Docker进阶：mysql 主从复制、redis集群3主3从【扩缩容案例】
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首先，确保你已经安装了Docker。
1.1 docker 安装 tomcat（默认最新版）
1、创建一个目录用于存放程序文件。mkdir -p /home/my-projects2、在终端或命令行界面中执行以下命令来拉取Tomcat的Docker镜像：[root@zyl-server ~]# docker pull tomcat3、查看Docker中已下载的Tomcat镜像[root@zyl-server ~]# docker images tomcatREPOSITORY TAG IMAGE ID CREATED SIZEtomcat latest fb5657adc892 20 months ago 680MBtomcat 8.0 ef6a7c98d192 4 years ago 356MB[root@zyl-server ~]#4、下载完成后，通过以下命令启动Tomcat容器，将宿主机的8080端口映射到容器的8080端口：[root@zyl-server ~]# docker run -d -p 8080:8080 -v /home/my-projects:/usr/local/tomcat/webapps --privileged=true --name my-tomcat tomcat8419cf96aaa10b2b3590e12d7d0973343dd9ab18a066be96c07e9bfa0875f632[root@zyl-server ~]#参数说明：-p 小写 主机端口：容器端口-P 大写 随机分配端口--name my-tomcat 指定容器的名称为my-tomcat-it 交互式模式运行-d 后台运行-v /home/my-projects:/usr/local/tomcat/webapps：将宿主机当前目录下的/home/my-projects目录挂载到容器中Tomcat的webapps目录，以便可以在宿主机上访问到Tomcat中部署的应用程序。5、查看正在运行的Docker容器列表，该命令将列出当前正在运行的容器的详细信息，包括容器ID、镜像名称、创建时间、状态等。如果希望查看所有包括已停止的容器，可以添加 -a 参数，即 docker ps -a[root@zyl-server ~]# docker psCONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES8419cf96aaa1 tomcat "catalina.sh run" 16 seconds ago Up 15 seconds 0.0.0.0:8080->8080/tcp, :::8080->8080/tcp my-tomcat[root@zyl-server ~]#6、进入tomcat容器的命令行界面（拷贝webapps.dist下的文件到webapps---因为镜像是精简版的）[root@zyl-server ~]# docker exec -it 8419cf96aaa1 /bin/bashroot@8419cf96aaa1:/usr/local/tomcat# cp -r webapps.dist/* webapps/root@8419cf96aaa1:/usr/local/tomcat# lsBUILDING.txt LICENSE README.md RUNNING.txt conf logs temp webapps.distCONTRIBUTING.md NOTICE RELEASE-NOTES bin lib native-jni-lib webapps workroot@8419cf96aaa1:/usr/local/tomcat# cd webappsroot@8419cf96aaa1:/usr/local/tomcat/webapps# lsROOT docs examples host-manager index.html managerroot@8419cf96aaa1:/usr/local/tomcat/webapps#7、容器启动后，你可以通过在浏览器中访问 http://ip:8080 来验证Tomcat是否成功安装。如果一切正常，你将看到Tomcat的欢迎页面。[root@zyl-server home]# curl http://localhost:8080<!DOCTYPE html><html lang="en"> <head> <meta charset="UTF-8" /> <title>Apache Tomcat/10.0.14</title> <link href="favicon.ico" rel="icon" type="image/x-icon" /> <link href="tomcat.css" rel="stylesheet" type="text/css" /> </head>。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。
8、发布项目只需在宿主机的/home/my-projects，配置即可，如：[root@zyl-server my-projects]# mkdir myweb[root@zyl-server my-projects]# cd myweb/[root@zyl-server myweb]# vi index.html[root@zyl-server myweb]#写入内容：<!DOCTYPE html><html><head><meta charset="utf-8"></head><body><h1>醉颜凉的第一个web项目。</h1><p>Hello Apache Tomcat/10.0.14</p></body></html>
1.2 docker 指定安装 tomcat8.0
要下载特定版本的Tomcat镜像，可以在 docker pull 命令后面添加
1、指定pull tomcat8.0，下载Tomcat 8.0版本的镜像[root@zyl-server ~]# docker pull tomcat:8.02、基于 Tomcat 8.0 版本的镜像启动一个容器，并将容器的 8080 端口映射到主机的 8081 端口上。[root@zyl-server myweb]# docker run -d -p 8081:8080 --name tomcat tomcat:8.0f71f3050a4af5fe02587a4f8f61c8af1e5d254be4ad9b1ae98309c7b46e61be4[root@zyl-server myweb]#解释：-d 参数表示以后台模式运行容器。-p 8081:8080 参数表示将容器的 8080 端口映射到主机的 8081 端口。这样，当你在浏览器中访问 http://localhost:8081 时，将会被转发到容器中的 Tomcat 服务器。--name tomcat 参数指定容器的名称为 "tomcat"。
1.3 docker 安装 mysql 5.7（数据卷配置）
1、拉取 MySQL 5.7 镜像：docker pull mysql:5.72、在启动容器之前，创建一个目录来持久化 MySQL 数据（）。使用以下命令创建一个目录，用于存储数据库文件：创建一个目录作为 Docker 数据卷并将其挂载到 MySQL 容器中，可以确保 MySQL 数据在容器被删除或重启后仍然存在。[root@zyl-server ~]# mkdir -p /mysql/data[root@zyl-server ~]#3、使用以下命令启动 MySQL 5.7 容器：docker run -d -p 3306:3306 --name mysql-5.7 -e MYSQL_ROOT_PASSWORD=123456 -v /mysql/data:/var/lib/mysql mysql:5.74、查看正在运行的Docker容器列表：[root@zyl-server ~]# docker run -d -p 3306:3306 --name mysql-5.7 -e MYSQL_ROOT_PASSWORD=123456 -v /mysql/data:/var/lib/mysql -v /mysql/log:/var/log/mysql -v /mysql/conf:/etc/mysql/conf.d mysql:5.7ddba7f4cf1f89ea7627a3c3628d7479c31bfdb7d0b0dd82e78cb50ce5b4726d8[root@zyl-server ~]#[root@zyl-server ~]# docker psCONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMESddba7f4cf1f8 mysql:5.7 "docker-entrypoint.s…" 22 seconds ago Up 21 seconds 0.0.0.0:3306->3306/tcp, :::3306->3306/tcp, 33060/tcp mysql-5.7f71f3050a4af tomcat:8.0 "catalina.sh run" 36 minutes ago Up 36 minutes 0.0.0.0:8081->8080/tcp, :::8081->8080/tcp tomcat8419cf96aaa1 tomcat "catalina.sh run" 48 minutes ago Up 48 minutes 0.0.0.0:8080->8080/tcp, :::8080->8080/tcp my-tomcat[root@zyl-server ~]#5、进入mysql-5.7容器：docker exec -it ddba7f4cf1f8 /bin/bash6、以 root 用户身份登录到 MySQL 数据库（密码 123456 访问 MySQL 服务）：root@db84734dad6a:/# mysql -u root -pEnter password: //（123456）Welcome to the MySQL monitor. Commands end with ; or \g.Your MySQL connection id is 2Server version: 5.7.36 MySQL Community Server (GPL)Copyright (c) 2000, 2021, Oracle and/or its affiliates.Oracle is a registered trademark of Oracle Corporation and/or itsaffiliates. Other names may be trademarks of their respectiveowners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.mysql>7、例如，创建一个名为 "mydatabase" 的数据库：CREATE DATABASE mydatabase;8、使用 USE 命令切换到所需的数据库：USE mydatabase;9、例如，创建一个名为 "users" 的表，包含 id、name 和 email 列：CREATE TABLE users ( id INT, name VARCHAR(50), email VARCHAR(100));10、使用 INSERT INTO 语句。向 "users" 表插入三条数据：INSERT INTO users (id, name, email) VALUES (1, 'John', 'john@example.com'), (2, 'Jane', 'jane@example.com'), (3, 'Tom', 'tom@example.com');11、本地使用数据库管理工具远程连接：
