JP4549005B2 - File transfer method and apparatus, program for implementing the method, and recording medium - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for transferring the same file to a plurality of computers on a network, and a program and a recording medium for implementing the method, and in particular, a content management server and a client cooperate with each other to a plurality of clients. The present invention relates to a file transfer method and apparatus for transferring the same content, a program for implementing the method, and a recording medium.
[0002]
[Prior art]
As network infrastructure such as broadband is developed, it is required to transmit large-capacity contents from a server to a plurality of clients efficiently and at low cost.
[0003]
FIG. 5 shows a wide area network (WAN) for transmitting content by directly connecting the content management server SV1 and a plurality of clients without using a distributed server.
[0004]
In this case, as indicated by the dotted line, the content is transmitted from the content management server SV1 to each client, and the same content flows redundantly on the WAN communication line, which is the backbone, so the transmission efficiency is poor. In addition, there is a problem that the backbone load increases in proportion to the number of clients, and content transmission to the clients is delayed. In order to solve this problem, the backbone had to be strengthened, and the cost was high.
[0005]
FIG. 6 shows a wide area network including content management distributed servers SV2 to SV6, respectively, in a local area network (LAN) connected to each other by a WAN communication line.
[0006]
The distributed servers SV2 to SV6 are mirror servers, and content is transmitted from the content management server SV1 to each client via the distributed server as indicated by a dotted line. For this reason, the load on the backbone is reduced as compared with the case of FIG.
[0007]
[Problems to be solved by the invention]
However, a management function is required to make the contents of the distributed servers SV2 to SV6 always the same as the contents of the content management server SV1. In addition, installation costs and maintenance costs for the distributed servers SV2 to SV6 are generated, resulting in high costs. Furthermore, since the same content flows redundantly in the backbone as in the case of FIG. 5, transfer efficiency is poor.
[0008]
In view of such problems, an object of the present invention is to provide a file transfer method and apparatus capable of efficiently distributing the same file to a plurality of computers on a network at a low cost, a program for implementing this method, and It is to provide a recording medium.
[0009]
[Means for solving the problems and their effects]
In one aspect of the present invention, in a file transfer method for transferring the same file from a transfer source computer on a network to a plurality of transfer destination computers via a router, each computer is on a network associated with the router to which the computer is connected. Having an identification code,
(A) creating a transfer table that represents the identification code on the network based on the connection relationship between the transfer source computer and the plurality of transfer destination computers, and a tree structure with the transfer code of the transfer source computer as a top hierarchy; Divide identification codes of the same hierarchy and system into the same group,
(B) The transfer source computer refers to the transfer table, and transmits the file to one computer in each group of the next layer of the top layer,
(C) The received computer refers to the transfer table and transfers the received file to other computers in the group to which the computer belongs. Transfer the file to one computer in the group,
The step (c) is repeated up to the lowest hierarchy for each system.
[0010]
According to this configuration, a file can be distributed to a plurality of computers on a network without having a distributed server in each group. Therefore, an increase in cost due to the installation of the distributed server can be avoided.
[0011]
In addition, since it is possible to avoid the same file from being duplicated through the communication line, the content can be transferred more efficiently than when a distributed server is provided.
[0012]
Furthermore, all the computers that have received the content need only be processed according to the same transfer processing program, and even if the number of computers to be distributed increases, there is no need to change the transfer program.
[0013]
Other objects, configurations and effects of the present invention will become apparent from the following description.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0015]
FIG. 1 shows a wide area network in which a plurality of LANs are connected in a tree shape via WAN communication lines.
[0016]
A local area network LAN1 in Tokyo is connected to a local area network LAN2A in Osaka on the one hand via a WAN communication line, and is connected to a local area network LAN2B in Sendai on the other hand. The local area network LAN 2A is further connected to a local area network LAN 3A in Fukuoka via a WAN communication line. The local area network LAN 2B is further connected to the local area network LAN 3B in Iwate via a WAN communication line.
