JP2007018294A - File distribution system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a file distribution system capable of suitably improving distribution efficiency. <P>SOLUTION: A server 3 includes a server file transfer control part 33. A client 5 includes a client file transfer control part 53. The client 5 has a file transfer server function and transfers a distribution file in response to the request of another client 5. A file distribution managing part 32 of the server 3 manages a file distribution by transmitting a distribution instruction, which includes a transfer source to which each client should transmit a file transfer request as a request source, to a request source client. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a file distribution system for distributing a distribution file from a server to a plurality of clients, and more particularly to a technique for efficiently distributing in a short time.

  Conventionally, a file distribution system is realized by a file transfer server function such as an FTP server. FIG. 15 shows an example of a conventional file distribution system. In the file distribution system 101 of FIG. 15, a server 103 is connected to each of a plurality of clients 105 via a network such as the Internet. The server 103 has a file transfer server function, and transmits a distribution file to each client 105. For example, the distribution system 101 is video content, and each client 105 is a display control device that controls a video display device such as a large display.

  As shown in FIG. 15, in the conventional file distribution system, the server 103 selects the number of clients 105 with the number of simultaneous distributions (the number of simultaneous connections, for example, four), and transmits a distribution instruction to these clients 105. When receiving the distribution instruction, the client 105 downloads the distribution file from the server 103 and notifies the server 103 of the download completion. Such an operation is repeated until distribution to all the clients 105 is completed.

  FIG. 16 shows a file transfer operation taking two clients 105a and 105b as an example. In this example, the number of simultaneous distributions is 1. When the server 103 sends a delivery instruction to the first client 105a (Sa101), the client 105a sends a file transfer request command (GET) to the server 103 (Sa102). Upon receiving the file transfer request, the server 103 performs file transfer to the client 105a that sent the request according to the file transfer protocol (FTP) (Sa103). When the file transfer is completed, the client 105a transmits a file transfer completion notification to the server 103 (Sa104). When the server 103 receives the file transfer completion notification, the server 103 selects the next client 105b, and the same processing is performed between the server 103 and the client 105b (Sb101 to Sb104).

  The above file distribution system performs unilateral file transfer using the server side as an information supply source. A cache server is known as a technique for performing more efficient file distribution. The cache server stores a file obtained from the server via the Internet or the like, and supplies the file to a plurality of clients connected via a LAN or the like.

Further, in the file distribution system disclosed in Patent Document 1, in order to improve the efficiency of file distribution, a plurality of clients form an autonomous distributed download user network such as an ad hoc network. The server divides the distribution file into a plurality of files and distributes them to a plurality of clients in the download user network. The plurality of clients exchange the divided distribution files and combine the collected files to generate the original file.
JP 2002-132613 A (page 4-7, FIG. 1)

  However, in the conventional file distribution system as shown in FIG. 15, since the one-way file distribution from the server as the information providing source is performed, the server-side network line becomes a bottleneck, and the distribution efficiency is improved. It is difficult to increase. Such a problem becomes prominent in large-scale distribution such as video. In addition, although a cache server can improve distribution efficiency, it may not be suitable for server-driven distribution. For example, a cache server may not be suitable for a system in which file distribution to a large number of display control devices is led by a server. Although the technique of Patent Document 1 can also improve the distribution efficiency, the application field is limited because it is necessary to form a download user network such as ad hoc, and is suitable for the case where server-led distribution is performed. There may not be.

  The present invention has been made to solve the conventional problems, and an object of the present invention is to provide a file distribution system capable of suitably improving distribution efficiency.

  The file distribution system of the present invention distributes a distribution file from a server to a plurality of clients. In this file distribution system, the server requests a distribution instruction including a server file storage unit for storing the distribution file and a transfer source server or a transfer source client to which each client should transmit a file transfer request as a request source client. In order to realize the functions of the file distribution management unit to be transmitted to the original client and the transfer source server, the request for the distribution file read from the server file storage unit in response to the file transfer request received from the request source client A server file transfer control unit that transfers the file to the original client, and in order for the client to realize the function of the request source client, the file is transferred to the transfer source server or the transfer source client included in the distribution instruction received from the server. Send a transfer request In order to realize the function of the distribution processing unit that receives the distribution file, the client file storage unit that stores the distribution file received by the distribution processing unit, and the transfer source client, from another client as the request source client A client file transfer control unit that transfers the distribution file read from the client file storage unit to the request source client in response to the received file transfer request.