解决插入中文报错：
INSERT INTO users (id, name, email) VALUES (4, '张三', 'zhangsan@example.com');1、查看数据库的编码方式SHOW VARIABLES LIKE 'character_set_database';SHOW VARIABLES LIKE 'character%';
2、修改数据库的字符集：[root@zyl-server ~]# cd /mysql/conf[root@zyl-server conf]# pwd/mysql/conf[root@zyl-server conf]#vi my.cnf，写入下面内容,my.cnf 为前面挂载的数据卷：[client]default_character_set=utf8[mysqld]collation_server=utf8_general_cicharacter_set_server=utf83、修改前面创建的数据库、表的字符集：ALTER DATABASE mydatabase CHARACTER SET utf8;ALTER TABLE users CONVERT TO CHARACTER SET utf8;3、重新启动mysql容器[root@zyl-server conf]# docker restart mysql-5.7mysql-5.7[root@zyl-server conf]#4、再次查看数据库编码方式：mysql> SHOW VARIABLES LIKE 'character%';+--------------------------+----------------------------+| Variable_name | Value |+--------------------------+----------------------------+| character_set_client | utf8 || character_set_connection | utf8 || character_set_database | utf8 || character_set_filesystem | binary || character_set_results | utf8 || character_set_server | utf8 || character_set_system | utf8 || character_sets_dir | /usr/share/mysql/charsets/ |+--------------------------+----------------------------+8 rows in set (0.00 sec)mysql>
5、插入数据测试INSERT INTO users (id, name, email) VALUES (4, '张三', 'zhangsan@example.com');
总结： docker安装完mysql，运行实例之后，建议先修改完字符集编码后再建库建表。
在创建 MySQL 数据库和表之前，先确保 MySQL 的字符集编码设置是正确的。如果你没有设置正确的字符集编码，就可能会在处理文本数据时出现乱码等问题，影响数据的完整性和可读性。
1.4 演示–删除mysql容器，里面的数据是否能正常恢复
[root@zyl-server ~]# docker psCONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMESddba7f4cf1f8 mysql:5.7 "docker-entrypoint.s…" 27 minutes ago Up 20 minutes 0.0.0.0:3306->3306/tcp, :::3306->3306/tcp, 33060/tcp mysql-5.7[root@zyl-server ~]#1、删除刚创建 MySQL 容器（线上环境慎用） docker rm -f mysql-5.7[root@zyl-server ~]# docker rm -f mysql-5.7mysql-5.7[root@zyl-server ~]#2、重新启动MySQL 容器[root@zyl-server ~]# docker run -d -p 3306:3306 --name mysql-5.7 -e MYSQL_ROOT_PASSWORD=123456 -v /mysql/data:/var/lib/mysql -v /mysql/log:/var/log/mysql -v /mysql/conf:/etc/mysql/conf.d mysql:5.70f129eb516f74872334f3c46b9b57b0808de2441bfd0db3a54c564aca838ddff[root@zyl-server ~]#[root@zyl-server ~]# docker psCONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES0f129eb516f7 mysql:5.7 "docker-entrypoint.s…" 5 seconds ago Up 3 seconds 0.0.0.0:3306->3306/tcp, :::3306->3306/tcp, 33060/tcp mysql-5.7[root@zyl-server ~]#3、进入重新启动的MySQL 容器docker exec -it mysql-5.7 /bin/bash或者docker exec -it 0f129eb516f7 /bin/bash4、验证，刚才创建的mydatabase库和users表数据[root@zyl-server ~]# docker exec -it mysql-5.7 /bin/bashroot@0f129eb516f7:/# mysql -u root -pEnter password:Welcome to the MySQL monitor. Commands end with ; or \g.Your MySQL connection id is 2Server version: 5.7.36 MySQL Community Server (GPL)Copyright (c) 2000, 2021, Oracle and/or its affiliates.Oracle is a registered trademark of Oracle Corporation and/or itsaffiliates. Other names may be trademarks of their respectiveowners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.mysql> show databases;+--------------------+| Database |+--------------------+| information_schema || mydatabase || mysql || performance_schema || sys |+--------------------+5 rows in set (0.00 sec)mysql>mysql> use mydatabase;Database changedmysql> select * from users;+------+--------+----------------------+| id | name | email |+------+--------+----------------------+| 1 | John | john@example.com || 2 | Jane | jane@example.com || 3 | Tom | tom@example.com || 4 | 张三 | zhangsan@example.com |+------+--------+----------------------+4 rows in set (0.00 sec)mysql>
总结：使用 Docker 数据卷的方法来进行存储。保留 MySQL 数据库和表的持久化数据。容器实例删除，里面的数据在重启启动容器实例之后也能正常恢复
1.5 docker 安装 redis7.0.9 （数据卷配置）
1、宿主机下/下创建 /apps/redis 目录[root@zyl-server /]# mkdir -p /apps/redis2、在/apps/redis 目录，创建redis.conf文件3、修改redis.conf文件## 开启redis验证，添加该行（可选）requirepass 123456## 允许redis远程连接，注释# bind 127.0.0.1# bind 127.0.0.1## 将 daemonize yes 改为 daemonize no因为该配置和docker run -d 参数冲突，会导致容器启动一直失败## 开启redis 数据持久化 appendonly yes （可选）appendonly yes1、运行以下命令来下载并运行 Redis7.0.9 的 Docker 镜像：docker run -d -p 6379:6379 --privileged=true --name my-redis -v /apps/redis/redis.conf:/etc/redis/redis.conf -v /apps/redis/data:/data -d redis:7.0.9 redis-server /etc/redis/redis.conf这个命令将以后台方式运行Redis容器，并进行以下配置：开放主机的6379端口并将其映射到容器的6379端口。启用特权模式，以便在容器内部执行一些特殊操作（如修改文件权限）。将容器的名称设置为my-redis。将主机上的/apps/redis/redis.conf文件挂载到容器内的/etc/redis/redis.conf文件，以应用自定义的Redis配置。将主机上的/apps/redis/data目录挂载到容器内的/data目录，以作为Redis数据的持久化存储。2、检查容器的运行状态：[root@zyl-server redis]# docker psCONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES6293c1f5fc5e redis:7.0.9 "docker-entrypoint.s…" About a minute ago Up About a minute 0.0.0.0:6379->6379/tcp, :::6379->6379/tcp my-redis3、在 my-redis容器中打开交互式终端docker exec -it my-redis /bin/bash4、连接到Redis服务器：[root@zyl-server redis.conf]# docker exec -it my-redis /bin/bashroot@508d58462ff3:/data# redis-cli或者使用docker exec -it my-redis redis-cli在Docker容器中打开一个交互式终端，并直接进入Redis客户端。127.0.0.1:6379> set k1 v1(error) NOAUTH Authentication required.127.0.0.1:6379>这是因为redis设置了密码，我们需要使用密码来进行验证之后再来对redis客户端进行操作，否则我们没有操作redis缓存数据库的权限。解决方法----> 我们使用命令：auth '123456'127.0.0.1:6379> auth '123456'OK127.0.0.1:6379> set k1 v1OK127.0.0.1:6379> get k1"v1"127.0.0.1:6379>1.6 宿主机修改redis.conf配置文件，验证redis 容器内生效
