JP2009265919A - File sharing system and relay server - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for sharing a file among different networks, and enhancing accessibility to the file. <P>SOLUTION: A terminal device 20-1 of a LAN 1 tries to access a shared file 210 stored in a terminal device 20-3 connected to a LAN 2, in reference to a sharing list 100-1 held in a relay server 10-1. The relay server 10-1 transfers, when the shared file 210 is cached in a volatile memory 15 of the relay server 10-1, the cached shared file 210 to the terminal device 20-1. A relay server 10-2 and the relay server 10-1 cooperatively transfer the shared file 210 stored in the terminal device 20-3, to the terminal device 20-1 when the shared file 210 is not cached. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technique for sharing a file between a plurality of networks.

  In a LAN (Local Area Network), a file can be shared between terminal devices by using a file sharing protocol. The user can access the shared file by selecting the shared file listed on the monitor of the terminal device.

  There is also a technology for sharing files existing in different LANs. For example, file sharing can be performed between LANs constructed on different floors in the company. An employee on one floor can access a file or the like existing on a LAN on another floor by referring to the network shared folder.

JP 2007-128179 A JP-T-2004-524602

  As described above, it is possible to share files between different LANs. However, considering the convenience of the user, a mechanism for dynamically notifying information on the shared files to other LANs is necessary.

  Patent Document 1 discloses a technique for dynamically providing information on a shared file that is currently accessible to a user in a file sharing system. The information processing apparatus detects the operating state of another information processing apparatus that provides a shared file, and displays only information on the shared file that is currently viewable on the user interface.

  With the technique of Patent Document 1, the user can know a shared file that can be browsed at present. However, it is impossible to access a shared file held by an information processing apparatus that is not operating. Eventually, it is necessary to wait for the information processing apparatus holding the shared file to operate. For example, it is inconvenient when it is desired to confirm the contents of the shared file in a hurry.

  Patent Document 2 discloses a technique in which a plurality of other terminal devices cache shared resources stored in a certain terminal device in a via-to-peer environment.

  With the technology of Patent Document 2, while another terminal device caches the shared resource, the user can access the shared resource even when the terminal device holding the original shared resource goes offline. is there. However, since the shared resource is cached by the terminal device used by the user, the online state cannot be expected continuously, and if the user goes offline, the user cannot access the shared resource. .

  In view of the above problems, an object of the present invention is to provide a technique for sharing a file between different networks and improving the accessibility to the file.

  In order to solve the above-described problem, the file sharing system according to claim 1 includes a first network in which a first relay server is arranged and a second network in which a second relay server is arranged, and the first relay The server exchanges information of files shared in each network with the second relay server, thereby creating a shared file list, and a share recorded in the shared file list A copy storage unit that stores a copy of the file in the storage unit, and an access request that designates the shared file in the second network recorded in the shared file list from the first terminal device in the first network If the specified shared file is stored in the storage unit, the shared file is acquired from the storage unit, and the specified shared file is acquired. If the file is not stored in the storage unit, the shared file is acquired from the second terminal device storing the specified shared file via the second relay server, and the acquired shared file is requested from the request source. A file acquisition unit for transferring to the first terminal device.

  According to a second aspect of the present invention, in the file sharing system according to the first aspect, the first relay server stores a copy of a new shared file when the new shared file is added to the shared file list. A cache update unit stored in the unit.

  According to a third aspect of the present invention, in the file sharing system according to the second aspect, the cache update unit copies a new shared file only when there is a request from a terminal device that provides the new shared file. A request receiving unit stored in the storage unit.

  According to a fourth aspect of the present invention, in the file sharing system according to any one of the first to third aspects, the first relay server includes an encryption unit that encrypts the shared file stored in the storage unit. It is characterized by that.

  According to a fifth aspect of the present invention, information on a file shared in each network is exchanged with a relay server arranged in the first network and a remote relay server arranged in the second network. Thus, a list creation unit that creates a shared file list, a copy storage unit that stores a copy of the shared file recorded in the shared file list in a storage unit, and the first terminal device in the first network When an access request specifying a shared file in the second network recorded in the shared file list is received, if the specified shared file is stored in the storage unit, the shared file is acquired from the storage unit. If the designated shared file is not stored in the storage unit, the designated shared file is passed through the remote relay server. Get the shared files from a second terminal device that stores, for a file acquisition unit for transferring the shared file obtained to the requesting said first terminal device, comprising: a.

  According to a sixth aspect of the present invention, in the relay server according to the fifth aspect, when a new shared file is added to the shared file list, a cache update for storing a copy of the new shared file in the storage unit Part.

