Mongodb exception: connect failed

#Here's the environment: 1. Linux(x64): **16.04** 2. MongoDB: **3.2.15** #Error: root@system-test:~# mongo MongoDB shell version: 3.2.15 connecting to: test 2017-07-25T07:31:28.528+0000 W NETWORK [thread1] Failed to connect to 127.0.0.1:27017, in(checking socket for error after poll), reason: errno:111 Connection refused 2017-07-25T07:31:28.530+0000 E QUERY [thread1] Error: couldn't connect to server 127.0.0.1:27017, connection attempt failed : connect@src/mongo/shell/mongo.js:229:14 @(connect):1:6 exception: connect failed root@system-test:~# **When I tried to see the status I get this:** root@system-test:~# sudo service mongodb status ● mongodb.service - High-performance, schema-free document-oriented database Loaded: loaded (/etc/systemd/system/mongodb.service; disabled; vendor preset: enabled) Active: failed (Result: exit-code) since Tue 2017-07-25 07:45:32 UTC; 1min 8s ago Process: 1721 ExecStart=/usr/bin/mongod --quiet --config /etc/mongod.conf (code=exited, status=14) Main PID: 1721 (code=exited, status=14) Jul 25 07:45:32 system-test systemd: Started High-performance, schema-free document-oriented database. Jul 25 07:45:32 system-test systemd: mongodb.service: Main process exited, code=exited, status=14/n/a Jul 25 07:45:32 system-test systemd: mongodb.service: Unit entered failed state. Jul 25 07:45:32 system-test systemd: mongodb.service: Failed with result 'exit-code'. #How it happened: I tried to stop MongoDB and did the following **sudo service mongo stop** [This didn't work]. Then i tried **kill - 2 ** [Seem didn't worked too] But after this command **#mongo** stopped working and getting the above error. Please help guys