749e565825ab6e5 192.168.184.132:6387
   slots: (0 slots) slave
   replicates a25da2e5be0487b3109b23e807b2d4c9c23e5a1a
S: 888158ad30d9a173175b115974b9d1cc5b39736e 192.168.184.132:6381
   slots: (0 slots) slave
   replicates 29a79c9f9a007bf80fdfc2ffaaf1cf27d29396c2
S: a11993ddc7a726e3ad476858fb53bdc97d4834b8 192.168.184.132:6384
   slots: (0 slots) slave
   replicates 1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e
S: 9ef7a5bb156de64a969688eade8535399983dd00 192.168.184.132:6389
   slots: (0 slots) slave
   replicates 29a79c9f9a007bf80fdfc2ffaaf1cf27d29396c2
[OK] All nodes agree about slots configuration.
>>> Check for open slots...
>>> Check slots coverage...
[OK] All 16384 slots covered.

搞定，扩容成功。
添加6390的从节点（6391和6392）
xxxxx1和xxxxx2替换成：6390（也就是想加入的Master节点）的id

redis-cli --cluster add-node 192.168.184.132:6391 192.168.184.132:6390 --cluster-slave --cluster-master-id xxxxx1

#比如添加6391
redis-cli --cluster add-node 192.168.184.132:6391 192.168.184.132:6390 --cluster-slave --cluster-master-id a25da2e5be0487b3109b23e807b2d4c9c23e5a1a

-----------------------------

redis-cli --cluster add-node 192.168.184.132:6392 192.168.184.132:6390 --cluster-slave --cluster-master-id xxxxx2

#比如添加6392
redis-cli --cluster add-node 192.168.184.132:6392 192.168.184.132:6390 --cluster-slave --cluster-master-id a25da2e5be0487b3109b23e807b2d4c9c23e5a1a

再次检查集群

root@aubin:/data# redis-cli --cluster check 192.168.184.132:6390
192.168.184.132:6390 (a25da2e5...) -> 1 keys | 4096 slots | 3 slaves.
192.168.184.132:6386 (29a79c9f...) -> 2 keys | 4096 slots | 2 slaves.
192.168.184.132:6382 (1ff5a2a1...) -> 0 keys | 4096 slots | 1 slaves.
192.168.184.132:6383 (af282884...) -> 2 keys | 4096 slots | 2 slaves.
[OK] 5 keys in 4 masters.
0.00 keys per slot on average.
>>> Performing Cluster Check (using node 192.168.184.132:6390)
M: a25da2e5be0487b3109b23e807b2d4c9c23e5a1a 192.168.184.132:6390
   slots:[0-1364],[5461-6826],[10923-12287] (4096 slots) master
   3 additional replica(s)
S: 5f34c1cd5a35e1195522695143941d044f1cdb96 192.168.184.132:6392
   slots: (0 slots) slave
   replicates a25da2e5be0487b3109b23e807b2d4c9c23e5a1a
M: 29a79c9f9a007bf80fdfc2ffaaf1cf27d29396c2 192.168.184.132:6386
   slots:[1365-5460] (4096 slots) master
   2 additional replica(s)
S: a86979e7ff21ca39bad8da1ce63c551f2598c779 192.168.184.132:6391
   slots: (0 slots) slave
   replicates a25da2e5be0487b3109b23e807b2d4c9c23e5a1a
S: 92d06bfb428a1358149c209c336152cae3304c66 192.168.184.132:6388
   slots: (0 slots) slave
   replicates af28288480e3398b18402e4475c9ae52c39ea776
M: 1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e 192.168.184.132:6382
   slots:[6827-10922] (4096 slots) master
   1 additional replica(s)
M: af28288480e3398b18402e4475c9ae52c39ea776 192.168.184.132:6383
   slots:[12288-16383] (4096 slots) master
   2 additional replica(s)
S: c9d7f4ed642fa2fde013f2b060476b542b9af76e 192.168.184.132:6385
   slots: (0 slots) slave
   replicates af28288480e3398b18402e4475c9ae52c39ea776
S: 5b20d04646f7f38eb57266b81749e565825ab6e5 192.168.184.132:6387
   slots: (0 slots) slave
   replicates a25da2e5be0487b3109b23e807b2d4c9c23e5a1a
S: 888158ad30d9a173175b115974b9d1cc5b39736e 192.168.184.132:6381
   slots: (0 slots) slave
   replicates 29a79c9f9a007bf80fdfc2ffaaf1cf27d29396c2
S: a11993ddc7a726e3ad476858fb53bdc97d4834b8 192.168.184.132:6384
   slots: (0 slots) slave
   replicates 1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e
S: 9ef7a5bb156de64a969688eade8535399983dd00 192.168.184.132:6389
   slots: (0 slots) slave
   replicates 29a79c9f9a007bf80fdfc2ffaaf1cf27d29396c2
[OK] All nodes agree about slots configuration.
>>> Check for open slots...
>>> Check slots coverage...
[OK] All 16384 slots covered.