  With this configuration, the file transfer control unit is provided in the client. That is, not only the server but also the client is provided with the file transfer server function. Since the client transfers the file to other clients, the delivery efficiency is improved. Further, the file distribution management unit of the server transmits a distribution instruction including the transfer source server or the transfer source client to each client. As a result, the server can control the relationship between the file transfer request source and the transfer source, such as which device transfers the file from which device, and can manage file distribution. In this way, the distribution efficiency can be suitably improved while managing the file distribution to the client.

  In the file delivery system of the present invention, when the delivery processing unit of the client receives a delivery file from the transfer source server or the transfer source client included in the delivery instruction received from the server, a file transfer completion notification is sent to the server. The file distribution management unit of the server transmits a distribution management table storage unit that stores a distribution management table that records distribution states to the plurality of clients, and each client transmits a file transfer request as the requesting client. A transfer source determination unit for determining the transfer source server or the transfer source client to be transmitted, and a distribution instruction including the transfer source server or the transfer source client determined by the transfer source determination unit is transmitted to the request source client The distribution instruction transmission unit to perform and the request source client It includes a transfer completion notification receiving unit that receives the file transfer completion notification, the delivery status updating unit that updates the distribution management table and the file transfer completion notification is received.

  With this configuration, when the request source client acquires the distribution file from the transfer source client, a file transfer completion notification is sent to the server. The server can collect the file transfer completion notification, update the distribution management table, and manage the distribution status to the client.

  In the file delivery system of the present invention, the file delivery management unit of the server stores communication efficiency data in each combination of the server and the plurality of clients, and the communication efficiency data is based on the communication efficiency data. The transfer source server or the transfer source client for each client is determined according to efficiency.

  With this configuration, it is possible to improve the distribution efficiency by determining the transfer source server or the transfer source client so that the communication efficiency becomes high based on the distribution efficiency data.

  In the file distribution system of the present invention, the file distribution management unit of the server stores individual simultaneous connection number data of the server and the client, and the number of simultaneous connections is based on the simultaneous connection number data. The transfer source server or the transfer source client is determined according to.

  With this configuration, by determining the transfer source server or the transfer source client within the range of the simultaneous connection number based on the simultaneous connection number data, high distribution efficiency can be obtained by utilizing simultaneous distribution.

  Another aspect of the present invention is a file distribution server device that distributes a distribution file to a plurality of clients. The file distribution server device includes a server file storage unit for storing the distribution file, and a distribution instruction including a transfer source server or a transfer source client to which each client should transmit a file transfer request as a request source client. In order to realize the functions of the file distribution management unit to be transmitted and the transfer source server, the distribution file read from the server file storage unit in response to the file transfer request received from the request source client is transmitted to the request source client. And a server file transfer control unit for transferring. This configuration also provides the above-described advantages.

  Another aspect of the present invention is a file distribution client device constituting a file distribution system that distributes a distribution file from a server to a plurality of clients. The file distribution client device functions as a request client of file distribution by receiving the distribution file by transmitting the file transfer request to the transfer source server or transfer source client included in the distribution instruction received from the server. A distribution processing unit for realizing the above, a client file storage unit for storing the distribution file received by the distribution processing unit, and the client file storage unit in response to the file transfer request received from another client as the request source client A client file transfer control unit that realizes the function of the transfer source client for file distribution by transferring the distribution file read from the request source client to the request source client. This configuration also provides the above-described advantages.

  Another aspect of the present invention is a file delivery method for delivering a delivery file from a server to a plurality of clients. In this file distribution method, the server transmits a distribution instruction including a transfer source server or a transfer source client to which each client should transmit a file transfer request as a request source client, and the client includes: Transmitting the file transfer request to the transfer source server or transfer source client included in the distribution instruction received from the server and receiving the distribution file in order to realize the function of the request source client; Transferring the distribution file read from a server file storage unit in response to the file transfer request received from the request source client to the request source client in order to realize the function of the transfer source server; The source client To realize the function, and a step of transferring the distribution file read from the client file storage unit in response to the file transfer request received from the other clients as the requesting client to the requesting client. This configuration also provides the above-described advantages.

  Another aspect of the present invention is a program executed in a file distribution system that distributes a distribution file from a server to a plurality of clients. The program includes a step of transmitting, from the server, a distribution instruction including a transfer source server or a transfer source client to which each client should transmit a file transfer request as a request source client, and the client sends the request to the request source client. In order to realize the function of the original client, transmitting the file transfer request to the transfer source server or the transfer source client included in the distribution instruction received from the server and receiving the distribution file; and Transferring the distribution file read from the server file storage unit in response to the file transfer request received from the request source client to realize the function of the transfer source server; and Source client function In order to realize, the file distribution system executes the step of transferring the distribution file read from the client file storage unit to the request source client in response to the file transfer request received from another client as the request source client. Let This configuration also provides the above-described advantages.

