1. 注意事项

1.1. 升级路径

1. 仅支持 GA 版本之间的升级
   • MySQL 5.7 GA 版本链接： https://dev.mysql.com/downloads/mysql/5.7.html
   • MySQL 8.0 GA 版本链接：https://dev.mysql.com/downloads/mysql/8.0.html
2. MySQL 5.7-> MySQL 8.0，建议升级至 5.7 最新版，再升级 8.0。
3. MySQL 5.6-> MySQL 5.7 -> MySQL 8.0，不支持跨大版本升级。
4. MySQL 8.0.x -> MySQL 8.0.z，支持跨小版本升级。

1.2. MySQL Shell 升级检查

可通过 MySQL Shell 工具进行版本升级检查，以验证是否满足升级条件。该工具适用于 MySQL5.7 和 MySQL 8.0 的所有 GA 版本。

官方文档链接：https://dev.mysql.com/doc/mysql-shell/8.0/en/mysql-shell-utilities-upgrade.html

1.2.1. MySQL Shell 安装

MySQL Shell 下载链接：https://dev.mysql.com/downloads/shell/

1. 安装 MySQL Shell

sudo wget https://cdn.mysql.com//Downloads/MySQL-Shell/mysql-shell-8.0.30-linux-glibc2.12-x86-64bit.tar.gz
sudo tar -xzvf mysql-shell-8.0.30-linux-glibc2.12-x86-64bit.tar.gz 
sudo mv mysql-shell-8.0.30-linux-glibc2.12-x86-64bit /usr/local/
sudo ln -s /usr/local/mysql-shell-8.0.30-linux-glibc2.12-x86-64bit /usr/local/mysql-shell
sudo chown -R /usr/local/mysql-shell*

cat ~/.bash_profile
export PATH=$PATH:/usr/local/mysql-shell/bin

2. 运行 MySQL Shell

可直接执行 mysqlsh，进入 cli 交互模式，在执行升级检查时，指定 用户名/密码。

[mysql@localhost ~]$ mysqlsh
MySQL Shell 8.0.30

Copyright (c) 2016, 2022, Oracle and/or its affiliates.
Oracle is a registered trademark of Oracle Corporation and/or its affiliates.
Other names may be trademarks of their respective owners.

Type '\help' or '\?' for help; '\quit' to exit.
 MySQL  JS > 

也可在执行 mysqlsh 时，通过参数选项-u与-p直接指定 用户名/密码。

[mysql@localhost ~]$ mysqlsh -uroot -P5306 -p
Please provide the password for 'root@localhost:5306': <输入 root 密码>

 MySQL  localhost:5306  JS > \status
MySQL Shell version 8.0.30

Connection Id:                10
Current schema:               
Current user:                 root@127.0.0.1
SSL:                          Not in use.
Using delimiter:              ;
Server version:               5.7.22-log MySQL Community Server (GPL)
Protocol version:             Classic 10
Client library:               8.0.30
Connection:                   localhost via TCP/IP
TCP port:                     5306
Server characterset:          utf8mb4
Schema characterset:          utf8mb4
Client characterset:          utf8mb4
Conn. characterset:           utf8mb4
Result characterset:          utf8mb4
Compression:                  Disabled
Uptime:                       11 hours 49 min 17.0000 sec

Threads: 1  Questions: 371  Slow queries: 0  Opens: 616  Flush tables: 4  Open tables: 31  Queries per second avg: 0.008

以上信息显示，当前 MySQL 服务器版本为 MySQL 5.7.22 社区版。

1.2.2. 升级检查

假设数据库 192.168.3.227 版本为 5.7.22，欲升级 8.0.30。则可通过如下几种方式检查升级。

【注意】
通过 configPath指定配置文件 my.cnf，可以检查新、旧版本冲突的配置项。

1. 以交互模式，执行升级检查。

[mysql@localhost ~]$ mysqlsh
MySQL Shell 8.0.30

Copyright (c) 2016, 2022, Oracle and/or its affiliates.
Oracle is a registered trademark of Oracle Corporation and/or its affiliates.
Other names may be trademarks of their respective owners.

