MongoDB

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MongoDB_table_infobox_0

MongoDBMongoDB_table_caption_0
Developer(s)MongoDB_header_cell_0_0_0 MongoDB Inc.MongoDB_cell_0_0_1
Initial releaseMongoDB_header_cell_0_1_0 February 11, 2009; 11 years ago (2009-02-11)MongoDB_cell_0_1_1
Stable releaseMongoDB_header_cell_0_2_0 4.4.2
  / 18 November 2020; 28 days ago (2020-11-18)MongoDB_cell_0_2_1
RepositoryMongoDB_header_cell_0_3_0 Q1165204#P1324MongoDB_cell_0_3_1
Written inMongoDB_header_cell_0_4_0 C++, Go, JavaScript, PythonMongoDB_cell_0_4_1
Operating systemMongoDB_header_cell_0_5_0 Windows Vista and later, Linux, OS X 10.7 and later, Solaris, FreeBSDMongoDB_cell_0_5_1
Available inMongoDB_header_cell_0_6_0 EnglishMongoDB_cell_0_6_1
TypeMongoDB_header_cell_0_7_0 Document-oriented databaseMongoDB_cell_0_7_1
LicenseMongoDB_header_cell_0_8_0 Source-availableMongoDB_cell_0_8_1
WebsiteMongoDB_header_cell_0_9_0 Q1165204?uselang=en#P856MongoDB_cell_0_9_1

MongoDB is a cross-platform document-oriented database program. MongoDB_sentence_0

Classified as a NoSQL database program, MongoDB uses JSON-like documents with optional schemas. MongoDB_sentence_1

MongoDB is developed by MongoDB Inc. and licensed under the Server Side Public License (SSPL). MongoDB_sentence_2

History MongoDB_section_0

See also: MongoDB Inc. § History MongoDB_sentence_3

10gen software company began developing MongoDB in 2007 as a component of a planned platform as a service product. MongoDB_sentence_4

In 2009, the company shifted to an open-source development model, with the company offering commercial support and other services. MongoDB_sentence_5

In 2013, 10gen changed its name to MongoDB Inc. MongoDB_sentence_6

On October 20, 2017, MongoDB became a publicly traded company, listed on NASDAQ as MDB with an IPO price of $24 per share. MongoDB_sentence_7

On October 30, 2019, MongoDB teamed up with Alibaba Cloud, who will offer its customers a MongoDB-as-a-service solution. MongoDB_sentence_8

Customers can use the managed offering from BABA's global data centers. MongoDB_sentence_9

MongoDB_table_general_1

MongoDB release historyMongoDB_table_caption_1
VersionMongoDB_header_cell_1_0_0 Release dateMongoDB_header_cell_1_0_1 Feature notesMongoDB_header_cell_1_0_2 RefsMongoDB_header_cell_1_0_3
1.0MongoDB_cell_1_1_0 February 2009MongoDB_cell_1_1_1 MongoDB_cell_1_1_2 MongoDB_cell_1_1_3
1.2MongoDB_cell_1_2_0 December 2009MongoDB_cell_1_2_1 MongoDB_cell_1_2_2 MongoDB_cell_1_2_3
1.4MongoDB_cell_1_3_0 March 2010MongoDB_cell_1_3_1 MongoDB_cell_1_3_2 MongoDB_cell_1_3_3
1.6MongoDB_cell_1_4_0 August 2010MongoDB_cell_1_4_1 MongoDB_cell_1_4_2 MongoDB_cell_1_4_3
1.8MongoDB_cell_1_5_0 March 2011MongoDB_cell_1_5_1 MongoDB_cell_1_5_2 MongoDB_cell_1_5_3
2.0MongoDB_cell_1_6_0 September 2011MongoDB_cell_1_6_1 MongoDB_cell_1_6_2 MongoDB_cell_1_6_3
2.2MongoDB_cell_1_7_0 August 2012MongoDB_cell_1_7_1 MongoDB_cell_1_7_2 MongoDB_cell_1_7_3
2.4MongoDB_cell_1_8_0 March 2013MongoDB_cell_1_8_1 MongoDB_cell_1_8_2 MongoDB_cell_1_8_3
2.6MongoDB_cell_1_9_0 April 8, 2014MongoDB_cell_1_9_1 MongoDB_cell_1_9_2 MongoDB_cell_1_9_3
3.0MongoDB_cell_1_10_0 March 3, 2015MongoDB_cell_1_10_1 MongoDB_cell_1_10_2 MongoDB_cell_1_10_3
3.2MongoDB_cell_1_11_0 December 8, 2015MongoDB_cell_1_11_1 MongoDB_cell_1_11_2 MongoDB_cell_1_11_3
3.4MongoDB_cell_1_12_0 November 29, 2016MongoDB_cell_1_12_1 MongoDB_cell_1_12_2 MongoDB_cell_1_12_3
3.6MongoDB_cell_1_13_0 November 2017MongoDB_cell_1_13_1 MongoDB_cell_1_13_2 MongoDB_cell_1_13_3
4.0MongoDB_cell_1_14_0 June 2018MongoDB_cell_1_14_1 MongoDB_cell_1_14_2 MongoDB_cell_1_14_3
4.2MongoDB_cell_1_15_0 August 2019MongoDB_cell_1_15_1 MongoDB_cell_1_15_2 MongoDB_cell_1_15_3
4.4MongoDB_cell_1_16_0 July 2020MongoDB_cell_1_16_1 MongoDB_cell_1_16_2 MongoDB_cell_1_16_3

