KR20070038665A - Distributed file system and operating method thereof - Google Patents

Abstract

The present invention relates to a method for configuring a server for a distributed file system that supports the standard protocol, WebDAV. In order to operate the distributed file system efficiently, the server of the distributed file system directly manages the meta information of the stored files in the form of a database by the file index server instead of relying on the general file system. It is characterized by a separate configuration to be processed by the file handling server. With this separate configuration, all file operations (file copy, move, delete, directory creation, etc.) except for uploads and downloads in distributed file systems can be done in a database independent of the physical storage that stores the actual data. . According to the method of the present invention, a large file operation can be processed by an effective processing of a database when building a distributed file system. In addition, it is possible to separate the processing of uploads and downloads in which a large amount of traffic is generated from the processing of the remaining file operations, and thus, it is possible to effectively configure a server and a network for a service.

WebDAV

Description

Distributed file system and its operation method {DISTRIBUTED FILE SYSTEM AND OPERATING METHOD THEREOF}

1 is a diagram illustrating a distributed file system according to an exemplary embodiment of the present invention.

2 illustrates a protocol between a WebDAV client, a file index server, and a file index DB for file operations for changing List, Move, Copy, Delete, and file property values.

3 illustrates a protocol between a client, a file index server, a file index DB, a file handling server, and physical storage for a file operation corresponding to upload or download of a file.

The present invention relates to a method and system for enabling a server for a distributed file system supporting a standard protocol, WebDAV.

WebDAV is an IETF standard that has been in place since 1999 to support co-authoring activities on the Web. It is an extension of the HTTP standard protocol that allows co-editing and managing files on the Internet between remote users. It is defined. WebDAV aims to define an HTTP extension that enables distributed Web authoring tools with a wide range of common uses while supporting jointly desired user needs in a new way among remote groups.

A distributed file system is a system that allows a computer to access a remote disk over a network and use it as if it were a local disk. Representative examples of distributed file systems include NFS, Andrew File System, and file sharing on Microsoft Networks.

A service called a web storage service or a web hard service has been widely used as a service for storing files and accessing them when needed in remote locations connected to a network on the Internet.

These services have been commonly used to upload or download documents through operations within dedicated client software or web browsers. However, this method does not connect a remote disk like a local disk, so the user has to access a file on the web or learn to use a dedicated client software.

In addition, even when a distributed file system is constructed through the WebDAV protocol between server and clients, when a general file system such as a Unix system is used on the server side, performance decreases when a large number of users access the distributed file system at the same time. do.

As described above, a distributed file system based on WebDAV can be usefully used for a web storage service. However, in the case of targeting a large user, server-side performance needs to be improved.

Accordingly, the present invention manages the meta information of a file including a directory structure directly in the form of a database by the file index DB, and requires only the retrieval or modification of the meta information of the file. WebDAV requests are handled by the file index server, and the upload and download of the actual file contents are characterized by a separate configuration for processing by the file handling server.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

In addition, when a part is said to "include" a certain component, which means that it may further include other components, except to exclude other components unless otherwise stated.

According to the present invention, for efficient WebDAV-based distributed file system operation, the construction of a server system in a client-server structure does not depend on the general file system (eg, Microsoft Windows file system or Unix file system). The key is to manage information directly in the form of DB.

This method of mapping WebDAV commands delivered between client and server to the file index DB's operation that directly manages file metadata allows the user to respond to the user's query within a certain time even when there are large files or directories. There is this. In addition, all file operations (Copy, Move, Rename, Delete, List, etc.) except the upload and download that the actual file contents are delivered are virtually performed only on the file index DB, so operations on large files can be processed immediately. Do.

1 is a diagram illustrating a distributed file system according to an exemplary embodiment of the present invention.

As shown in FIG. 1, a distributed file system according to an exemplary embodiment of the present invention includes a distributed file system server part and a distributed file system client part, and communicates with each other through a WebDAV protocol.

The distributed file system client receives a command for using the distributed file system of the user and delivers it to the server, and delivers the result to the file system of the user side.

The distributed file system server receives and processes requests from the distributed file system client. The distributed file system server is composed of a file index server, a file index DB, a file handling server, and physical storage for storing the actual contents of the file.

File Index Sever is responsible for processing Copy, Move, Rename, etc. commands that can be processed only by searching or changing the metadata of files as operations in the file index DB. In FIG. 1, it is indicated that the processing by the file index server is sequentially performed by protocols 1, 2, 3, and 4.