[0017]
In the local area network LAN1, the content management server SV1 is connected to the clients A1-1 and A1-2 via the router R11 and further via the router R12, and on the other hand, the clients B1-1 and B1 are further connected via the router R13. -2. This router R12 is connected to a router R21A in the local area network LAN 2A via a WAN communication line. In the local area network LAN 2A, the router R21A is connected to the clients A2-1 and A2-2 via the R22A. This router R22A is connected to a router R31A in the local area network LAN 3A via a WAN communication line. In the local area network LAN 3A, clients A3-1 to A3-4 are connected to the router R31A.
[0018]
The router R13 of the local area network LAN1 is connected to the router R21B of the local area network LAN2B via the WAN communication line, and further connected to the clients B2-1 and B2-2 via the router R22B, and further connected to the router R23B on the other side. To the client B2-3. This router R22B is connected to a router R31B in the local area network LAN 3B via a WAN communication line. In the local area network LAN 3B, clients B3-1 to B3-4 are connected to the router R31B. The router R23B in the local area network LAN 2B is connected to the router R32B in the local area network LAN 3B via a WAN communication line. In the local area network LAN 3B, a client B 3-5 is connected to the router R32B.
[0019]
In the content distribution method according to the present embodiment, in a tree-structured network with the content management server SV1 as the top hierarchy, the clients are divided into groups of the same hierarchy and the same system, and the content management server SV1 and any one client in each group Thus, the content is transferred as indicated by a dotted line in FIG.
[0020]
FIG. 2 is a flowchart showing a content transfer procedure of the content management server SV1. In the following, the step identification codes in the figure are shown in parentheses.
[0021]
(S1) A content transfer table indicating how to transfer content efficiently is created. This table is created as follows based on the IP address of each client and the routing table set in each router.
[0022]
First, the number of routers to be reached from the content management server SV1 to each client is obtained by referring to the routing table, and the client name is grouped by the number of routers and series via the route as shown in FIG. To do. The client name as the client identification code is an IP address or FQDN (Fully Qualified Domain Name), and is represented by the reference numerals in FIG. 1 in FIG. 4 for simplicity.
[0023]
For example, data is transferred to the clients A2-1 and A2-2 from the content management server SV1 through four routers R11, R12, R21A, and R22A. Data is transferred to the clients B2-1 and B2-2 from the content management server SV1 through the four routers R11, R12, R21B, and R22B. Data is transferred to the client B2-3 from the content management server SV1 through the four routers R11, R12, R21B, and R23B. Therefore, these are clients of the same hierarchy.
[0024]
Clients A2-1 and A2-2 and clients B2-1 and B2-2 have the same number of routed routers, but are of different series and are therefore divided into different groups. Since the clients B2-1 and B2-2 and the client B2-3 have the same route to the router R21B in the same local area network LAN2B, they belong to the same group. Since the clients B3-1 to B3-4 and B3-5 are respectively connected to the routers R22B and R23B in the local area network LAN 2B, they are different sub-sequences in the sequence 2 and belong to different groups.
[0025]
A content transfer table having a hierarchical structure as shown in FIG. 4B is created from the number of via routers and the series. Each layer has the same number of routed routers, and the number of routed routers increases in the lower layer. The top hierarchy is the content management server SV1, but it is omitted because it does not need to be listed in the table.
[0026]
(S2) The content management server determines an arbitrary one of each series of the hierarchy 1 closest to the top hierarchy as the transfer destination client. For example, the clients A1-1 and B1-1 are determined as transfer destination clients.
[0027]
(S3) The content management server specifies the determined client and opens a transmission path.
[0028]
(S4) An inquiry is made to each of these clients as to whether or not the content is encrypted before being transmitted.
[0029]
(S5) If the client has selected encryption, the process proceeds to step S6; otherwise, the process proceeds to step S7.
[0030]
(S6) If the content to be transmitted is not encrypted, it is encrypted and stored in the storage device.