Type '\help' or '\?' for help; '\quit' to exit.
 MySQL  JS > 
 
# 方式1: 检查 URI root@192.168.3.227:5306 处的 MySQL 服务器以升级到 MySQL 服务器版本 8.0.30。用户密码和配置文件路径作为选项字典的一部分提供
 MySQL  JS >  util.checkForServerUpgrade('root@192.168.3.227:5306', {"password":"root", "targetVersion":"8.0.30", "configPath":"/etc/my.cnf"})

# 方式2: 检查 URI root@192.168.3.227:5306 处的 MySQL 服务器是否升级到与当前 MySQL Shell 版本号（默认）匹配的 MySQL 服务器版本号，并返回 JSON 输出以供进一步处理：
 MySQL  JS >  util.checkForServerUpgrade('root@192.168.3.227:5306', {"password":"root", "outputFormat":"JSON", "configPath":"/etc/my.cnf"})

2. 以命令模式，执行升级检查。

# 方式1: 指定服务器的 my.cnf 配置文件，检查 MySQL 服务器 root@192.168.3.227:5306 是否升级到版本 8.0.30，并返回 JSON 输出：
[mysql@localhost ~]$ mysqlsh -- util checkForServerUpgrade root@192.168.3.227:5306 --target-version=8.0.30 --output-format=JSON --config-path=/etc/my.cnf

# 方式2：将连接信息用大括号括起来，作为 mysqlsh 的连接选项，检查 MySQL 服务器是否升级到版本 8.0.30，并返回 JSON 输出
[mysql@localhost ~]$ mysqlsh -- util check-for-server-upgrade { --user=root --host=192.168.3.227 --port=5306 } --target-version=8.0.30 --output-format=JSON --config-path=/etc/my.cnf

# 方式3：使用套接字连接 MySQL 5.7 服务器，检查其是否能升级到与 MySQL Shell 匹配的 MySQL 服务器版本。
[mysql@localhost ~]$ mysqlsh --socket=/mysql/socket/mysql.sock --user=root -e "util.checkForServerUpgrade()"

3. 关于升级检查工具的帮助

mysqlsh> util.help("checkForServerUpgrade")

【权限需求】

版本号低于 MySQL Shell 8.0.20 时，用于运行升级检查器实用程序的用户帐户必须具有 ALL 权限。从 MySQL Shell 8.0.21 开始，用户帐户需要 RELOAD、PROCESS 和 SELECT 权限。

1.2.3. 调整冲突项

根据升级检查结果，手动纠正影响升级的配置项，其中可能需要关注的注意事项如下：

1. MySQL 5.7 的默认身份验证插件为 mysql_native_password，而 MySQL 8.0 的默认身份验证插件变更为 cache_sha2_password。即 MySQL 全局系统变量 default_authentication_plugin 的默认值从 mysql_native_password 变为 caching_sha2_password。该变化仅影响升级后的新建用户，不影响存量用户。

若启用新的验证插件，则需要通过如下命令修改用户密码。

ALTER USER <用户名> IDENTIFIED WITH caching_sha2_password BY '<密码>';

2. 如想继续保持适用 mysql_native_password 身份验证插件，可为 MySQL 服务器的配置文件（Linux 系统默认位置为 /etc/my.cnf）中增加如下参数。

[mysqld]
default_authentication_plugin=mysql_native_password

【注意】
在 MySQL 8.0 版本中，用户验证方式配置项 default_authentication_plugin 已废弃。替换为 authentication_policy

3. 需将分区表的存储引擎调整为 InnoDB

若数据库中存在存储引擎不是 InnoDB 的分区表，需将这些分区表的存储引擎调整为 InnoDB。命令语法如下：

ALTER TABLE <表名> ENGINE=InnoDB;

4. 默认字符集已从 latin1 更改为 utf8mb4。将影响如下系统变量：

   • character_set_server 和 character_set_database 系统变量的默认值已从 latin1 更改为 utf8mb4。
   • collat​​ion_server 和 collat​​ion_database 系统变量的默认值已从 latin1_swedish_ci 更改为 utf8mb4_0900_ai_ci。

5. 从 MySQL 8.0.11 开始，禁止使用与服务器初始化时使用的设置不同的 lower_case_table_names 设置来启动服务器。

更多需注意的事项，参考链接：https://dev.mysql.com/doc/refman/8.0/en/upgrading-from-previous-series.html

