JP4361498B2 - Data processing system, request source device, data processing method, request source device control method, and program - Google Patents

Description

  The present invention provides a data processing system, a central device, an auxiliary device, a request source device, a central service method, which are suitable for preventing as much access as possible from being concentrated on one central device when acquiring data via a network, The present invention relates to an auxiliary service method, a request source method, and a program for realizing these on a computer.

Conventionally, a technique of downloading various data to a terminal via a network via the Internet has been used. Such techniques are disclosed in the following documents, for example.
Japanese Patent Application Laid-Open No. 2004-287731

  The technology disclosed in this document is as follows. That is, the central device accepts input of files to be downloaded to a plurality of terminals, divides the accepted file into a plurality of pieces, and each of the divided results (hereinafter referred to as “sectors”), A pair with the position of the sector in the file is transmitted. On the other hand, each of the plurality of terminals receives the pair transmitted from the download central device, acquires the sector specified in the received pair and the position of the sector in the file, and acquires the sector of the acquired sector. When the contents are stored in the obtained location in the storage area for restoring the file to be downloaded and the contents of all sectors are stored in the storage area, the contents stored in the storage area are stored. Let it be a downloaded file.

  On the other hand, for example, when trying to provide data to a user in a network game or various web services, there is a problem that access to the data providing server is concentrated.

  Conventionally, a plurality of data providing servers are prepared so that each user can access a separate server, or a server to which an actual download process is performed by inquiring to a certain server is specified. Random techniques have been widely used.

On the other hand, the technology for preventing concentration of access to the data providing server as much as possible is not sufficient from the conventional technology, and various technologies according to the application are strongly demanded.
The present invention has been made to solve the above-described problems, and is a data processing system suitable for preventing as much as possible access from being concentrated on one device when acquiring data via a network, It is an object of the present invention to provide a central device, an auxiliary device, a request source device, a central service method, an auxiliary service method, a request source method, and a program for realizing them on a computer.

In order to achieve the above object, the following invention is disclosed in accordance with the principle of the present invention.
A data processing system according to a first aspect of the present invention includes a central device, a plurality of auxiliary devices, and a request source device, and is configured as follows.

First, the central device includes a data storage unit, a division unit, and a delivery unit.
Here, the data storage unit stores the data in association with the identifier, the dividing unit divides the stored data into a plurality of fragments, and the delivery unit, for each of the plurality of divided fragments, And a position where the data identifier and the fragment are arranged in the data (hereinafter referred to as “arrangement position”) are delivered to at least one of the plurality of auxiliary devices.

  That is, the central device stores data that will be downloaded to the requesting device in the future in the storage unit, but divides it into a plurality of pieces. Then, the original data is made into a triple with information that can be restored in the future, and each of the triples is delivered to an appropriate auxiliary device. For example, if the number of triplets is 128 and the number of auxiliary devices is 512, each triplet is delivered to four auxiliary devices, and each auxiliary device receives delivery of one triplet. It is like this.

  However, for example, a mode may be adopted in which each triplet is delivered to six auxiliary devices and each auxiliary device receives delivery of one or two triplets. However, the number of triplets delivered to each auxiliary device should not be biased (although it may be different), and the number of auxiliary devices to which each triplet is delivered (may be different) should also be biased. It is desirable.

On the other hand, each of the plurality of auxiliary devices includes a reception unit and a fragment storage unit.
Here, the accepting unit accepts a triplet of fragments, identifiers, and arrangement positions delivered from the central apparatus, and the fragment storage unit stores the accepted fragments, identifiers, and arrangement positions in association with each other.

  That is, each auxiliary device stores a triple of a fragment delivered from the central device, an identifier, and an arrangement position indicating where the fragment was in the original data. As described above, the number of triplets delivered from the central device is not necessarily one, and may be plural. As a result, when there is a request from the request source device in the future, preparations are made for responding to the information included in this triplet.

Further, the request source device includes an auxiliary request transmission unit.
Here, the auxiliary request transmission unit transmits an auxiliary request designating an identifier of desired data to an auxiliary device that is communicably connected to the request source device among a plurality of auxiliary devices.