在Redis的配置文件redis.conf中，可以设置参数databases来指定Redis服务器的数据库数量。
默认情况下，Redis服务器的数据库数量为16，这意味着你可以在一个Redis实例中创建最多16个不同的数据库。每个数据库都是独立的，并且可以使用SELECT命令进行切换。
1、redis.conf 服务器的数据库数量databases 162、使用SELECT命令切换到指定的数据库。在命令行中输入的SELECT 18表示要切换到数据库18127.0.0.1:6379> select 18(error) ERR DB index is out of range127.0.0.1:6379>3、修改宿主机redis.conf,保存databases 204、重启 my-redis 容器docker restart my-redis5、验证[root@zyl-server redis.conf]# docker exec -it my-redis redis-cli127.0.0.1:6379> auth '123456'OK127.0.0.1:6379> select 18OK127.0.0.1:6379[18]>----结论---------修改宿主机redis.conf,容器内生效。。2.1 启动主节点容器mysql-master（3306）
1、启动主节点容器mysql-master：docker run -p 3306:3306 --name mysql-master \-v /mydata/mysql-master/log:/var/log/mysql \-v /mydata/mysql-master/data:/var/lib/mysql \-v /mydata/mysql-master/conf:/etc/mysql \-e MYSQL_ROOT_PASSWORD=123456 \-d mysql:5.7以后台模式运行MySQL 5.7容器作为主节点：各个选项的含义：-p 3306:3306：将主机的3306端口映射到容器的3306端口，这样可以从主机上访问MySQL服务。--name mysql-master：给容器指定一个名称为"mysql-master"。-v /mydata/mysql-master/log:/var/log/mysql：将主机上的"/mydata/mysql-master/log"目录挂载到容器中的"/var/log/mysql"目录，用于持久化存储MySQL的日志文件。-v /mydata/mysql-master/data:/var/lib/mysql：将主机上的"/mydata/mysql-master/data"目录挂载到容器中的"/var/lib/mysql"目录，用于持久化存储MySQL的数据文件。-v /mydata/mysql-master/conf:/etc/mysql：将主机上的"/mydata/mysql-master/conf"目录挂载到容器中的"/etc/mysql"目录，用于持久化存储MySQL的配置文件。-e MYSQL_ROOT_PASSWORD=123456：设置MySQL的root用户密码为"123456"。-d mysql:5.7：使用MySQL 5.7镜像启动一个后台运行的容器。2、列出正在运行的Docker容器：[root@zyl-server ~]# docker psCONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES5ea683a60e95 mysql:5.7 "docker-entrypoint.s…" 5 seconds ago Up 4 seconds 0.0.0.0:3306->3306/tcp, :::3306->3306/tcp, 33060/tcp mysql-master[root@zyl-server ~]#3、cd /mydata/mysql-master/conf目录新建my.cnf文件vi my.cnf[mysqld]## 设置server_id，同一局域网中需要唯一server_id=101## 指定不需要同步的数据库名称binlog-ignore-db=mysql ## 开启二进制日志功能log-bin=mall-mysql-bin ## 设置二进制日志使用内存大小（事务）binlog_cache_size=1M ## 设置使用的二进制日志格式（mixed,statement,row）binlog_format=mixed ## 二进制日志过期清理时间。默认值为0，表示不自动清理。expire_logs_days=7 ## 跳过主从复制中遇到的所有错误或指定类型的错误，避免slave端复制中断。## 如：1062错误是指一些主键重复，1032错误是因为主从数据库数据不一致slave_skip_errors=1062##将MySQL容器的字符集和排序规则设置为UTF-8编码collation_server=utf8_general_cicharacter_set_server=utf84、修改后，重启mysql-master容器实例[root@zyl-server conf]# docker restart mysql-mastermysql-master[root@zyl-server conf]# docker psCONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES5ea683a60e95 mysql:5.7 "docker-entrypoint.s…" 6 minutes ago Up 16 seconds 0.0.0.0:3306->3306/tcp, :::3306->3306/tcp, 33060/tcp mysql-master[root@zyl-server conf]#5、进入到mysql-master容器docker exec -it mysql-master /bin/bash6、进入MySQL容器后以root用户身份登录到MySQL数据库root@5ea683a60e95:/# mysql -u root -pEnter password:Welcome to the MySQL monitor. Commands end with ; or \g.Your MySQL connection id is 2Server version: 5.7.36-log MySQL Community Server (GPL)Copyright (c) 2000, 2021, Oracle and/or its affiliates.Oracle is a registered trademark of Oracle Corporation and/or itsaffiliates. Other names may be trademarks of their respectiveowners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.mysql>7、创建数据同步用户，在MySQL数据库中创建一个名为'slave'的用户，并设置密码为'123456'，该用户允许从任何主机连接：CREATE USER 'slave'@'%' IDENTIFIED BY '123456';mysql> CREATE USER 'slave'@'%' IDENTIFIED BY '123456';Query OK, 0 rows affected (0.00 sec)mysql>8、为'slave'用户授予复制（REPLICATION）相关的权限和客户端（CLIENT）权限：GRANT REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'slave'@'%';mysql> GRANT REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'slave'@'%';Query OK, 0 rows affected (0.00 sec)mysql>2.2 启动从节点容器mysql-slave（3307）
1、启动从节点容器mysql-slave：docker run -p 3307:3306 --name mysql-slave \-v /mydata/mysql-slave/log:/var/log/mysql \-v /mydata/mysql-slave/data:/var/lib/mysql \-v /mydata/mysql-slave/conf:/etc/mysql \-e MYSQL_ROOT_PASSWORD=123456 \-d mysql:5.72、列出正在运行的Docker容器：[root@zyl-server ~]# docker psCONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES77e48a50155d mysql:5.7 "docker-entrypoint.s…" 5 seconds ago Up 4 seconds 33060/tcp, 0.0.0.0:3307->3306/tcp, :::3307->3306/tcp mysql-slave5ea683a60e95 mysql:5.7 "docker-entrypoint.s…" 12 minutes ago Up 6 minutes 0.0.0.0:3306->3306/tcp, :::3306->3306/tcp, 33060/tcp mysql-master[root@zyl-server ~]#3、cd /mydata/mysql-slave/conf目录新建my.cnf文件vi my.conf[mysqld]## 设置server_id，同一局域网中需要唯一server_id=102## 指定不需要同步的数据库名称binlog-ignore-db=mysql ## 开启二进制日志功能，以备Slave作为其它数据库实例的Master时使用log-bin=mall-mysql-slave1-bin ## 设置二进制日志使用内存大小（事务）binlog_cache_size=1M ## 设置使用的二进制日志格式（mixed,statement,row）binlog_format=mixed ## 二进制日志过期清理时间。默认值为0，表示不自动清理。expire_logs_days=7 ## 跳过主从复制中遇到的所有错误或指定类型的错误，避免slave端复制中断。