MySQL Server版本升级

>说明：
基于安全等保或业务迭代需要，需要对MySQL数据库版本进行迭代升级时，可参考此文档
测试环境：CentOS 7.6
当前数据库：MySQL v5.7.10 
目标数据库：MySQL v5.7.36

# 编译新版数据库

步骤：略...
参考文档地址：https://wiki.netimed.cn/project-5/doc-29/

# 升级步骤

## 停止运行服务

步骤：略...
停止运行所有和数据库进行连接，并且可写入数据的服务，示例：java，tomcat，php等

## 停止数据库运行

`CentOS`:
```bash
service mysql stop

# 或

systemctl stop  mysqld

```

## 备份数据

通过`cp -rp` 指令对数据进行全量备份，也可进一步压缩

**相关指令:**
```bash
cp -rp OriMysqlDataPath OriMysqlDataPath_bak
tar -cvf  OriMysqlDataPath_bef.tar  OriMysqlDataPath
```
其中：
- `OriMysqlDataPath`为原始数据库数据目录
- `OriMysqlDataPath_bak`为备份后的目录
- `OriMysqlDataPath_bef.tar`为打包备份后的文件名称

## 启动并更新数据库

启动数据库
```bash
[root@localhost logs]# systemctl  start mysqld
[root@localhost logs]# systemctl status  mysqld
● mysqld.service - MySQL Server
   Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
   Active: active (running) since Mon 2022-06-13 18:11:02 CST; 27min ago
     Docs: man:mysqld(8)
           http://dev.mysql.com/doc/refman/en/using-systemd.html
 Main PID: 10841 (mysqld)
   CGroup: /system.slice/mysqld.service
           └─10841 /data/mysql/basedir/bin/mysqld --defaults-file=/data/mysql/basedir/etc/my.cnf

Jun 13 18:11:02 upload_hrs_sql systemd[1]: Started MySQL Server.

```

成功启动后，查看日志会打印报错：
```
2022-06-13T10:11:03.753102Z 0 [Note] Server socket created on IP: '0.0.0.0'.
2022-06-13T10:11:03.760317Z 0 [Note] Failed to start slave threads for channel ''
2022-06-13T10:11:03.763938Z 0 [ERROR] Incorrect definition of table performance_schema.replication_connection_status: expected column 'RECEIVED_TRANSACTION_SET' at position 7 to have type longtext, found type text.
2022-06-13T10:11:03.764236Z 0 [ERROR] Incorrect definition of table performance_schema.replication_group_member_stats: expected column 'COUNT_TRANSACTIONS_ROWS_VALIDATING' at position 6, found 'COUNT_TRANSACTIONS_VALIDATING'.
2022-06-13T10:11:03.765091Z 0 [Note] Event Scheduler: Loaded 0 events
2022-06-13T10:11:03.765312Z 0 [Note] /data/mysql/basedir/bin/mysqld: ready for connections.
Version: '5.7.36-log'  socket: '/data/mysql/tmp/mysql.sock'  port: 3306  Source distribution
2022-06-13T10:14:37.425239Z 5 [Warning] InnoDB: Table mysql/innodb_table_stats has length mismatch in the column name table_name.  Please run mysql_upgrade
2022-06-13T10:14:37.425264Z 5 [Warning] InnoDB: Table mysql/innodb_index_stats has length mismatch in the column name table_name.  Please run mysql_upgrade
[root@localhost logs]#
```

其中的`[ERROR]`和`[Warning]`级别日志内容均表示版本升级后需要对数据库进行更新操作

更新指令如下：
```bash
[root@localhost logs]# /data/mysql/basedir/bin/mysql_upgrade  -uroot -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.time_zone_transition_type                    OK
mysql.user                                         OK
Found outdated sys schema version 1.5.0.
Upgrading the sys schema.
Checking databases.
...
```

更新完毕后重启数据库
```bash
systemctl  restart mysqld
```

再次启动后，查看日志，无新增报错则表示执行完成