  In the present invention, the server is provided with the above-described file delivery management unit in addition to the file transfer control unit, and the client is provided with the file transfer control unit in addition to the delivery processing unit, so that the file delivery is managed by the server. It is possible to provide a file distribution system having an effect that distribution efficiency can be preferably improved.

  Hereinafter, a file distribution system according to an embodiment of the present invention will be described with reference to the drawings.

  A file distribution system according to an embodiment of the present invention is shown in FIG. 1, a file distribution system 1 includes a server 3 and a plurality of clients 5 a, 5 b, 5 c..., And these computer devices are connected via the Internet 7.

  In the present embodiment, video content is distributed as a distribution file. The clients 5a, 5b, 5c,... Are video display control devices, which are connected to the display devices 9a, 9b, 9c,. The display devices 9a, 9b, 9c,... May be installed at various places and may have various sizes. Hereinafter, the clients 5a, 5b, 5c,... Are collectively referred to as the client 5, and the display devices 9a, 9b, 9c,.

  As shown in FIG. 1, in the file distribution system 1 of the present embodiment, the server 3 includes a server file storage unit 31, a file distribution management unit 32, and a server file transfer control unit 33. On the other hand, the client 5 includes a distribution processing unit 51, a client file storage unit 52, and a client file transfer control unit 53.

  In the server 3, the server file storage unit 31 stores a distribution file to be distributed to the client 5. The file delivery management unit 32 has a processing function for managing file delivery of the entire system. The server file transfer control unit 33 has a file transfer server function, and transfers a distribution file using a file transfer protocol.

  On the other hand, in the client 5, the distribution processing unit 51 has a function of receiving a file using a file transfer protocol. The client file storage unit 52 stores the distribution file received by the distribution processing unit 51. Similar to the server file transfer control unit 33 on the server side, the client file transfer control unit 53 has a file transfer server function and executes file transfer using a file transfer protocol.

  As described above, in this embodiment, the client 5 is provided with the client file transfer control unit 53. That is, not only the server 3 but also the client 5 has a file transfer server function. As a result, file transfer between the clients 5 is also possible.

  Here, the side that transfers the distribution file is called the transfer source, and the side that requests the transfer of the file from the transfer source is called the request source (the request source is also the transfer destination). In the present embodiment, not only the server 3 but also the client 5 can be the transfer source. The request source is the client 5.

  In FIG. 1, the file delivery management unit 32 of the server 3 has a processing function for managing file delivery of the entire system as described above. File distribution management refers to controlling the relationship between a transfer source and a request source (that is, a transfer destination) such as which device transfers a file from which device. The file delivery management unit 3 manages file delivery by issuing an instruction to each client 5. More specifically, the file distribution management unit 32 generates a distribution instruction including a transfer source server or a transfer source client to which each client 5 should transmit a file transfer request as a request source client, and transmits the distribution instruction to the request source client. To do. Thereby, the file delivery management part 32 can manage the flow of the whole delivery that which apparatus receives a file from which apparatus.

  2 and 3 show the configurations of the server 3 and the client 5, respectively. In FIG. 2, the server 3 includes an operation unit 34 in addition to the server file storage unit 31, the file distribution management unit 32, and the server file transfer control unit 33 described above.

  As described above, the server file storage unit 31 stores a distribution file to be distributed to the client 5. A large number of distribution files are stored, and a distribution file selected from them is distributed.

  The operation unit 34 includes an input device such as a keyboard and a pointing device. The operation unit 34 is operated, and selection of a file to be distributed is input. In addition, the selection of the client 5 as the delivery destination is also input.

  In the present embodiment, the distribution file is video content. Video content is distributed to a plurality of clients 5 in advance and displayed at a predetermined display time. Therefore, a display time schedule may also be input from the operation unit 34 and distributed to the client 5 together with the video content.

  The file distribution management unit 32 includes a transfer source determination unit 321, a distribution instruction transmission unit 322, a transfer completion notification reception unit 323, a distribution state update unit 324, and a distribution management table storage unit 325. The transfer source determination unit 321 determines a transfer source server or a transfer source client to which each client 5 should transmit a file transfer request as a request source client. The distribution instruction transmission unit 322 transmits a distribution instruction including the transfer source server or the transfer source client determined by the transfer source determination unit 321 to the request source client. The transfer completion notification receiving unit 323 receives a file transfer completion notification from the request source client. When the file transfer completion notification is received, the distribution status update unit 324 updates the distribution status data in the distribution management table and records the distribution completion.

