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MongoDB Logo.png
Developer(s) MongoDB Inc.
Initial release 2009 (2009)
Stable release 3.0.6[1] / 24 August 2015 (2015-08-24)
Development status Active
Written in C++, JavaScript, C
Operating system Cross-platform
Available in English
Type Document-oriented database
License GNU AGPL v3.0 (drivers: Apache license)

MongoDB (from humongous) is a cross-platform document-oriented database. Classified as a NoSQL database, MongoDB eschews the traditional table-based relational database structure in favor of JSON-like documents with dynamic schemas (MongoDB calls the format BSON), making the integration of data in certain types of applications easier and faster. Released under a combination of the GNU Affero General Public License and the Apache License, MongoDB is free and open-source software.

First developed by the software company MongoDB Inc. in October 2007 as a component of a planned platform as a service product, the company shifted to an open source development model in 2009, with MongoDB offering commercial support and other services.[2] Since then, MongoDB has been adopted as backend software by a number of major websites and services, including Craigslist, eBay, and Foursquare among others. As of July 2015, MongoDB is the fourth most popular type of database management system, and the most popular for document stores.[3]

Main features[edit]

Some of the features include:[4]


Instead of taking a business subject and breaking it up into multiple relational structures, MongoDB can store the business subject in the minimal number of documents. For example, instead of storing title and author information in two distinct relational structures, title, author, and other title-related information can all be stored in a single document called Book.[5]

Ad hoc queries

MongoDB supports search by field, range queries, regular expression searches. Queries can return specific fields of documents and also include user-defined JavaScript functions.


Any field in a MongoDB document can be indexed (indices in MongoDB are conceptually similar to those in RDBMSes). Secondary indices are also available.


MongoDB provides high availability with replica sets.[6] A replica set consists of two or more copies of the data. Each replica set member may act in the role of primary or secondary replica at any time. The primary replica performs all writes and reads by default. Secondary replicas maintain a copy of the data of the primary using built-in replication. When a primary replica fails, the replica set automatically conducts an election process to determine which secondary should become the primary. Secondaries can also perform read operations, but the data is eventually consistent by default.

Load balancing

MongoDB scales horizontally using sharding.[7] The user chooses a shard key, which determines how the data in a collection will be distributed. The data is split into ranges (based on the shard key) and distributed across multiple shards. (A shard is a master with one or more slaves.) MongoDB can run over multiple servers, balancing the load and/or duplicating data to keep the system up and running in case of hardware failure. Automatic configuration is easy to deploy, and new machines can be added to a running database.

File storage

MongoDB can be used as a file system, taking advantage of load balancing and data replication features over multiple machines for storing files.

This function, called Grid File System,[8] is included with MongoDB drivers and available for development languages (see "Language Support" for a list of supported languages). MongoDB exposes functions for file manipulation and content to developers. GridFS is used, for example, in plugins for NGINX[9] and lighttpd.[10] Instead of storing a file in a single document, GridFS divides a file into parts, or chunks, and stores each of those chunks as a separate document.[11]

In a multi-machine MongoDB system, files can be distributed and copied multiple times between machines transparently, thus effectively creating a load-balanced and fault-tolerant system.


MapReduce can be used for batch processing of data and aggregation operations. The aggregation framework enables users to obtain the kind of results for which the SQL GROUP BY clause is used.

Server-side JavaScript execution

JavaScript can be used in queries, aggregation functions (such as MapReduce), and sent directly to the database to be executed.

Capped collections

MongoDB supports fixed-size collections called capped collections. This type of collection maintains insertion order and, once the specified size has been reached, behaves like a circular queue.