Table 1 shows an example of the schema of the file index DB used to manage meta information about a file. Although the actual DB schema stores more information than this, including file characteristic elements and user authentication information, only the fields directly related to the present invention are shown in Table 1.

Field name Data type Usage RESOURCE_ID LONG INTEGER Unique serial number given to the file RESOURCE_TYPE CHAR (1) Indicates whether the file is a regular file or a directory URI String Display the logical address of the file in the form of a Uniform Resource Identifier (URI) DELETE_YN CHAR (1) Indicates whether the file has been deleted

When downloading a file to a user's local file system or uploading a user's local file to a distributed file system, use a file handling server to transfer physical storage and data. In FIG. 1, the processing by the file handling server is sequentially performed by protocols 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. .

When files are stored in physical storage, they are managed independently of the directory hierarchy contained within the URI of the file, maintaining constant performance regardless of the number of levels or the number of files in the directory hierarchy.

When a user performs an operation on a file in a distributed file system, the client passes authentication and commands via WebDAV to the file index server.

FIG. 2 shows a protocol between a WebDAV client, a file index server, and a file index DB for file operations for changing List, Move, Copy, and file property values processed by the file index server.

As shown in FIG. 2, the file operation is completed by simply inquiring or changing the value of the file index DB by the file index server after a user authentication process using WebDAV authentication between the client and the file index server. It does not require communication with the physical storage where the physical files are stored.

Table 2 shows the WebDAV methods delivered from the client for file operation processing in the file index server shown in FIG. 2.

3 illustrates a protocol between a client, a file index server, a file index DB, a file handling server, and physical storage for a file operation corresponding to upload or download of a file. As shown in FIG. 2, the file operation for uploading and downloading is first performed through a user authentication procedure using WebDAV authentication between the client and the file index server, and then the file index server searches for the value of the file index DB for upload or download. Check that the download can be processed. Then, the client sends a request for uploading and downloading back to the file handling server, and the file handling server checks the file status again by checking the file index DB, and then performs READ or WRITE on the physical storage and returns the result value. Pass it to the client.

The embodiments of the present invention described above are not only implemented through the apparatus and the method, but may also be implemented through a program for realizing a function corresponding to the configuration of the embodiment of the present invention or a recording medium on which the program is recorded. Implementation may be easily implemented by those skilled in the art from the description of the above-described embodiments.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

According to the present invention, all file operations except file upload and download are processed by the file index server to read or write data in the file index DB, so that an efficient distributed file system based on the WebDAV protocol can be constructed.

According to the present invention, there is a table in the file index DB that maps a directory path of a file recognized by a user to a directory path of a physical file system, and a file index server and a file handling server can search a URI for the entire directory path. Therefore, performance is not degraded by increasing the depth of the user directory hierarchy or the number of files stored in the distributed file system.

In addition, according to the present invention, since upload and download requiring actual file data transmission on the network are handled only by the file handling server, upload and download traffic requiring a large amount of network can be efficiently configured as separate servers and networks. .

In addition, the distributed file system based on the WebDAV protocol according to the configuration of the present invention can be applied to a service field called a web storage service or a web hard service which stores pay user data in storage in an internet data center as a commercial service.

Claims (3)

In the configuration of a distributed file system based on the WebDAV protocol, A client interworking with the user's file system; A file handling server that receives a WebDAV protocol request for uploading and downloading from the client and reads / writes it to physical storage; A file index server that receives a WebDAV protocol request for all file operations except uploads and downloads from the client, and converts the file into an SQL query for a file index DB that stores meta information about the file; A file index DB for providing meta information of the file to the file index server and the file handling server. In a distributed file system including a client, a file index server, a file index DB and a file handling server, the client and file index server interworking method, A first step of generating a corresponding database SQL query when the client makes a WebDAV access request to the file index server; A second step of processing in the file index DB by the SQL query generated in the first step, A third step of converting the file index DB processing result of the second step into a WebDAV access response and delivering the result to a client; And a fourth step of the client connecting to the file handling server to perform an actual upload or download when the client request is upload or download. The method of claim 2, The first step, An operation of a file index server that operates as shown in the following table in a WebDAV method generated by a file operation on a client. (uri represents the URI value of that file)

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