  The server file transfer control unit 33 includes a transfer request receiving unit 331 and a transfer processing unit 332. The transfer request receiving unit 331 receives a file transfer request command from the request source client. The transfer processing unit 332 transmits the distribution file in the server file storage unit 31 to the request source client.

  As described above, the server file transfer control unit 33 has a file transfer server function, communicates with the requesting client using a file transfer protocol, and transfers the distribution file. The server file transfer control unit 33 may be configured by an FTP server or the like. The server file transfer control unit 33 may be physically separated from the file distribution management unit 32.

  On the other hand, in the client 5 of FIG. 3, the distribution processing unit 51 includes a transfer instruction receiving unit 511, a transfer request transmitting unit 512, a file receiving processing unit 513, and a completion notification transmitting unit 514. The transfer instruction receiving unit 511 receives a distribution instruction from the distribution instruction transmitting unit 322 of the server 3. The transfer request transmission unit 512 transmits a file transfer request to the transfer source server or transfer source client included in the distribution instruction. The file reception processing unit 513 receives the distribution file from the transfer source and stores it in the client file storage unit 52. The completion notification transmission unit 514 transmits a file transfer completion notification to the server 3.

  The distribution processing unit 51 receives a distribution file from the transfer source server 3 or the client 5 using a file transfer protocol. The distribution processing unit 51 may have a configuration of a client of the FTP system.

  In the client 5, the client file transfer control unit 53 includes a transfer request receiving unit 531 and a transfer processing unit 532. The configuration of the client file transfer control unit 53 may be the same as that of the server file transfer control unit 33 of the server 3. That is, the client file transfer control unit 53 may be realized by a file transfer server function such as an FTP server.

  The client 5 further includes a schedule control unit 54 and a display control unit 55. In the present embodiment, the distribution file is video content. The schedule control unit 54 controls the display schedule of the distribution file. Schedule data (display start time, etc.) is distributed together with the distribution file and stored in the client file storage unit 52. The schedule control unit 54 detects the arrival of the display start time based on the schedule data.

  The display control unit 55 performs processing for displaying the distribution file on the display device 9. When the schedule control unit 54 informs the display control unit 55 that the display start time has arrived, the display control unit 55 reads the distribution file from the client file storage unit 52 and causes the display device 9 to display it.

  4 to 6 show the file delivery operation by the file delivery system 1 of the present embodiment. In order to simplify the explanation, first, a delivery process to the two clients 5a and 5b will be described as an example. In this example, the distribution file is transferred from the server 3 to the client 5a, and then the distribution file is transferred from the client 5a to the client 5b. In FIG. 4, two clients are represented as CL5a and CL5b, and the server 3 is represented as SVR.

  First, the file delivery management unit 32 of the server 3 selects the first delivery target client 5a. Then, the file distribution management unit 32 determines the server 3 itself as a transfer source to which the client 5a should transmit a file transfer request. The file distribution management unit 32 generates a distribution instruction including the server 3 that is the transfer source, and transmits it to the client 5a (Sa1). The address of the server 3 is added to the distribution instruction.

  The distribution processing unit 51 of the client 5a receives the distribution instruction from the server 3, and transmits a file transfer request command (GET) to the address of the server 3 included in the distribution instruction (Sa2).

  The file transfer request is received by the server file transfer control unit 33 of the server 3. In accordance with the file transfer request, the server file transfer control unit 33 transfers the distribution file read from the server file storage unit 31 to the requesting client 5a (Sa3).

  The transferred distribution file is stored in the client file storage unit 52 of the client 5a. When the file transfer ends, the distribution processing unit 51 of the client 5a transmits a file transfer completion notification to the server 3 (Sa4).

  When receiving the file transfer completion notification from the client 5a, the file distribution management unit 32 of the server 3 records the completion of distribution to the client 5a. Here, the distribution management table in the distribution management table storage unit 325 is updated. Further, the file distribution management unit 32 selects the next distribution target client 5b. Then, the file distribution management unit 32 sets the client 5a as a transfer source client to which the client 5b should transmit a file transfer request. The file distribution management unit 32 generates a distribution instruction including the address of the transfer source client 5a and transmits it to the client 5b (Sb1).

  The distribution processing unit 51 of the client 5b transmits a file transfer request command to the address of the client 5a included in the distribution instruction received from the server 3 (Sb2).

  The file transfer request is received by the client file transfer control unit 53 of the client 5a. In accordance with the file transfer request, the client file transfer control unit 53 transfers the distribution file read from the client file storage unit 52 to the requesting client 5b (Sb3).