  According to a seventh aspect of the present invention, in the relay server according to the sixth aspect, the cache update unit copies the new shared file only when there is a request from a terminal device that provides the new shared file. And a request receiving unit stored in the storage unit.

  The invention according to claim 8 is the relay server according to any one of claims 5 to 7, further comprising an encryption unit for encrypting the shared file stored in the storage unit.

  The file sharing system of the present invention realizes sharing of files between different networks by exchanging the shared file list of each network by the relay server. The terminal device of each network can easily access a shared file provided in a different network by referring to the shared file list. Furthermore, since a copy of the file shared in each network is stored in the storage unit provided in the relay server, even if the terminal device that provides the shared file goes offline, Access is possible.

  Since the relay server is normally maintained in an online state, it is unlikely that the relay server is frequently offline like a terminal device, and the accessibility to the shared file is increased.

  Further, since the relay server caches the shared file within the range of the volatile memory capacity, the storage of the relay server is not compressed.

  Furthermore, since the shared file is stored in the volatile memory, the content of the shared file can be prevented from leaking even if the relay server is illegally taken away.

  When the shared file list is updated, the new shared file is stored in the storage unit of the relay server, so that the accessibility to the shared file with high interest to the user is improved.

{Overall configuration of file sharing system}
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an overall view of a file sharing system according to the present embodiment. This file sharing system includes a LAN 1 and a LAN 2 connected via the Internet 3.

  A relay server 10-1 and terminal devices 20-1 and 20-2 are connected to the LAN 1. A relay server 10-2 and terminal devices 20-3 and 20-4 are connected to the LAN2. In the following description, when a common description is given to the relay servers 10-1 and 10-2, they are collectively referred to as the relay server 10 as appropriate. Moreover, when performing a common description about the terminal devices 20-1 to 20-4, the terminal device 20 is appropriately named as appropriate.

  For example, LAN 1 is a LAN of a head office building, and LAN 2 is a LAN of a branch office building in a remote place. The relay servers 10-1 and 10-2 can exchange data between the LAN 1 and the LAN 2 via the Internet 3 by exchanging data.

  The terminal devices 20-1 and 20-2 are terminals used by users of the LAN 1, and store various types of shared files 210. Then, the terminal devices 20-1 and 20-2 create and hold shared lists 200-1 and 200-2 in which a list of files provided by the self-device as the shared file 210 is recorded. The relay server 10-1 collects the sharing lists 200-1 and 200-2 from the terminal devices 20-1 and 20-2, and reflects the information described in these lists in the sharing list 100-1.

  The terminal devices 20-3 and 20-4 are terminals used by users of the LAN 2 and store various types of shared files 210. Then, the terminal devices 20-3 and 20-4 create and hold shared lists 200-3 and 200-4 in which a list of files provided by the own device as the shared file 210 is recorded. The relay server 10-2 collects the sharing lists 200-3 and 200-4 from the terminal devices 20-3 and 20-4, and reflects the information described in these lists in the sharing list 100-2.

  Further, the relay servers 10-1 and 10-2 exchange information recorded in the respective sharing lists 100-1 and 100-2. When the relay server 10-1 receives the information recorded in the share list 100-2, the relay server 10-1 also reflects the information recorded in the share lists 200-3 and 200-4 in the share list 100-1. Similarly, when the relay server 10-2 receives the information recorded in the sharing list 100-1, the relay server 10-2 also reflects the information recorded in the sharing lists 200-1 and 200-2 in the sharing list 100-2. In this way, the sharing lists 100-1 and 100-2 include all information of files shared by the LAN1 and LAN2, respectively.

  In the sharing lists 100-1 and 100-2, the file name of the shared file 210, the terminal identification information of the terminal device 20 storing the shared file 210, and the terminal device 20 storing the shared file 210, which relay Information indicating whether the server 10 is connected is included.

  In the following description, the sharing lists 200-1 to 200-4 are collectively referred to as a sharing list 200 as appropriate. Further, the sharing lists 100-1 and 100-2 are collectively referred to as a sharing list 100 as appropriate.

  The relay servers 10-1 and 10-2 can browse the contents of the share lists 100-1 and 100-2 on the terminal devices 20 connected to the LAN 1 and the LAN 2, respectively. The user of the terminal device 20 tries to access the shared file 210 by browsing the sharing lists 100-1 and 100-2. When the relay servers 10-1 and 10-2 accept access to the shared file 210, the relay servers 10-1 and 10-2 identify the terminal device 20 storing the shared file 210 by referring to the shared lists 100-1 and 100-2. The shared file 210 is transferred to the requesting terminal device 20 by transferring the shared file 210 between the relay servers.