## 如：1062错误是指一些主键重复，1032错误是因为主从数据库数据不一致slave_skip_errors=1062 ## relay_log配置中继日志relay_log=mall-mysql-relay-bin ## log_slave_updates表示slave将复制事件写进自己的二进制日志log_slave_updates=1 ## slave设置为只读（具有super权限的用户除外）read_only=1##将MySQL容器的字符集和排序规则设置为UTF-8编码collation_server=utf8_general_cicharacter_set_server=utf84、修改后，重启mysql-slave容器实例:[root@zyl-server conf]# docker restart mysql-slavemysql-slave[root@zyl-server conf]#[root@zyl-server conf]# docker psCONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES77e48a50155d mysql:5.7 "docker-entrypoint.s…" 2 minutes ago Up 17 seconds 33060/tcp, 0.0.0.0:3307->3306/tcp, :::3307->3306/tcp mysql-slave5ea683a60e95 mysql:5.7 "docker-entrypoint.s…" 15 minutes ago Up 9 minutes 0.0.0.0:3306->3306/tcp, :::3306->3306/tcp, 33060/tcp mysql-master[root@zyl-server conf]#5、在主数据mysql-master库查看主从同步状态docker exec -it mysql-master /bin/bashroot@5ea683a60e95:/# mysql -u root -pmysql> show master status;+-----------------------+----------+--------------+------------------+-------------------+| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |+-----------------------+----------+--------------+------------------+-------------------+| mall-mysql-bin.000001 | 617 | | mysql | |+-----------------------+----------+--------------+------------------+-------------------+1 row in set (0.00 sec)mysql>6、进入mysql-slave 容器：docker exec -it mysql-slave /bin/bashmysql -u root -p[root@zyl-server conf]# docker exec -it mysql-slave /bin/bashroot@77e48a50155d:/# mysql -u root -pEnter password:Welcome to the MySQL monitor. Commands end with ; or \g.Your MySQL connection id is 2Server version: 5.7.36-log MySQL Community Server (GPL)Copyright (c) 2000, 2021, Oracle and/or its affiliates.Oracle is a registered trademark of Oracle Corporation and/or itsaffiliates. Other names may be trademarks of their respectiveowners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.mysql>7、在从数据库mysql-slave中配置主从复制，配置MySQL复制的主服务器信息：change master to master_host='192.168.234.10', master_user='slave', master_password='123456', master_port=3306, master_log_file='mall-mysql-bin.000001', master_log_pos=617, master_connect_retry=30;mysql> change master to master_host='192.168.234.10', master_user='slave', master_password='123456', master_port=3306, master_log_file='mall-mysql-bin.000001', master_log_pos=617, master_connect_retry=30;Query OK, 0 rows affected, 2 warnings (0.01 sec)mysql>其中master_log_file，master_log_pos为mysql-master中查到的结果：mysql> show master status;+-----------------------+----------+--------------+------------------+-------------------+| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |+-----------------------+----------+--------------+------------------+-------------------+| mall-mysql-bin.000001 | 617 | | mysql | |+-----------------------+----------+--------------+------------------+-------------------+1 row in set (0.00 sec)各个参数含义如下：MASTER_HOST：指定主服务器的IP地址或主机名。MASTER_USER：指定用于复制的用户（在之前创建的'slave'用户）。MASTER_PASSWORD：指定复制用户的密码。MASTER_PORT：指定主服务器的端口号。MASTER_LOG_FILE：指定主服务器的二进制日志文件名。MASTER_LOG_POS：指定要从哪个位置开始复制主服务器的二进制日志。MASTER_CONNECT_RETRY：指定在连接失败后重试连接的时间间隔（以秒为单位）。8、在从数据库mysql-master中查看主从同步状态：mysql> show slave status \G;*************************** 1. row *************************** Slave_IO_State: Master_Host: 192.168.234.10 Master_User: slave Master_Port: 3306 Connect_Retry: 30 Master_Log_File: mall-mysql-bin.000001 Read_Master_Log_Pos: 617 Relay_Log_File: mall-mysql-relay-bin.000001 Relay_Log_Pos: 4 Relay_Master_Log_File: mall-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: NULLMaster_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)ERROR:No query specifiedmysql>当Slave_IO_Running和Slave_SQL_Running状态为"No"时，表示MySQL复制的I/O线程和SQL线程都未在运行。
原因：从数据库未开启主从同步
解决：启动从服务器的复制进程
9、在从数据库中开启主从同步mysql> start slave;Query OK, 0 rows affected (0.00 sec)mysql>10、再次在从数据库mysql-master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: 192.168.234.10 Master_User: slave Master_Port: 3306 Connect_Retry: 30 Master_Log_File: mall-mysql-bin.000001 Read_Master_Log_Pos: 617 Relay_Log_File: mall-mysql-relay-bin.000002 Relay_Log_Pos: 325 Relay_Master_Log_File: mall-mysql-bin.000001 Slave_IO_Running: Yes Slave_SQL_Running: Yes 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: 537 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: 0Master_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: 101 Master_UUID: 4dd5c496-49ba-11ee-a195-0242ac110002 Master_Info_File: /var/lib/mysql/master.info SQL_Delay: 0 SQL_Remaining_Delay: NULL Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates 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)ERROR:No query specifiedmysql>
2.3 主数据库建库测试
1、例如，创建一个名为 "mydatabase" 的数据库：CREATE DATABASE mydatabase;2、使用 USE 命令切换到所需的数据库：USE mydatabase;3、例如，创建一个名为 "users" 的表，包含 id、name 和 email 列：CREATE TABLE users ( id INT, name VARCHAR(50), email VARCHAR(100));4、使用 INSERT INTO 语句。向 "users" 表插入三条数据：INSERT INTO users (id, name, email) VALUES (1, 'John', 'john@example.com'), (2, 'Jane', 'jane@example.com'), (3, 'Tom', 'tom@example.com');
2.4 从数据库验证
1、从数据库查看数据库列表：mysql> show databases;+--------------------+| Database |+--------------------+| information_schema || mydatabase || mysql || performance_schema || sys |+--------------------+5 rows in set (0.00 sec)mysql>
2、切换到mydatabase数据库USE mydatabase;3、显示当前数据库中的所有表SHOW TABLES;4、查询"users"表中的所有记录：select * from users;mysql> select * from users;+------+------+------------------+| id | name | email |+------+------+------------------+| 1 | John | john@example.com || 2 | Jane | jane@example.com || 3 | Tom | tom@example.com |+------+------+------------------+3 rows in set (0.00 sec)mysql>
