I'm attempting to deploy a very simple app to Heroku. The code for the application can be found on Ray Wenderlich's site, here: http://www.raywenderlich.com/61078/write-simple-node-jsmongodb-web-service-ios-app I keep getting the same error whenever I try to have Heroku compile the code...
var mongoHost = "mongodb://username:password#ds041140.mongolab.com:41140/heroku_app23491233";
var mongoPort = 41140;
var collectionDriver;
var mongoClient = new MongoClient(new Server(mongoHost, mongoPort)); //B
mongoClient.open(function(err, mongoClient) { //C
if (!mongoClient) {
console.error("Error! Exiting... Must start MongoDB first");
process.exit(1); //D
}
var db = mongoClient.db("heroku_app23491233"); // E
collectionDriver = new CollectionDriver(db); //F
});
When I type heroku logs, the error I get comes from if (!mongoClient) above...
app[web.1]: Error! Exiting... Must start MongoDB first
I'm sure the problem lies somewhere in my attempt to connect to the MongoLab database. I've copied the URI from MongoLab and I've created a user with the proper credentials.
I can connect to localhost just fine with very similar code, so I'm not sure what is going wrong in this example.
Thank you.
Based on the docs, my best guess is that it's because the Server constructor expects the first argument to contain only the host name (in the case of your MongoLab, ds041140.mongolab.com). However, I think you can pass your connection string into MongoClient.connect:
// Make sure to replace username and password with the proper values.
var mongoHost = "mongodb://username:password#ds041140.mongolab.com:41140/heroku_app23491233";
MongoClient.connect(mongoHost, function(err, db) {
if (err) return console.log(err);
db.collection('mongoclient_test').update({a:1}, {b:1}, {upsert:true}, function(err, result) {
db.close();
if (err) return console.log(err);
console.log('Okay', result);
});
});
Documentation Page For MongoClient
Hopefully that helps!
Related
My NodeJS application hangs on the “find” query of the MongoDB when accessed by the 200 or more users simultaneously.
To demonstrate/reproduce the issue I have built following small POC which has one route and it connects to the MongoDB and fetches the data. When I create around 500 simultaneous request using LoadUIweb, sometimes, the “findone” function of collection never returns.
var express = require('express');
var mongodb = require('mongodb');
var config = require('../Config/Config');
var logger = require('../Config/LogManager');
var app = express();
var MONGODB_URI = config.PCMMongoDB;
var db;
var coll;
// Initialize connection once
mongodb.MongoClient.connect(MONGODB_URI, function(err, database) {
if(err) throw err;
db = database;
coll = db.collection('FacilitySettings');
app.listen(3000);
console.log('Listening on port 3000');
});
// Reuse database/collection object
app.get('/', function(req, res) {
logger.loggerinfo.info("Got the request");
//var result = new Array();
coll.find({}, function(err, docs) {
logger.loggerinfo.info("Got the Response", err);
docs.each(function(err, doc) {
if(err){
logger.loggerinfo.info("Got the error while iterating", err);
res.end();
}
if(doc) {
logger.loggerinfo.info("Iterated the Response");
res.write(JSON.stringify(doc) + "\n");
//result.push(doc);
}
else {
logger.loggerinfo.info("Returned the Response");
res.end();
}
});
});
});
The “FacilitySettings” collection has around 100 documents.
When the server hangs, it prints “Got the Request” and “Got the Response” but it never prints “Iterated the Response” and “returned the Response”. It doesn’t seem that the Nodes server itself is hanged because it accepts the new request. It seems that the result from the MongoDB is never returned.
When I check the last executed queries on the MongoDB, it seems that the query never reaches the MongoDB.
I am using following versions:
MongoDB: 3.2.3,
Nodes: 5.2.0,
MongoDB driver: 2.1.7
Has anyone encountered this issue before? What are the tools available, for MongoDB or for Nodes, to trace the cause? Who is the culprit here? Is it MongoDB or is it Node’s MongoDB native driver?
Posting this just incase anyone else comes across same issue.
I updated the MongoDB driver (version 2.1.13) and issue seems to be resolved now. Then I took a diif between the version I was using, v 2.1.7 and 2.1.13 and I found that there were few changes made to cursor class, noticeable around the exhaust condition. I am not sure if this is a relevant change or there is something else that has been fixed which resolved my case.
I'm using node js, express and postgresql as backend.
This is the approach I used to make a rest API:
exports.schema = function (inputs, res) {
var query = knex('schema')
.orderBy('sch_title', 'asc')
.select();
query.exec(function (err, schemas) {
if(err){
var response = {
message: 'Something went wrong when trying to fetch schemas',
thrownErr: err
};
console.error(response);
res.send(500, response);
}
if(schemas.length === 0){
var message = 'No schemas was found';
console.error(message);
res.send(400, message);
return;
}
res.send(200, schemas);
});
};
It works but after a while postgres logs an error and it's no longer working:
sorry, too man clients already
Do I need a close each request somehow? Could not find any about this in the express docs. What can be wrong?
