Question

I have a mongodb replica set on mongolab.

I’m using nodejs + mongoose. When I’m trying to connect from my local machine everything goes ok.
But after deployment to heroku something wrong happens and mongoose got strange error:

[Error: no primary server found in set]

Here some code (server.js):

async.series([
  function(callback){
    console.log('DB Connection: ' + siteConf.mongo_url);
    mongoose.connect(siteConf.mongo_url, siteConf.mongo_options, callback);
  },      
  function(callback){
    http.createServer(app).listen(siteConf.port, callback);
  }
],
function(err, results){

 if (err) {
   console.log(err);
 }

 console.log('Running in ' + (process.env.NODE_ENV || 'development') + ' mode @ ' + siteConf.uri);
  }
);

This url I’m using as connection string:

mongodb://username:[e-mail]:39897/pm_prod,mongodb://someid-a1.mongolab.com:39897

The main thing I can’t understand is: what is the differences between my maching and heroku cloud hosting.

I already tried to remove node_modules and npm install them to be sure that I have same versions as on heroku. (Because heroku do this on each deploy).

Thanks, and sorry for my bad english

Answer 1

This may be a URI problem. The format for DB URIs is:

mongodb://<user>:<pass>@host:port,host:port,...,host:port/db_name

That means that

mongodb://username:[e-mail]:39897/pm_prod,mongodb://someid-a1.mongolab.com:39897

should be:

mongodb://username:[e-mail]:39897,someid-a1.mongolab.com:39897/pm_prod

It’s also worth noting for others: If you are using Heroku’s MongoLab add-on, your URI is available as an environment variable at process.env.MONGOLAB_URI, so you don’t have to place the URI in your code.

This could also be related to a running question about connectivity between Heroku and Mongo. See https://github.com/jcottr/temps-mort, which references two tickets for the Node Mongo driver:

https://jira.mongodb.org/browse/NODE-4

https://jira.mongodb.org/browse/NODE-5