3.1 前言–数据库分区技术
哈希取余分区：通过将数据的哈希值与分区数进行取余运算来确定数据所属的分区。例如，如果有4个分区，对数据的哈希值进行取余运算，将其分配到0至3之间的一个分区。这种方法简单且容易实现，但可能会导致数据分布不均衡。
一致性哈希算法分区：一致性哈希算法使用一个哈希环来表示分区的范围，数据的哈希值将映射到哈希环上的某个位置。在一致性哈希算法中，当分区发生变化时，只有少量的数据需要重新映射到新的分区，因此可以实现动态的分区扩展或缩减。这种方法能够提供较好的负载均衡和可扩展性。
哈希槽分区：哈希槽分区将数据均匀地分布在一组预定义的哈希槽中。每个分区被映射到一个哈希槽，数据的哈希值决定了它所属的哈希槽。这种方法可以随着分区数的增加或减少而调整哈希槽数量，从而实现动态的扩展和缩减。这种方法提供了良好的负载均衡和扩展性。
这些分区技术可以用于在数据库中水平划分数据以提高性能、灵活性和可伸缩性。每种分区技术都有其特定的优点和适用场景，选择合适的分区技术应根据具体需求和系统特点进行评估。
3.2 redis集群–3主3从搭建
1、启动6个Redis节点docker run -d --name redis-node-1 --net host --privileged=true -v /data/redis/share/redis-node-1:/data redis:6.0.8 --cluster-enabled yes --appendonly yes --port 6381docker run -d --name redis-node-2 --net host --privileged=true -v /data/redis/share/redis-node-2:/data redis:6.0.8 --cluster-enabled yes --appendonly yes --port 6382docker run -d --name redis-node-3 --net host --privileged=true -v /data/redis/share/redis-node-3:/data redis:6.0.8 --cluster-enabled yes --appendonly yes --port 6383docker run -d --name redis-node-4 --net host --privileged=true -v /data/redis/share/redis-node-4:/data redis:6.0.8 --cluster-enabled yes --appendonly yes --port 6384docker run -d --name redis-node-5 --net host --privileged=true -v /data/redis/share/redis-node-5:/data redis:6.0.8 --cluster-enabled yes --appendonly yes --port 6385docker run -d --name redis-node-6 --net host --privileged=true -v /data/redis/share/redis-node-6:/data redis:6.0.8 --cluster-enabled yes --appendonly yes --port 6386参数：--name: 指定容器的名称，例如redis-node-1、redis-node-2等。--net host: 使用主机网络模式，使容器可以使用主机的网络栈。--privileged=true: 在容器内部提供特权访问，通常用于需要访问主机设备或文件系统的情况。-v /data/redis/share/redis-node-X:/data: 将主机上的/data/redis/share/redis-node-X目录挂载到容器内的/data目录，用于持久化存储Redis数据。redis:6.0.8: 指定使用的Redis镜像及版本号。--cluster-enabled yes: 启用Redis集群功能。--appendonly yes: 开启AOF（Append Only File）持久化方式。--port XXXX: 指定Redis节点的端口号，例如6381、6382等。2、列出当前正在运行的Docker容器[root@zyl-server ~]# docker psCONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES51fa09a6a3e6 redis:6.0.8 "docker-entrypoint.s…" 5 seconds ago Up 4 seconds redis-node-674faf0961119 redis:6.0.8 "docker-entrypoint.s…" 6 seconds ago Up 5 seconds redis-node-52bb58b50c70a redis:6.0.8 "docker-entrypoint.s…" 6 seconds ago Up 5 seconds redis-node-49a0fd2b62b14 redis:6.0.8 "docker-entrypoint.s…" 6 seconds ago Up 5 seconds redis-node-3cb67d2dfecd0 redis:6.0.8 "docker-entrypoint.s…" 6 seconds ago Up 6 seconds redis-node-259bcc7ed00e5 redis:6.0.8 "docker-entrypoint.s…" 7 seconds ago Up 6 seconds redis-node-1[root@zyl-server ~]#3、进入redis-node-1 为6台机器配置构建集群关系redis-cli --cluster create 192.168.234.10:6381 192.168.234.10:6382 192.168.234.10:6383 192.168.234.10:6384 192.168.234.10:6385 192.168.234.10:6386 --cluster-replicas 1[root@zyl-server ~]# docker exec -it redis-node-1 /bin/bashroot@zyl-server:/data# redis-cli --cluster create 192.168.234.10:6381 192.168.234.10:6382 192.168.234.10:6383 192.168.234.10:6384 192.168.234.10:6385 192.168.234.10:6386 --cluster-replicas 1>>> Performing hash slots allocation on 6 nodes...Master[0] -> Slots 0 - 5460Master[1] -> Slots 5461 - 10922Master[2] -> Slots 10923 - 16383Adding replica 192.168.234.10:6385 to 192.168.234.10:6381Adding replica 192.168.234.10:6386 to 192.168.234.10:6382Adding replica 192.168.234.10:6384 to 192.168.234.10:6383>>> Trying to optimize slaves allocation for anti-affinity[WARNING] Some slaves are in the same host as their masterM: 1ea11eda762c317ac5b9f398827c51085e553652 192.168.234.10:6381 slots:[0-5460] (5461 slots) masterM: f0a14e3d08738655dd7ed0b702187f7096f06bba 192.168.234.10:6382 slots:[5461-10922] (5462 slots) masterM: 553a35ceea6fb2f0d2c668923d6650f65525a370 192.168.234.10:6383 slots:[10923-16383] (5461 slots) masterS: dd03b2ff3629d360da59294c0b547849de41e8fb 192.168.234.10:6384 replicates f0a14e3d08738655dd7ed0b702187f7096f06bbaS: 0b1cfb29bc066c74a831a948e3c23f8dc6e0bbe6 192.168.234.10:6385 replicates 553a35ceea6fb2f0d2c668923d6650f65525a370S: 6ebb4441ded1cfb4ce346e4349e155a685acdffd 192.168.234.10:6386 replicates 1ea11eda762c317ac5b9f398827c51085e553652Can 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 clusterWaiting for the cluster to join.>>> Performing Cluster Check (using node 192.168.234.10:6381)M: 1ea11eda762c317ac5b9f398827c51085e553652 192.168.234.10:6381 slots:[0-5460] (5461 slots) master 1 additional replica(s)M: f0a14e3d08738655dd7ed0b702187f7096f06bba 192.168.234.10:6382 slots:[5461-10922] (5462 slots) master 1 additional replica(s)S: 0b1cfb29bc066c74a831a948e3c23f8dc6e0bbe6 192.168.234.10:6385 slots: (0 slots) slave replicates 553a35ceea6fb2f0d2c668923d6650f65525a370M: 553a35ceea6fb2f0d2c668923d6650f65525a370 192.168.234.10:6383 slots:[10923-16383] (5461 slots) master 1 additional replica(s)S: 6ebb4441ded1cfb4ce346e4349e155a685acdffd 192.168.234.10:6386 slots: (0 slots) slave replicates 1ea11eda762c317ac5b9f398827c51085e553652S: dd03b2ff3629d360da59294c0b547849de41e8fb 192.168.234.10:6384 slots: (0 slots) slave replicates f0a14e3d08738655dd7ed0b702187f7096f06bba[OK] All nodes agree about slots configuration.>>> Check for open slots...>>> Check slots coverage...[OK] All 16384 slots covered.
