一、描述
漏掃發現MySQL有低風險漏洞，自己寫方案、自己做測試、自己升級。
版本：MySQL 5.7.25 升級到MySQL 5.7.28最新版本。
架構：主從架構
二、升級流程
1、下載最新版數據庫軟件MySQL 5.7.28
2、上傳到指定目錄
3、備份數據庫軟件、數據庫數據目錄、my.cnf
4、解壓縮數據庫軟件到指定路徑
5、關閉備庫
6、使用新版軟件啓動備庫，mysqld_safe &
7、登錄備庫，發現版本已升級，使用mysql_upgrade命令升級系統數據庫
8、無報錯的話，重啓備庫。
9、主庫按照備庫流程走一遍
10、最後確認主備庫是否一致
三、部分內容
# mysql_upgrade -uroot -p
mysql_upgrade: [Warning] Using a password on the command line interface can be insecure.
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Found outdated sys schema version 1.5.1.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.
mysql> status
--------------
mysql Ver 14.14 Distrib 5.7.28, for linux-glibc2.12 (x86_64) using EditLine wrapper
Connection id: 2
Current database:
Current user: root@localhost
SSL: Not in use
Current pager: stdout
Using outfile: ''
Using delimiter: ;
Server version: 5.7.28-log MySQL Community Server (GPL)
Protocol version: 10
Connection: Localhost via UNIX socket
Server characterset: utf8mb4
Db characterset: utf8mb4
Client characterset: utf8mb4
Conn. characterset: utf8mb4
UNIX socket: /tmp/mysql.sock
Uptime: 27 sec