  When the file transfer ends, the distribution processing unit 51 of the client 5b transmits a file transfer completion notification to the file distribution management unit 32 of the server 3 (Sb4). Here, since the file transfer completion notification is sent to the server 3 instead of the transfer source, the server 3 can collect the file transfer completion notification and manage the distribution progress. The file distribution management unit 32 of the server 3 records the completion of distribution to the client 5b in the distribution management table.

  FIG. 7 shows an example of file distribution processing to more clients 5. In this example, four clients 5a to 5d (CL5a to CL5d) are shown.

  The client 5a receives the transfer of the distribution file from the server 3. The server 3 sends a delivery instruction including the address of the server 3 to the client 5a (Sa1), the client 5a sends a file transfer request to the server 3 (Sa2), the server 3 transfers the file to the client 5a (Sa3), The client 5a sends a file transfer completion notification to the server 3 (Sa4).

  The client 5b receives the transfer of the distribution file from the client 5a. The server 3 sends a delivery instruction including the address of the client 5a to the client 5b (Sb1), the client 5b sends a file transfer request to the client 5a (Sb2), the client 5a transfers the file to the client 5b (Sb3), The client 5b sends a file transfer completion notification to the server 3 (Sb4). The file transfer operation so far is the same as in FIGS.

  Next, the client 5 c receives the transfer of the distribution file from the server 3. The server 3 sends a delivery instruction including the address of the server 3 to the client 5c (Sc1), the client 5c sends a file transfer request to the server 3 (Sc2), the server 3 transfers the file to the client 5c (Sc3), The client 5c sends a file transfer completion notification to the server 3 (Sc4).

  The client 5d receives the transfer of the distribution file from the client 5a. The server 3 sends a delivery instruction including the address of the client 5a to the client 5d (Sd1), the client 5d sends a file transfer request to the client 5a (Sd2), and the client 5a transfers the file to the client 5d (Sd3). The client 5d sends a file transfer completion notification to the server 3 (Sd4).

  In the above file distribution, since the client 5b and the client 5c can simultaneously receive the distribution file from the client 5a and the server 3, respectively, more distribution can be executed in a short time, and thus the distribution efficiency is improved.

  FIG. 8 shows a distribution process to more clients 5. The server 3 determines the status of the network, and sends a distribution instruction for notifying the request source (transfer destination) client 5 to the transfer source server 3 or another client 5 functioning as a proxy server. Each client 5 receives a file transfer from the server 3 or another client 5 in accordance with an instruction from the server 3. In practice, more clients 5 than in FIG. 8 may be provided to distribute video content to more display devices. A plurality of servers 3 may be provided, and files may be distributed between each server 3 and the plurality of clients 5. For example, one server 3 distributes a file to hundreds of clients 5. Furthermore, by providing several servers 3, the file can be distributed to 1000 or more clients 5.

  As described above, the file distribution system 1 according to the present embodiment also implements the file transfer function between the clients 5 by mounting the file transfer server function on the client 5 and by an instruction from the server 3 on the center side. . Although the server 3 collectively controls the file providing source to each client 5, the distribution data can be distributed by the client 5 on behalf of the server 3.

  In a large-scale system in which a large number of clients 5 are connected to one server 3 via a network as in the present embodiment, the merit of improving file distribution efficiency is great. Then, the distribution efficiency can be dramatically increased by making the client 5 a server temporarily without relying only on the center side for file distribution.

  Further, in this embodiment, the server 3 controls the relationship between the transfer source and the request source. Therefore, unlike the conventional cache server method, the distribution is basically performed by the push method led by the center side. Therefore, distribution to each client 5 is appropriately performed under the management of the server 3.

  FIG. 9 shows an example of a distribution management table processed by the distribution management unit 32. The distribution management table in FIG. 9 is composed of a connection state relationship table of each client 5. The distribution management table is data of a client list and is used for managing a distribution state (completed / uncompleted). Further, as will be described below, the distribution management table is a client list in which the presence / absence of transfer capability of each client 5 is also stored, and is used for processing for determining and controlling the transfer source of each client 5.

  In FIG. 9, the client ID is an ID given to each client 5. In this example, five clients are represented by CL1 to CL5. The IP address of each client 5 is stored together with the client ID.

  “Transferability” is data indicating whether file transfer is possible. Here, it is assumed that some clients 5 have a file transfer function (client file transfer control unit 53). When the client 5 has a file transfer function, “transfer possibility” is “possible”. In the example of FIG. 9, CL1, 2, and 3 can transfer files, and CL4 and CL5 cannot.

  The “distribution status” is data indicating whether the distribution to each client 5 is completed or not. The “distribution status” is rewritten from “incomplete” to “completed” by the distribution status update unit 324 when the transfer completion notification receiving unit 323 receives the file transfer completion notification. In the example of FIG. 9, the transfer of CL1, 2, and 3 has been completed, and the transfer of CL4 and CL5 has not been completed.

