MySQL 5.7 升级到 8.0

1.升级前检查

要注意操作系统 glibc 的版本, 下载可支持的版本的 mysql 相关的程序包

# 查看操作系统支持的 glibc 版本
strings /lib/x86_64-linux-gnu/libc.so.6 | grep GLIBC_

wget https://downloads.mysql.com/archives/get/p/43/file/mysql-shell-8.0.36-linux-glibc2.12-x86-64bit.tar.gz
tar xf mysql-shell-8.0.36-linux-glibc2.12-x86-64bit.tar.gz -C /tmp/
cd /tmp/mysql-shell-8.0.34-linux-glibc2.12-x86-64bit/bin
./mysqlsh -uroot -p -S /tmp/mysql.sock -e "util.checkForServerUpgrade()" > util.checkForServerUpgrade.log

2.下载安装包

wget https://downloads.mysql.com/archives/get/p/23/file/mysql-8.0.36-linux-glibc2.12-x86_64.tar.xz
tar xf mysql-8.0.36-linux-glibc2.12-x86_64.tar.xz -C /usr/local/
cd /usr/local && mv mysql-8.0.36-linux-glibc2.12-x86_64 mysql-8.0.36

3.逻辑备份

mysqldump -uroot -p --routines --set-gtid-purged=OFF --single-transaction --databases XXX1  XXX2 > /data/all-databases-`date +%F`.sql
# --routines 备份存储过程和函数

4.关闭数据库

mysql -h127.0.0.1 -uroot -p'xxx'
select version();
show variables like 'innodb_fast_shutdown';
set global innodb_fast_shutdown=0;
shutdown;
exit;

5.备份数据目录和配置文件

cp -r /data/local/mysql/data /data/local/mysql/data_`date +%F`
cp /etc/my.cnf /etc/my.cnf_`date +%F`

6.修改配置文件

# /etc/my.cnf

[mysqld]
user=mysql
basedir=/usr/local/mysql-8.0.36
datadir=/data/local/mysql/data
server_id=3
port=3306
socket=/tmp/mysql.sock
log_bin=/data/local/mysql/binlog/bin-log
binlog_format = ROW
max_binlog_size = 100M
log_slave_updates
expire_logs_days=7

long_query_time=5
slow_query_log=ON
slow_query_log_file=/data/local/mysql/slow_query.log

log-error=/data/local/mysql/mysql-error.log
log_timestamps=SYSTEM

max_connections=1000
max_allowed_packet=500M
skip-name-resolve=1

character_set_server=utf8
collation-server=utf8_general_ci

# For 8.0
sql_mode = STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_ENGINE_SUBSTITUTION
default_authentication_plugin=mysql_native_password
default-storage-engine=INNODB

[mysql]
socket=/tmp/mysql.sock
default-character-set=utf8

7.执行升级

/usr/local/mysql-8.0.36/bin/mysqld_safe --defaults-file=/etc/my.cnf --user=mysql --upgrade=FORCE

# 会一直卡住
# error 日志看到以下输出, 说明升级完成
# Server upgrade from '80036' to '80036' completed.

# 新开窗口, 连上 mysql 执行命令查看
select version();

8.修改环境变量及启动脚本

export PATH=$PATH:/usr/local/mysql-8.0.36/bin

# /etc/init.d/mysqld
basedir=/usr/local/mysql-8.0.36

9.重启 mysql

systemctl daemon-reload
/etc/init.d/mysqld restart