Main features MongoDB_section_1

Ad-hoc queries MongoDB_section_2

MongoDB supports field, range query, and regular-expression searches. MongoDB_sentence_10

Queries can return specific fields of documents and also include user-defined JavaScript functions. MongoDB_sentence_11

Queries can also be configured to return a random sample of results of a given size. MongoDB_sentence_12

Indexing MongoDB_section_3

Fields in a MongoDB document can be indexed with primary and secondary indices. MongoDB_sentence_13

Replication MongoDB_section_4

MongoDB provides high availability with replica sets. MongoDB_sentence_14

A replica set consists of two or more copies of the data. MongoDB_sentence_15

Each replica-set member may act in the role of primary or secondary replica at any time. MongoDB_sentence_16

All writes and reads are done on the primary replica by default. MongoDB_sentence_17

Secondary replicas maintain a copy of the data of the primary using built-in replication. MongoDB_sentence_18

When a primary replica fails, the replica set automatically conducts an election process to determine which secondary should become the primary. MongoDB_sentence_19

Secondaries can optionally serve read operations, but that data is only eventually consistent by default. MongoDB_sentence_20

Load balancing MongoDB_section_5

MongoDB scales horizontally using sharding. MongoDB_sentence_21

The user chooses a shard key, which determines how the data in a collection will be distributed. MongoDB_sentence_22

The data is split into ranges (based on the shard key) and distributed across multiple shards. MongoDB_sentence_23

(A shard is a master with one or more replicas.). MongoDB_sentence_24

Alternatively, the shard key can be hashed to map to a shard – enabling an even data distribution. MongoDB_sentence_25

MongoDB can run over multiple servers, balancing the load or duplicating data to keep the system up and running in case of hardware failure. MongoDB_sentence_26

File storage MongoDB_section_6

MongoDB can be used as a , called GridFS, with load balancing and data replication features over multiple machines for storing files. MongoDB_sentence_27

This function, called , is included with MongoDB drivers. MongoDB_sentence_28

MongoDB exposes functions for file manipulation and content to developers. MongoDB_sentence_29

GridFS can be accessed using mongofiles utility or plugins for Nginx and lighttpd. MongoDB_sentence_30

GridFS divides a file into parts, or chunks, and stores each of those chunks as a separate document. MongoDB_sentence_31

Aggregation MongoDB_section_7

MongoDB provides three ways to perform aggregation: the aggregation pipeline, the map-reduce function, and single-purpose aggregation methods. MongoDB_sentence_32

Map-reduce can be used for batch processing of data and aggregation operations. MongoDB_sentence_33

But according to MongoDB's documentation, the Aggregation Pipeline provides better performance for most aggregation operations. MongoDB_sentence_34

The aggregation framework enables users to obtain the kind of results for which the SQL GROUP BY clause is used. MongoDB_sentence_35

Aggregation operators can be strung together to form a pipeline – analogous to Unix pipes. MongoDB_sentence_36

The aggregation framework includes the $lookup operator which can join documents from multiple collections, as well as statistical operators such as standard deviation. MongoDB_sentence_37

Server-side JavaScript execution MongoDB_section_8

JavaScript can be used in queries, aggregation functions (such as MapReduce), and sent directly to the database to be executed. MongoDB_sentence_38

Capped collections MongoDB_section_9

MongoDB supports fixed-size collections called capped collections. MongoDB_sentence_39