  The “delivery instruction” is data for recording which client 5 has transferred the file to which client 5. In this example, the transfer destination (request source) client 5 is recorded in the “distribution instruction” of the transfer source client 5. The “distribution instruction” is recorded when the transfer source is determined by the transfer source determination unit 321 in the distribution management unit 32 of FIG. In the example of FIG. 9, CL1 is the transfer source of CL2. Therefore, the distribution instruction transmission unit 322 of the distribution management unit 32 sends a distribution instruction including the address of CL1 to CL2. Similarly, CL2 is the transfer source of CL4, and CL3 is the transfer source of CL5. In the illustrated example, there is no transfer source of CL1 and CL3. This indicates that CL1 and CL3 receive file transfer directly from the server body.

  FIG. 10 shows changes in the distribution management table accompanying the progress of file distribution. The upper part of FIG. 10 shows a state before file distribution starts. The “distribution status” of all the clients 5 is “incomplete” and the “distribution instruction” is “none”. From this state, the distribution management unit 32 sequentially selects the clients 5 whose “distribution state” is “incomplete”. Then, the distribution management unit 32 causes the selected client 5 to receive the file transfer from the server body or the client 5 that can transfer the file.

  In the middle part of FIG. 10, the file is transferred to CL1, and the distribution state is changed to complete. More specifically, the distribution management unit 32 sends a distribution instruction including the address of the server body to CL1, CL1 receives the file from the server file transfer control unit 33 of the server 3, and sends a file transfer completion notification to the file distribution management. The file distribution management unit 32 updates the “distribution status” of CL1 to “completed”.

  Further, the distribution management unit 32 sets CL1 as the transfer source of CL2. Thereby, in the middle part of FIG. 9, CL2 is recorded in the “distribution instruction” of CL1. The distribution management unit 32 notifies CL2 of the address of CL1 and causes the file to be acquired from CL1.

  Such processing is repeated, and the undelivered client 5 is sequentially selected, the transfer source is determined, and file distribution is performed. The lower part of FIG. 10 shows a state similar to FIG. That is, the distribution has been completed up to CL1, 2, and 3, CL2 and CL5 are designated as the transfer source of CL4 and CL5, and the file transfer completion notification of CL4 and CL5 is awaited.

  Next, in the present embodiment, a more preferable configuration for determining a transfer source for each request source client will be described. In this configuration, the file distribution management unit 32 of the server 3 stores communication efficiency data for each combination of the server 3 and the client 5, and determines a transfer source server or a transfer source client based on the communication efficiency data.

  FIG. 11A is a distribution relation table. This table is a list of connection relationships between servers and clients and their communication efficiency. The numerical values in the table indicate the communication efficiency between two points in numerical form. Communication efficiency represents the magnitude of the communication speed between two points. In this example, the larger the numerical value, the higher the communication speed and the higher the efficiency. “0” indicates unreachable. As shown in the figure, the evaluation values in the upper half and the lower half of the connection relationship table are the same, that is, the connection relationship table is line-symmetric about the diagonal line. This is because the bidirectional communication efficiency is the same. However, in the case of a line having an asymmetric communication speed such as ADSL, the bidirectional communication efficiency is also set differently.

  The distribution management unit 32 stores such a distribution relation table in FIG. 11A together with transfer enable / disable data in FIG. 11B. “Transferability” in FIG. 11B corresponds to the same data in FIG.

  The transfer source determining unit 321 of the distribution managing unit 32 determines the transfer source server 3 or the client 5 with reference to the distribution relation table. FIG. 12 illustrates a process of first determining the transfer source of CL1. The transfer source determination unit 321 selects CL1 as a client that is reachable from the server and has high communication efficiency (the communication efficiency between the server 3 and CL1 is higher than the communication efficiency between the server 3 and CL2). Then, the distribution management unit 32 performs file transfer using CL1 as the request source client and the server body as the transfer source server. Such processing is repeated, and a connection with high communication efficiency is preferentially selected. Thereby, the overall distribution efficiency can also be improved. Although only three clients are shown in FIGS. 11 and 12, it is a matter of course that more clients may be provided.

  Next, another example of the configuration for determining the transfer source will be described. Here, in addition to the above communication efficiency, the maximum number of simultaneous connections is considered. FIG. 13 shows a connection relation table used in the present embodiment. As shown in the figure, the maximum number of connections (the number of simultaneous connections) of the server 3 and each client 5 is added to the connection relation table of FIG. The maximum number of connections varies depending on the device. Since CL3 does not have a file transfer function (file transfer is impossible), the maximum number of connections is also zero. The transfer source determination unit 321 of the distribution management unit 32 refers to the maximum connection number and determines the transfer source within the range of the maximum connection number.

