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MySQL5.7升级到8.0过程详解【转】

作者:互联网

前言:

不知不觉,MySQL8.0已经发布好多个GA小版本了。目前互联网上也有很多关于MySQL8.0的内容了,MySQL8.0版本基本已到稳定期,相信很多小伙伴已经在接触8.0了。本篇文章主要介绍从5.7升级到8.0版本的过程及注意事项,有想做版本升级的小伙伴可以参考下。

1.升级前准备及注意事项

首先,我们要大概了解下MySQL5.7和8.0有哪些不同,参考官方文档和其他网友文章,概括总结出MySQL8.0以下几点新特性:

根据版本变化及官方升级教程,列举出以下几点注意事项:

2.具体升级过程

下面以Linux系统为例,展示下具体升级过程。我的系统是CentOS7.7,原版本是MySQL5.7.23,以In-Place方式直接升级到MySQL8.0.19。

2.1 下载解压安装包

官网下载对应版本的tar包,可通过wget下载或者本地下载后上传。

下载地址:
https://downloads.mysql.com/archives/community/
选择mysql-8.0.19-linux-glibc2.12-x86_64.tar.xz

image.png

执行以下步骤解压tar包:

# 安装包上传至原安装包目录下 我的是/usr/local/ 
cd /usr/local/

# 解压安装包
xz -d mysql-8.0.19-linux-glibc2.12-x86_64.tar.xz
tar -xvf mysql-8.0.19-linux-glibc2.12-x86_64.tar

# 文件夹重命名为mysql8 
mv mysql-8.0.19-linux-glibc2.12-x86_64 mysql8

# 更改文件夹所属
chown -R mysql.mysql /usr/local/mysql8/

2.2 更改配置文件my.cnf

因5.7版本与8.0版本参数有所不同,为了能顺利升级,我们需要更改部分配置参数。主要注意sql_mode、basedir、密码认证插件及字符集设置,其他参数最好还是按照原5.7的来,不需要做调整。下面展示下更改后的配置文件:

# 最后几个for8.0的参数要格外注意
[mysqld]
user = mysql        
datadir = /data/mysql/data  
port = 3306               

socket = /data/mysql/tmp/mysql.sock
pid-file  = /data/mysql/tmp/mysqld.pid
tmpdir = /data/mysql/tmp    
skip_name_resolve = 1
max_connections = 2000
group_concat_max_len = 1024000
lower_case_table_names = 1
log_timestamps=SYSTEM
max_allowed_packet = 32M
binlog_cache_size = 4M
sort_buffer_size = 2M
read_buffer_size = 4M
join_buffer_size = 4M
tmp_table_size = 96M
max_heap_table_size = 96M
max_length_for_sort_data = 8096
default_time_zone = '+8:00'

#logs
server-id = 1003306
log-error = /data/mysql/logs/error.log
slow_query_log = 1
slow_query_log_file = /data/mysql/logs/slow.log
long_query_time = 3
log-bin = /data/mysql/logs/binlog
binlog_format = row
log_bin_trust_function_creators = 1
gtid_mode = ON
enforce_gtid_consistency = ON

#for8.0
sql_mode = STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_ENGINE_SUBSTITUTION
character-set-server = utf8
collation_server = utf8_general_ci
basedir = /usr/local/mysql8
skip_ssl
default_authentication_plugin=mysql_native_password

2.3 执行升级程序

所有前置工作准备好后就可以开始正式升级了,不过升级前还是建议先全库备份下。万事俱备后,按照如下指示进行正式升级。

# 进入原5.7 mysql命令行 正确关闭数据库
mysql> select version();
+------------+
| version()  |
+------------+
| 5.7.23-log |
+------------+
1 row in set (0.00 sec)

mysql> show variables like 'innodb_fast_shutdown';
+----------------------+-------+
| Variable_name        | Value |
+----------------------+-------+
| innodb_fast_shutdown | 1     |
+----------------------+-------+
1 row in set (0.00 sec)
# 确保数据都刷到硬盘上,更改成0
mysql> set global innodb_fast_shutdown=0;
Query OK, 0 rows affected (0.00 sec)

mysql> shutdown;
Query OK, 0 rows affected (0.00 sec)

mysql> exit
Bye

# 退出至终端 用mysql8.0.19客户端直接启动
[root@centos ~]# /usr/local/mysql8/bin/mysqld_safe --defaults-file=/etc/my.cnf --user=mysql & 
[1] 23333
[root@centos ~]# 2020-05-20T07:07:02.337626Z mysqld_safe Logging to '/data/mysql/logs/error.log'.
2020-05-20T07:07:02.366244Z mysqld_safe Starting mysqld daemon with databases from /data/mysql/data

# 可观察下错误日志看是否报错 然后重新登录测试
[root@centos ~]# mysql -uroot -p123456 
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 17
Server version: 8.0.19 MySQL Community Server - GPL

Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> select version();
+-----------+
| version() |
+-----------+
| 8.0.19    |
+-----------+
1 row in set (0.00 sec)

2.4 环境变量修改

因basedir由/usr/local/mysql变成了/usr/local/mysql8,故相关环境变量推荐修改下。可按照以下步骤来操作验证:

# 修改mysql服务启动项配置
vi /etc/init.d/mysql
# 修改basedir目录
basedir=/usr/local/mysql8

# 修改PATH变量
vi /etc/profile 
# 将PATH中的/usr/local/mysql/bin改为/usr/local/mysql8/bin 

# 生效验证
[root@centos ~]# source /etc/profile
[root@centos ~]# which mysql
/usr/local/mysql8/bin/mysql
[root@centos ~]# mysql -V
mysql  Ver 8.0.19 for linux-glibc2.12 on x86_64 (MySQL Community Server - GPL)

总结:

至此,我们的数据库由5.7成功升级至8.0!对比MySQL安装过程及升级过程,发现二者很相似,其实升级过程并不复杂,复杂的是升级后的验证及兼容测试,特别是对于复杂的业务库,MySQL版本升级还是要小心的。真实环境建议先升级从库,验证无误后再逐步对主库进行升级

转自

MySQL5.7升级到8.0过程详解 - MySQL技术 - 博客园
https://www.cnblogs.com/mysqljs/p/12936024.html

标签:8.0,local,MySQL5.7,升级,详解,usr,mysql,data
来源: https://www.cnblogs.com/paul8339/p/16611732.html