平时做技术实践时，很多问题不是概念不会，而是细节没串起来。拿“MySQL8 主从同步容器化部署”来说，它看着像小点，放到项目里常会牵出环境、配置、兼容性和维护成本。下面按实际采用顺序，把思路、关键写法和容易踩坑的地方讲清楚，便于大家直接对照操作。
一、引言
在这个场景下，本章主要讲解借助Docker容器化部署的方式实现MySQL的主从运行模式（一主一从）。默认双节点都安装了Docker、docker-compose。
详解
1、示例环境
| 主节点 | 从节点 | 主从架构 |
|---|---|---|
| 192.168.25.130 | 192.168.25.131 | 主从同步；异步模式 |
2、主节点安装MySQL
1）新建目录
>> mkdir -p /opt/software/mysql8/{conf,logs,init,secrets} /data/mysql8/{data,backup}
>> cd /opt/software/mysql82）新建docker-compose.yml文件
>> vim docker-compose.yml # 内容如下，复制粘贴即可
---
# 定义密钥
secrets:
passwd_root:
file: ./secrets/passwd_root.txt
passwd_sync:
file: ./secrets/passwd_sync.txt
services:
mysql8:
container_name: mysql-master
image: mysql:8.0.45
user: root
restart: unless-stopped
privileged: true
ports:
- 30096:3306
volumes:
- /data/mysql8/data:/var/lib/mysql # 数据目录挂载
- ./conf/my.cnf:/etc/my.cnf:ro # 配置文件只读挂载（不允许容器内对其写操作）
- ./logs:/var/log/mysql
- ./init/:/docker-entrypoint-initdb.d/:ro
- /etc/localtime:/etc/localtime
secrets: # 挂载secrets; 默认挂载至容器内的 /run/secrets/ 路径
- passwd_root
- passwd_sync
environment:
TZ: Asia/Shanghai
MYSQL_ROOT_PASSWORD_FILE: "/run/secrets/passwd_root"
MYSQL_USER_PASSWORD_FILE: "/run/secrets/passwd_sync"
healthcheck:
test: ["CMD-SHELL", "MYSQL_PWD="$$(cat /run/secrets/passwd_root)" mysql -h 127.0.0.1 -uroot --protocol=TCP -e 'SELECT 1' >/dev/null 2>&1 || exit 1"]
interval: 10s
timeout: 5s
retries: 5
start_period: 60s
...
3）新建设置文件
>> vim ./conf/my.cnf # 内容如下，复制粘贴即可
[client]
default-character-set = utf8mb4
socket = /var/lib/mysql/mysql.sock
[mysql]
default-character-set = utf8mb4
[mysqld]
server-id = 1
user = mysql
autocommit = 1
datadir = /var/lib/mysql
socket = /var/lib/mysql/mysql.sock
pid-file = /var/log/mysql/mysqld.pid
log-error = /var/log/mysql/mysqld.log
symbolic-links = 0
character-set-server=utf8mb4
# binlog
log-bin = master-bin
# 指定哪些库表不进行同步
replicate-wild-ignore-table = information_schema.%
# 字段变化增量值
auto_increment_increment = 2
# 初始字段ID
auto_increment_offset = 1
# 忽略所有复制产生的错误
slave-skip-errors = all
binlog_cache_size=16M
binlog_format=ROW
binlog_row_image=FULL
max_binlog_cache_size=1GB
# 设置单个 binlog 文件的最大大小
max_binlog_size = 300M
# binlog日志保留时间，单位秒，30天
binlog_expire_logs_seconds=2592000
ft_min_word_len=4
connect_timeout=600
interactive_timeout=1800
wait_timeout=600
# 启用GTID
gtid_mode = ON
enforce_gtid_consistency = ON
group_concat_max_len = 102400
lower-case-table_names=1
character-set-server=utf8mb4
collation-server=utf8mb4_general_ci
default-storage-engine=innodb
# 密码认证插件
default_authentication_plugin=mysql_native_password
default-time-zone = '+08:00'
slow_query_log=1
#输出死锁
innodb_print_all_deadlocks=1
long_query_time=10
max_connections=4096
max_connect_errors=1024
max_allowed_packet=64M
back_log=512
interactive_timeout=3600
sort_buffer_size=2M
join_buffer_size=2M
read_buffer_size=2M
read_rnd_buffer_size=2M
