带有 MySQL 连接的 Nodejs 集群 [英] Nodejs Cluster with MySQL connections

问题描述

查看Nodejs集群的建议以及连接mysql服务器的方法.我们是为每个子进程打开一个连接还是只为所有进程打开一个连接?还是我们为所有子进程创建一个连接池?推荐的方法是什么?

Looking on advice on clustering of Nodejs and the method of connection to mysql server. Do we open one connection for each child process or just one single connection for all processes? Or do we create a connection pool for all the child processes? Which is the recommended method?

一个节点进程

var mysql      = require('mysql');
var connection = mysql.createConnection({
  host     : 'example.org',
  user     : 'bob',
  password : 'secret'
});

connection.connect(function(err) {
  if (err) {
    console.error('error connecting: ' + err.stack);
    return;
  }

  console.log('connected as id ' + connection.threadId);
});

节点集群选项 1:

var cluster = require('cluster');
var http = require('http');
var numCPUs = require('os').cpus().length;

if (cluster.isMaster) {
  // Fork workers.
  for (var i = 0; i < numCPUs; i++) {
    cluster.fork();
  }

  cluster.on('exit', function(worker, code, signal) {
    console.log('worker ' + worker.process.pid + ' died');
  });
} else {
  // open one connection for each process
  var mysql      = require('mysql');
    var connection = mysql.createConnection({
      host     : 'example.org',
      user     : 'bob',
      password : 'secret'
    });

    connection.connect(function(err) {
      if (err) {
        console.error('error connecting: ' + err.stack);
        return;
      }

      console.log('connected as id ' + connection.threadId);
    });
}

选项 2:

var cluster = require('cluster');
var http = require('http');
var numCPUs = require('os').cpus().length;

var mysql = require('mysql');
var pool  = mysql.createPool({
    connectionLimit : 10,
    host            : 'example.org',
    user            : 'bob',
    password        : 'secret'
});

if (cluster.isMaster) {
  // Fork workers.
  for (var i = 0; i < numCPUs; i++) {
    cluster.fork();
  }

  cluster.on('exit', function(worker, code, signal) {
    console.log('worker ' + worker.process.pid + ' died');
  });
} else {

  // accept http connections and query
  pool.query('SELECT 1 + 1 AS solution', function(err, rows, fields) {
     if (err) throw err;

     console.log('The solution is: ', rows[0].solution);
  });
}

推荐答案

经过反复试验，我使用了选项 2，它运行良好.全局创建连接并在集群中使用.

After some trial and error, I'm using option 2 and it is working well. Created the connection globally and use in the cluster.

每次需要查询时，getConnection.

Each time you need to query, getConnection.

pool.getConnection(function(err, connection) {
        if(err) {
            console.log('Error getting sql connection');
            console.dir(err);

            if(typeof connection !== "undefined")
                connection.release();

            callback(err);
        }

        if(typeof cb === "undefined") {
            //console.log('with 2 params');
            connection.query( sql, function(err, rows) {
                connection.release();
                console.dir(sql);
                // console.dir('data=>' + data);

                if(err) {
                    console.log('err:' + err);
                    callback(err, rows);
                }else{
                    console.log( rows );
                    callback(err, rows);
                }
            });
        } else {
            // console.log('with 3 params:' + cb);
            connection.query( sql, data, function(err, rows){
                connection.release();
                console.log(sql);
                console.dir(data);

                if(err) {
                    console.log('err:' + err);
                    callback(err, rows);
                }else{
                    console.log( rows );
                    callback(err, rows);
                }

            });
        }
    });
}

这篇关于带有 MySQL 连接的 Nodejs 集群的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！