[0031]
(S7) Referring to the content transfer table, it is determined whether or not it is necessary to request the transfer of the content to the transfer destination client. If it is determined that the transfer is necessary, the process proceeds to step S8. Otherwise, the process proceeds to step S9. move on.
[0032]
(S8) The content transfer table created in step S1 is transmitted.
[0033]
(S9) Content that is not encrypted or not is transmitted according to the determination in step S5.
[0034]
FIG. 3 is a flowchart showing the content transfer procedure of the client that receives the content.
[0035]
(S11) In response to step S3 of FIG. 2, the transmission path establishment is accepted. The following steps S13 to S15 are performed in accordance with the type of received data.
[0036]
(S13) If it is the encryption inquiry in step S4 of FIG. 2, it is determined whether encryption is necessary. If it is possible to decrypt the encrypted data by hardware or software and there is no problem even if the decryption process takes time, or if there is some problem, if security is important, it is determined that encryption is necessary. . This determination is made, for example, based on predetermined data set in advance by human judgment, or based on whether decoding hardware or software is incorporated. Next, the process returns to step S12.
[0037]
(S14) If it is a content transfer table, it is received and stored in the storage device. If the content transfer table is encrypted, it is decrypted and stored in the storage device. Next, the process returns to step S12.
[0038]
(S15) If it is content, it is received and stored in the storage device. If the content is encrypted, it is stored in the storage device while being decrypted.
[0039]
(S16) If the content transfer table is received in step S14, the process proceeds to step S17, and if not, the process ends.
[0040]
(S17) The transfer destination client is determined as follows with reference to the content transfer table. That is, all the other clients in the group to which the self belongs and any one client in the group of the same series and one lower hierarchy as this group are determined as the transfer destination clients.
[0041]
(S18) The same processing as steps S3 to S9 in FIG. 2 is executed for each determined client.
[0042]
(S19, S20) If the transfer destination client is powered off or cannot be transferred due to a transfer path or a failure of the transfer destination client, the transfer destination client name in the content transfer table of FIG. The corresponding incomplete flag is set to “1”, and this content transfer table is returned to the content management server.
[0043]
The process of FIG. 3 is applied to all clients in the content transfer table.
[0044]
By such processing, for example, the client A1-1 in FIG. 1 transfers the content received from the content management server to the client A1-2, and the content transfer table and content received from the content management server to the client A2-1. Forward. In response to this transfer, the client A2-1 transfers the content to the client A2-2, and transfers the content transfer table and the content to the client A3-1. In response to this transfer, the client A3-1 transfers the content to the clients A3-2 to A3-4. Similarly, the client B1-1 transfers the received content to the client B1-2, and transfers the received content transfer table and content to the client B2-1.
In response to this, the client B2-1 transfers the received content to the clients B2-2, B2-3, and B3-5, and transfers the received content transfer table and content to the client B3-1. In response to this, the client B3-1 transfers the received content to the clients B3-2 to B3-4.
[0045]
The content management server refers to the content transfer table returned from the client, creates a content transfer table similar to that in FIG. 4B only for the client whose content has not been transmitted due to a failure or the like, and performs the processing of FIG. The received client performs the process shown in FIG.
[0046]
By such processing, content can be distributed to all clients without having a content management distributed server in the local area network of each group. Therefore, an increase in cost due to the installation of the distributed server can be avoided.
[0047]
Further, in the present embodiment, since the same content passes only once through the WAN communication line, which is the backbone between the local area networks, the content can be transferred more efficiently than when a distributed server is provided as shown in FIG. Can do.
[0048]
Furthermore, all clients that have received the content transfer table need only be processed according to the same transfer processing program, and even if the number of clients increases, there is no need to change the transfer program.
[0049]
Note that the present invention includes various other modifications.
[0050]
For example, the series may be divided corresponding to the branch of the router. Specifically, in FIG. 1, since the router R21B branches to the routers R22B and R23B, the clients B2-1 and B2-1 and the client B2-3 are set as different series in the series 2, and the client B2- You may divide into the group of 1 and B2-1, and the group of client B2-3.
