mongo - couldn't connect to server 127.0.0.1:27017

Question

I am coming from riak and redis where I never had an issue with this services starting, or to interact.

This is a pervasive problem with mongo and am rather clueless

Answer 1

I had same problem to connect mongodb after install using brew on macOS.

The problem was also mongod.lock but before i had mongodb 3.6 installed and database directory was /usr/local/var/mongodb and it have old files and mongod.lock

Simple i moved my old database files to different folder and removed everything from /usr/local/var/mongodb

Then restarted :

brew services restart mongodb

And it's working fine now.