4、主节点查看集群状态root@zyl-server:/data# redis-cli -p 6381##获取有关Redis集群的信息，例如集群的状态、节点数量、槽位分配情况127.0.0.1:6381> cluster infocluster_state:okcluster_slots_assigned:16384cluster_slots_ok:16384cluster_slots_pfail:0cluster_slots_fail:0cluster_known_nodes:6cluster_size:3cluster_current_epoch:6cluster_my_epoch:1cluster_stats_messages_ping_sent:138cluster_stats_messages_pong_sent:146cluster_stats_messages_sent:284cluster_stats_messages_ping_received:141cluster_stats_messages_pong_received:138cluster_stats_messages_meet_received:5cluster_stats_messages_received:284127.0.0.1:6381>##获取当前集群中所有节点的信息127.0.0.1:6381> cluster nodesf0a14e3d08738655dd7ed0b702187f7096f06bba 192.168.234.10:6382@16382 master - 0 1693680656000 2 connected 5461-109220b1cfb29bc066c74a831a948e3c23f8dc6e0bbe6 192.168.234.10:6385@16385 slave 553a35ceea6fb2f0d2c668923d6650f65525a370 0 1693680659111 3 connected1ea11eda762c317ac5b9f398827c51085e553652 192.168.234.10:6381@16381 myself,master - 0 1693680659000 1 connected 0-5460553a35ceea6fb2f0d2c668923d6650f65525a370 192.168.234.10:6383@16383 master - 0 1693680657069 3 connected 10923-163836ebb4441ded1cfb4ce346e4349e155a685acdffd 192.168.234.10:6386@16386 slave 1ea11eda762c317ac5b9f398827c51085e553652 0 1693680658091 1 connecteddd03b2ff3629d360da59294c0b547849de41e8fb 192.168.234.10:6384@16384 slave f0a14e3d08738655dd7ed0b702187f7096f06bba 0 1693680660128 2 connected127.0.0.1:6381>
3.3 redis集群–主从容错切换迁移案例
master：6381下线，slave：6386上位：
1、停止redis-node-1的Docker容器[root@zyl-server ~]# docker stop redis-node-1redis-node-1[root@zyl-server ~]#2、列出当前正在运行的Docker容器[root@zyl-server ~]# docker psCONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES51fa09a6a3e6 redis:6.0.8 "docker-entrypoint.s…" 10 hours ago Up 10 hours redis-node-674faf0961119 redis:6.0.8 "docker-entrypoint.s…" 10 hours ago Up 10 hours redis-node-52bb58b50c70a redis:6.0.8 "docker-entrypoint.s…" 10 hours ago Up 10 hours redis-node-49a0fd2b62b14 redis:6.0.8 "docker-entrypoint.s…" 10 hours ago Up 10 hours redis-node-3cb67d2dfecd0 redis:6.0.8 "docker-entrypoint.s…" 10 hours ago Up 10 hours redis-node-2[root@zyl-server ~]#3、进入名为redis-node-2的Docker容器docker exec -it redis-node-2 /bin/bash4、连接到Redis节点root@zyl-server:/data# redis-cli -p 6382127.0.0.1:6382>5、##获取有关Redis集群的信息，例如集群的状态、节点数量、槽位分配情况127.0.0.1:6382> cluster infocluster_state:okcluster_slots_assigned:16384cluster_slots_ok:16384cluster_slots_pfail:0cluster_slots_fail:0cluster_known_nodes:6cluster_size:3cluster_current_epoch:7cluster_my_epoch:2cluster_stats_messages_ping_sent:1260cluster_stats_messages_pong_sent:1243cluster_stats_messages_meet_sent:1cluster_stats_messages_auth-ack_sent:1cluster_stats_messages_sent:2505cluster_stats_messages_ping_received:1243cluster_stats_messages_pong_received:1261cluster_stats_messages_fail_received:1cluster_stats_messages_auth-req_received:1cluster_stats_messages_received:2506127.0.0.1:6382>##获取当前集群中所有节点的信息127.0.0.1:6382> cluster nodes6ebb4441ded1cfb4ce346e4349e155a685acdffd 192.168.234.10:6386@16386 master - 0 1693716720009 7 connected 0-54601ea11eda762c317ac5b9f398827c51085e553652 192.168.234.10:6381@16381 master,fail - 1693716449472 1693716444000 1 disconnected0b1cfb29bc066c74a831a948e3c23f8dc6e0bbe6 192.168.234.10:6385@16385 slave 553a35ceea6fb2f0d2c668923d6650f65525a370 0 1693716719000 3 connected553a35ceea6fb2f0d2c668923d6650f65525a370 192.168.234.10:6383@16383 master - 0 1693716721031 3 connected 10923-16383f0a14e3d08738655dd7ed0b702187f7096f06bba 192.168.234.10:6382@16382 myself,master - 0 1693716720000 2 connected 5461-10922dd03b2ff3629d360da59294c0b547849de41e8fb 192.168.234.10:6384@16384 slave f0a14e3d08738655dd7ed0b702187f7096f06bba 0 1693716722056 2 connected127.0.0.1:6382>
还原之前的3主3从：
1、启动名为redis-node-1的Docker容器[root@zyl-server ~]# docker start redis-node-1redis-node-1[root@zyl-server ~]#2、获取当前集群中所有节点的信息127.0.0.1:6382> cluster nodes6ebb4441ded1cfb4ce346e4349e155a685acdffd 192.168.234.10:6386@16386 master - 0 1693716888112 7 connected 0-54601ea11eda762c317ac5b9f398827c51085e553652 192.168.234.10:6381@16381 slave 6ebb4441ded1cfb4ce346e4349e155a685acdffd 0 1693716888000 7 connected0b1cfb29bc066c74a831a948e3c23f8dc6e0bbe6 192.168.234.10:6385@16385 slave 553a35ceea6fb2f0d2c668923d6650f65525a370 0 1693716887097 3 connected553a35ceea6fb2f0d2c668923d6650f65525a370 192.168.234.10:6383@16383 master - 0 1693716889129 3 connected 10923-16383f0a14e3d08738655dd7ed0b702187f7096f06bba 192.168.234.10:6382@16382 myself,master - 0 1693716887000 2 connected 5461-10922dd03b2ff3629d360da59294c0b547849de41e8fb 192.168.234.10:6384@16384 slave f0a14e3d08738655dd7ed0b702187f7096f06bba 0 1693716886000 2 connected127.0.0.1:6382>