1.3. 回退方案

1. 执行物理备份。若升级失败，恢复物理备份，并将 /usr/local/mysql 软连接指向旧版 MySQL Server 目录；启动旧版 MySQL。
2. 执行逻辑备份。若升级失败，搭建新版数据库，利用逻辑备份恢复数据。

2. 升级前备份

根据数据库大小，可选择备份方式：物理备份或逻辑备份。

2.1. 物理备份

查看数据目录位置，并执行物理备份

1. 查看数据目录

[mysql@localhost local]$ mysql -uroot -proot -P5306

mysql> show global variables like '%datadir%';
+---------------+------------------+
| Variable_name | Value            |
+---------------+------------------+
| datadir       | /mysql/database/ |
+---------------+------------------+
1 row in set (0.00 sec)

2. 停机备份

设置 innodb_fast_shutdown=0，将数据库关闭方式调整为慢关闭。在 MySQL 主要版本之间升级或降级之前使用 慢关闭 技术，以便在升级过程更新文件格式时做好所有数据文件的准备。

# 1. 调整服务器为慢关闭，并停机
[mysql@localhost ~]$ mysql -u root -p --execute="SET GLOBAL innodb_fast_shutdown=0"
[mysql@localhost ~]$ sudo systemctl stop mysqld

# 2. 执行物理备份
[root@localhost ~]# tar -czvf /mysql/database_bak.tgz /mysql/database/
[root@localhost ~]# ls -l /mysql/
total 524
drwxr-xr-x. 2 mysql mysql   4096 Aug 26 23:53 bin-log
drwxr-xr-x. 5 mysql mysql   4096 Aug 27 12:34 database
-rw-r--r--. 1 root  root  497132 Aug 27 12:53 database_bak.tgz
drwxr-xr-x. 2 mysql mysql   4096 Aug 26 23:47 mysql-log
drwxr-xr-x. 2 mysql mysql   4096 Aug 26 23:53 mysql-tmp
drwxr-xr-x. 2 mysql mysql   4096 Aug 27 12:34 pid
drwxr-xr-x. 2 mysql mysql   4096 Aug 26 23:47 redo-log
drwxr-xr-x. 2 mysql mysql   4096 Aug 26 23:46 relay-log
drwxr-xr-x. 2 mysql mysql   4096 Aug 27 12:34 socket
drwxr-xr-x. 2 mysql mysql   4096 Aug 26 23:46 undo-log

2.2. 逻辑备份

[mysql@localhost ~]$ mysqldump -uroot -h<IP> -P<端口> -p --defaults-extra-file=/etc/my.cnf --set-gtid-purged=off --databases <DB1> <DB2> <DB3> | gzip >/mysqldata/backup/`date +%Y%m%d`_SumDB.sql.gz

3. 执行升级

适用于 5.7.x->5.7.39、5.7.39->8.0.28、8.0.28->8.0.30。其中，5.7.x->5.7.39 需执行 mysql_upgrade 完成系统库（如 mysql）的升级。

另需特别注意，新旧版本配置项的区别。一部分在 8.0.x 中已废弃的配置项，需在配置文件中去除。

MySQL 8.0 默认身份验证插件由 mysql_native_password 调整为 caching_sha2_password，为避免应用报错。升级至 MySQL 8.0 版本后，需在配置文件中增加配置项。

[mysqld]
authentication_policy= mysql_native_password 

【注意】
在 MySQL 8.0 版本中，用户验证方式配置项 default_authentication_plugin 已废弃。替换为 authentication_policy

3.1. 二进制包安装

[root@localhost ~]# export VERSION=5.7.39
[root@localhost ~]# wget https://cdn.mysql.com//Downloads/MySQL-5.7/mysql-${VERSION}-el7-x86_64.tar.gz

[root@localhost ~]# export VERSION=8.0.28
[root@localhost ~]# export VERSION=8.0.30
[root@localhost ~]# wget https://cdn.mysql.com//Downloads/MySQL-8.0/mysql-${VERSION}-el7-x86_64.tar.gz

[root@localhost ~]# tar -xzvf mysql-${VERSION}-el7-x86_64.tar.gz
[root@localhost ~]# mv mysql-${VERSION}-el7-x86_64 /usr/local/