This type of collection maintains insertion order and, once the specified size has been reached, behaves like a circular queue. MongoDB_sentence_40

Transactions MongoDB_section_10

MongoDB claims to support multi-document ACID transactions since the 4.0 release in June 2018. MongoDB_sentence_41

This claim was found to not be true as MongoDB violates snapshot isolation. MongoDB_sentence_42

Editions MongoDB_section_11

MongoDB Community Server MongoDB_section_12

The MongoDB Community Edition is free and available for Windows, Linux, and OS X. MongoDB_sentence_43

MongoDB Enterprise Server MongoDB_section_13

MongoDB Enterprise Server is the commercial edition of MongoDB, available as part of the MongoDB Enterprise Advanced subscription. MongoDB_sentence_44

MongoDB Atlas MongoDB_section_14

MongoDB is also available as an on-demand fully managed service. MongoDB_sentence_45

MongoDB Atlas runs on AWS, Microsoft Azure, and Google Cloud Platform. MongoDB_sentence_46

Architecture MongoDB_section_15

Programming language accessibility MongoDB_section_16

MongoDB has official drivers for major programming languages and development environments. MongoDB_sentence_47

There are also a large number of unofficial or community-supported drivers for other programming languages and frameworks. MongoDB_sentence_48

Serverless access MongoDB_section_17

MongoDB Stitch provides serverless access to MongoDB and other services. MongoDB_sentence_49

Client libraries are available for JavaScript, iOS, and Android. MongoDB_sentence_50

Management and graphical front-ends MongoDB_section_18

The primary interface to the database has been the mongo shell. MongoDB_sentence_51

Since MongoDB 3.2, MongoDB Compass is introduced as the native GUI. MongoDB_sentence_52

There are products and third-party projects that offer user interfaces for administration and data viewing. MongoDB_sentence_53

Licensing MongoDB_section_19

MongoDB Community Server MongoDB_section_20

As of October 2018, MongoDB is released under the Server Side Public License (SSPL), a license developed by the project. MongoDB_sentence_54

It replaces the GNU Affero General Public License, and is nearly identical to the GNU General Public License version 3, but requires that those making the software publicly available as part of a "service" must make the service's entire source code available under this license. MongoDB_sentence_55

The SSPL was submitted for certification to the Open Source Initiative but later withdrawn. MongoDB_sentence_56

The language drivers are available under an Apache License. MongoDB_sentence_57

In addition, MongoDB Inc. offers proprietary licenses for MongoDB. MongoDB_sentence_58

The last versions licensed as AGPL version 3 are 4.0.3 (stable) and 4.1.4. MongoDB_sentence_59

MongoDB has been removed from the Debian, Fedora and Red Hat Enterprise Linux distributions due to the licensing change. MongoDB_sentence_60

Fedora determined that the SSPL version 1 is not a free software license because it is "intentionally crafted to be aggressively discriminatory" towards commercial users. MongoDB_sentence_61

Bug reports and criticisms MongoDB_section_21

Security MongoDB_section_22

Due to the default security configuration of MongoDB, allowing anyone to have full access to the database, data from tens of thousands of MongoDB installations has been stolen. MongoDB_sentence_62

Furthermore, many MongoDB servers have been held for ransom. MongoDB_sentence_63

From the MongoDB 2.6 release onwards, the binaries from the official MongoDB RPM and DEB packages bind to localhost by default. MongoDB_sentence_64

From MongoDB 3.6, this default behavior was extended to all MongoDB packages across all platforms. MongoDB_sentence_65

As a result, all networked connections to the database will be denied unless explicitly configured by an administrator. MongoDB_sentence_66

Technical criticisms MongoDB_section_23

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. MongoDB_sentence_67

In this scenario it is also possible for MongoDB to roll back writes that have been acknowledged. MongoDB_sentence_68

This issue was addressed since version 3.4.0 released in November 2016 (and back-ported to v3.2.12). MongoDB_sentence_69

Before version 2.2, locks were implemented on a per-server process basis. MongoDB_sentence_70

With version 2.2, locks were implemented at the database level. MongoDB_sentence_71

Since version 3.0, pluggable storage engines were introduced, and each storage engine may implement locks differently. MongoDB_sentence_72

With MongoDB 3.0 locks are implemented at the collection level for the MMAPv1 storage engine, while the WiredTiger storage engine uses an optimistic concurrency protocol that effectively provides document-level locking. MongoDB_sentence_73

