Mongodb exception: connect failed

Question

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[1]: Started High-performance, schema-free document-oriented database.
Jul 25 07:45:32 system-test systemd[1]: mongodb.service: Main process exited, code=exited, status=14/n/a
Jul 25 07:45:32 system-test systemd[1]: mongodb.service: Unit entered failed state.
Jul 25 07:45:32 system-test systemd[1]: 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 <PID> [Seem didn't worked too]

But after this command #mongo stopped working and getting the above error.

Please help guys

Answer 1

sudo service mongo stop [This didn't work]

As MongoDB BOL mongo is an interactive JavaScript shell interface to MongoDB, which provides a powerful interface for systems administrators as well as a way for developers to test queries and operations directly with the database. mongo also provides a fully functional JavaScript environment for use with a MongoDB.

And mongod is the primary daemon process for the MongoDB system. It handles data requests, manages data access, and performs background management operations.

As simple language we can say that mongo is shell interface for MongoDB. And mongod is server , which handles data requests, manages data access, and performs background management operations.

So, in place sudo service mongo stop it should be the below mention command

sudo service mongod stop

As MongoDB documented Here Some of basic procedure to check MongoDB services in RHEL is as mention below:

Start MongoDB

sudo service mongod start

Stop MongoDB

sudo service mongod stop

Restart MongoDB

sudo service mongod restart

Verify that MongoDB has started successfully

sudo chkconfig mongod on

Begin using MongoDB

Start a mongo shell on the same host machine as the mongod

mongo --host 127.0.0.1:27017

Answer 2

As your service mongodb status tells, your mongod process don't exists. So, if you try to connect (with mongo -program) to your mongod, you cannot.

So, restart your mongod sudo service mongodb restart, try now to connect it mongo.

If you want to see what happens when you shutdown, start following mongodb.log tail -f /var/log/mongodb/mongodb.log and then in other terminal say sudo service mongodb stop, some times shutdown process can take quite long time.. As startup process too.

Answer 3

I also ran into same issue. But was able to resolve by completely removing mongo first

sudo apt-get purge mongodb-org*

Then performing following

sudo apt update
sudo apt install -y mongodb
sudo systemctl status mongodb

You can refer to following link for the same: https://www.digitalocean.com/community/tutorials/how-to-install-mongodb-on-ubuntu-18-04

Answer 4

This question is for Linux, but for fellow windows users who found their way here and want a windows solution...

the problem is your Mongodb service is stopped. So do the following steps:

    1) cntrl-alt-del and open your task manager
    2) click on 'services'
    3) scroll down to MongoDB
    4) right click and hit 'start' (or 'restart')

go back to your mongo.exe file and your mongo shell should work now

Answer 5

If the problem is related to a remote access, here is the solution for anyone who has the problem

show iptable rules line numbers

sudo iptables -L --line-numbers

The output will be something like this

...
num  target     prot opt source               destination
1    ACCEPT     all  --  anywhere             anywhere             ctstate RELATED,ESTABLISHED
2    ACCEPT     all  --  anywhere             anywhere
3    INPUT_direct  all  --  anywhere             anywhere
4    INPUT_ZONES_SOURCE  all  --  anywhere             anywhere
5    INPUT_ZONES  all  --  anywhere             anywhere
6    DROP       all  --  anywhere             anywhere             ctstate INVALID
7    REJECT     all  --  anywhere             anywhere             reject-with icmp-host-prohibited
8    ACCEPT     tcp  --  172.16.84.102        anywhere             tcp dpt:27017 state NEW,ESTABLISHED

Chain FORWARD (policy ACCEPT)
num  target     prot opt source               destination
1    ACCEPT     all  --  anywhere             anywhere             ctstate RELATED,ESTABLISHED
2    ACCEPT     all  --  anywhere             anywhere
3    FORWARD_direct  all  --  anywhere             anywhere
4    FORWARD_IN_ZONES_SOURCE  all  --  anywhere             anywhere
5    FORWARD_IN_ZONES  all  --  anywhere             anywhere
6    FORWARD_OUT_ZONES_SOURCE  all  --  anywhere             anywhere
7    FORWARD_OUT_ZONES  all  --  anywhere             anywhere
8    DROP       all  --  anywhere             anywhere             ctstate INVALID
9    REJECT     all  --  anywhere             anywhere             reject-with icmp-host-prohibited

Chain OUTPUT (policy ACCEPT)
num  target     prot opt source               destination
...

The problem is caused by the rule

7    REJECT     all  --  anywhere             anywhere             reject-with icmp-host-prohibited

Delete it but keep security team informed about this operation

Here is how to delete a rule using the type ( input in out case ) and line number ( 7 in out case )

sudo iptables -D INPUT 7

Now test your connection to mongo db from other machines and it has to be working now.

Note: This solution will work if you already configured the /etc/mongod.conf by:

• commenting

  bindIp: 127.0.0.1

• Adding

  bindIpAll: true

• Uncommenting security and adding

  authorization: 'enabled'

Enjoy it :)