[root@localhost ~]# chown -R mysql:mysql /usr/local/mysql-${VERSION}-el7-x86_64

[root@localhost ~]# ls -l /usr/local/|grep mysql
lrwxrwxrwx. 1 mysql mysql   34 Aug 26 23:05 mysql -> /usr/local/mysql-5.7.22-el7-x86_64
drwxr-xr-x. 9 mysql mysql 4096 Aug 26 23:02 mysql-5.7.22-el7-x86_64
drwxr-xr-x. 9 mysql mysql 4096 Aug 27 12:30 mysql-5.7.39-el7-x86_64
lrwxrwxrwx. 1 mysql mysql   44 Aug 27 00:04 mysql-shell -> mysql-shell-8.0.30-linux-glibc2.12-x86-64bit
drwxr-xr-x. 6 mysql mysql 4096 Aug 27 00:02 mysql-shell-8.0.30-linux-glibc2.12-x86-64bit

3.2. 版本升级

3.2.1. 升级检查

参考 1.2 MySQL Shell 升级检查 完成升级前检查，及冲突项调整。

[mysql@localhost ~]$ export VERSION=5.7.39
[mysql@localhost ~]$ export VERSION=8.0.28
[mysql@localhost ~]$ export VERSION=8.0.30

[mysql@localhost ~]$ whereis mysqlsh
mysqlsh: /usr/local/mysql-shell-8.0.30-linux-glibc2.12-x86-64bit/bin/mysqlsh

[mysql@localhost ~]$ mysqlsh -- util checkForServerUpgrade root@192.168.3.227:5306 --target-version=${VERSION} --output-format=JSON --config-path=/etc/my.cnf

3.2.2. 备份数据库

参考 2 升级前备份，完成停机备份。

[mysql@localhost ~]$ mysql -u root -p --execute="SET GLOBAL innodb_fast_shutdown=0"
[mysql@localhost ~]$ mysql -u root -p --execute="show GLOBAL variables like \"datadir%\""
Enter password: 
+---------------+------------------+
| Variable_name | Value            |
+---------------+------------------+
| datadir       | /mysql/database/ |
+---------------+------------------+

[mysql@localhost ~]$ sudo systemctl stop mysqld

[mysql@localhost ~]$ tar -czvf /mysql/database_bak.tgz /mysql/database/

设置 innodb_fast_shutdown=0，将数据库关闭方式变更为慢关闭。在 MySQL 主要版本之间升级或降级之前使用 慢关闭 技术，以便在升级过程更新文件格式时做好所有数据文件的准备。

3.2.3. MySQL 软件升级

# 1. 更新 MySQL 软连接
[root@localhost ~]# export VERSION=5.7.39
[root@localhost ~]# export VERSION=8.0.28
[root@localhost ~]# export VERSION=8.0.30

[root@localhost ~]# ls -l /usr/local/|grep mysql
[root@localhost ~]# rm /usr/local/mysql
[root@localhost ~]# ln -s /usr/local/mysql-${VERSION}-el7-x86_64 /usr/local/mysql
[root@localhost ~]# chown -R mysql:mysql /usr/local/mysql

# 2. 检查权限
[root@localhost ~]# ls -l /usr/local/|grep mysql
lrwxrwxrwx. 1 mysql mysql   34 Aug 27 12:37 mysql -> /usr/local/mysql-5.7.39-el7-x86_64
drwxr-xr-x. 9 mysql mysql 4096 Aug 26 23:02 mysql-5.7.22-el7-x86_64
drwxr-xr-x. 9 mysql mysql 4096 Aug 27 12:30 mysql-5.7.39-el7-x86_64
lrwxrwxrwx. 1 mysql mysql   44 Aug 27 00:04 mysql-shell -> mysql-shell-8.0.30-linux-glibc2.12-x86-64bit
drwxr-xr-x. 6 mysql mysql 4096 Aug 27 00:02 mysql-shell-8.0.30-linux-glibc2.12-x86-64bit

3.2.4. 更新配置文件

[root@localhost ~]# ls -l /etc/my.cnf 
-rw-r--r--. 1 root root 2396 Aug 26 23:47 /etc/my.cnf
[root@localhost ~]# cp /etc/my.cnf /etc/my.cnf.bak

