How To Install and Configure MongoDB on CentOS 7

In this article, we will learn how to install and configure MongoDB on CentOS 7. MongoDB is an open-source NoSQL database that stores documents in a JSON-like format called BSON. Unlike traditional relational databases, MongoDB doesn't require a predefined schema and offers high availability, performance, and automatic scaling capabilities.

Prerequisites

• CentOS 7 installed on the Linux machine
• A user with root privileges

Adding the MongoDB Repository

By default, the MongoDB repository is not available in CentOS 7. We need to add the MongoDB repository to the local machine first.

vi /etc/yum.repos.d/mongodb-org.repo

Add the following content to the repository file ?

[mongodb-org-3.2]
name=MongoDB Repository
baseurl=https://repo.mongodb.org/yum/redhat/$releasever/mongodb-org/3.2/x86_64/
gpgcheck=1
enabled=1
gpgkey=https://www.mongodb.org/static/pgp/server-3.2.asc

Update the system to refresh the repository information ?

yum update

Loaded plugins: fastestmirror
base                                             | 3.6 kB  00:00
extras                                           | 3.4 kB  00:00
mongodb-org-3.2                                 | 2.5 kB  00:00
updates                                          | 3.4 kB  00:00
mongodb-org-3.2/7/primary_db                    | 54 kB  00:01
Determining fastest mirrors
* base: mirror.dhakacom.com
* extras: mirror.dhakacom.com
* updates: mirror.dhakacom.com
No packages marked for update

Installing MongoDB

Once the repository is configured, install MongoDB using the yum command ?

yum install mongodb-org

Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
...
Installing:
 mongodb-org            x86_64    3.2.11-1.el7    mongodb-org-3.2    5.8 k
Installing for dependencies:
 mongodb-org-mongos     x86_64    3.2.11-1.el7    mongodb-org-3.2    5.6 M
 mongodb-org-server     x86_64    3.2.11-1.el7    mongodb-org-3.2    12 M
 mongodb-org-shell      x86_64    3.2.11-1.el7    mongodb-org-3.2    6.7 M
 mongodb-org-tools      x86_64    3.2.11-1.el7    mongodb-org-3.2    41 M
...
Complete!

Starting MongoDB Service

Start the MongoDB service ?

systemctl start mongod

Check the status of the MongoDB service ?

systemctl status mongod

mongod.service - SYSV: Mongo is a scalable, document-oriented database.
   Loaded: loaded (/etc/rc.d/init.d/mongod)
   Active: active (running) since Fri 2016-11-25 14:09:25 IST; 12s ago
     Docs: man:systemd-sysv-generator(8)
  Process: 9901 ExecStart=/etc/rc.d/init.d/mongod start (code=exited, status=0/SUCCESS)
   CGroup: /system.slice/mongod.service
           ??9912 /usr/bin/mongod -f /etc/mongod.conf

Configuring Process Limits

By default, MongoDB may show warnings about low process limits. To fix this, edit the process limits configuration ?

vi /etc/security/limits.d/20-nproc.conf

Change the soft process limit from 4096 to 32000 ?

* soft nproc 32000
root soft nproc unlimited

Restart MongoDB to apply the changes ?

systemctl restart mongod

Creating an Administrator User

Connect to MongoDB and create an administrator user ?

mongo
use admin
db.createUser(
    {
        user: "admin",
        pwd: "password123",
        roles: [ { role: "userAdminAnyDatabase", db: "admin" } ]
    }
)

Successfully added user: {
    "user" : "admin",
    "roles" : [
        {
            "role" : "userAdminAnyDatabase",
            "db" : "admin"
        }
    ]
}

Verify the user creation ?

show users

{
    "_id" : "admin.admin",
    "user" : "admin",
    "db" : "admin",
    "roles" : [
        {
            "role" : "userAdminAnyDatabase",
            "db" : "admin"
        }
    ]
}

Conclusion

We have successfully installed and configured MongoDB on CentOS 7, including setting up the repository, adjusting process limits, and creating an administrator user. MongoDB is now ready for use with proper configuration and security settings.