I am trying to use the mean stack as described here : http://mean.io/
after install, when making "grunt", there is an error :
debugger listening on port 5858
4 Jan 01:47:40 - [nodemon] reading ignore list
Express app started on port 3000
events.js:72
throw er; // Unhandled 'error' event
^
Error: failed to connect to [localhost:27017]
at null.<anonymous> (/mean/node_modules/mongoose/node_modules/mongodb/lib/mongodb/connection/server.js:540:74)
at EventEmitter.emit (events.js:106:17)
at null.<anonymous> (/mean/node_modules/mongoose/node_modules/mongodb/lib/mongodb/connection/connection_pool.js:140:15)
at EventEmitter.emit (events.js:98:17)
at Socket.<anonymous> (/mean/node_modules/mongoose/node_modules/mongodb/lib/mongodb/connection/connection.js:478:10)
at Socket.EventEmitter.emit (events.js:95:17)
at net.js:441:14
at process._tickCallback (node.js:415:13)
4 Jan 01:47:40 - [nodemon] app crashed - waiting for file changes before starting...
I tried the troubleshooting as specified on the site : Updating Grunt, bower and cleaning npm and bower caches worked well. but updating npm gives an error too:
npm ERR! error rolling back Error: Refusing to delete: /usr/local/bin/npm not in /usr/local/lib/node_modules/npm
This looks like a conflict between homebrew and npm. but anyway i have version 1.3.21 installed.
There is the same error when i am trying node server.
do you have an idea on what i can do to make the server work ?
It may be too easy, but seems like your MongoDB server is not actually running. After having installed Mongo (on your Mac, I assume?), you have to open a Terminal window/tab, run mongod and leave it running (or use screen, etc.). You can try to access MongoDB CLI by typing mongo to make sure the server is running.
@desgnl: if you don't want to run mongod command everytime you are running the grunt, you can always use third party services like MongoDB Hosting: Database-as-a-Service by MongoLab https://mongolab.com Hope this helps too!
来源：https://stackoverflow.com/questions/20915513/error-when-starting-the-server-with-grunt-or-node-server