[0051]
The content transfer table in FIG. 4B may be created by a person based on the routing table of each router and the client identification code. The content transfer table may be in a list format indicating a tree structure. The content transfer table may be obtained by adding a layer identification code, a series identification code, and a group identification code to each client identification code. Further, the content transfer table may be distributed to all clients in advance, and the transfer of the content transfer table may be omitted in content transfer.
[0052]
Further, when the content cannot be transferred, the information of only the client name may be transmitted to the content management server instead of the content transfer table of FIG.
[0053]
Further, the present invention is applicable not only to the content transfer of the content management server but also to the case of transferring a file from any computer to other computers.
[0054]
As is clear from the above description, the present invention includes the following supplementary notes.
[0055]
(Appendix 1) In a file transfer method for transferring the same file from a transfer source computer on a network to a plurality of transfer destination computers via a router, each computer has an identification code on the network associated with the router to which the computer is connected. Have
(A) creating a transfer table that represents the identification code on the network based on the connection relationship between the transfer source computer and the plurality of transfer destination computers, and a tree structure with the transfer code of the transfer source computer as a top hierarchy; Divide identification codes of the same hierarchy and system into the same group,
(B) The transfer source computer refers to the transfer table, and transmits the file to one computer in each group of the next layer of the top layer,
(C) The received computer refers to the transfer table and transfers the received file to other computers in the group to which the computer belongs. Transfer the file to one computer in the group,
A file transfer method characterized by repeating step (c) up to the lowest hierarchy for each system. (1)
(Supplementary note 2) The file transfer method according to supplementary note 1, wherein the transfer source computer is a content management server. (2)
(Supplementary note 3) The file transfer method according to supplementary note 1, wherein, in the step (a), the identification code is an IP address, and the transfer table is created based on the IP address and a routing table.
[0056]
(Supplementary note 4) The file transfer method according to supplementary note 1, wherein in the steps (b) and (c), the transfer table is also transmitted to the transfer destination of the file.
[0057]
(Additional remark 5) In said step (b) and (c), when there is no further transfer destination in a transfer destination computer, the said transfer table is not transmitted, When the received computer does not receive this transfer table, The file transfer method according to appendix 4, wherein it is determined that the file need not be transferred.
[0058]
(Supplementary Note 6) If transfer to the transfer destination computer is impossible in the step (c), information indicating that is added to the transfer table and the transfer table is transmitted to the transfer source computer at the top layer. The file transfer method according to appendix 4 or 5, characterized in that:
[0059]
(Supplementary Note 7) The transfer source computer at the top layer creates a transfer table in step (a) for a computer that is not transferred based on the transfer table to which the information is added, and based on the transfer table, The file transfer method according to appendix 6, wherein the processes of steps (b) and (c) are performed.
[0060]
(Supplementary Note 8) A program for causing a computer to transfer a received file to another computer on the network based on a transfer table, wherein the transfer table represents a transfer destination computer identification code in a tree structure and has the same hierarchy and the same The system identification code is divided into the same group,
(1) By referring to the transfer table, the received file is transferred to other computers in the group to which the self belongs.
(2) By referring to the transfer table, if there is a lower layer next to the own layer, the file is transferred to one computer in each group of the layer.
A program characterized by that. (3)
(Supplementary note 9) A computer-readable recording medium on which the program according to supplementary note 8 is recorded. (4)
(Supplementary Note 10) a processor;
A storage device coupled to the processor and storing the program according to attachment 9.
A file transfer apparatus comprising: (5)
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a wide area network in which a plurality of LANs are connected in a tree form via WAN communication lines according to an embodiment of the present invention.
FIG. 2 is a flowchart showing a content transfer procedure of the content management server SV1 in FIG.
FIG. 3 is a flowchart showing a content transfer procedure of a client that receives content.
FIG. 4A is a table for explaining grouping, and FIG. 4B is a diagram showing a content transfer table.
FIG. 5 is a schematic diagram showing a conventional wide area network in which content is distributed from a management server to a plurality of clients.
