nodejs mysql 오류 : 연결이 끊어졌습니다 서버가 연결을 닫았습니다

nodejs mysql 오류 : 연결이 끊어졌습니다 서버가 연결을 닫았습니다

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mysql 노드를 사용할 때 서버에 의해 TCP 연결이 종료되었다는 오류가 12:00에서 2:00 사이에 나타납니다. 다음은 전체 메시지입니다.

Error: Connection lost: The server closed the connection.
at Protocol.end (/opt/node-v0.10.20-linux-x64/IM/node_modules/mysql/lib/protocol/Protocol.js:73:13)
at Socket.onend (stream.js:79:10)
at Socket.EventEmitter.emit (events.js:117:20)
at _stream_readable.js:920:16
at process._tickCallback (node.js:415:13)

이 솔루션은 . 그런데 이렇게 해보면 문제도 나옵니다. 지금은 어떻게해야할지 모르겠습니다. 누구든지이 문제를 충족합니까?

솔루션을 따르는 방법은 다음과 같습니다.

    var handleKFDisconnect = function() {
    kfdb.on('error', function(err) {
        if (!err.fatal) {
            return;
        }
        if (err.code !== 'PROTOCOL_CONNECTION_LOST') {
            console.log("PROTOCOL_CONNECTION_LOST");
            throw err;
        }
        log.error("The database is error:" + err.stack);

        kfdb = mysql.createConnection(kf_config);

        console.log("kfid");

        console.log(kfdb);
        handleKFDisconnect();
    });
   };
   handleKFDisconnect();

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이 코드 를 사용 하여 서버 연결 해제를 처리하십시오.

var db_config = {
  host: 'localhost',
    user: 'root',
    password: '',
    database: 'example'
};

var connection;

function handleDisconnect() {
  connection = mysql.createConnection(db_config); // Recreate the connection, since
                                                  // the old one cannot be reused.

  connection.connect(function(err) {              // The server is either down
    if(err) {                                     // or restarting (takes a while sometimes).
      console.log('error when connecting to db:', err);
      setTimeout(handleDisconnect, 2000); // We introduce a delay before attempting to reconnect,
    }                                     // to avoid a hot loop, and to allow our node script to
  });                                     // process asynchronous requests in the meantime.
                                          // If you're also serving http, display a 503 error.
  connection.on('error', function(err) {
    console.log('db error', err);
    if(err.code === 'PROTOCOL_CONNECTION_LOST') { // Connection to the MySQL server is usually
      handleDisconnect();                         // lost due to either server restart, or a
    } else {                                      // connnection idle timeout (the wait_timeout
      throw err;                                  // server variable configures this)
    }
  });
}

handleDisconnect();

귀하의 코드에서 나는 부품이 누락되었습니다. connection = mysql.createConnection(db_config);

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이 메커니즘에 대한 원래 사용 사례를 기억하지 않습니다. 요즘에는 유효한 사용 사례를 생각할 수 없습니다.

Your client should be able to detect when the connection is lost and allow you to re-create the connection. If it important that part of program logic is executed using the same connection, then use transactions.

tl;dr; Do not use this method.

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A pragmatic solution is to force MySQL to keep the connection alive:

setInterval(function () {
    db.query('SELECT 1');
}, 5000);

I prefer this solution to connection pool and handling disconnect because it does not require to structure your code in a way thats aware of connection presence. Making a query every 5 seconds ensures that the connection will remain alive and PROTOCOL_CONNECTION_LOST does not occur.

Furthermore, this method ensures that you are keeping the same connection alive, as opposed to re-connecting. This is important. Consider what would happen if your script relied on LAST_INSERT_ID() and mysql connection have been reset without you being aware about it?

However, this only ensures that connection time out (wait_timeout and interactive_timeout) does not occur. It will fail, as expected, in all others scenarios. Therefore, make sure to handle other errors.

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To simulate a dropped connection try

connection.destroy();

More information here: https://github.com/felixge/node-mysql/blob/master/Readme.md#terminating-connections

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Creating and destroying the connections in each query maybe complicated, i had some headaches with a server migration when i decided to install MariaDB instead MySQL. For some reason in the file etc/my.cnf the parameter wait_timeout had a default value of 10 sec (it causes that the persistence can't be implemented). Then, the solution was set it in 28800, that's 8 hours. Well, i hope help somebody with this "güevonada"... excuse me for my bad english.

참고URL : https://stackoverflow.com/questions/20210522/nodejs-mysql-error-connection-lost-the-server-closed-the-connection