Even with versions prior to 3.0, one approach to increase concurrency is to use sharding. MongoDB_sentence_74

In some situations, reads and writes will yield their locks. MongoDB_sentence_75

If MongoDB predicts a page is unlikely to be in memory, operations will yield their lock while the pages load. MongoDB_sentence_76

The use of lock yielding expanded greatly in 2.2. MongoDB_sentence_77

Up until version 3.3.11, MongoDB could not do collation-based sorting and was limited to byte-wise comparison via memcmp which would not provide correct ordering for many non-English languages when used with a Unicode encoding. MongoDB_sentence_78

The issue was fixed on August 23, 2016. MongoDB_sentence_79

Prior to MongoDB 4.0, queries against an index were not atomic. MongoDB_sentence_80

Documents which were being updated while the query was running could be missed. MongoDB_sentence_81

The introduction of the snapshot read concern in MongoDB 4.0 eliminated this phenomenon. MongoDB_sentence_82

Although MongoDB claims in an undated article entitled "MongoDB and Jepsen" that their database passed Distributed Systems Safety Research company Jepsen's tests, which it called “the industry’s toughest data safety, correctness, and consistency Tests”, Jepsen published an article in May 2020 stating that MongoDB 3.6.4 had in fact failed their tests, and that the newer MongoDB 4.2.6 has more problems including “retrocausal transactions” where a transaction reverses order so that a read can see the result of a future write.. Jepsen noted in their report that MongoDB omitted any mention of these findings on MongoDB's "MongoDB and Jepsen" page. MongoDB_sentence_83

Prominent users MongoDB_section_24

MongoDB is known to be used by Barclays; Bosch; Cisco; the City of Chicago; Codecademy; Coinbase; eBay; Foursquare; HSBC; IBM; Orange S.A.; Sega; The Gap, Inc.; Uber; Urban Outfitters; and U.S. MongoDB_sentence_84 Immigration and Customs Enforcement. MongoDB_sentence_85

MongoDB World MongoDB_section_25

MongoDB World is an annual developer conference hosted by MongoDB, Inc. MongoDB_sentence_86

MongoDB_table_general_2

YearMongoDB_header_cell_2_0_0 DatesMongoDB_header_cell_2_0_1 CityMongoDB_header_cell_2_0_2 VenueMongoDB_header_cell_2_0_3 NotesMongoDB_header_cell_2_0_4
2014MongoDB_cell_2_1_0 June 23–25MongoDB_cell_2_1_1 New YorkMongoDB_cell_2_1_2 Sheraton Times Square HotelMongoDB_cell_2_1_3 MongoDB_cell_2_1_4
2015MongoDB_cell_2_2_0 June 1–2MongoDB_cell_2_2_1 New YorkMongoDB_cell_2_2_2 Sheraton Times Square HotelMongoDB_cell_2_2_3 MongoDB_cell_2_2_4
2016MongoDB_cell_2_3_0 June 28–29MongoDB_cell_2_3_1 New YorkMongoDB_cell_2_3_2 New York Hilton MidtownMongoDB_cell_2_3_3 MongoDB_cell_2_3_4
2017MongoDB_cell_2_4_0 June 20–21MongoDB_cell_2_4_1 ChicagoMongoDB_cell_2_4_2 Hyatt Regency ChicagoMongoDB_cell_2_4_3 First year not in New York CityMongoDB_cell_2_4_4
2018MongoDB_cell_2_5_0 June 26–27MongoDB_cell_2_5_1 New YorkMongoDB_cell_2_5_2 New York Hilton MidtownMongoDB_cell_2_5_3 MongoDB_cell_2_5_4
2019MongoDB_cell_2_6_0 June 17–19MongoDB_cell_2_6_1 New YorkMongoDB_cell_2_6_2 New York Hilton MidtownMongoDB_cell_2_6_3 MongoDB_cell_2_6_4
2020MongoDB_cell_2_7_0 May 4–6MongoDB_cell_2_7_1 New YorkMongoDB_cell_2_7_2 New York Hilton MidtownMongoDB_cell_2_7_3 Canceled due to COVID-19 pandemic but was held entirely online as opposed to an in-person conference.MongoDB_cell_2_7_4

See also MongoDB_section_26

MongoDB_unordered_list_0


Credits to the contents of this page go to the authors of the corresponding Wikipedia page: en.wikipedia.org/wiki/MongoDB.