根据 1.2.2 及 1.2.3 升级检查中，检测出的冲突项，调整配置文件 /etc/my.cnf。

1. 适用 5.7.x 配置文件

# 5.7.x 配置文件
[mysql@localhost ~]$ export MEMTOTAL=$(grep MemTotal /proc/meminfo|awk '{print $2}')
[mysql@localhost ~]$ export INNODB_BUFFER=$(( MEMTOTAL * 1024 * 8 / 10 ))
[mysql@localhost ~]$ echo ${INNODB_BUFFER}

[mysql@localhost ~]$ cat /etc/my.cnf
[mysqld]
bind-address=0.0.0.0
port= 5306
user= mysql
basedir=/usr/local/mysql
datadir=/mysql/database/
socket=/mysql/socket/mysql.sock
tmpdir=/mysql/mysql-tmp/
log-error=/mysql/mysql-log/mysql.err
pid-file=/mysql/pid/mysql.pid

default-authentication-plugin=mysql_native_password

### Server Config  ###
server-id= 100
autocommit = 1  
character_set_server= utf8mb4 
collation-server = utf8mb4_general_ci
skip_name_resolve = 1  
open_files_limit = 65535
max_connections = 3000  
max_connect_errors = 100  
interactive_timeout = 18800  
wait_timeout = 18800 
transaction_isolation = READ-COMMITTED  
explicit_defaults_for_timestamp = 1  
sql_mode = "STRICT_TRANS_TABLES,NO_ENGINE_SUBSTITUTION,NO_ZERO_DATE,NO_ZERO_IN_DATE,ERROR_FOR_DIVISION_BY_ZERO" 
table_open_cache = 4000
max_allowed_packet = 16M
join_buffer_size = 128M  
tmp_table_size = 128M
max_heap_table_size = 128M  
read_buffer_size = 16M  
read_rnd_buffer_size = 32M  
sort_buffer_size = 32M
lower_case_table_names= 1
explicit_defaults_for_timestamp=true

### slow query config ###
slow_query_log = on
long_query_time = 600
slow_query_log_file =/mysql/mysql-log/slowquery.log

### binlog config ###
#gtid_mode = on
#enforce_gtid_consistency = on
innodb-file-per-table = 1
#sync_binlog = 1

log-bin=/mysql/bin-log/mysql-bin
binlog_format = row
# binlog_expire_logs_seconds = 172800      #  
max_binlog_size = 1G
binlog_ignore_db = mysql
binlog_ignore_db = information_schema
binlog_ignore_db = performation_schema
binlog_ignore_db = sys

### innodb config ###
innodb_log_files_in_group = 5
innodb_log_group_home_dir = /mysql/redo-log/
innodb_undo_directory =  /mysql/undo-log/
#innodb_page_size = 16K

# 0.8*Physical Memory for the dedicated MySQL Server，be equal to or a multiple of innodb_buffer_pool_chunk_size * innodb_buffer_pool_instances
innodb_buffer_pool_size = 2560M 
innodb_buffer_pool_instances = 20 
innodb_log_file_size = 1G
innodb_log_buffer_size = 100M
#innodb_thread_concurrency = 64

[mysql]
default-character-set=utf8mb4
socket=/mysql/socket/mysql.sock

[client]
default-character-set=utf8mb4
socket=/mysql/socket/mysql.sock
### client user config ###
#host = localhost    
#user = root
#password = 'syzx123'
[mysqld_safe]  
socket=/mysql/socket/mysql.sock
log-error=/mysql/mysql-log/mysql.err
pid-file=/mysql/pid/mysql.pid

2. 适用 8.0.x 配置文件

export MEMTOTAL=$(grep MemTotal /proc/meminfo|awk '{print $2}')
export INNODB_BUFFER=$(( MEMTOTAL * 1024 * 8 / 10 ))
echo ${INNODB_BUFFER}


[mysql@localhost ~]$ cat >  /etc/my.cnf << EOF
[mysqld]
bind-address=0.0.0.0
port= 5306
user= mysql
basedir=/usr/local/mysql
datadir=/mysql/database/
socket=/mysql/socket/mysql.sock

tmpdir=/mysql/mysql-tmp/
log-error=/mysql/mysql-log/mysql.err
pid-file=/mysql/pid/mysql.pid
authentication_policy= mysql_native_password   # MySQL 5.7 无此参数

