在AWS上的Lambda中重用Mysql连接

我有很多lambda调用，而且我总是在查询数据库，所以我希望我的lambda能够重用connection，所以我要在构造函数中建立连接，如下所示：

let mysqlConnection = mysql.createConnection({
  host: process.env.HOST,
  user: process.env.DB_USER,
  password: process.env.BDB_PWD,
  port: process.env.DB_PORT,
  database: process.env.DB_NAME
});

dbConn.connect(function(err) {
  if (err) {
    throw new Error('Error during connecting to db');
  } else {
    console.log("Database is connected");
  }
});

我在处理程序中将callbackWaitsForEmptyEventLoop设置为false：

exports.handler = (event, context) => {
  context.callbackWaitsForEmptyEventLoop = false;
  event.Records.forEach(record => {
   processEvent(JSON.parse(record.body), context);
  });
 };

当mysql连接失败时，我正在销毁mysql连接，我在verifysEvent函数中的查询如下所示：

  mysqlConnection.query(sql, values, function (err, rows) {
    if (err) {
      mysqlConnection.destroy();
      context.fail();
    } 
  }

但是我不时收到一个lambda错误。我猜有时候lambda想要重用不可用的连接。

 "Error: Error during connecting to db",
    "    at Handshake.<anonymous> (/var/task/lambda.js:34:13)",
    "    at Handshake.<anonymous> (/var/task/node_modules/mysql/lib/Connection.js:525:10)",
    "    at Handshake._callback (/var/task/node_modules/mysql/lib/Connection.js:491:16)",
    "    at Handshake.Sequence.end (/var/task/node_modules/mysql/lib/protocol/sequences/Sequence.js:83:24)",
    "    at Protocol.handleNetworkError (/var/task/node_modules/mysql/lib/protocol/Protocol.js:369:14)",
    "    at Connection._handleNetworkError (/var/task/node_modules/mysql/lib/Connection.js:421:18)",
    "    at Connection._handleConnectTimeout (/var/task/node_modules/mysql/lib/Connection.js:417:8)",
    "    at Object.onceWrapper (events.js:286:20)",
    "    at Socket.emit (events.js:198:13)",
    "    at Socket.EventEmitter.emit (domain.js:448:20)"

我有什么办法可以防止这种情况发生？还是应该销毁连接并再次连接？