  For example, it is assumed that the terminal device 20-1 browses the share list 100-1 and requests access to the shared file 210 stored in the terminal device 20-3. The relay server 10-1 specifies from the contents recorded in the share list 100-1 that the terminal storing the designated shared file 210 is the terminal device 20-3. Moreover, it specifies that the specified terminal device 20-3 is connected to the relay server 10-2. Therefore, the relay server 10-1 makes an acquisition request for the shared file 210 to the relay server 10-2. The relay server 10-2 acquires the shared file 210 designated from the terminal device 20-3 and transfers it to the relay server 10-1. The relay server 10-1 further transfers the received shared file 210 to the terminal device 20-1. In this way, the entity of the shared file 210 is transferred to the requesting terminal device 20.

  As described above, the file sharing system according to the present embodiment can share files between LANs at remote locations. Each LAN user can access the shared file 210 by referring to the sharing lists 100-1 and 100-2 held by the relay servers 10-1 and 10-2. The shared file 210 can be accessed with a simple operation without being aware of whether the shared file 210 is stored in the terminal device 20.

  In constructing such a system, the protocol to be used is not particularly limited. For example, it is convenient to use a SIP (Session Initiation Protocol) which is a call control protocol. A SIP server is arranged on the Internet 3, and the relay servers 10-1 and 10-2 perform registration processing (Register) on the SIP server. As a result, the relay servers 10-1 and 10-2 can transmit and receive data using the SIP via the Internet 3 using the SIP server. The SUBSCRIBE method is convenient for exchanging the shared lists 100-1 and 100-2. When the lists are updated, if the SUBSCRIBE method is executed in advance, the updated lists are reflected in each other. In addition, the transfer process of the shared file 210 can be executed by establishing a media session between the relay servers using the INVITE method.

{Configuration of relay server}
The configuration of the relay server 10 will be described. As illustrated in FIG. 2, the relay server 10 includes a communication control unit 11, a shared list management unit 12, a shared file management unit 13, a hard disk 14, and a volatile memory 15.

  The hard disk 14 stores a share list 100 reflecting the contents of the share list 200 acquired from each terminal device 20.

  The volatile memory 15 is a semiconductor memory such as a RAM (Random Access Memory). The volatile memory 15 stores a copy of the shared file 210 provided by the terminal device 20. The volatile memory 15 is used like a cache memory that stores the shared file 210.

  The communication control unit 11 executes various communication processes for using the file sharing system via the LAN 1 or LAN 2 and the Internet 3.

  The share list management unit 12 executes a process of reflecting the share list 200 acquired from each terminal device 20 in the share list 100. Further, when the share list 100 in the hard disk 14 is updated, the share list management unit 12 transfers the updated share list 100 to the other relay server 10. Alternatively, when the updated sharing list 100 is received from the other relay server 10, a process for reflecting the updated contents on the sharing list 100 in the hard disk 14 is executed. As described above, the shared list management unit 12 manages the latest list of files shared in the LAN1 and LAN2.

  When a new shared file is added to the share list 100, the shared file management unit 13 acquires the new shared file 210 from the LAN1 or LAN2 terminal device 20, and stores the acquired shared file 210 in the volatile memory 15. To do. The new shared file includes not only a file with a new file name but also a file with the same file name but different time stamp and file size. The shared file management unit 13 also has a function of setting a storage period of the shared file 210 stored in the volatile memory 15.

  In addition, the shared file management unit 13 encrypts the shared file 210 stored in the volatile memory 15. The volatile memory 15 may include important data held by the terminal device 20. Even when the relay server 10 is illegally taken out, the use of the volatile memory is unlikely to cause data leakage, but the shared file 210 stored in the volatile memory 15 is encrypted. Thus, the possibility of data leakage can be eliminated more effectively. Alternatively, even if the relay server 10 receives an intrusion from an external network, data leakage can be prevented by encrypting the shared file 210. The shared file management unit 13 also decrypts the shared file 210 stored in the volatile memory 15 when transferring the shared file 210 in response to an access request (legitimate access request) from the terminal device 20.

{Configuration of terminal device}
The configuration of the terminal device 20 will be described. As illustrated in FIG. 3, the terminal device 20 includes a communication control unit 21, a shared list management unit 22, and a storage unit 24. The storage unit 24 stores shared files 210, 210... Provided to the network by the terminal device 20 and a shared list 200 in which a list of the shared files 210 is recorded.

  The communication control unit 21 controls various communication processes performed with the relay server 10 via the LAN.

  The share list management unit 22 performs update management of the share list 200. When the content of the share list 200 is updated, the share list management unit 22 transmits the latest share list 200 to the relay server 10.