  FIG. 14 shows a transfer source determination process considering the number of simultaneous connections as well as the communication efficiency. First, CL1 that is reachable from the server 3 and has high communication efficiency is selected, and the server body is set as the transfer source of CL1. Since the maximum number of connections of the server 3 is 1, one client is selected. Then, the distribution from the server 3 to CL1 is completed, and the file transfer completion notification is received by the server 3. In the figure, completion of CL1 is recorded.

  Next, CL3 and CL4 that are reachable from CL1 and have high communication efficiency are selected. The maximum number of connections of CL1 is 2. That is, CL3 and CL4 are within the range of the maximum number of connections of CL1. Therefore, CL1 is set as the transfer source of CL3 and CL4. At the same time, a distribution instruction including the address of CL1 is issued to CL2 and CL3.

  Further, the server 3 tries to continue the direct delivery from the server itself. However, since the distribution instruction has already been issued to CL2 and CL3, there is no distribution instruction target, and the direct distribution from the server 3 is ended. Although only three clients are shown in FIGS. 13 and 14, it is a matter of course that more clients may be provided.

  The file distribution system 1 according to the embodiment of the present invention has been described above. According to the present embodiment, the file transfer control unit 53 is provided in the client 5. That is, not only the server 3 but also the client 5 has the function of a file transfer server. Since the client 5 transfers the file to the other client 5, the distribution efficiency is improved. Further, the file distribution management unit 32 of the server 3 transmits a distribution instruction including the transfer source server or the transfer source client to each client 5. As a result, the server 3 can control the relationship between the file transfer request source and the transfer source, such as from which device the file is transferred to which device, and can manage file distribution. In this way, distribution efficiency can be suitably improved while managing file distribution to the client 5.

  In this embodiment, when the request source client receives the distribution file from the transfer source server or the transfer source client, a file transfer completion notification is sent from the request source client to the server 3, and the distribution management table is updated by the server 3. Is done. Since the file transfer completion notification is sent to the server 3, the server 3 can collect the file transfer completion notification and update the distribution management table, and can suitably manage the distribution state.

  In the present embodiment, as described with reference to FIG. 11, the file delivery management unit 32 stores communication efficiency data for each combination of the server 3 and the plurality of clients 5. The transfer source server or transfer source client for each client 5 is determined based on the communication efficiency. With this configuration, it is possible to improve the distribution efficiency by determining the transfer source server or the transfer source client so that the communication efficiency becomes high based on the distribution efficiency data.

  In the present embodiment, the file distribution management unit 32 stores the individual simultaneous connection number data of the server 3 and the client 5 as shown in FIG. 13, and based on the simultaneous connection number data. The transfer source server or transfer source client is determined according to the number of simultaneous connections. With this configuration, by determining the transfer source server or the transfer source client within the range of the simultaneous connection number based on the simultaneous connection number data, high distribution efficiency can be obtained by utilizing simultaneous distribution.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and it goes without saying that those skilled in the art can modify the above-described embodiments within the scope of the present invention.

  As described above, in the file distribution system according to the present invention, not only the server but also the client has a file transfer function, and the server controls the relationship between the request source and the transfer source of the file transfer. While managing the file distribution to the client on the server side, it has an effect that the distribution efficiency can be suitably improved. For example, it is useful as a large-scale file distribution system for video contents.

The figure which shows the file delivery system in embodiment of this invention The figure which shows the structure of the server of the file distribution system Diagram showing the configuration of the client of the file delivery system The figure which shows the file delivery processing in the file delivery system The figure which shows the file delivery processing in the file delivery system The figure which shows the file delivery processing in the file delivery system The figure which shows the file delivery processing in the file delivery system The figure which shows the file delivery processing in the file delivery system The figure which shows the example of a delivery management table The figure which shows the delivery process using a delivery management table (A) Diagram showing an example of a connection relation table (b) Diagram showing an example of a transfer availability table Diagram showing distribution process using connection relation table Diagram showing an example of a connection relationship table that includes the maximum number of connections Diagram showing distribution process using connection relation table Diagram showing a conventional file distribution system The figure which shows the conventional file delivery processing

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 File delivery system 3 Server 5 Client 31 Server file memory | storage part 32 File delivery management part 33 Server file transfer control part 51 Delivery processing part 52 Client file memory | storage part 53 Client file transfer control part 321 Transfer source determination part 322 Delivery instruction | indication transmission part 323 Transfer completion notification receiving unit 324 Distribution status update unit 325 Distribution management table storage unit

