Docker搭建MySQL主從複製

Docker搭建MySQL主從複製

1. 主從服務器上分別安裝Docker

   1.1 Docker 要求 CentOS 系統的內核版本高於 3.10

   [root@localhost ~]# uname -r
   3.10.0-693.el7.x86_64

   1.2 確保 yum 包更新到最新。

   [root@localhost ~]# sudo yum update
   Loaded plugins: fastestmirror, langpacks
   Loading mirror speeds from cached hostfile
    * base: mirrors.cqu.edu.cn
    * extras: mirrors.cqu.edu.cn

base | 3.6 kB 00:00:00
docker-ce-stable | 3.5 kB 00:00:00
extras | 2.9 kB 00:00:00
updates | 2.9 kB 00:00:00

1.3 安裝須要的軟件包， yum-util 提供yum-config-manager功能，另外兩個是devicemapper驅動依賴的

[root@localhost ~]# sudo yum install -y yum-utils device-mapper-persistent-data lvm2
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile

* base: mirrors.cqu.edu.cn
* extras: mirrors.cqu.edu.cn
* updates: mirrors.cqu.edu.cn

Package yum-utils-1.1.31-52.el7.noarch already installed and latest version
Package device-mapper-persistent-data-0.8.5-1.el7.x86_64 already installed and latest version
Package 7:lvm2-2.02.185-2.el7_7.2.x86_64 already installed and latest version
Nothing to do

1.4 設置yum源

[root@localhost ~]# sudo yum-config-manager --add-repo https://download.docker.com/l...
Loaded plugins: fastestmirror, langpacks
adding repo from: https://download.docker.com/l...
grabbing file https://download.docker.com/l... to /etc/yum.repos.d/docker-ce.repo
repo saved to /etc/yum.repos.d/docker-ce.repo

1.5 安裝docker

[root@localhost ~]# sudo yum install docker-ce
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile

* base: mirrors.cqu.edu.cn
* extras: mirrors.cqu.edu.cn
* updates: mirrors.cqu.edu.cn

Package 3:docker-ce-19.03.8-3.el7.x86_64 already installed and latest version
Nothing to do

1.6 啓動docker並設置docker自動啓動

[root@localhost ~]# sudo systemctl start docker
[root@localhost ~]# sudo systemctl enable docker

1.7 檢測docker是否安裝成功

[root@localhost ~]# docker version
Client: Docker Engine - Community

Version:           19.03.8
API version:       1.40
Go version:        go1.12.17
Git commit:        afacb8b
Built:             Wed Mar 11 01:27:04 2020
OS/Arch:           linux/amd64
Experimental:      false

Server: Docker Engine - Community

Engine:
 Version:          19.03.8
 API version:      1.40 (minimum version 1.12)
 Go version:       go1.12.17
 Git commit:       afacb8b
 Built:            Wed Mar 11 01:25:42 2020
 OS/Arch:          linux/amd64
 Experimental:     false
containerd:
 Version:          1.2.13
 GitCommit:        7ad184331fa3e55e52b890ea95e65ba581ae3429
runc:
 Version:          1.0.0-rc10
 GitCommit:        dc9208a3303feef5b3839f4323d9beb36df0a9dd
docker-init:
 Version:          0.18.0
 GitCommit:        fec3683

2. ##### docker更換國內阿里倉庫，並下載安裝MySQL

2.1 docker更換國內阿里倉庫

sudo mkdir -p /etc/docker
sudo tee /etc/docker/daemon.json <<-'EOF'
{

"registry-mirrors": ["https://rdwyjupq.mirror.aliyuncs.com"]

}
EOF
sudo systemctl daemon-reload
sudo systemctl restart docker

2.2 安裝MySQL

​    2.2.1 下載MySQL

[root@localhost ~]# docker pull mysql
Using default tag: latest
latest: Pulling from library/mysql
c499e6d256d6: Pull complete
22c4cdf4ea75: Pull complete
6ff5091a5a30: Pull complete
2fd3d1af9403: Pull complete
0d9d26127d1d: Pull complete
54a67d4e7579: Pull complete
fe989230d866: Pull complete
3a808704d40c: Pull complete
826517d07519: Pull complete
69cd125db928: Pull complete
b5c43b8c2879: Pull complete
1811572b5ea5: Pull complete
Digest: sha256:b69d0b62d02ee1eba8c7aeb32eba1bb678b6cfa4ccfb211a5d7931c7755dc4a8
Status: Downloaded newer image for mysql:latest
docker.io/library/mysql:latest

​    2.2.2 查看MySQL鏡像

[root@localhost ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
mysql latest 9228ee8bac7a 4 days ago 547MB