###  Server Config  ###
server-id= 100
autocommit = 1  
character_set_server= utf8mb4 
collation-server = utf8mb4_general_ci
skip_name_resolve = 1  
open_files_limit = 65535
max_connections = 3000  
max_connect_errors = 100  
interactive_timeout = 18800  
wait_timeout = 18800 
transaction_isolation = READ-COMMITTED  
explicit_defaults_for_timestamp = 1  
sql_mode = "STRICT_TRANS_TABLES,NO_ENGINE_SUBSTITUTION,NO_ZERO_DATE,NO_ZERO_IN_DATE,ERROR_FOR_DIVISION_BY_ZERO" 
table_open_cache = 4000
max_allowed_packet = 16M
join_buffer_size = 128M  
tmp_table_size = 128M
max_heap_table_size = 128M  
read_buffer_size = 16M  
read_rnd_buffer_size = 32M  
sort_buffer_size = 32M
lower_case_table_names= 1
explicit_defaults_for_timestamp=true

### slow query config ###
slow_query_log = on
long_query_time = 600
slow_query_log_file =/mysql/mysql-log/slowquery.log

###  binlog config ###
#gtid_mode = on
#enforce_gtid_consistency = on
innodb-file-per-table = 1
#sync_binlog = 1

log-bin=/mysql/bin-log/mysql-bin
binlog_format = row
binlog_expire_logs_seconds = 172800
max_binlog_size = 1G
binlog_ignore_db = mysql
binlog_ignore_db = information_schema
binlog_ignore_db = performation_schema
binlog_ignore_db = sys

### innodb config ###
innodb_log_files_in_group = 5
innodb_log_group_home_dir = /mysql/redo-log/
innodb_undo_directory =  /mysql/undo-log/
#innodb_page_size = 16K

# 0.8*Physical Memory for the dedicated MySQL Server，be equal to or a multiple of innodb_buffer_pool_chunk_size * innodb_buffer_pool_instances
innodb_buffer_pool_size = ${INNODB_BUFFER}
innodb_buffer_pool_instances = 20 
innodb_log_file_size = 1G
innodb_log_buffer_size = 100M
#innodb_thread_concurrency = 64

[mysql]
default-character-set=utf8mb4
socket=/mysql/socket/mysql.sock

[client]
default-character-set=utf8mb4
socket=/mysql/socket/mysql.sock
### client user config ###
#host = localhost    
#user = root
#password = 'syzx123'
[mysqld_safe]  
socket=/mysql/socket/mysql.sock
log-error=/mysql/mysql-log/mysql.err
pid-file=/mysql/pid/mysql.pid
EOF

3.2.5. 启动新版数据库

• 启动数据库

[mysql@localhost ~]$ whereis mysqld_safe
mysqld_safe: /usr/local/mysql-5.7.39-el7-x86_64/bin/mysqld_safe

[mysql@localhost ~]$ mysqld_safe --user=mysql --datadir=/mysql/database &
[1] 5037

• 查看启动日志

# 5.7.22 -> 5.7.39
[mysql@localhost ~]$ tail -f /mysql/mysql-log/mysql.err
2022-08-27T06:38:04.800235Z 0 [Warning] CA certificate ca.pem is self signed.
2022-08-27T06:38:04.800295Z 0 [Note] Skipping generation of RSA key pair as key files are present in data directory.
2022-08-27T06:38:04.800386Z 0 [Note] Server hostname (bind-address): '0.0.0.0'; port: 5306
2022-08-27T06:38:04.800405Z 0 [Note]   - '0.0.0.0' resolves to '0.0.0.0';
2022-08-27T06:38:04.800449Z 0 [Note] Server socket created on IP: '0.0.0.0'.
2022-08-27T06:38:04.804077Z 0 [Note] Failed to start slave threads for channel ''
2022-08-27T06:38:04.807186Z 0 [Warning] Optional native table 'performance_schema'.'processlist' has the wrong structure or is missing.
2022-08-27T06:38:04.807336Z 0 [Note] Event Scheduler: Loaded 0 events
2022-08-27T06:38:04.807532Z 0 [Note] /usr/local/mysql-5.7.39-el7-x86_64/bin/mysqld: ready for connections.
Version: '5.7.39-log'  socket: '/mysql/socket/mysql.sock'  port: 5306  MySQL Community Server (GPL)