3、停止上位的slave：6386，相当于给master：6381，上位机会docker stop redis-node-64、获取当前集群中所有节点的信息127.0.0.1:6382> cluster nodes6ebb4441ded1cfb4ce346e4349e155a685acdffd 192.168.234.10:6386@16386 master,fail - 1693717524807 1693717521000 7 disconnected1ea11eda762c317ac5b9f398827c51085e553652 192.168.234.10:6381@16381 master - 0 1693717614888 8 connected 0-54600b1cfb29bc066c74a831a948e3c23f8dc6e0bbe6 192.168.234.10:6385@16385 slave 553a35ceea6fb2f0d2c668923d6650f65525a370 0 1693717614000 3 connected553a35ceea6fb2f0d2c668923d6650f65525a370 192.168.234.10:6383@16383 master - 0 1693717612843 3 connected 10923-16383f0a14e3d08738655dd7ed0b702187f7096f06bba 192.168.234.10:6382@16382 myself,master - 0 1693717615000 2 connected 5461-10922dd03b2ff3629d360da59294c0b547849de41e8fb 192.168.234.10:6384@16384 slave f0a14e3d08738655dd7ed0b702187f7096f06bba 0 1693717615913 2 connected127.0.0.1:6382>
5、重新启动6386[root@zyl-server ~]# docker start redis-node-6redis-node-6[root@zyl-server ~]#6、获取当前集群中所有节点的信息127.0.0.1:6382> cluster nodes6ebb4441ded1cfb4ce346e4349e155a685acdffd 192.168.234.10:6386@16386 slave 1ea11eda762c317ac5b9f398827c51085e553652 0 1693717773565 8 connected1ea11eda762c317ac5b9f398827c51085e553652 192.168.234.10:6381@16381 master - 0 1693717772000 8 connected 0-54600b1cfb29bc066c74a831a948e3c23f8dc6e0bbe6 192.168.234.10:6385@16385 slave 553a35ceea6fb2f0d2c668923d6650f65525a370 0 1693717773000 3 connected553a35ceea6fb2f0d2c668923d6650f65525a370 192.168.234.10:6383@16383 master - 0 1693717771000 3 connected 10923-16383f0a14e3d08738655dd7ed0b702187f7096f06bba 192.168.234.10:6382@16382 myself,master - 0 1693717772000 2 connected 5461-10922dd03b2ff3629d360da59294c0b547849de41e8fb 192.168.234.10:6384@16384 slave f0a14e3d08738655dd7ed0b702187f7096f06bba 0 1693717771547 2 connected127.0.0.1:6382>
3.4 redis集群–读写error
1、进入redis-node-1，set k1 v1[root@zyl-server ~]# docker exec -it redis-node-1 /bin/bashroot@zyl-server:/data# redis-cli -p 6381127.0.0.1:6381> set k1 v1(error) MOVED 12706 192.168.234.10:6383127.0.0.1:6381> set k2 v2OK127.0.0.1:6381> set k3 v3OK127.0.0.1:6381> set k4 v4(error) MOVED 8455 192.168.234.10:6382127.0.0.1:6381>这个错误提示是因为尝试执行的命令被Redis集群转发到了错误的节点。在Redis集群中，不同的槽位可能分布在不同的节点上，并且某些命令需要在正确的节点上执行。
解决方法如下：使用-c 选项来启用集群模式
首先，使用redis-cli连接到Redis集群中的任意一个节点：redis-cli -c -h <任意一个节点IP地址> -p <任意一个节点端口>。root@zyl-server:/data# redis-cli -p 6381 -c127.0.0.1:6381> FLUSHALL ##清空当前Redis节点上的所有数据OK127.0.0.1:6381>2、使用了-c 选项来启用集群模式，后再set测试在集群中，不同的键会根据其哈希值被分配到不同的槽位和节点上。127.0.0.1:6381> set k1 v1-> Redirected to slot [12706] located at 192.168.234.10:6383OK192.168.234.10:6383> set k2 v2-> Redirected to slot [449] located at 192.168.234.10:6381OK192.168.234.10:6381> set k3 v3OK192.168.234.10:6381> set k4 v4-> Redirected to slot [8455] located at 192.168.234.10:6382OK192.168.234.10:6382>键"k1"被重定向到位于192.168.234.10:6383的槽位[12706]上。键"k2"被重定向到位于192.168.234.10:6381的槽位[449]上。键"k3"直接被设置在位于192.168.234.10:6381的节点上。键"k4"被重定向到位于192.168.234.10:6382的槽位[8455]上。3.5 redis集群–主从扩容案例（4主4从）
在原来3主3从基础上，变为4主4从，新增master：6387，slave：6388。
新建6387、6388两个节点+新建后启动+查看是否8节点。
1、创建两个Redis节点，并将它们加入到Redis集群中docker run -d --name redis-node-7 --net host --privileged=true -v /data/redis/share/redis-node-7:/data redis:6.0.8 --cluster-enabled yes --appendonly yes --port 6387docker run -d --name redis-node-8 --net host --privileged=true -v /data/redis/share/redis-node-8:/data redis:6.0.8 --cluster-enabled yes --appendonly yes --port 6388-d参数表示以后台模式运行容器。--name参数指定了容器的名称为"redis-node-7"。--net host参数表示容器与主机共享网络命名空间，以便容器能够使用主机的网络。--privileged=true参数授予容器特权级别，以便在容器中执行底层操作。-v /data/redis/share/redis-node-7:/data参数将主机上的目录/data/redis/share/redis-node-7挂载到容器内的/data目录。这样可以持久化保存容器内的数据。redis:7.0.9指定了使用的Redis镜像和版本。--cluster-enabled yes表示启用Redis集群。--appendonly yes表示启用AOF（Append Only File）持久化模式。--port 6387表示将Redis节点的端口设置为6387。