It is a sub-module of MongoDB. gridfs can be used to store files persistently Based on MongoDB. it also supports distributed applications (File distributed storage and reading ). gridfs is a tool for users to store large objects in MongoDB. It has a size limit for data (document) Storage in MongoDB and bson format, up to 16 Mb. however, in actual system development, the function of uploading images or files is often available. These files may be of large size .. we can use gridfs to help manage these files.
The file table of Mongo GFS consists of the table name. Files and table name. Chunks. The former is the file information, and the latter is the file content. The two are associated with files_id through _ id.
Gridfs splits large file objects into multiple small chunks (File fragments), which are generally 256 k/number. Each Chunk is used as a document of MongoDB) stored in the chunks collection .. the gridfs module creates chunks and files information for each file. the actual content of each file is stored in chunks (binary data). The file-related meta data (filename, content_type, and custom attributes) will be stored in the files set. documents in the files set are in the bson format. You can use MongoDB indexes and other features. Of course, you can perform data analysis on files.
Use Cases: if your system has the following scenarios:
1) there are a large number of uploaded images (User uploads, System File releases, etc)
2) The magnitude of files is growing rapidly. It is possible that the file system query performance bottleneck of the single-host operating system may exceed the expansion range of the single-host hard disk.
3) file backup (not applicable to gridfs, which can be done by third parties, but not convenient), failover and repair of file system access ..
4) file indexing: in addition to the file itself, more metadata information needs to be associated (for example, not only files are stored, you also need to save the published author/release time/file tag attributes and other custom information of some files...
5) based on 4), the classification of files is fuzzy. If the file system of the operating system is used, the folder classification relationship is chaotic or cannot be classified ..
6) The current system is web-based, and the access to images is routed according to the URL rules .. (normal file systems can also)
7) the file size is small and large, and the file may be migrated/deleted ..
The following are two ppt files that describe MongoDB's gridfs, including the advantages of gridfs over traditional file system storage and Network File System storage. Although the content is similar, the introduction methods vary. We recommend it to you.
Gridfs and MongoDB
View more presentations from Mitch pirtle
Grid FS
View more presentations from Chris powers
MongoDB gridfs
View More PowerPoint from XUE WEI
Use MongoDB storage to upload physical files and perform squid acceleration (based on the ASPX page)
Performance testing of hundreds of millions of MongoDB data volumes
Topics on MongoDB data aggregation
Http://www.oschina.net/question/12_29127
MongoDB-based gridfs Image Storage
File storage policy based on MongoDB gridfs