# 5.7.39 -> 8.0.28
[mysql@localhost ~]$ tail -f /mysql/mysql-log/mysql.err
2022-08-27T09:11:49.072611Z mysqld_safe Logging to '/mysql/mysql-log/mysql.err'.
2022-08-27T09:11:49.097374Z mysqld_safe Starting mysqld daemon with databases from /mysql/database
2022-08-27T09:11:49.323913Z 0 [System] [MY-010116] [Server] /usr/local/mysql/bin/mysqld (mysqld 8.0.30) starting as process 20988
2022-08-27T09:11:49.329516Z 0 [Warning] [MY-013907] [InnoDB] Deprecated configuration parameters innodb_log_file_size and/or innodb_log_files_in_group have been used to compute innodb_redo_log_capacity=5368709120. Please use innodb_redo_log_capacity instead.
2022-08-27T09:11:49.331022Z 1 [System] [MY-013576] [InnoDB] InnoDB initialization has started.
2022-08-27T09:11:49.777746Z 1 [System] [MY-013577] [InnoDB] InnoDB initialization has ended.
2022-08-27T09:11:51.985112Z 4 [System] [MY-013381] [Server] Server upgrade from '80028' to '80030' started.
2022-08-27T09:11:56.709359Z 4 [System] [MY-013381] [Server] Server upgrade from '80028' to '80030' completed.
2022-08-27T09:11:56.836015Z 0 [Warning] [MY-010068] [Server] CA certificate ca.pem is self signed.
2022-08-27T09:11:56.836056Z 0 [System] [MY-013602] [Server] Channel mysql_main configured to support TLS. Encrypted connections are now supported for this channel.
2022-08-27T09:11:56.855514Z 0 [System] [MY-010931] [Server] /usr/local/mysql/bin/mysqld: ready for connections. Version: '8.0.30'  socket: '/mysql/socket/mysql.sock'  port: 5306  MySQL Community Server - GPL.
2022-08-27T09:11:56.855511Z 0 [System] [MY-011323] [Server] X Plugin ready for connections. Bind-address: '::' port: 33060, socket: /mysql/socket/mysqlx.sock

# 8.0.28 -> 8.0.30
[mysql@localhost ~]$ tail -f /mysql/mysql-log/mysql.err
2022-08-27T09:11:49.072611Z mysqld_safe Logging to '/mysql/mysql-log/mysql.err'.
2022-08-27T09:11:49.097374Z mysqld_safe Starting mysqld daemon with databases from /mysql/database
2022-08-27T09:11:49.323913Z 0 [System] [MY-010116] [Server] /usr/local/mysql/bin/mysqld (mysqld 8.0.30) starting as process 20988
2022-08-27T09:11:49.329516Z 0 [Warning] [MY-013907] [InnoDB] Deprecated configuration parameters innodb_log_file_size and/or innodb_log_files_in_group have been used to compute innodb_redo_log_capacity=5368709120. Please use innodb_redo_log_capacity instead.
2022-08-27T09:11:49.331022Z 1 [System] [MY-013576] [InnoDB] InnoDB initialization has started.
2022-08-27T09:11:49.777746Z 1 [System] [MY-013577] [InnoDB] InnoDB initialization has ended.
2022-08-27T09:11:51.985112Z 4 [System] [MY-013381] [Server] Server upgrade from '80028' to '80030' started.
2022-08-27T09:11:56.709359Z 4 [System] [MY-013381] [Server] Server upgrade from '80028' to '80030' completed.
2022-08-27T09:11:56.836015Z 0 [Warning] [MY-010068] [Server] CA certificate ca.pem is self signed.
2022-08-27T09:11:56.836056Z 0 [System] [MY-013602] [Server] Channel mysql_main configured to support TLS. Encrypted connections are now supported for this channel.
2022-08-27T09:11:56.855514Z 0 [System] [MY-010931] [Server] /usr/local/mysql/bin/mysqld: ready for connections. Version: '8.0.30'  socket: '/mysql/socket/mysql.sock'  port: 5306  MySQL Community Server - GPL.
2022-08-27T09:11:56.855511Z 0 [System] [MY-011323] [Server] X Plugin ready for connections. Bind-address: '::' port: 33060, socket: /mysql/socket/mysqlx.sock

