理解docker部署springboot-搭建mysql主从集群（二）

冷不防 2022-06-07 00:07 162阅读 0赞

搭建mysql集群目的是为springboot提供数据服务

这一篇文章主要是记录了在docker环境下搭建MySQL主从集群的过程，以及在准备搭建的过程中遇到的一些问题，问题主要包括docker版本的升级以及centos内核的升级。在执行docker restart ID命令重启容器经常会出现崩溃并且network等命令在1.7版本中无法使用（network命令1.9之后提供），所以把docker升级到更高的版本，这必须要升级centos的内核版本，由于阿里云的服务器的内核版本是2.6不能满足大部分docker版本的要求，固升级内核版本为3.1，升级的过程具体可以[参考][Link 1]

版本升级的[参考][Link 2]，执行过程如下：

[root@iZwz9cps5bpzjurg8m4ax0Z bin]# curl -sSL -O https://get.docker.com/builds/Linux/x86_64/docker-1.9.1 && chmod +x docker-1.9.1 && mv docker-1.9.1 /usr/local/bin/docker
    mv: overwrite `/usr/local/bin/docker'? y
    [root@iZwz9cps5bpzjurg8m4ax0Z bin]# cp /usr/local/bin/docker /usr/bin/docker
    cp: overwrite `/usr/bin/docker'? y
    [root@iZwz9cps5bpzjurg8m4ax0Z bin]# service docker start
    Starting docker:	                                   [  OK  ]
    [root@iZwz9cps5bpzjurg8m4ax0Z bin]# docker -v
    Docker version 1.9.1, build a34a1d5

在升级的过程中，如果发现docker的旧版本已经安装就会报冲突的错误，因此在安装新的版本之前应该使用yum remove docker命令将旧的移除。

主从MySQL集群总体的思路：  
1、下载MySQL镜像  
2、在虚拟机（或者windows等）中配置MySQL的配置文件  
3、根据配置文件运行MySQL的docker镜像  
4、修改master和slave主从数据库的关系

### 下载MySQL镜像 ###

第一次尝试通过docker search mysql直接搜的，下载特别慢，后来经过查找发现下边这两种是比较快速的：

docker pull daocloud.io/mysql
    docker pull hub.c.163.com/library/mysql:latest

这两个都是国内的镜像，下载速度非常快

### 在虚拟机（或者windows等）中配置MySQL的配置文件 ###

配置文件和非docker方式的mysql集群的配置一致，如下：

# Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
    #
    # This program is free software; you can redistribute it and/or modify
    # it under the terms of the GNU General Public License as published by
    # the Free Software Foundation; version 2 of the License.
    #
    # This program is distributed in the hope that it will be useful,
    # but WITHOUT ANY WARRANTY; without even the implied warranty of
    # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    # GNU General Public License for more details.
    #
    # You should have received a copy of the GNU General Public License
    # along with this program; if not, write to the Free Software
    # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
    
    
    #
    # The MySQL Community Server configuration file.
    #
    # For explanations see
    # http://dev.mysql.com/doc/mysql/en/server-system-variables.html
    
    
    [client]
    port        = 3306
    socket      = /var/run/mysqld/mysqld.sock
    
    
    [mysqld_safe]
    pid-file    = /var/run/mysqld/mysqld.pid
    socket      = /var/run/mysqld/mysqld.sock
    nice        = 0
    
    
    [mysqld]
    user        = mysql
    pid-file    = /var/run/mysqld/mysqld.pid
    socket      = /var/run/mysqld/mysqld.sock
    port        = 3306
    basedir     = /usr
    datadir     = /var/lib/mysql
    tmpdir      = /tmp
    lc-messages-dir = /usr/share/mysql
    explicit_defaults_for_timestamp
    
    
    log-bin = mysql-bin 
    server-id = 1 
    
    
    # Instead of skip-networking the default is now to listen only on
    # localhost which is more compatible and is not less secure.
    #bind-address   = 127.0.0.1
    