{File access procedure}
A file access method in the file sharing system having the above-described configuration will be described with reference to the flowcharts of FIGS. The flowcharts of FIGS. 4 and 5 show the flow of processing executed in the relay server 10.

  First, the cache processing of the shared file 210 by the relay server 10 will be described using the flowchart of FIG. The share list management unit 12 checks whether or not a new share file 210 has been added to the share list 100 (step S11). As described above, not only when the shared file 210 having a new file name is added to the shared list 100, but also when the time stamp or file size of the shared file 210 previously listed is changed, the new file name is added. It is determined that the shared file 210 has been added.

  When the new shared file 210 is added to the share list 100, the shared file management unit 13 acquires the shared file 210 from the terminal device 20 that stores the original of the new shared file 210 (step S12). Then, the shared file management unit 13 stores the acquired new shared file 210 in the volatile memory 15 (step S13).

  In step S <b> 13, if the terminal device 20 storing the original shared file 210 exists on the same LAN, the relay server 10 directly acquires the shared file 210 of the terminal device 20. If the terminal device 20 exists in another LAN, the relay server 10-1 or 10-2 cooperates to acquire the shared file 210. Alternatively, as will be described later, only the shared file 210 provided on the same LAN may be cached.

  By performing such processing, a relatively new copy of the shared file 210 provided to the network is cached in the volatile memory 15 of the relay server 10.

  Next, the flow of processing in which the terminal device 20 accesses the shared file 210 provided on a different LAN will be described with reference to the flowchart of FIG. Here, a case where the terminal device 20-1 accesses the shared file 210 stored in the terminal device 20-3 will be described as an example.

  The user of the terminal device 20-1 accesses the sharing list 100-1 of the relay server 10-1, and refers to the sharing list 100-1. The user of the terminal device 20-1 designates the shared file 210 stored in the terminal device 20-3 from the shared files 210 listed in the share list 100-1, and makes an access request. This access request is transmitted to the relay server 10-1.

  When the relay server 10-1 receives a file access request from the terminal device 20-1 (Yes in Step S21), the relay server 10-1 checks whether the shared file 210 to be accessed is stored in the volatile memory 15 (Step S22). ).

  When the shared file 210 to be accessed is stored in the volatile memory 15 (Yes in step S22), the relay server 10-1 acquires the corresponding shared file 210 from the volatile memory 15 (step S23).

  When the shared file 210 to be accessed is not stored in the volatile memory 15 (No in step S22), the relay server 10-1 identifies and identifies the terminal device 20 in which the original shared file 210 is stored. The shared file 210 is acquired from the terminal device 20 that has been made (step S24).

  In this example, the relay server 10-1 specifies that the owner of the shared file 210 is the terminal device 20-3. Note that the owner of the shared file 210 indicates the terminal device 20 that stores the original of the shared file 210. The terminal device 20-3 that is the owner of the shared file 210 can be identified as a terminal connected to the relay server 10-2 by referring to the sharing list 100-1. First, the relay server 10-1 transmits an acquisition request for the designated shared file 210 to the relay server 10-2. When receiving the acquisition request, the relay server 10-2 specifies that the owner of the designated shared file 210 is the terminal device 20-3. The relay server 10-2 acquires the specified shared file 210 from the terminal device 20-3, and transfers the acquired shared file 210 to the relay server 10-1.

  If the owner of the shared file 210 is the terminal device 20 connected to the LAN 1 in step S24, the relay server 10-1 acquires the shared file 210 directly from the terminal device 20 that is the owner of the shared file 210. To do.

  As described above, the relay server 10-1 acquires the shared file 210 from the volatile memory 15 storing a copy of the shared file 210 or the terminal device 20 storing the original of the shared file 210. Then, the relay server 10-1 transfers the acquired shared file 210 to the terminal device 20-1 that is the access request source of the shared file 210 (step S25).

  As described above, according to the file sharing system of the present embodiment, first, by distributing and managing the shared file 210 within the file sharing network, the burden of operating the file server can be reduced. Can do. On the other hand, by storing a copy of the newly added shared file 210 in the volatile memory 15 of the relay server 10, the file can be stored even when the terminal device 20 providing the shared file 210 goes offline. The situation where access is impossible can be avoided.

  In particular, a file newly provided as a shared file 210 to the network may be accessed with high frequency by the user. Since the shared file 210 that is of great interest to such a user is cached in the relay server 10, the accessibility to the shared file 210 is enhanced. For example, it is assumed that after the user publishes the shared file 210 on his / her terminal device 20, the user goes out with the terminal device 20 offline. Even in this case, since the shared file 210 is cached in the relay server 10, other users can access the new shared file 210.

