koa+sequelize 间歇性的报超时，我该从何处着手开始排查 SequelizeConnectionError: connect ETIMEDOUT

啥叫间歇性：就是每天总报三四个这样的错误，请求就500了，但是程序也没重启，其他请求都好好的。

连接配置 "teacher": { “db”: { “logging”: false, “username”: “prod”, “password”: “xxxxxxxxxxxx”, “dialect”: “mysql”, “database”: “teacher”, “host”: “xxxxxxxxxxxx”, “port”: “3306”, “operatorsAliases”: true, “define”: { “freezeTableName”: true, “paranoid”: true }, “pool”: { “max”: 30, “min”: 0, “acquire”: 10000, “idle”: 10000 } } }