DB/MongoDB

mongodb wiki intro

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MongoDB
MongoDB Logo.png
Developer(s)10gen
Initial release2009
Stable release2.2.2 / 27 November 2012; 34 days ago
Development statusActive
Written inC++
Operating systemCross-platform
Available inEnglish
TypeDocument-oriented database
LicenseGNU AGPL v3.0 (drivers: Apache license)
Websitewww.mongodb.org


MongoDB (from "humongous") is an open source document-oriented database system developed and supported by 10gen. It is part of the NoSQLfamily of database systems. Instead of storing data in tables as is done in a "classical" relational database, MongoDB stores structured data as JSON-like documents with dynamic schemas (MongoDB calls the format BSON), making the integration of data in certain types of applications easier and faster.

10gen began Development of MongoDB in October 2007. The database is used by MTV Networks,[1] Craigslist,[2] Foursquare[3] and UIDAI Aadhaar. MongoDB is the most popular NoSQL database management system.[4]

Binaries are available for Windows, Linux, OS X, and Solaris.

Contents

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[edit]History

Development of MongoDB began at 10gen in 2007, when the company was building a platform as a service similar to Windows Azure or Google App Engine.[5] In 2009, MongoDB was open sourced as a stand-alone product[6] with an AGPL license.

In March 2010, from version 1.4, MongoDB has been considered production ready.[7]

The latest stable version, 2.2, was released in August 2012.

[edit]Licensing and support

MongoDB is available for free under the GNU Affero General Public License.[6] The language drivers are available under an Apache License. In addition, 10gen offers commercial licenses for MongoDB.[8]

[edit]Main features

The following is a brief summary of some of the main features:

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.
Indexing
Any field in a MongoDB document can be indexed (indices in MongoDB are conceptually similar to those in RDBMSes). Secondary indices are also available.
Replication
MongoDB supports master-slave replication. A master can perform reads and writes. A slave copies data from the master and can only be used for reads or backup (not writes). The slaves have the ability to select a new master if the current one goes down.
Load balancing
MongoDB scales horizontally using sharding.[9] The developer 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 could be used as a file system, taking advantage of load balancing and data replication features over multiple machines for storing files.
This function, called GridFS,[10] is included with MongoDB drivers and available with no difficulty 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.[11] and lighttpd[12]
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.
Aggregation
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), are 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.

For further information on the points listed look up the MongoDB Developer Manual

[edit]Use cases and production deployments

MongoDB is well suited for the following cases[13]:

  • Archiving and event logging
  • Document and Content Management Systems. As a document-oriented (JSON) database, MongoDB's flexible schemas are a good fit for this.
  • E-commerce. Several sites are using MongoDB as the core of their ecommerce infrastructure (often in combination with an RDBMS for the final order processing and accounting).
  • Gaming. High performance small read/writes are a good fit for MongoDB; also for certain games geospatial indexes can be helpful.
  • High volume problems. Problems where a traditional DBMS might be too expensive for the data in question. In many cases developers would traditionally write custom code to a filesystem instead using flat files or other methodologies.
  • Mobile. Specifically, the server-side infrastructure of mobile systems. Geospatial indexes are key here.
  • Operational data store of a web site. MongoDB is very good at real-time inserts, updates, and queries. Scalability and replication are provided which are necessary functions for large web sites' real-time data stores. Specific web use case examples:
    • content management
    • comment storage, management, voting
    • user registration, profile, session data
  • Projects using iterative/agile development methodologies. Mongo's BSON data format makes it very easy to store and retrieve data in a document-style / "schemaless" format. Addition of new properties to existing objects is easy and does not generally require blocking "ALTER TABLE" style operations.
  • Real-time stats/analytics

[edit]Enterprises that use MongoDB

Many enterprises use and have production deployments of MongoDB[14]

[edit]Data manipulation: collections and documents

MongoDB stores structured data as JSON-like documents, using dynamic schemas (called BSON), rather than predefined schemas.

