Docker MySQL 8.0.45性能优化配置文档方式

宿主机                         容器内
──────────────────────────────────────────
/data/mysql8/conf/  ──bind──▶ /etc/mysql/conf.d/
  ├── max_allowed_packet.cnf       (由 my.cnf 中 !includedir 自动加载)
  └── performance.cnf

/data/mysql8/data/  ──bind──▶ /var/lib/mysql/

!includedir /etc/mysql/conf.d/

宿主机文件                     挂载关系        容器内加载路径
────────────────────────────────────────────────────────────
/data/mysql8/conf/     ──bind mount──▶  /etc/mysql/conf.d/
  └─ performance.cnf                      └─ 被 my.cnf 的 !includedir 自动加载

docker inspect mysql8 --format '{{json .Mounts}}' | python3 -m json.tool

[
    {
        "Type": "bind",
        "Source": "/data/mysql8/conf",
        "Destination": "/etc/mysql/conf.d",
        "RW": true
    },
    {
        "Type": "bind",
        "Source": "/data/mysql8/data",
        "Destination": "/var/lib/mysql",
        "RW": true
    }
]

# Step 1: 在宿主机创建配置文件
cat > /data/mysql8/conf/performance.cnf << 'EOF'
[mysqld]
innodb_buffer_pool_size = 2G
innodb_buffer_pool_instances = 2
innodb_log_file_size = 256M
# ... 其他参数 ...
max_allowed_packet = 512M
EOF

# Step 2: 验证容器内可见
docker exec mysql8 cat /etc/mysql/conf.d/performance.cnf

# Step 3: 优雅关闭 + 重启（innodb_log_file_size 变更需额外处理）
docker exec mysql8 mysql -uroot -p -e "SET GLOBAL innodb_fast_shutdown=0;"
docker exec mysql8 rm -f /var/lib/mysql/ib_logfile*
docker restart mysql8

# Step 4: 验证参数已从配置文件加载
docker exec mysql8 mysql -uroot -p -e "SHOW VARIABLES LIKE 'innodb_buffer_pool_size';"
# 预期: 2147483648 (2G)

# 重启
docker restart mysql8

# 验证关键参数仍为优化值
docker exec mysql8 mysql -uroot -p -e "
SHOW VARIABLES LIKE 'innodb_buffer_pool_size';
SHOW VARIABLES LIKE 'innodb_log_file_size';
SHOW VARIABLES LIKE 'max_allowed_packet';
"

/data/mysql8/conf/
├── max_allowed_packet.cnf    # [mysqld] max_allowed_packet=512M
└── performance.cnf           # [mysqld] 全部 InnoDB/连接/缓存优化参数

值为 0：每秒写入日志并刷盘（性能最高，可能丢 1 秒数据）
值为 1：每次提交都写入并刷盘（最安全，性能最低）  ← 默认
值为 2：每次提交写入，每秒刷盘（平衡方案）        ← 当前

服务器总内存:     7.7 GB
系统预留:         ~1.0 GB
其他服务:         ~3.0 GB
MySQL Buffer Pool: 2.0 GB
剩余可用:         ~1.7 GB

[mysqld]

# ===== InnoDB 核心优化 =====
# Buffer Pool: 最重要参数，设为可用内存 60-70%
# 当前服务器 7.7G 总内存，分配 2G 给 MySQL
innodb_buffer_pool_size = 2G
innodb_buffer_pool_instances = 2

# Redo Log: 增大减少 checkpoint 频率
innodb_log_file_size = 256M
innodb_log_buffer_size = 64M

# IO 容量: SSD 推荐 1000-2000，HDD 保持 200
innodb_io_capacity = 1000
innodb_io_capacity_max = 3000

# 刷新策略: 1=每次刷盘(最安全), 2=每秒刷盘(平衡)
innodb_flush_log_at_trx_commit = 2
innodb_flush_method = O_DIRECT

# ===== 连接与线程 =====
thread_cache_size = 32
max_connections = 300
wait_timeout = 3600
interactive_timeout = 3600

# ===== 表缓存 =====
table_open_cache = 4000
table_definition_cache = 4000

# ===== 临时表 =====
tmp_table_size = 64M
max_heap_table_size = 64M

# ===== 排序与 JOIN 缓冲 (per-session) =====
sort_buffer_size = 512K
join_buffer_size = 512K
read_buffer_size = 256K
read_rnd_buffer_size = 512K

# ===== 慢查询日志 =====
slow_query_log = ON
long_query_time = 2
slow_query_log_file = /var/lib/mysql/slow.log

# ===== Binlog =====
binlog_cache_size = 1M
binlog_expire_logs_seconds = 604800

# ===== 其他 =====
max_allowed_packet = 512M

# 1. 优雅关闭 MySQL (完整刷盘)
docker exec mysql8 mysql -uroot -p -e "SET GLOBAL innodb_fast_shutdown=0;"

# 2. 删除旧 redo log 文件
docker exec mysql8 rm -f /var/lib/mysql/ib_logfile*

# 3. 重启容器（会自动创建新大小的 redo log）
docker restart mysql8

# 确认所有参数已生效
docker exec mysql8 mysql -uroot -p -e "
SHOW VARIABLES LIKE 'innodb_buffer_pool_size';
SHOW VARIABLES LIKE 'innodb_log_file_size';
SHOW VARIABLES LIKE 'innodb_flush_log_at_trx_commit';
SHOW VARIABLES LIKE 'innodb_io_capacity';
SHOW VARIABLES LIKE 'slow_query_log';
SHOW VARIABLES LIKE 'max_allowed_packet';
"

docker exec mysql8 mysqldumpslow /var/lib/mysql/slow.log

SHOW STATUS LIKE 'Innodb_buffer_pool_read%';
-- read_requests / (reads + read_requests) 应 > 95%