Installing mongodb 3.2 in Codio using the built-in Terminal (Ubuntu 14.04.3) - mongodb

Question

I am trying to install mongodb 3.2 into codio using the terminal and I am following the guide on their website here. (I'm new to mongodb and nosql)
I got to Step 4 Installing mongodb using this command:
sudo apt-get install -y mongodb-org
Got the following at the end:
..
The following packages will be upgraded:
mongodb-org
1 upgraded, 0 newly installed, 0 to remove and 51 not upgraded.
2 not fully installed or removed.
Need to get 3,554 B of archives.
After this operation, 0 B of additional disk space will be used.
Get:1 http://repo.mongodb.org/apt/ubuntu/ trusty/mongodb-org/3.2/multiverse mongodb-org amd64 3.2.2 [3,554 B]
Fetched 3,554 B in 0s (249 kB/s)
(Reading database ... 37250 files and directories currently installed.)
Preparing to unpack .../mongodb-org_3.2.2_amd64.deb ...
Unpacking mongodb-org (3.2.2) over (3.2.1) ...
Setting up mongodb-org-server (3.2.2) ...
start: Job failed to start
invoke-rc.d: initscript mongod, action "start" failed.
dpkg: error processing package mongodb-org-server (--configure):
subprocess installed post-installation script returned error exit status 1
dpkg: dependency problems prevent configuration of mongodb-org:
mongodb-org depends on mongodb-org-server; however:
Package mongodb-org-server is not configured yet.
dpkg: error processing package mongodb-org (--configure):
dependency problems - leaving unconfigured
Errors were encountered while processing:
mongodb-org-server
mongodb-org
E: Sub-process /usr/bin/dpkg returned an error code (1)
Then I run
sudo service mongod start
or
sudo service mongodb start
Both commands will response with start: Job failed to start or mongodb: unrecognized service
Am I missing something here like e.g. mongodb requires other packages to be installed? following wrong guide version? do I need to create config file? if I do how? because it did not create one, or mongodb doesn't work on codio using the built-in terminal? Is mongodb-org-server already installed or running? I've been searching for exact or similar things, also tried different command but no luck.

Answer 1

This is because of the ulimit settings in the service script of mongod.
Mongodb recommends 64000 for 'open files' key in ulimit settings.
https://docs.mongodb.org/manual/reference/ulimit/#recommended-settings
In codio this is set to 4096.
run the below command in codio terminal and see the 'open files' setting.
ulimit -a
I don't think this value can be changed at OS level in codio. However, we can remove this setting (NOT recommended by MongoDb) from the upstart file.
Steps:
1. To keep it simple and less verbose, start with installing just mongodb-org-server instead of installing the complete mongodb-org.
sudo apt-get install -y mongodb-org-server
2. As we know it fails with errors - '..Job failed to start ..' bla..bla. Just ignore them for a min. Edit '/etc/init/mongod.conf' file as root in whatever editor you like. I like vim. :)
sudo vim /etc/init/mongod.conf
3. Comment out(type '#' at the beginning of the line) the line starts with 'limit nofile' as below. Then save and close the file.
#limit nofile 64000 64000
4. Now install the complete 'mongodb-org' package by running the command in terminal as shown below.
sudo apt-get install -y mongodb-org
5. Go ahead try mongo in terminal now. If the mongod service is running, it connects to the default db successfully.
Hope this helps.
Thank you.