主从缩容

目的是移除6390（Master）和6391、6392（Slave）。
删除从节点6391。xxx1替换成：6391的容器id

redis-cli --cluster del-node 192.168.184.132:6391 xxx1

#比如删除从节点6391
root@aubin:/data# redis-cli --cluster del-node 192.168.184.132:6391 a86979e7ff21ca39bad8da1ce63c551f2598c779
>>> Removing node a86979e7ff21ca39bad8da1ce63c551f2598c779 from cluster 192.168.184.132:6391
>>> Sending CLUSTER FORGET messages to the cluster...
>>> Sending CLUSTER RESET SOFT to the deleted node.

删除从节点6392。xxx2替换成：6392的容器id

redis-cli --cluster del-node 192.168.184.132:6392 xxx2

#比如删除从节点6392
root@aubin:/data# redis-cli --cluster del-node 192.168.184.132:6392 5f34c1cd5a35e1195522695143941d044f1cdb96
>>> Removing node 5f34c1cd5a35e1195522695143941d044f1cdb96 from cluster 192.168.184.132:6392
>>> Sending CLUSTER FORGET messages to the cluster...
>>> Sending CLUSTER RESET SOFT to the deleted node.

删除Master节点6390之前，必须先把槽位给其他Master节点。
- xxxxxx1：随便一个Master节点，我们这里指定6386

redis-cli --cluster reshard xxxxxx1

#比如
redis-cli --cluster reshard 192.168.184.132:6386

输入删除的槽位数：因为6390的槽位是4096个，所以输入：4096
再输入谁来接收这些残留下来的槽位的容器id，我们这里把4096个都给6383，所以输入6383的容器id：af28288480e3398b18402e4475c9ae52c39ea776（哪个Master节点都行）
再输入删除的这个Master节点的id，也就是6390的容器id：a25da2e5be0487b3109b23e807b2d4c9c23e5a1a
再输入：done
再输入：yes

此时6390的槽位已经全部给了6383，这个时候可以删除6390节点了。xxx1为6390的容器id

redis-cli --cluster del-node 192.168.184.132:6390 xxx1

#比如
redis-cli --cluster del-node 192.168.184.132:6390 a25da2e5be0487b3109b23e807b2d4c9c23e5a1a

再次检查一下集群

root@aubin:/data# redis-cli --cluster check 192.168.184.132:6383
192.168.184.132:6383 (af282884...) -> 3 keys | 8192 slots | 3 slaves.
192.168.184.132:6382 (1ff5a2a1...) -> 0 keys | 4096 slots | 1 slaves.
192.168.184.132:6386 (29a79c9f...) -> 2 keys | 4096 slots | 2 slaves.
[OK] 5 keys in 3 masters.
0.00 keys per slot on average.
>>> Performing Cluster Check (using node 192.168.184.132:6383)
M: af28288480e3398b18402e4475c9ae52c39ea776 192.168.184.132:6383
   slots:[0-1364],[5461-6826],[10923-16383] (8192 slots) master
   3 additional replica(s)
S: a11993ddc7a726e3ad476858fb53bdc97d4834b8 192.168.184.132:6384
   slots: (0 slots) slave
   replicates 1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e
S: 888158ad30d9a173175b115974b9d1cc5b39736e 192.168.184.132:6381
   slots: (0 slots) slave
   replicates 29a79c9f9a007bf80fdfc2ffaaf1cf27d29396c2
S: 5b20d04646f7f38eb57266b81749e565825ab6e5 192.168.184.132:6387
   slots: (0 slots) slave
   replicates af28288480e3398b18402e4475c9ae52c39ea776
S: c9d7f4ed642fa2fde013f2b060476b542b9af76e 192.168.184.132:6385
   slots: (0 slots) slave
   replicates af28288480e3398b18402e4475c9ae52c39ea776
S: 92d06bfb428a1358149c209c336152cae3304c66 192.168.184.132:6388
   slots: (0 slots) slave
   replicates af28288480e3398b18402e4475c9ae52c39ea776
M: 1ff5a2a15526e3d7984b231cf7e47f8f442e4a9e 192.168.184.132:6382
   slots:[6827-10922] (4096 slots) master
   1 additional replica(s)
M: 29a79c9f9a007bf80fdfc2ffaaf1cf27d29396c2 192.168.184.132:6386
   slots:[1365-5460] (4096 slots) master
   2 additional replica(s)
S: 9ef7a5bb156de64a969688eade8535399983dd00 192.168.184.132:6389
   slots: (0 slots) slave
   replicates 29a79c9f9a007bf80fdfc2ffaaf1cf27d29396c2
[OK] All nodes agree about slots configuration.
>>> Check for open slots...
>>> Check slots coverage...
[OK] All 16384 slots covered.