thread_cache_size=256
table_open_cache=10000
max_heap_table_size=64M
tmp_table_size=64M
thread_stack=192KB
local_infile=0
skip-name-resolve
skip-external-locking
# innodb
innodb_buffer_pool_size=2048M
#ibdata1的数据设置应该和本地ibdata1大小的一致
innodb_data_file_path=ibdata1:1G;ibdata2:1G:autoextend
innodb_temp_data_file_path=ibtmp1:12M:autoextend:max:5G
innodb_read_io_threads=8
innodb_write_io_threads=8
innodb_file_per_table=1
#将InnoDB的日志刷新方式调整为O_DIRECT，可以减少数据在缓存和磁盘之间的复制
innodb_flush_method=O_DIRECT
#将InnoDB的日志刷新策略调整为每秒刷新，可以提高性能
innodb_flush_log_at_trx_commit=2
innodb_lock_wait_timeout=120
innodb_thread_concurrency=16
innodb_log_buffer_size=8M
#将InnoDB日志文件大小调整为256M，可以减少写入磁盘的次数，提高性能
innodb_log_file_size=256M
innodb_redo_log_capacity=268435456
innodb_buffer_pool_size=4G
innodb_log_files_in_group=3
innodb_max_dirty_pages_pct=90
innodb_open_files=10000
skip_replica_start
log_replica_updates
sql_mode="NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO"
relay-log=relay.log
relay-log-index=slave-relay.index
log_bin_trust_function_creators = 1
4）新建初始化需的文件
# 创建密码文件
>> echo "super@ADMIN_2026" > ./secrets/passwd_root.txt # root密码
>> echo "sync@ADMIN_2026" > ./secrets/passwd_sync.txt # 主从同步用户密码
>> vim ./init/init.sh # 可根据需要修改
#! /bin/bash
set -euo pipefail
SYNC_PASSWORD="$(cat "$MYSQL_USER_PASSWORD_FILE")"
# 执行指定SQL，可自定义；这里只用于创建用户
mysql -uroot -p"$MYSQL_ROOT_PASSWORD" << EOF
create user sync@'%' identified with mysql_native_password by "${SYNC_PASSWORD}";
grant replication slave on *.* to sync@'%';
flush privileges;
set global max_connect_errors=1000;
EOF
5）启动主节点MySQL
# 授权
>> chmod -R 755 /data/mysql8 /opt/software/mysql8; chmod +x ./init/*.sh; chmod 644 secrets/*
# 启动
>> docker-compose up -d
>> docker-compose logs -f # 启动后，查看日志如下图
3、从节点安装MySQL
1）新建目录
>> mkdir -p /opt/software/mysql8/{conf,logs,init,secrets,scripts} /data/mysql8/data
>> cd /opt/software/mysql8
2）新建docker-compose.yml文件
>> vim docker-compose.yml # 内容如下，复制粘贴即可
---
---
# 定义密钥
secrets:
passwd_root:
file: ./secrets/passwd_root.txt
services:
mysql8:
container_name: mysql-slave
image: mysql:8.0.45
user: root
restart: unless-stopped
privileged: true
ports:
- 30096:3306
volumes:
- /data/mysql8/data:/var/lib/mysql # 数据目录挂载
- ./conf/my.cnf:/etc/my.cnf
- ./logs:/var/log/mysql
- ./init/:/docker-entrypoint-initdb.d/:ro
- /etc/localtime:/etc/localtime
secrets: # 挂载secrets; 默认挂载至容器内的 /run/secrets/ 路径
- passwd_root
environment:
TZ: Asia/Shanghai
MYSQL_ROOT_PASSWORD_FILE: "/run/secrets/passwd_root"
MYSQL_MASTER_HOST: 192.168.25.130 # MySQL Master节点，根据实际情况修改
MYSQL_MASTER_PORT: 30096 # MySQL Master节点端口
healthcheck:
test: ["CMD-SHELL", "MYSQL_PWD="$$(cat /run/secrets/passwd_root)" mysql -h127.0.0.1 -uroot --protocol=TCP -e 'SELECT 1' >/dev/null 2>&1 || exit 1"]
interval: 10s
timeout: 5s
retries: 5
start_period: 60s
...