An element of data is called a document, and documents are stored in collections. One collection may have any number of documents.

Compared to relational databases, we could say collections are like tables, and documents are like records. But there is one big difference: every record in a table has the same fields (with, usually, differing values) in the same order, while each document in a collection can have completely different fields from the other documents. The only schema requirement mongo places on documents (aside from size limits) is that they must contain an '_id' field with a unique, non-array value.

A typical table in a relational database, accessible by SQL, could be depicted like this:

Last NameFirst NameDate of Birth
DUMONTJean01-22-1963
PELLERINFranck09-19-1983
GANNONDustin11-12-1982
Every record in an SQL-accessible table has the same fields, in the same order.

In contrast, a typical MongoDB collection would look like this:

{
    "_id": ObjectId("4efa8d2b7d284dad101e4bc9"),
    "Last Name": "DUMONT",
    "First Name": "Jean",
    "Date of Birth": "01-22-1963"
},
{
    "_id": ObjectId("4efa8d2b7d284dad101e4bc7"),
    "Last Name": "PELLERIN",
    "First Name": "Franck",
    "Date of Birth": "09-19-1983",
    "Address": "1 chemin des Loges",
    "City": "VERSAILLES"
}
Each document in a MongoDB collection can have different fields from the other documents (Note: "_id" field is obligatory, automatically created by MongoDB; it's a unique index which identifies the document. Its value need not be the default MongoID type shown here—the user may specify any non-array value for _id as long as the value is unique).

In a document, new fields can be added or existing ones suppressed, modified or renamed at any moment. There is no predefined schema. A document structure is very simple: it follows theJSON format, and consists of a series of key-value pairs, so that a document is the equivalent of the feature called in various computer languages "associative arrays", "maps", "dictionaries", "hash-tables" or "hashes". The key of the key-value pair is the name of the field, the value in the key-value pair is the field's content. The key and value are separated by ":", as shown.

A value can be a number; a string; true or false; binary data such as an image; an array of values (each of which can be of different type); or an entire subordinate document:

{
    "_id": ObjectId("4efa8d2b7d284dad101e4bc7"),
    "Last Name": "PELLERIN",
    "First Name": "Franck",
    "Date of Birth": "09-19-1983",
    "phoneNumber": [
        {
            "type": "home",
            "number": "212 555-1234"
        },
        {
            "type": "fax",
            "number": "646 555-4567",
            "verified":  false
        }
    ],
    "Address": {
        "Street": "1 chemin des Loges",
        "City": "VERSAILLES"
    },
    "Months at Present Address":  37
}

Here we can see that the field "Address" contains a subordinate document possessing two fields, "Street" and "City".

[edit]Language support

MongoDB has official drivers for a variety of popular programming languages and development environments.[15]. Web programming language Opa also has built-in support for MongoDB, which is tightly integrated in the language and offers a type-safety layer on top of MongoDB.[16] There are also a large number of unofficial or community-supported drivers for other programming languages and frameworks.[17]

[edit]HTTP/REST interfaces

There are REST and HTTP interfaces that allow the manipulation of MongoDB entries via HTTP GET, POST, UPDATE, and DELETE calls.

An overview of the available HTTP/REST interfaces can be found on the website of MongoDB

[edit]Management and graphical front-ends

[edit]MongoDB tools

In a MongoDB installation the following commands are available:

