This file consists solutions of some common mongodb problems.

mongodb_issue_solve

#mongodb running problem in ubuntu 16.04

#socket permission deny

sudo chown mongodb:mongodb /tmp/mongodb-27017.sock
sudo systemctl restart mongod.service
mongo


#mongodb lock due to iptable conflict

sudo rm /var/lib/mongodb/mongod.lock
sudo systemctl restart mongod.service

#create datapath for mongodb and set appropriate permission. 
#set this datapath in the dbPath field of /etc/mongod.conf

sudo mkdir -p /var/lib/mongodb 
sudo chmod 0755 /var/lib/mongodb
sudo chown -R mongodb:mongodb /var/lib/mongodb
sudo systemctl restart mongod.service

Thanks for sharing <3