3）新建设置文件
>> vim ./conf/my.cnf # 内容如下，复制粘贴即可
[client]
default-character-set = utf8mb4
socket = /var/lib/mysql/mysql.sock
[mysql]
default-character-set = utf8mb4
[mysqld]
server-id = 2
user = mysql
autocommit = 1
datadir = /var/lib/mysql
socket = /var/lib/mysql/mysql.sock
pid-file = /var/log/mysql/mysqld.pid
log-error = /var/log/mysql/mysqld.log
symbolic-links = 0
character-set-server=utf8mb4
# binlog
log-bin = slave-bin
# 指定哪些库表不进行同步
replicate-wild-ignore-table = information_schema.%
# 字段变化增量值
auto_increment_increment = 2
# 初始字段ID
auto_increment_offset = 1
# 忽略所有复制产生的错误
slave-skip-errors = all
binlog_cache_size=16M
binlog_format=ROW
binlog_row_image=FULL
max_binlog_cache_size=1GB
# 设置单个 binlog 文件的最大大小
max_binlog_size = 300M
# binlog日志保留时间，单位秒，30天
binlog_expire_logs_seconds=2592000
ft_min_word_len=4
connect_timeout=600
interactive_timeout=1800
wait_timeout=600
# 启用GTID
gtid_mode = ON
enforce_gtid_consistency = ON
group_concat_max_len = 102400
lower-case-table_names=1
character-set-server=utf8mb4
collation-server=utf8mb4_general_ci
default-storage-engine=innodb
# 密码认证插件
default_authentication_plugin=mysql_native_password
default-time-zone = '+08:00'
slow_query_log=1
#输出死锁
innodb_print_all_deadlocks=1
long_query_time=10
max_connections=4096
max_connect_errors=1024
max_allowed_packet=64M
back_log=512
interactive_timeout=3600
sort_buffer_size=2M
join_buffer_size=2M
read_buffer_size=2M
read_rnd_buffer_size=2M
thread_cache_size=256
table_open_cache=10000
max_heap_table_size=64M
tmp_table_size=64M
thread_stack=192KB
local_infile=0
skip-name-resolve
skip-external-locking
# innodb
innodb_buffer_pool_size=2048M
#ibdata1的数据设置应该和本地ibdata1大小的一致
innodb_data_file_path=ibdata1:1G;ibdata2:1G:autoextend
innodb_temp_data_file_path=ibtmp1:12M:autoextend:max:5G
innodb_read_io_threads=8
innodb_write_io_threads=8
innodb_file_per_table=1
#将InnoDB的日志刷新方式调整为O_DIRECT，可以减少数据在缓存和磁盘之间的复制
innodb_flush_method=O_DIRECT
#将InnoDB的日志刷新策略调整为每秒刷新，可以提高性能
innodb_flush_log_at_trx_commit=2
innodb_lock_wait_timeout=120
innodb_thread_concurrency=16
innodb_log_buffer_size=8M
#将InnoDB日志文件大小调整为256M，可以减少写入磁盘的次数，提高性能
innodb_log_file_size=256M
innodb_redo_log_capacity=268435456
innodb_buffer_pool_size=4G
innodb_log_files_in_group=3
innodb_max_dirty_pages_pct=90
innodb_open_files=10000
skip_replica_start
log_replica_updates
sql_mode="NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO"
relay-log=relay.log
relay-log-index=slave-relay.index
log_bin_trust_function_creators = 1
4）新建初始化需的文件
# 创建密码文件
>> echo "super@ADMIN_2026" > ./secrets/passwd_root.txt # root密码，和主节点一致
>> vim ./init/backup.sh # 可根据需要修改
#!/bin/bash
set -euo pipefail
# 备份主节点的数据
echo "开始备份主节点数据..."
sleep 5
/usr/bin/mysqldump -h${MYSQL_MASTER_HOST} -P${MYSQL_MASTER_PORT} -uroot -p"${MYSQL_ROOT_PASSWORD}" --all-databases --source-data=2 --single-transaction > /var/lib/mysql/backup.sql
# 导入备份数据
echo "正在导入备份数据..."
sleep 5
/usr/bin/mysql -uroot -p"${MYSQL_ROOT_PASSWORD}" < /var/lib/mysql/backup.sql
5）启动从节点MySQL
# 授权
>> chmod -R 755 /data/mysql8 /opt/software/mysql8; chmod +x ./init/*.sh; chmod 644 secrets/*
>> docker-compose up -d # 若要重新执行，则需要先清空data目录
4、设置主从同步
# 创建主从同步SQL脚本
>> cd /opt/software/mysql8
>> vim scripts/replica.sql # 内容如下，根据实际情况调整
STOP REPLICA;
RESET REPLICA;
CHANGE REPLICATION SOURCE TO SOURCE_HOST = '192.168.25.130', SOURCE_PORT = 30096, SOURCE_AUTO_POSITION = 1, GET_SOURCE_PUBLIC_KEY = 1, SOURCE_SSL = 1, SOURCE_RETRY_COUNT = 60, SOURCE_CONNECTION_AUTO_FAILOVER = 1, SOURCE_CONNECT_RETRY = 30; START REPLICA USER = 'sync' PASSWORD = 'sync@ADMIN_2026';
# 执行
>> sleep 30; mysql -h192.168.25.131 -P30096 -uroot -p'super@ADMIN_2026' --socket=/data/mysql8/data/mysql.sock < ./scripts/replica.sql
# 验证同步状态
>> mysql -h192.168.25.131 -P30096 -uroot -p'super@ADMIN_2026' --socket=/data/mysql8/data/mysql.sock -e "show replica statusG"
落到代码里，总的来说，MySQL8 主从同步部署适合结合实际项目边做边理解。先抓住核心思路，再逐步补上细节和边界处理，最后效果会更稳定，也更容易复用。