FIG. 6 is a schematic diagram showing a conventional wide area network in which content is distributed from a management server to a plurality of clients via a distributed server.
[Explanation of symbols]
SV1 Content management servers SV2 to SV6 Distributed servers LAN1, LAN2A, LAN2B, LAN3A, LAN3B Local area networks R11 to R13, R21A, R22A, R21B, R22B, R23B, R31A, R31B, R32B Routers A1-1, A1-2, B1 -1, B1-2, A2-1, A2-2, B2-1 to B2-3, A3-1 to A3-4, B3-1 to B3-5 Client

Claims (12)

In a file transfer method for transferring the same file from a host computer on a network to a plurality of client computers via a router, each computer has an on-network identification code associated with the router to which the computer is connected,
(A) creating a transfer table in which the identification code on the network is represented in a tree structure with the identification code of the host computer as a top hierarchy based on the connection relationship between the host computer and the plurality of client computers; Divide the same system identification code into the same group,
(B) The host computer refers to the transfer table and sends the file to one client computer in each group of the next layer of the top layer,
(C) The received client computer refers to the transfer table and transfers the received file to another client computer in the group to which the client computer belongs. Transfer the file to one client computer in each group in the hierarchy;
Just repeat the step (c) until the bottom of the hierarchy for each line, in step (b) and (c),
If the destination client computer has additional destinations, it also sends the transfer table to the file destination,
If the destination client computer has no further destinations, it will not send the forwarding table,
If the client computer that has received the file does not receive the transfer table, the client computer determines that the file need not be transferred.
A file transfer method characterized by the above.   2. The file transfer method according to claim 1, wherein the host computer is a content management server.   3. The file transfer method according to claim 1, wherein in the step (a), the identification code is an IP address, and the transfer table is created based on the IP address and a routing table. In the step (c), when transfer to the transfer destination client computer is impossible, information indicating that is added to the transfer table and the transfer table is transmitted to the top-level host computer. The file transfer method according to any one of claims 1 to 3 . The top-tier host computer creates a transfer table in step (a) for a computer that has not been transferred based on the transfer table to which the information is added, and the steps (b) and The file transfer method according to claim 4 , wherein the process of (c) is performed. 6. The file transfer method according to claim 1, wherein the transfer table is encrypted, and a client computer that receives the transfer table decrypts and refers to the transfer table. A program stored in a storage unit of a client computer and causing the client computer to transfer a received file to another client computer on a network based on the transfer table, the transfer table being a top-level file transfer The identification codes of all the transfer destination client computers from the host computer to the end of the next hierarchy are represented in a tree structure, and the identification codes of the same hierarchy and the same system are divided into the same group , and the transfer source of the received file Received from
(A) When the transfer table is received from the transfer source,
(1) By referring to the transfer table, the received file is transferred to another client computer in the group to which the self belongs.
(2) By referring to the transfer table, if there is a lower layer next to the own layer, the file is transferred to one client computer in each group of the lower layer ,
In step (2) above,
If the transfer destination client computer has a further transfer destination, the transfer table is also sent to the transfer destination of the file,
If there is no further forwarding destination in the destination client computer, the forwarding table is not sent,
(B) If the transfer table is not received from the transfer source, it is determined that the file need not be transferred.
A program characterized by that. 8. The program according to claim 7 , wherein the identification code is an IP address, and the forwarding table is created based on the IP address and a routing table. In step (1) or (2), if transfer to the transfer destination client computer is impossible for the client computer, information indicating that is added to the transfer table and the transfer table is added to the top layer. 9. The program according to claim 7 , wherein the program is transmitted to a host computer. The program according to any one of claims 7 to 9 , wherein the received transfer table is encrypted, and the client computer is caused to decrypt and refer to the encrypted transfer table. . Wherein the program according to any one of claims 7 to 10 is recorded, the computer-readable recording medium. A processor;
A storage device coupled to the processor and storing the program according to any one of claims 7 to 10 ,
A file transfer apparatus comprising:

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