What is MongoDB

Relational databases were developed during the '70s, when the needs of applications were different than today's environments. The scale of internet today is huge and what Amazon learnedis that performance is an essential and also a very important feature of a website.
For today's needs, a new database had to be engineered, this is how Mongo was born.
Mongo is a new database, of the type NoSQL with modern essential features builtin like:

  • Safety and Availability using ReplicaSets
  • Performance and Scalability with automatic sharding
  • Flexible schema for modern agile applications
Main Features

Replication - MongoDB has the ability to automatically synchronize data across multiple servers. Replication is also available on SQL databases but MongoDB has also automatic failover and automatic node recovery, so there is no need to install additional tools to achieve this. More info at https://docs.mongodb.org/manual/replication/. In production a replicaset from at least 3 servers is recommended as per the diagram below:

Mongo database


Load balancing - Sharding on RDBMS systems require all the logic to be applied on the application code. Changes in the application code are not required on MongoDB because this is done automatically, you just need to choose a shard key. More info at https://docs.mongodb.org/manual/sharding/.
You can find a recommended architecture for production below. To ensure that your systems are highly available each shard should be a replica set.
 

Shared cluster production architecture


File storage - MongoDB documents have a limit of 16MB per document. For use cases with files that are larger than 16MB MongoDB developed GridFS, a very convenient way to store and retrieve files. More info at https://docs.mongodb.org/manual/core/gridfs/.

Aggregation - MongoDB supports Map-Reduce but for most of the queries, Aggregation framework is much faster. Aggregations are used for complex queries to process the data set. They are similar with 'Group By' from SQL but aggregation can do more complex processing like filters, document transformations. More info at https ://docs.mongodb.org/manual/aggregation/.

Flexible schema - When developing agile applications the database schema is changed very often, so you need to use schema migrations that can be quite cumbersome for a complex schema. MongoDB doesn't have this schema restrictions.

Online features from the Mongo company:
MMS - free of charge monitoring. You can see below what kind of information is collected. More info at mms.mongodb.org.

 

MongoDB graph



Backup - external automatic backup with a free tier price plan for small datasets. Technically they'll setup a replica set member so database cache will not be affected.
Education - free online courses for DBA's, programmers. Starting from December MongoDB company will initially launch certification exams. 

MongoDB versus SQL
Advantages

1. Scalability is built-in without additional tools to be installed
2. Dynamic schema which is very welcomed on today agile applications

Disadvantages

1. Consistency is not guaranted but latest libraries for mongoDB have more safer options enabled by default.
2. More easy to find programmers and DBA's with SQL experience

MongoDB versus CouchDB
MongoDB Advantages

- MongoDB is a better general database, suitable to replace MySQL
- Cluster deployments out of the box with automatic failover
- Automatic sharding built-in

CouchDB Advantages

- Better performance on writes

Performance recommendations

1. Schema: Name of fields to be short names
2. Use indexes and perform profiling to check for slow queries
3. Allocate lots of RAM (mongo is very aggressive and wants to add all dataset in memory). Sharing a dedicated machine with other services is not recommended if you have a large data set. Mongo process will tell OS that he needs most of the RAM, other services will be pushed out and the machine will use swap.
4. Replicasets to be odd numbers. MongoDB has the option to use machines only as arbitrers that don't store any data, and are used only for elections. For production as a minimum configuration is recommended a replica set of 3 machines with 2 machines storing data and an arbitrer.
5. Don't use mongodump to perform backup as it will add to RAM data that is not used. Use instead a replica set member with a low priority.

Clients

US government https://www.mongodb.com/industries/government.
Analytics companies
Craiglist, eBay, Foursquare, Cisco, Openstack, Openshift
More info at https://www.mongodb.com/customers.

How we use it

English Attack! - https://assist-software.net/project/english-attack
New features of website including coaching mechanism required to store and analysis in real time lots of key metrics. To accomplish this in realtime we used nodeJS and MongoDB and Redis for caching the heavy queries.
Right now we have a dataset of 30G and the hardware is cluster from 3 machines forming a replica set.
The following diagram shows the architecture:

Replica set primary with secondary and arbiter

Zelgor Analytics - https://assist-software.net/project/zelgor-iphone-game
Database for analytics of Zelgor mobile application is on MongoDB and helped us performing very fast analysis of large volumes of data.

Conclusions

In the new era of high performance web applications use of a database like MongoDB is not optional. One way or another any application will have to use it.
So if you need help on developing MongoDB applications please contact us.
As a MongoDB partner company we will be more than happy to help you!
 

MongoDB logo

Update: Please take a look at my last blog posts: Cloud offering: Comparison between IaaS, PaaS, SaaS, BaaS

Share on:

Want to stay on top of everything?

Get updates on industry developments and the software solutions we can now create for a smooth digital transformation.

* I read and understood the ASSIST Software website's terms of use and privacy policy.

Frequently Asked Questions

1. What is ASSIST Software's development process?  

The Software Development Life Cycle (SDLC) we employ defines the following stages for a software project. Our SDLC phases include planning, requirement gathering, product design, development, testing, deployment, and maintenance.

2. What software development methodology does ASSIST Software use?  

ASSIST Software primarily leverages Agile principles for flexibility and adaptability. This means we break down projects into smaller, manageable sprints, allowing continuous feedback and iteration throughout the development cycle. We also incorporate elements from other methodologies to increase efficiency as needed. For example, we use Scrum for project roles and collaboration, and Kanban boards to see workflow and manage tasks. As per the Waterfall approach, we emphasize precise planning and documentation during the initial stages.

3. I'm considering a custom application. Should I focus on a desktop, mobile or web app?  

We can offer software consultancy services to determine the type of software you need based on your specific requirements. Please explore what type of app development would suit your custom build product.   

  • A web application runs on a web browser and is accessible from any device with an internet connection. (e.g., online store, social media platform)   
  • Mobile app developers design applications mainly for smartphones and tablets, such as games and productivity tools. However, they can be extended to other devices, such as smartwatches.    
  • Desktop applications are installed directly on a computer (e.g., photo editing software, word processors).   
  • Enterprise software manages complex business functions within an organization (e.g., Customer Relationship Management (CRM), Enterprise Resource Planning (ERP)).

4. My software product is complex. Are you familiar with the Scaled Agile methodology?

We have been in the software engineering industry for 30 years. During this time, we have worked on bespoke software that needed creative thinking, innovation, and customized solutions. 

Scaled Agile refers to frameworks and practices that help large organizations adopt Agile methodologies. Traditional Agile is designed for small, self-organizing teams. Scaled Agile addresses the challenges of implementing Agile across multiple teams working on complex projects.  

SAFe provides a structured approach for aligning teams, coordinating work, and delivering value at scale. It focuses on collaboration, communication, and continuous delivery for optimal custom software development services. 

5. How do I choose the best collaboration model with ASSIST Software?  

We offer flexible models. Think about your project and see which models would be right for you.   

  • Dedicated Team: Ideal for complex, long-term projects requiring high continuity and collaboration.   
  • Team Augmentation: Perfect for short-term projects or existing teams needing additional expertise.   
  • Project-Based Model: Best for well-defined projects with clear deliverables and a fixed budget.   

Contact us to discuss the advantages and disadvantages of each model. 

ASSIST Software Team Members

See the past, present and future of tech through the eyes of an experienced Romanian custom software company. The ASSIST Insider newsletter highlights your path to digital transformation.

* I read and understood the ASSIST Software website's terms of use and privacy policy.

Follow us

© 2025 ASSIST Software. All rights reserved. Designed with love.