  The shared file 210 cached in the relay server 10 is stored in the volatile memory of the relay server 10. Therefore, the shared file 210 written in the past is evicted from the storage area by writing the new shared file 210. Thereby, only the shared file 210 with higher access request is cached, and the shared file 210 with lower access request is driven out of the memory, so that the storage area can be used effectively. Further, the storage such as the hard disk 14 of the relay server 10 is not compressed.

{Others}
In the above embodiment, the shared file management unit 13 stores the newly added shared file 210 in the volatile memory 15. Although the stored shared file 15 will be erased by overwriting any other data, a period for storing it in the volatile memory 15 may be explicitly set.

  In the above embodiment, the case where the relay server 10 caches all the shared files 210 newly added to the share list 100 has been described. As another embodiment, the terminal device 20 to which the new shared file 210 is added may explicitly transmit a cache request to the relay server 10. The shared file management unit 13 caches the new shared file 210 only when there is a request from the terminal device 20. It is possible to avoid the storage area of the volatile memory 15 being used by the less important shared file 210, and the shared file 210 having a higher access request can be kept in the volatile memory 15 for a long time.

  The relay server 10 may cache all the new shared files 210 provided in the LAN1 and LAN2, but may cache only the shared files 210 of the LAN managed by the own device. . For example, the relay server 10-1 caches only the new shared file 210 provided on the LAN 1, and the relay server 10-2 caches only the new shared file 210 provided on the LAN 2.

  In the above embodiment, the file sharing system in which two LANs are connected has been described as an example. However, the file sharing system in this embodiment can be similarly applied to a system in which three or more LANs are connected. is there.

It is a network block diagram of the file sharing system which concerns on embodiment. It is a functional block diagram of a relay server. It is a functional block diagram of a terminal device. It is a flowchart which shows the flow of the cache process performed by a relay server. It is a flowchart which shows the flow of the file access process performed by a relay server.

Explanation of symbols

1 LAN
2 LAN
3 Internet 10 (10-1, 10-2) Relay server 14 Hard disk 15 Volatile memory 20 (20-1 to 20-4) Terminal device 100 (100-1, 100-2) Shared list 200 (200-1) 200-4) Shared list 210 Shared file

Claims (8)

A first network in which the first relay server is arranged;
A second network in which the second relay server is arranged;
With
The first relay server is
A list creation unit that creates a shared file list by exchanging information of files shared in each network with the second relay server;
A copy storage unit for storing a copy of the shared file recorded in the shared file list in a storage unit;
When an access request specifying a shared file in the second network recorded in the shared file list is received from a first terminal device in the first network, the specified shared file is stored in the storage unit. If the shared file is obtained from the storage unit and the designated shared file is not stored in the storage unit, the designated shared file is stored via the second relay server. A file acquisition unit that acquires a shared file from the terminal device of 2 and transfers the acquired shared file to the first terminal device of the request source;
A file sharing system comprising: The file sharing system according to claim 1,
The first relay server is
A cache update unit that stores a copy of the new shared file in the storage unit when a new shared file is added to the shared file list;
A file sharing system comprising: The file sharing system according to claim 2,
The cache update unit
Only when there is a request from a terminal device that provides a new shared file, a request receiving unit that stores a copy of the new shared file in the storage unit,
A file sharing system comprising: The file sharing system according to any one of claims 1 to 3,
The first relay server is
An encryption unit for encrypting the shared file stored in the storage unit;
A file sharing system comprising: A relay server arranged in the first network,
A list creation unit that creates a shared file list by exchanging information of files shared in each network with a remote relay server arranged in the second network;
A copy storage unit that stores a copy of the shared file recorded in the shared file list in a storage unit;
When an access request specifying a shared file in the second network recorded in the shared file list is received from a first terminal device in the first network, the specified shared file is stored in the storage unit. If the shared file is acquired from the storage unit and the designated shared file is not stored in the storage unit, the designated shared file is stored via the remote relay server. A file acquisition unit that acquires a shared file from the terminal device and transfers the acquired shared file to the requesting first terminal device;
A relay server comprising: The relay server according to claim 5, further comprising:
A cache update unit that stores a copy of the new shared file in the storage unit when a new shared file is added to the shared file list;
A relay server comprising: The relay server according to claim 6,
The cache update unit
Only when there is a request from a terminal device that provides a new shared file, a request receiving unit that stores a copy of the new shared file in the storage unit,
Including a relay server. The relay server according to any one of claims 5 to 7, further comprising:
An encryption unit for encrypting the shared file stored in the storage unit;
A relay server comprising:

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