节点JS mysql数据库断开连接 [英] Node JS mysql database disconnect

问题描述

我正在使用Node JS，我正在尝试连接到mysql数据库。它因超时而不断断开连接，所以我写了一个函数来重新连接，如果它超时。虽然我需要它是一个连续的连接或我的代码中的引用将无法正常工作。这是我的相关代码：

I am using Node JS and I am trying to connect to a mysql database. It keeps getting disconnected due to a timeout so I wrote a function to reconnect if it does timeout. Although I need it to be a continuous connection or references in my code won't work. Here is my relevant code:

var mysql = require('mysql');
var connection = mysql.createConnection({
    host     : '.........', // MySQL Host
    user     : '.........', // MySQL User
    password : '.........', // MySQL Password
    database : '.........' // MySQL Databse
});

// MYSQL INFO

//connection.connect();

function replaceClientOnDisconnect(connection) {
  connection.on("error", function (err) {
    if (!err.fatal) {
      console.log('Databse Error, error not fatal');
      return;
    }

    if (err.code !== "PROTOCOL_CONNECTION_LOST") {
      throw err;
      console.log('PROTOCOL_CONNECTION_LOST Error: Reconnecting to database...');
    }

    setTimeout(function () {
        connection.destroy();
        connection = mysql.createConnection(connection.config);
        replaceClientOnDisconnect(connection);
        connection.connect(function (error) {
          if (error) {
            process.exit(1);
          } else {
              console.log('Reconnected to database!');
          }
    }, 1000); // 1 sec
    });
  });
}

// And run this on every connection as soon as it is created.
replaceClientOnDisconnect(connection);

推荐答案

您可以使用样本

var dbConfig = {
        host: '----',
        user: '----',
        password: '----',
        database: '----',
        port: ----
    };

var connection;
function handleDisconnect() {
    connection = mysql.createConnection(dbConfig);  // Recreate the connection, since the old one cannot be reused.
    connection.connect( function onConnect(err) {   // The server is either down
        if (err) {                                  // or restarting (takes a while sometimes).
            console.log('error when connecting to db:', err);
            setTimeout(handleDisconnect, 10000);    // 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 onError(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();

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