In some failure scenarios where an application can access two distinct MongoDB processes, but these processes cannot access each other, it is possible for MongoDB to return stale reads. In this scenario it is also possible for MongoDB to acknowledge writes that will be rolled back.[12]

Before version 2.2, concurrency control was implemented on a per-mongod basis. With version 2.2, concurrency control was implemented at the database level.[13] Since version 3.0,[14] pluggable storage engines were introduced, and each storage engine may implement concurrency control differently.[15] With MongoDB 3.0 concurrency control is implemented at the collection level for the MMAPv1 storage engine,[16] and at the document level with the WiredTiger storage engine.[17] With versions prior to 3.0, one approach to increase concurrency is to use sharding.[18] In some situations, reads and writes will yield their locks. If MongoDB predicts a page is unlikely to be in memory, operations will yield their lock while the pages load. The use of lock yielding expanded greatly in 2.2.[19]

Another criticism is related to the limitations of MongoDB when used on 32-bit systems.[20] In some cases, this was due to inherent memory limitations.[21][self-published source] MongoDB recommends 64-bit systems and that users provide sufficient RAM for their working set. Compose, a provider of managed MongoDB infrastructure, recommends a scaling checklist for large systems.[22]

Additionally, MongoDB does not support collation-based sorting and is limited to byte-wise comparison via memcmp,[23] which will not provide correct ordering for many non-English languages[24] when used with a Unicode encoding.


Language support[edit]

MongoDB has official drivers for a variety of popular programming languages and development environments.[25] There are also a large number of unofficial or community-supported drivers for other programming languages and frameworks.[26]

Management and graphical front-ends[edit]

Record insertion in MongoDB with Robomongo 0.8.5.

Most administration is done from command line tools such as the mongo shell because MongoDB does not include a GUI-style administrative interface. There are third-party projects that offer user interfaces for administration and data viewing.[27]

Licensing and support[edit]

MongoDB is available for free under the GNU Affero General Public License.[28] The language drivers are available under an Apache License. In addition, MongoDB Inc. offers proprietary licenses for MongoDB.[2]


United Software Associates published a benchmark using YCSB as a basis of all the tests. MongoDB provides greater performance than Couchbase Server or Cassandra in all the tests they ran, in some cases by as much as 25x.[29]

Another benchmark for top NoSQL databases was done by End Point, which compares MongoDB with other NoSQL database solutions.[30]

Production deployments[edit]

Large-scale deployments of MongoDB are tracked by MongoDB Inc. Notable users of MongoDB include:

  • Adobe: Many of the world's most recognizable brands use Adobe Experience Manager to accelerate development of digital experiences that increase customer loyalty, engagement and demand. Adobe uses MongoDB to store petabytes of data in the large-scale content repositories underpinning the Experience Manager.[31]
  • Amadeus IT Group uses MongoDB for its back-end software.[32]
  • The Compact Muon Solenoid at CERN uses MongoDB as the primary back-end for the Data Aggregation System for the Large Hadron Collider.[33]
  • Craigslist: With 80 million classified ads posted every month, Craigslist needs to archive billions of records in multiple formats, and must be able to query and report on these archives at runtime. Craigslist migrated from MySQL to MongoDB to support its active archive, with continuous availability mandated for regulatory compliance across 700 sites in 70 different countries.[34]
  • eBay uses MongoDB in the search suggestion and the internal Cloud Manager State Hub.[35]
  • FIFA (video game series): EA Sports FIFA is the world's best-selling sports video game franchise. To serve millions of players, EA's Spearhead development studio selected MongoDB[36] to store user data and game state. Auto-sharding makes it simple to scale MongoDB across EA's 250+ servers with no limits to growth as EA FIFA wins more fans.
  • Foursquare deploys MongoDB on Amazon AWS to store venues and user check-ins into venues.[37]
  • LinkedIn uses MongoDB as its backend DB.[38]
  • McAfee: MongoDB powers McAfee Global Threat Intelligence (GTI), a cloud-based intelligence service that correlates data from millions of sensors around the globe. Billions of documents are stored and analyzed in MongoDB to deliver real-time threat intelligence to other McAfee end-client products.[39]
  • MetLife uses MongoDB for “The Wall", a customer service application providing a "360-degree view" of MetLife customers.[40]
  • SAP uses MongoDB in the SAP PaaS.[41]
  • Shutterfly uses MongoDB for its photo platform. As of 2013, the photo platform stores 18 billion photos uploaded by Shutterfly's 7 million users.[42]
  • Tuenti uses MongoDB as its backend DB.[43]
  • Yandex: The largest search engine in Russia uses MongoDB to manage all user and metadata for its file sharing service. MongoDB has scaled[44] to support tens of billions of objects and TBs of data, growing at 10 million new file uploads per day.