  For example, if the central device, auxiliary device, and requesting device are located in the Internet, all devices can theoretically communicate with each other, but in practice, the requesting device has some auxiliary devices. In many cases, communication is possible only with a device. This restriction is due not only to the capacity of the communication path, but also because the IP address and port number, which are prerequisites for communicating with the auxiliary device, may not be known in the first place.

  In the case of a competitive network game, each player may first access a server called a lobby using his / her terminal and play a battle between the terminals introduced to this server. For example, information such as the IP address and port number of (some) auxiliary devices is provided at the stage of such introduction.

Each of the plurality of auxiliary devices further includes an auxiliary request receiving unit and an auxiliary response transmitting unit.
Here, the auxiliary request receiving unit receives the auxiliary request transmitted from the request source device, and the auxiliary response transmitting unit uses the identifier specified in the received auxiliary request among the fragments stored in the fragment storage unit. An auxiliary response designating the fragment stored in association with the arrangement position stored in association with the fragment is transmitted to the request source apparatus.

  In other words, when an auxiliary request is sent and received from the request source device to the auxiliary device, each auxiliary device looks at the items of the triple identifier stored by itself and determines the data requested by the request source device. It is determined whether or not it has a fragment, and if so, the content of the fragment, the arrangement position of the fragment in the original data, and the request source apparatus are transmitted. As a result, the request source apparatus can restore the desired data.

On the other hand, the request source device further includes an auxiliary response receiver and a central request transmitter.
Here, the auxiliary response receiving unit receives an auxiliary response transmitted from any of the plurality of auxiliary devices, and the central request transmitting unit receives the desired data from the fragment and the arrangement position specified in the received auxiliary response. If there is a fragment that is insufficient to restore, a central request specifying the identifier of the desired data and the location of the fragment is transmitted to the central device.

  That is, information necessary to restore the original data is collected from the fragments and the arrangement positions transmitted from each auxiliary device, and if it is not sufficient, the missing portion is requested from the central device. If so, no request is made to the central unit.

Further, the central device includes a central request reception unit and a central response transmission unit.
Here, the central request receiving unit receives a central request for designating an identifier and an arrangement position from the request source device, and the central response transmitting unit is specified in the received central request among the divided fragments. A central response is transmitted that specifies what is to be arranged at the designated arrangement position in the data of the identifier.

  As described above, in the information collected from the auxiliary device, when the desired data cannot be restored, the request source device requests the shortage from the central device, and the central device transmits the shortage to the request source device. is there.

The request source apparatus further includes a central response reception unit and a restoration unit.
Here, the central response receiving unit receives the central response transmitted from the central device, and the restoration unit includes the fragment specified in the received central response, the arrangement position specified in the central request, and the central request. Is transmitted, the desired data is restored from the fragment and arrangement position specified in the received auxiliary response.
That is, the original data is restored from the information related to the fragments collected from the auxiliary device and the information related to the fragments acquired from the central device if that is not enough.

  In accordance with the present invention, if a requesting device wishes to obtain certain data, it can reduce the access to the central device as much as possible, and collect the stored pieces of data distributed in the auxiliary device as desired. It is possible to provide a data processing system that restores the data.

The data processing system of the present invention can be configured as follows.
In other words, in the request source apparatus, the auxiliary request transmission unit transmits the auxiliary request by designating an identifier that does not overlap with other auxiliary requests and the lifetime of the request.
By using this identifier and life information, the auxiliary request is propagated in the network as will be described later. The lifetime information is typically an integer greater than or equal to 0 and corresponds to the so-called longest hop count.

On the other hand, each of the plurality of auxiliary devices further includes an auxiliary request transfer unit.
Here, the auxiliary request transfer unit
(P) If the identifier specified in the received auxiliary request is different from any of the identifiers specified in the previously received auxiliary request, the lifetime specified in the received auxiliary request is reduced.
(Q) If the lifetime is not exhausted, the auxiliary request with the reduced lifetime is transferred to the other auxiliary devices that have not transferred the received auxiliary request to the auxiliary device.

  As described above, the “lifetime” of an auxiliary request can be considered as the maximum number of times that the auxiliary request can be transferred between auxiliary devices. Then, the auxiliary device circulates an auxiliary request to another auxiliary device that does not know the location of the requesting device (it cannot communicate from the requesting device).

  The life may be reduced only when the fragment associated with the identifier specified in the received auxiliary request is not stored in the fragment storage unit. In this case, the lifetime means the maximum number of hops limited to the auxiliary device storing the fragment.