Claims (8)

In a file distribution system that distributes distribution files from a server to multiple clients,
The server
A server file storage unit for storing the delivery file;
A file distribution management unit that transmits a distribution instruction including a transfer source server or a transfer source client to which each client should transmit a file transfer request as a request source client; and
A server file transfer control unit for transferring the distribution file read from the server file storage unit to the request source client in response to the file transfer request received from the request source client in order to realize the function of the transfer source server; With
The client
In order to realize the function of the request source client, a distribution processing unit that transmits the file transfer request to the transfer source server or the transfer source client included in the distribution instruction received from the server and receives the distribution file;
A client file storage unit for storing a distribution file received by the distribution processing unit;
Client that transfers the distribution file read from the client file storage unit to the request source client in response to the file transfer request received from another client as the request source client in order to realize the function of the transfer source client A file delivery system comprising a file transfer control unit. When the distribution processing unit of the client receives the distribution file from the transfer source server or the transfer source client included in the distribution instruction received from the server, the file transfer completion notification is transmitted to the server,
The file delivery management unit of the server is
A distribution management table storage unit for storing a distribution management table that records distribution states to the plurality of clients;
A transfer source determination unit that determines the transfer source server or the transfer source client to which each client should send a file transfer request as the request source client;
A distribution instruction transmission unit that transmits a distribution instruction including the transfer source server or the transfer source client determined by the transfer source determination unit to the request source client;
A transfer completion notification receiver for receiving the file transfer completion notification from the requesting client;
A delivery status update unit that updates the delivery status of the delivery management table when the file transfer completion notification is received;
The file distribution system according to claim 1, further comprising:   The file delivery management unit of the server stores communication efficiency data in each combination of the server and the plurality of clients, and based on the communication efficiency data, the transfer source for each client according to the communication efficiency 3. The file delivery system according to claim 1, wherein a server or the transfer source client is determined.   The file distribution management unit of the server stores individual simultaneous connection number data of the server and the client, and based on the simultaneous connection number data, the transfer source server or the transfer according to the simultaneous connection number 4. The file delivery system according to claim 1, wherein an original client is determined. A file distribution server device that distributes distribution files to a plurality of clients,
A server file storage unit for storing the delivery file;
A file distribution management unit that transmits a distribution instruction including a transfer source server or a transfer source client to which each client should transmit a file transfer request as a request source client; and
A server file transfer control unit for transferring the distribution file read from the server file storage unit to the request source client in response to the file transfer request received from the request source client in order to realize the function of the transfer source server; ,
A file delivery server device comprising: A file delivery client device constituting a file delivery system for delivering a delivery file from a server to a plurality of clients,
A distribution processing unit that realizes the function of a file distribution request source client by transmitting the file transfer request to the transfer source server or transfer source client included in the distribution instruction received from the server and receiving the distribution file; ,
A client file storage unit for storing a distribution file received by the distribution processing unit;
The function of the transfer source client for file distribution is realized by transferring the distribution file read from the client file storage unit to the request source client in response to the file transfer request received from another client as the request source client A client file transfer control unit,
A file delivery client device comprising: A file delivery method for delivering a delivery file from a server to a plurality of clients,
Transmitting from the server a delivery instruction including a transfer source server or a transfer source client to which each client should send a file transfer request as a request source client; and
The client transmitting the file transfer request to the transfer source server or transfer source client included in the distribution instruction received from the server and receiving the distribution file in order to realize the function of the request source client; ,
Transferring the distribution file read from a server file storage unit to the request source client in response to the file transfer request received from the request source client in order for the server to realize the function of the transfer source server;
In order for the client to realize the function of the transfer source client, the distribution file read from the client file storage unit in response to the file transfer request received from another client as the request source client is sent to the request source client. A transfer step;
A file delivery method characterized by comprising: A program executed by a file distribution system for distributing a distribution file from a server to a plurality of clients,
Transmitting from the server a delivery instruction including a transfer source server or a transfer source client to which each client should send a file transfer request as a request source client; and
The client transmitting the file transfer request to the transfer source server or transfer source client included in the distribution instruction received from the server and receiving the distribution file in order to realize the function of the request source client; ,
Transferring the distribution file read from a server file storage unit to the request source client in response to the file transfer request received from the request source client in order for the server to realize the function of the transfer source server;
In order for the client to realize the function of the transfer source client, the distribution file read from the client file storage unit in response to the file transfer request received from another client as the request source client is sent to the request source client. A transfer step;
Is executed by the file distribution system.

Images