​    2.2.3 建立MySQL的掛載文件目錄（日誌、數據、配置）

[root@localhost ~]# mkdir -p /root/mysql/data /root/mysql/logs /root/mysql/conf

​    2.2.4 先啓動容器（爲了複製配置文件）（這種作法顯得多餘，可是Docker不是很精通的我沒想到更好的辦法，請各位大神指導）

[root@localhost conf]# docker run -d -p 3306:3306 --name mysql -e MYSQL_ROOT_PASSWORD="123456" mysql
05d161e69f3b2e3e4ebaa50f822934599a31e7ade330e1440a68aec9e404f7ae

​    2.2.5 複製配置文件

[root@localhost conf]# docker cp mysql:/etc/mysql/my.cnf /root/mysql/conf/

​    2.2.6 中止並刪容器

[root@localhost conf]# docker stop mysql
mysql
[root@localhost conf]# docker rm mysql
mysql

​    2.2.7 從新啓動容器（加上掛載）

[root@localhost conf]# docker run --name mysql -p 3306:3306 -e MYSQL_ROOT_PASSWORD=123456 --mount type=bind,src=/root/mysql/conf/my.cnf,dst=/etc/mysql/my.cnf --mount ty
pe=bind,src=/root/mysql/data,dst=/var/lib/mysql --mount type=bind,src=/root/mysql/logs,dst=/logs --restart=on-failure:3 -d mysql64824c7e84ceb3513b65a375c55f2c53bc653f95b119008296122b13ff632ba1

​    2.2.8 進入MySQL查詢現有字符集，結果都是utf8mb4

show variables like '%char%';

​    2.2.9 在掛載的配置文件更改字符集

character-set-server=utf8

default-character-set=utf8

default-character-set=utf8

​    2.2.10 重啓docker容器，並查看字符集已經更改，證實掛載的配置文件有效

![file](/img/bVbFAMj)

3. ##### 搭建主從複製數據庫

3.1 配置主Master庫

​    3.1.1 進入主庫掛載配置文件my.cnf，加入如下配置並重啓docker容器

[mysqld]
## 同一局域網內注意要惟一
server-id=100
## 開啓二進制日誌功能，能夠隨便取（關鍵）
log-bin=mysql-bin

​    3.1.2 在主Master庫執行語句

CREATE USER 'slave'@'%' IDENTIFIED BY '123456';
GRANT REPLICATION SLAVE, REPLICATION CLIENT ON . TO 'slave'@'%';

​    爲防止後面出現報錯[Authentication plugin 'caching_sha2_password' cannot be loaded]，執行下面語句

ALTER USER 'slave'@'%' IDENTIFIED BY 'password' PASSWORD EXPIRE NEVER; #修改加密規則
ALTER USER 'slave'@'%' IDENTIFIED WITH mysql_native_password BY 'password'; #更新一下用戶的密碼
FLUSH PRIVILEGES;
alter user 'slave'@'%' identified by '123456';

最後執行語句獲取File， Position

show master status;

3.2 配置從Slave庫

​    3.2.1 進入從庫掛載配置文件my.cnf，加入如下配置並重啓docker容器

[mysqld]
## 設置server_id,注意要惟一
server-id=101
## 開啓二進制日誌功能，以備Slave做爲其它Slave的Master時使用
log-bin=mysql-slave-bin
## relay_log配置中繼日誌
relay_log=edu-mysql-relay-bin

​    3.2.2 連接主從庫，在從庫執行語句

change master to master_host='192.168.47.128', master_user='slave', master_password='123456', master_port=3306, master_log_file='mysql-bin.000001', master_log_pos= 5938, master_connect_retry=30;

**master_host** ：Master的地址

**master_port**：Master的端口號，指的是容器的端口號

**master_user**：用於數據同步的用戶

**master_password**：用於同步的用戶的密碼

**master_log_file**：指定 Slave 從哪一個日誌文件開始複製數據，即上文中提到的 File 字段的值

**master_log_pos**：從哪一個 Position 開始讀，即上文中提到的 Position 字段的值

**master_connect_retry**：若是鏈接失敗，重試的時間間隔，單位是秒，默認是60秒

​    3.2.3 查看主從同步狀態

show slave status ;

![file](/img/bVbFAMk)

​    正常狀況下，SlaveIORunning 和 SlaveSQLRunning 都是No，由於咱們尚未開啓主從複製過程。
  
   3.2.4 開啓主從複製

start slave;

從新查看主從同步狀態， 這時SlaveIORunning 和 SlaveSQLRunning 都是Yes，若是你的SlaveIORunning 和 SlaveSQLRunning 其中一個是Connecting或者No，就證實配置有錯，查看Last_IO_Error報錯的詳細信息

經過下面命令，刪除已經配置的主從連接信息，從新進行配置

stop slave; reset master;