Nodejs代碼崩潰Mongodb服務器

Question

我在mongodb中的一個集合中有大約300k個文檔，這都是坐在AWS中。當我查詢這個特定的路由（thing2）時，看起來mongo處理太多了，所以mongod服務崩潰了。我已經爲我的代碼添加了限制，但它仍然無法工作。理想情況下，我希望能夠搜索特定關鍵字，但該部分現在已被註釋掉。

var express = require('express') 
var app = express() 

app.get('/', function (req, res) { 
    res.send('Hello World!') 
}); 

app.get('/thing2', function(req, res) { 

    var username = req.query.username 
    var keyword = req.query.keyword 

    var MongoClient = require('mongodb').MongoClient, 
     assert = require('assert'); 
    var url = 'mongodb://localhost:27017/my_db'; 

    MongoClient.connect(url, function(err, db) { 
     if (err) throw err; 

     var collection = db.collection('my_collection'); 
     /* collection.find({ $and: [ 
      * {"text" : {$regex : ".*"+keyword+".*"}}, 
      * {"username" : username} 
      * ] }).limit(5).toArray(function(err, docs) { 
      */ 

     collection.find({"user.screen_name" : username}).limit(1).toArray(function(err, docs) { 
      console.log("\n" + new Date().toLocaleString() + " " + username); 

      if (!err) { 
       console.log(docs.length) 
      } else { 
       console.log(err) 
      } 

      res.send(docs) 
     }); 
    }); 
}); 

app.listen(80, function() { 
    console.log('Listening on port 80!') 
}); 

我在控制檯中看到的錯誤是：

{ [MongoError: connection 0 to localhost:27017 closed] 
    name: 'MongoError', 
    message: 'connection 0 to localhost:27017 closed' } 

編輯：蒙戈日誌

2017-04-19T03:59:03.458+0000 I CONTROL [initandlisten] 
2017-04-19T03:59:03.458+0000 I CONTROL [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/enabled is 'always'. 
2017-04-19T03:59:03.458+0000 I CONTROL [initandlisten] **  We suggest setting it to 'never' 
2017-04-19T03:59:03.458+0000 I CONTROL [initandlisten] 
2017-04-19T03:59:03.458+0000 I CONTROL [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/defrag is 'always'. 
2017-04-19T03:59:03.458+0000 I CONTROL [initandlisten] **  We suggest setting it to 'never' 
2017-04-19T03:59:03.458+0000 I CONTROL [initandlisten] 
2017-04-19T03:59:03.471+0000 I FTDC  [initandlisten] Initializing full-time diagnostic data capture with directory '/var/lib/mongodb/diagnostic.data' 
2017-04-19T03:59:03.471+0000 I NETWORK [initandlisten] waiting for connections on port 27017 
2017-04-19T03:59:03.471+0000 I NETWORK [HostnameCanonicalizationWorker] Starting hostname canonicalization worker 
2017-04-19T03:59:04.003+0000 I FTDC  [ftdc] Unclean full-time diagnostic data capture shutdown detected, found interim file, some metrics may have been lost. OK 
2017-04-19T03:59:23.504+0000 I COMMAND [ftdc] serverStatus was very slow: { after basic: 40, after asserts: 110, after connections: 130, after extra_info: 160, after globalLock: 310, after locks: 540, after network: 630, after opcounters: 760, after opcountersRepl: 870, after storageEngine: 1120, after tcmalloc: 1540, after wiredTiger: 2690, at end: 3370 } 

Answer 1

的問題是，您連接過於頻繁。我會用貓鼬重做代碼：

var express = require('express') 
var app = express() 
var mongoose = require('mongoose'); 
mongoose.connect('mongodb://localhost/my_db') 
var collection = require('user'); 

app.get('/', function (req, res) { 
    res.send('Hello World!') 
}); 

app.get('/thing2', function(req, res) { 

    var username = req.query.username 
    var keyword = req.query.keyword 

    collection.find({"user.screen_name" : username}).limit(1).toArray(function(err, docs) { 
      console.log("\n" + new Date().toLocaleString() + " " + username); 

      if (!err) { 
       console.log(docs.length) 
      } else { 
       console.log(err) 
      } 
      res.send(docs) 
    }); 
}); 

app.listen(80, function() { 
    console.log('Listening on port 80!') 
}); 

您還可以模擬這樣的貓鼬架構（該文件的名稱是：「user.js的」）：

var mongoose  = require('mongoose'); 
var Schema  = mongoose.Schema; 

var UserSchema = new Schema({ 
    name: String, 
    userId : Number 
}); 
module.exports = mongoose.model('User', UserSchema); 

嘗試，使其工作最小化，然後隨着你的真實模型增加。 希望我的回答有幫助