MariaDB 池无法创建连接

Question

在运行我的 Node 项目 2-3 分钟后，我正面临每分钟左右弹出的警告/错误消息。一直在网上搜索，但找不到任何解决方案。

pool failed to create connection ((conn=-1, no: 45009, SQLState: 08S01) socket has unexpectedly been closed)

我的 db.js

const mysql = require("mysql"); //^2.18.1
const mariadb = require("mariadb"); //^2.5.3

const DB_OPTIONS = {
   host: "127.0.0.1",
   user: "root",
   password: "",
   database: "test-db",
   port: 3306,
   minDelayValidation: 5000
};

const connection = mariadb.createPool(DB_OPTIONS);

connection.getConnection().then((conn) => {
   console.log("Connected to DB!", conn.threadId);
   if (conn) conn.release();
}).catch((err) => {
   console.error("Error while connecting to DB", err);
});

module.exports = connection;

test.js

...
let database = require("./../middleware/db");
...
...
try 
{
   database.query(dbQuery, dbParameters).then((result) => {
      ...
   }).catch((dbCatchErr) => {
      ...
   })
}
catch (catchErr)
{
   console.error(catchErr);
}

MariaDB 版本：10.3.23