3.2.6. 系统库升级

低于 MySQL 8.0.16 的版本，需要执行 mysql_upgrade，以升级系统库（如 mysql）：

[mysql@localhost ~]$ whereis mysql_upgrade
mysql_upgrade: /usr/local/mysql-5.7.39-el7-x86_64/bin/mysql_upgrade

[mysql@localhost ~]$ mysql_upgrade -u root -P 5306 -p 
Enter password: 
Checking if update is needed.
Checking server version.
Running queries to upgrade MySQL server.
Checking system database.
mysql.columns_priv                                 OK
mysql.db                                           OK
mysql.engine_cost                                  OK
mysql.event                                        OK
mysql.func                                         OK
mysql.general_log                                  OK
mysql.gtid_executed                                OK
mysql.help_category                                OK
mysql.help_keyword                                 OK
mysql.help_relation                                OK
mysql.help_topic                                   OK
mysql.innodb_index_stats                           OK
mysql.innodb_table_stats                           OK
mysql.ndb_binlog_index                             OK
mysql.plugin                                       OK
mysql.proc                                         OK
mysql.procs_priv                                   OK
mysql.proxies_priv                                 OK
mysql.server_cost                                  OK
mysql.servers                                      OK
mysql.slave_master_info                            OK
mysql.slave_relay_log_info                         OK
mysql.slave_worker_info                            OK
mysql.slow_log                                     OK
mysql.tables_priv                                  OK
mysql.time_zone                                    OK
mysql.time_zone_leap_second                        OK
mysql.time_zone_name                               OK
mysql.time_zone_transition                         OK
mysql.time_zone_transition_type                    OK
mysql.user                                         OK
Found outdated sys schema version 1.5.1.
Upgrading the sys schema.
Checking databases.
sys.sys_config                                     OK
Upgrade process completed successfully.
Checking if update is needed.

在 MySQL 8.0.16 及更高版本中，将 mysql_upgrade 客户端废弃。系统库（如 mysql 库）升级在启动服务进程启动时，根据需要自动完成。

3.3. 开机自启

重启数据库，以验证升级结果。

[mysql@localhost ~]$ mysqladmin -u root -p shutdown

[mysql@localhost ~]$ ls  /usr/local/mysql/support-files/
magic  mysqld_multi.server  mysql-log-rotate  mysql.server

[mysql@localhost ~]$ sudo cp /usr/local/mysql/support-files/mysql.server /etc/init.d/mysqld
[mysql@localhost ~]$ sudo chmod +x /etc/init.d/mysqld
[mysql@localhost ~]$ sudo vi /etc/init.d/mysqld

# 修改 basedir 和 datadir
....
# If you change base dir, you must also change datadir. These may get
# overwritten by settings in the MySQL configuration files.

basedir=/usr/local/mysql
datadir=/mysql/database/
....

[mysql@localhost ~]$ sudo chkconfig --add mysqld
[mysql@localhost ~]$ sudo chkconfig --level 2345 mysqld on
[mysql@localhost ~]$ sudo chkconfig --list

mysql 数据库启停测试（opsuser 操作）：

[mysql@localhost ~]$ sudo systemctl start mysqld
[mysql@localhost ~]$ sudo systemctl stop  mysqld
[mysql@localhost ~]$ sudo systemctl status mysqld
[mysql@localhost ~]$ sudo systemctl enable mysqld  # 开机自启
# 或
/etc/init.d/mysqld start
/etc/init.d/mysqld stop
/etc/init.d/mysqld start

登陆数据库，查看升级结果

[mysql@localhost ~]$ mysql -uroot -P5306 -p
Enter password: 

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

mysql> select user,host from mysql.user;
+---------------+---------------+
| user          | host          |
+---------------+---------------+
| root          | %             |
| system        | %             |
| admin         | 192.168.3.22_ |
| mysql.session | localhost     |
| mysql.sys     | localhost     |
+---------------+---------------+
5 rows in set (0.00 sec)

3.4 主从架构的升级

MySQL 支持从低版本 MySQL 源库（即主库）复制到高版本 MySQL 的副本库（即从库），如 5.6 -> 5.7，5.7 -> 8.0。但不支持从高版本源库复制到低版本副本库。因此，在主从拓扑结构中，必须先将拓扑中的所有副本库（即从库）升级到目标 MySQL 版本，最后再升级主从复制拓扑中源库（即主库）的软件版本。