mongo - couldn't connect to server 127.0.0.1:27017

Normally this caused because you didn't start mongod process before you try starting mongo shell.

Start mongod server

mongod

Open another terminal window

Start mongo shell

mongo

Resolved.

This problem could be solved by the below mentioned 4 steps

1) Remove .lock file

sudo rm /var/lib/mongodb/mongod.lock 

2) repair the mongodb

mongod -–repair

3) start the mongod server

sudo service mongod start 

4) start the mongo client

mongo

For more details take a look at http://shakthydoss.com/error-couldnt-connect-to-server-127-0-0-127017-srcmongoshellmongo-js-exception-connect-failed/

http://shakthydoss.com/technical/error-couldnt-connect-to-server-127-0-0-127017-srcmongoshellmongo-js-exception-connect-failed/

This error is what you would see if the mongo shell was not able to talk to the mongod server.

This could be because the address was wrong (host or IP) or that it was not running. One thing to note is the log trace provided does not cover the "Fri Nov 9 16:44:06" of your mongo timestamp.

Can you:

1. Provide the command line arguments (if any) used to start your mongod process
2. Provide the log file activity from the mongod startup as well as logs during the mongo shell startup attempt?
3. Confirm that your mongod process is being started on the same machine as the mongo shell?