See also[edit]


  1. ^ "Release Notes for MongoDB 3.0". MongoDB. 
  2. ^ a b "10gen embraces what it created, becomes MongoDB Inc.". Gigaom. Retrieved 27 August 2013. 
  3. ^ "Popularity ranking of database management systems". Solid IT. Retrieved 2015-07-04. 
  4. ^ MongoDB. "MongoDB Developer Manual". MongoDB. 
  5. ^ Data Modeling for MongoDB
  6. ^ MongoDB. "Introduction to Replication". MongoDB. 
  7. ^ MongoDB. "Introduction to Sharding". MongoDB. 
  8. ^ MongoDB. "GridFS article on MongoDB Developer's Manual". MongoDB. 
  9. ^ "NGINX plugin for MongoDB source code". GitHub. 
  10. ^ "lighttpd plugin for MongoDB source code". Bitbucket. 
  11. ^ Malick Md. "MongoDB overview". Expertstown. 
  12. ^ Kyle Kingsbury (2015-04-20). "Call me maybe: MongoDB stale reads". Retrieved 2015-07-04. 
  13. ^ "MongoDB Jira Ticket 4328". 
  14. ^ Eliot Horowitz (2015-01-22). "Renaming Our Upcoming Release to MongoDB 3.0". MongoDB. Retrieved 2015-02-23. 
  15. ^ "MongoDB 2.8 release". MongoDB. 
  16. ^ MongoDB. "MMAPv1 Concurrency Improvement". MongoDB. 
  17. ^ MongoDB. "WiredTiger Concurrency and Compression". MongoDB. 
  18. ^ MongoDB. "FAQ Concurrency - How Does Sharding Affect Concurrency". MongoDB. 
  19. ^ MongoDB. "FAQ Concurrency - Do Operations Ever Yield the Lock". MongoDB. 
  20. ^ MongoDB (8 July 2009). "32-bit Limitations". MongoDB. 
  21. ^ David Mytton (25 September 2012). "Does Everybody Hate MongoDB". Server Density. 
  22. ^  Missing or empty |title= (help)[dead link]
  23. ^ "memcmp". 31 May 2013. Retrieved 26 April 2014. 
  24. ^ "MongoDB Jira ticket 1920". 
  25. ^ MongoDB. "MongoDB Drivers and Client Libraries". MongoDB. Retrieved 2013-07-08. 
  26. ^ MongoDB. "Community Supported Drivers". MongoDB. Retrieved 2014-07-09. 
  27. ^ MongoDB. "Admin UIs". Retrieved 15 September 2015. 
  28. ^ MongoDB. "The AGPL". The MongoDB NoSQL Database Blog. MongoDB. 
  29. ^ United Software Associates. "High Performance Benchmarking: MongoDB and NoSQL Systems" (PDF). 
  30. ^ End Point (13 April 2015). "Benchmarking Top NoSQL Databases; Apache Cassandra, Couchbase, HBase, and MongoDB" (PDF). 
  31. ^ MongoDB. "Adobe Experience Manager". MongoDB. 
  32. ^ "Presentation by Amadeus 11/2014". MongoDB. 
  33. ^ "Holy Large Hadron Collider, Batman!". MongoDB. 
  34. ^ MongoDB. "Craigslist". MongoDB. 
  35. ^ "MongoDB at eBay". Slideshare. 
  36. ^ "MongoDB based FIFA Online". MongoDB. 
  37. ^ "Experiences Deploying MongoDB on AWS". MongoDB. 
  38. ^ "Presentation by LinkedIn". MongoDB. 
  39. ^ MongoDB. "McAfee is Improving Global Cybersecurity with MongoDB". MongoDB. 
  40. ^ Doug Henschen (13 May 2013). "Metlife uses nosql for customer service". Information Week. Retrieved 8 November 2014. 
  41. ^ Richard Hirsch (30 September 2011). "The Quest to Understand the Use of MongoDB in the SAP PaaS". 
  42. ^ Guy Harrison (28 January 2011). "Real World NoSQL: MongoDB at Shutterfly". Gigaom. 
  43. ^ "We host the MongoDB user group meetup at our office". 
  44. ^ "Yandex: MongoDB". Yandex. 


External links[edit]