This error only occurs on production server. Not on developing machine.
Update
The app only brakes in one 'module'. The rest of the app works fine. So it's only some queries that gives the error.
Just keep one connection open for your whole app. The docs shows an example how to do this.
This code goes in your app.js...
var Knex = require('knex');
Knex.knex = Knex.initialize({
client: 'pg',
connection: {
// your connection config
}
});
And when you want to query in your controllers/middlewares...
var knex = require('knex').knex;
exports.schema = function (req, res) {
var query = knex('schema')
.orderBy('sch_title', 'asc')
.select();
// more code...
};
If you place Knex.initialize inside an app.use or app.VERB, it gets called repeatedly for each request thus you'll end up connecting to PG multiple times.
For most cases, you don't need to do an open+query+close for every HTTP request.
I am trying to run the simplest hello world with Node.js and the mssql package.
https://www.npmjs.org/package/mssql
I create a new folder, with an empty JS file (app.js)
I copy and paste the sample from the mssql package page to the js file.
I only change the config object with my DB connection settings.
I run npm install mssql which is successful.
I run node app.js
What happens is that the code doesn't get into the callback after creating a connection. So in the code below:
var connection = new sql.Connection(config, function(err) {
alert(1);
...
//more code...
});
I never get to the alert. No exceptions or errors either
I am probably missing something... Can you please help me spot it?
Update: I should mention that the DB is on Azure...
Try this on your server side it works fine on my end:
var sql = require("mssql");
var dbConfig = {
user:'sa',
password:'password1',
server:'serverName',
database:'DBName'
};
var connection = new sql.Connection(dbConfig, function (err) {
console.log(err);
var request = new sql.Request(connection);
request.query("Select 'Hello World' as var1", function (err, recordset, returnValue) {
if (!err ){
console.log(recordset) ;
}else{
console.log(err)
}
});
});
OK, after digging a bit in the docs for Tedious, I found out that if the DB is on Azure you must include options: {encrypt: true} in your configuration object.
Now everything is working as expected.
I am trying to figure out how to connect to my mongodb db using the native node mongo driver and I have two issues:
My password contains an # sign making it break the normal user:pass#host connection string format
How do I list databases from what I have below?
Any ideas on how to address this?
Here is an attempt which does not work:
var Mongo = require('mongodb');
var server = new Mongo.Server('mongodb://myhost', 27017);
var db = new Mongo.Db('test', server);
db.open(function(err, db) {
console.log(err); //unable to connect
});
For future readers, I was able to resolve this with the connection option uri_decode_auth. You will need to encodeURIComponent(password) before embedding it in the connection string.
Here's a complete working example:
MongoClient.connect(connection, { uri_decode_auth: true }, function(err, db) {
if(err) {
return cb(err);
}
db.admin().listDatabases(function(err, dbs) {
console.log(dbs);
});
});
As mentioned on this answer:
The solution is to replace # with %40
I tested with the C# driver and it works like a charm.
I've been looking for a way to do various operations on a mongo database, depending on which route a user connects to on my website. So doing a html-post to www.mysite.com/data would add info to a mongo DB, and doing a html-get at the same url would get data from the same database. I managed to solve that, but everytime I turn on my server with the website I get 5 connections registred at the mongo database. Why is this, and is it bad?
My code:
I'm runing this code in mongo.js:
var mongodb = require('mongodb');
module.exports.init = function (callback) {
var server = new mongodb.Server("127.0.0.1", 27017, {});
new mongodb.Db('test', server, {w: 1}).open(function (error, client) {
//export the client and maybe some collections as a shortcut
module.exports.client = client;
module.exports.myCollection = new mongodb.Collection(client, 'myCollection');
callback(error);
});
};
I initialize everything running (app.js):
/express set-up/
var mongo = require('./mongo.js');
/.../
mongo.init(function (error) {
if (error)
throw error;
app.listen(3000, function(){
console.log("Express server listening on port %d in %s mode",3000,
app.settings.env);
});
});
And, for example, the post looks like (still app.js):
app.post('/App', function(req, res) {
users = users.concat(req.body);
res.redirect('/App');
//Add user to MongoDB
mongo.myCollection.insert({name: req.body.name, car: req.body.car, website: req.body.website, phone: req.body.phone}, {safe:true}, function(err, objects) {
if (err)
console.warn(err.message);
});
Pretty sure my redirect isn't working as I want it too here, but that's another issue.
Anny suggestions on why I get five connects every time I start the server?
The five connections are because that is the default poolSize (5). You can adjust it, as outlined in the server options docs - it also mentions the default.