    
    #log-error  = /var/log/mysql/error.log
    
    
    # Recommended in standard MySQL setup
    sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES
    
    
    # Disabling symbolic-links is recommended to prevent assorted security risks
    symbolic-links=0
    
    
    # * IMPORTANT: Additional settings that can override those from this file!
    #   The files must end with '.cnf', otherwise they'll be ignored.
    #
    !includedir /etc/mysql/conf.d/

在centos中的以下两个配置目录中新建以下两个文件，并将上述配置填入  
/docker/mysql-cluster/master/my-m.cnf以及/docker/mysql-cluster/slave/my-s.cnf，my-m.cnf和my-s.cnf唯一的不同是server-id=1和server-id=2，server-id用来标识主从数据库

### 根据配置文件运行MySQL的docker镜像 ###

#master库
    docker run -d -e MYSQL_ROOT_PASSWORD=testcode --name mysql-master -v /docker/mysql-cluster/master/my-m.cnf:/etc/mysql/my.cnf -p 3307:3306 daocloud.io/mysql 
    
    #slave库
    docker run -d -e MYSQL_ROOT_PASSWORD=testcode --name mysql-slave -v /docker/mysql-cluster/slave/my-s.cnf:/etc/mysql/my.cnf -p 3308:3306 daocloud.io/mysql

一些参数解释：  
\-d，表示Detached mode，后台运行  
\-t，让Docker分配一个伪终端（pseudo-tty）并绑定到容器的标准输入上  
\-i，让容器的标准输入保持打开，可以-it配合用，与-d相对应  
\-e，表示传入的环境变量  
\-p，表示暴露的端口，即本机端口与docker端口映射  
\-v，表示挂载文件，这里挂载了本地的文件夹到docker的文件夹  
\--name，表示给容器起的名字，方便查看，若要配置主从，  
  
执行命令结束后可以看到

[root@iZwz9cps5bpzjurg8m4ax0Z master]# docker ps
    CONTAINER ID        IMAGE                       COMMAND                  CREATED             STATUS              PORTS                    NAMES
    812b841b5422        daocloud.io/mysql           "docker-entrypoint.sh"   4 seconds ago       Up 3 seconds        0.0.0.0:3308->3306/tcp   mysql-slave
    33225198ecc3        daocloud.io/mysql           "docker-entrypoint.sh"   2 minutes ago       Up 2 minutes        0.0.0.0:3307->3306/tcp   mysql-master

mysql-master和mysql-slave两个基于daocloud.io/mysql镜像的容器被先后启动。由于daocloud.io/mysql镜像中包含了vi，不需要再单独进行安装，docker logs 容器的ID 可以查看容器运行的日志。

### 修改master和slave主从数据库的关系 ###

执行docker exec -it mysql-master bash进去master库的vim环境中，执行mysql -uroot -p，进入docker中的mysql，执行

mysql> GRANT REPLICATION SLAVE ON *.* to 'backup'@'%' identified by 'master_123';
    
    mysql> show master status;
    +------------------+----------+--------------+------------------+-------------------+
    | File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
    +------------------+----------+--------------+------------------+-------------------+
    | mysql-bin.000003 |      439 |              |                  |                   |
    +------------------+----------+--------------+------------------+-------------------+

同样方式进入slave库，执行:

change master to master_host='对外主机IP',master_user='backup',master_password='master_123',master_log_file='mysql-bin.000003',master_log_pos=439,master_port=3307;

这里边有一些对应关系要注意。  
可以看到，在master上建立sdata库后，slave中也存了相同的库，主从关系搭建完毕  
  
![Center][]  
  
  
  
参考文章：  
http://blog.csdn.net/qq362228416/article/details/48569293  
http://www.jianshu.com/p/12c34395e76e  
http://www.cnblogs.com/felixzh/p/5194527.html

[Link 1]: https://www.2cto.com/os/201708/670531.html
[Link 2]: http://www.phpkoo.com/archives/305
[Center]: /images/20220607/2bdff8e0a22e449baefe882f906539fd.png