mongo
MongoDB offers an interactive shell called mongo,[18] which lets developers view, insert, remove, and update data in their databases, as well as get replication information, set up sharding, shut down servers, execute JavaScript, and more.
Administrative information can also be accessed through a web interface,[19] a simple webpage that serves information about the current server status. By default, this interface is 1000 ports above the database port (28017).
mongostat
mongostat[20] is a command-line tool that displays a summary list of status statistics for a currently running MongoDB instance: how many inserts, updates, removes, queries, and commands were performed, as well as what percentage of the time the database was locked and how much memory it is using. This tool is similar to the UNIX/Linux vmstat utility.
mongotop
mongotop[21] is a command-line tool providing a method to track the amount of time a MongoDB instance spends reading and writing data. mongotop provides statistics on the per-collection level. By default, mongotop returns values every second. This tool is similar to the UNIX/Linux top utility.
mongosniff
mongosniff[22] is a command-line tool providing a low-level tracing/sniffing view into database activity by monitoring (or "sniffing") network traffic going to and from MongoDB.mongosniff requires the Libpcap network library and is only available for Unix-like systems. A cross-platform alternative is the open source Wireshark packet analyzer which has full support for the MongoDB wire protocol.
mongoimport, mongoexport
mongoimport[23] is a command-line utility to import content from a JSON, CSV, or TSV export created by mongoexport[24] or potentially other third-party data exports. Usage information can be found in the MongoDB Manual's section on Importing and Exporting MongoDB Data.
mongodump, mongorestore
mongodump[25] is a command-line utility for creating a binary export of the contents of a Mongo database; mongorestore[26] can be used to reload a database dump. Data backup strategies and considerations are detailed in the MongoDB Manual's section on Backup and Restoration Strategies.

[edit]Monitoring plugins

There are MongoDB monitoring plugins available for the following network tools:

More monitoring and diagnostic tools for MongoDB are listed on MongoDB Admin Zone: Monitoring and Diagnostics

[edit]Cloud-based monitoring services

[edit]Web and desktop application GUIs

Several GUIs have been created by MongoDB's developer community to help visualize their data. Some popular ones are:

Open source tools

  • RockMongo: PHP-based MongoDB administration GUI tool
  • phpMoAdmin: another PHP GUI that runs entirely from a single 95kb self-configuring file
  • UMongo: a desktop application for all platforms.
  • Mongo3: a Ruby-based interface.
  • Meclipse: Eclipse plugin for interacting with MongoDB
  • MongoHub: a freeware native Mac OS X application for managing MongoDB. Version for other operating systems is built on Titanium Desktop.

More client tools for MongoDB are listed on MongoDB Administrator Manual

[edit]Business intelligence tools and solutions

  • Jaspersoft BI: Java based Report Designer and Report Server that supports MongoDB
  • RJMetrics: A hosted Business Intelligence Solution that supports MongoDB.
  • eCommerce Analytics: eCommerce Analytics Software that supports MongoDB data analysis.

[edit]See also

Portal iconFree software portal

[edit]References

  1. ^ MongoDB Powering MTV's Web Properties
  2. ^ MongoDB live at craigslist
  3. ^ MongoDB at foursquare - Presentation at MongoNYC
  4. ^ DB-Engines Ranking
  5. ^ MongoDB daddy: My baby beats Google BigTable
  6. ^ a b The MongoDB NoSQL Database Blog, The AGPL
  7. ^ The MongoDB NoSQL Database Blog, MongoDB 1.4 Ready for Production
  8. ^ MongoDB Support by 10gen
  9. ^ Article "Sharding" on MongoDB Administrator's Manual
  10. ^ GridFS article on MongoDB Developer's Manual
  11. ^ NGINX plugin for MongoDB source code
  12. ^ lighttpd plugin for MongoDB source code.
  13. ^ "Use Cases" article at MongoDB's web page
  14. ^ "Production Deployments" article on MongoDB web
  15. ^ http://www.mongodb.org/display/DOCS/Drivers
  16. ^ http://doc.opalang.org/manual/Hello--database
  17. ^ http://www.mongodb.org/display/DOCS/Drivers
  18. ^ mongo - The Interactive Shell
  19. ^ HTTP Console
  20. ^ mongostat Manual
  21. ^ mongotop Manual
  22. ^ mongosniff Manual
  23. ^ mongoimport Manual
  24. ^ mongoexport Manual
  25. ^ mongodump Manual
  26. ^ mongorestore Manual

[edit]Bibliography

[edit]External links


출처 - http://en.wikipedia.org/wiki/MongoDB







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