2、列出正在运行的Docker容器docker ps[root@zyl-server ~]# docker psCONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMESd9a5a558f377 redis:6.0.8 "docker-entrypoint.s…" 5 seconds ago Up 4 seconds redis-node-826773aa52c7c redis:6.0.8 "docker-entrypoint.s…" 6 seconds ago Up 5 seconds redis-node-751fa09a6a3e6 redis:6.0.8 "docker-entrypoint.s…" 11 hours ago Up 38 minutes redis-node-674faf0961119 redis:6.0.8 "docker-entrypoint.s…" 11 hours ago Up 11 hours redis-node-52bb58b50c70a redis:6.0.8 "docker-entrypoint.s…" 11 hours ago Up 11 hours redis-node-49a0fd2b62b14 redis:6.0.8 "docker-entrypoint.s…" 11 hours ago Up 11 hours redis-node-3cb67d2dfecd0 redis:6.0.8 "docker-entrypoint.s…" 11 hours ago Up 11 hours redis-node-259bcc7ed00e5 redis:6.0.8 "docker-entrypoint.s…" 11 hours ago Up 53 minutes redis-node-1[root@zyl-server ~]#3、进入6387容器实例内部docker exec -it redis-node-7 /bin/bash4、将新增的6387节点(空槽号)作为master节点加入原集群redis-cli --cluster add-node 自己实际IP地址:6387 自己实际IP地址:63816387 就是将要作为master新增节点6381 就是原来集群节点里面的领路人，相当于6387拜拜6381的码头从而找到组织加入集群redis-cli --cluster add-node 192.168.234.10:6387 192.168.234.10:6381root@zyl-server:/data# redis-cli --cluster add-node 192.168.234.10:6387 192.168.234.10:6381>>> Adding node 192.168.234.10:6387 to cluster 192.168.234.10:6381>>> Performing Cluster Check (using node 192.168.234.10:6381)M: 1ea11eda762c317ac5b9f398827c51085e553652 192.168.234.10:6381 slots:[0-5460] (5461 slots) master 1 additional replica(s)S: 0b1cfb29bc066c74a831a948e3c23f8dc6e0bbe6 192.168.234.10:6385 slots: (0 slots) slave replicates 553a35ceea6fb2f0d2c668923d6650f65525a370S: 6ebb4441ded1cfb4ce346e4349e155a685acdffd 192.168.234.10:6386 slots: (0 slots) slave replicates 1ea11eda762c317ac5b9f398827c51085e553652S: dd03b2ff3629d360da59294c0b547849de41e8fb 192.168.234.10:6384 slots: (0 slots) slave replicates f0a14e3d08738655dd7ed0b702187f7096f06bbaM: f0a14e3d08738655dd7ed0b702187f7096f06bba 192.168.234.10:6382 slots:[5461-10922] (5462 slots) master 1 additional replica(s)M: 553a35ceea6fb2f0d2c668923d6650f65525a370 192.168.234.10:6383 slots:[10923-16383] (5461 slots) master 1 additional replica(s)[OK] All nodes agree about slots configuration.>>> Check for open slots...>>> Check slots coverage...[OK] All 16384 slots covered.>>> Getting functions from cluster>>> Failed retrieving Functions from the cluster, skip this step as Redis version do not support function command (error = 'ERR unknown command `FUNCTION`, with args beginning with: `DUMP`, ')>>> Send CLUSTER MEET to node 192.168.234.10:6387 to make it join the cluster.[OK] New node added correctly.root@zyl-server:/data#
5、检查集群情况第1次，6387没有任何键、槽位或从节点。redis-cli --cluster check 192.168.234.10:6381
6、重新分派槽号命令:redis-cli --cluster reshard IP地址:端口号redis-cli --cluster reshard 192.168.234.10:6381
7、检查集群情况第2次root@zyl-server:/data# redis-cli --cluster check 192.168.234.10:6381
为什么6387是3个新的区间，以前的槽位号还是连续？
重新分配成本太高，所以前3家各自匀出来一部分，从6381/6382/6383三个旧节点分别匀出1364个坑位给新节点6387。
8、为主节点6387分配从节点6388命令：redis-cli --cluster add-node ip:新slave端口 ip:新master端口 --cluster-slave --cluster-master-id 新主机节点IDredis-cli --cluster add-node 192.168.234.10:6388 192.168.234.10:6387 --cluster-slave --cluster-master-id a8a40f0db21abc2db2c159e9c7931d2a7acdc8f2 -------这个是6387的编号，按照自己实际情况redis-cli --cluster add-node 192.168.234.10:6388 192.168.234.10:6387 --cluster-slave --cluster-master-id a8a40f0db21abc2db2c159e9c7931d2a7acdc8f2
9、检查集群情况第3次redis-cli --cluster check 192.168.234.10:6381
redis集群--主从扩容案例（4主4从）——————成功！！！
3.6 redis集群–主从缩容案例(4主4从—>3主3从)
目的：6387和6388下线。
1、检查集群情况1获得6388的节点IDredis-cli --cluster check 192.168.234.10:6388a0abf90dbec7d33cb0cd3179cb5efb7e653a1a4c2、将6388删除 ，从集群中将4号从节点6388删除命令：redis-cli --cluster del-node ip:从机端口 从机6388节点IDredis-cli --cluster del-node 192.168.234.10:6388 a0abf90dbec7d33cb0cd3179cb5efb7e653a1a4croot@zyl-server:/data# redis-cli --cluster del-node 192.168.234.10:6388 a03a551fb6f8320ee404f07254e6c934beb52d7e>>> Removing node a03a551fb6f8320ee404f07254e6c934beb52d7e from cluster 192.168.234.10:6388>>> Sending CLUSTER FORGET messages to the cluster...>>> Sending CLUSTER RESET SOFT to the deleted node.root@zyl-server:/data#3、再次检查集群redis-cli --cluster check 192.168.234.10:6381
4、将6387的槽号清空，重新分配，本例将清出来的槽号都给6381redis-cli --cluster reshard 192.168.234.10:6381
5、检查集群情况第二次redis-cli --cluster check 192.168.234.10:6381
6、将6387删除命令：redis-cli --cluster del-node ip:端口 6387节点IDredis-cli --cluster del-node 192.168.234.10:6387 f0eea5b2dfe28c742b00bb660bb67a2d0ee30004root@zyl-server:/data# redis-cli --cluster del-node 192.168.234.10:6387 f0eea5b2dfe28c742b00bb660bb67a2d0ee30004>>> Removing node f0eea5b2dfe28c742b00bb660bb67a2d0ee30004 from cluster 192.168.234.10:6387>>> Sending CLUSTER FORGET messages to the cluster...>>> Sending CLUSTER RESET SOFT to the deleted node.root@zyl-server:/data#7、检查集群情况第三次redis-cli --cluster check 192.168.234.10:6381
redis集群--主从缩容案例(4主4从--->3主3从)——————成功！！！
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来源地址：https://blog.csdn.net/qq_41840843/article/details/132630287