  Whether or not an auxiliary request has been transferred in the past is determined by an identifier (so-called “message ID”) specified in the auxiliary request.

Further, in each of the plurality of auxiliary devices, the auxiliary request receiving unit further receives an auxiliary request transferred from another auxiliary device among the plurality of auxiliary devices.
This means that an auxiliary request that is routed from another auxiliary device is also received, and the received auxiliary request is processed by the auxiliary response transmission unit and the auxiliary request transfer unit as described above. .

  According to the present invention, even if the requesting terminal does not directly know the location of the auxiliary device, if there is a route with a predetermined number of hops or less that reaches the auxiliary device, the auxiliary device also fragments You will be able to receive the offer.

In the request source device of the data processing system of the present invention, the auxiliary request transmission unit can be configured to transmit the auxiliary request by broadcast transmission or broadcast transmission.
That is, when it can be considered that an auxiliary device that can communicate from the request source device constitutes a certain local area network, an auxiliary request is sent from the request source device to the auxiliary device using broadcast type transmission or broadcast transmission. Send it.
The present invention is one of the preferred embodiments of the present invention, and according to the present invention, an auxiliary request can be efficiently transmitted to an auxiliary device.

Further, in the central device of the data processing system of the present invention, the delivery unit is configured to deliver each of the triplets to a device selected at random from a plurality of auxiliary devices or to a device having the lowest delivery cost. be able to.
In other words, by randomly determining an auxiliary device to which each triplet is to be delivered, the bias in the distribution of the triplet is reduced.
Or, the delivery destination is the one with the lowest delivery cost, for example, the auxiliary device that has the smallest number of hops during communication related to delivery and the communication network topology is closest, or the one with the largest communication bandwidth. By doing so, the bias of the triple distribution is reduced.
According to the present invention, it is expected that the number of triplets held by each auxiliary device is equalized, and it is possible to prevent adverse effects such as concentration of access only on a specific auxiliary device as much as possible.

A central device according to another aspect of the present invention is a central device in the data processing system.
An auxiliary device according to another aspect of the present invention is an auxiliary device in the data processing system.
A request source device according to another aspect of the present invention is a request source device in the data processing system.

  A central service method according to another aspect of the present invention is executed by a central device that communicates with a plurality of auxiliary devices and a request source device, and the central device stores data in association with an identifier, a data storage unit, and a division unit And a delivery unit, a central request reception unit, and a central response transmission unit, which include a dividing step, a delivery step, a central request reception step, and a central response transmission step, and is configured as follows.

  That is, in the dividing step, the dividing unit divides the stored data into a plurality of pieces.

  On the other hand, in the delivery process, for each of the plurality of divided fragments, the delivery unit includes the fragment, the identifier of the data, and the position where the fragment is placed in the data (hereinafter referred to as “placement position”). The triplet is delivered to at least one of the plurality of auxiliary devices.

  Further, in the central request receiving step, the central request receiving unit receives a central request designating an identifier and an arrangement position from the request source device.

  Then, in the central response transmission step, the central response transmission unit designates the divided fragment that is to be arranged at the designated arrangement position in the data of the identifier designated in the received central request. Send.

  An auxiliary service method according to another aspect of the present invention is executed by a central device and an auxiliary device that communicates with a request source device. The auxiliary device includes a reception unit, a fragment storage unit, an auxiliary request reception unit, and an auxiliary response transmission. And includes a reception process, a fragment storage process, an auxiliary request reception process, and an auxiliary response transmission reception process, and is configured as follows.

  That is, in the reception process, the reception unit receives a triple of a fragment, an identifier, and an arrangement position delivered from the central device.

  On the other hand, in the fragment storage step, the fragment storage unit stores the received fragment, the identifier, and the arrangement position in association with each other.

  Further, in the auxiliary request receiving step, the auxiliary request receiving unit receives an auxiliary request transmitted from the request source device.

  Then, in the auxiliary response transmission step, the auxiliary response transmission unit associates the fragment stored in association with the identifier specified in the received auxiliary request among the fragments stored in the fragment storage unit and the fragment. An auxiliary response designating the stored arrangement position is transmitted to the request source apparatus.

  A request source method according to another aspect of the present invention is executed by a central apparatus and a request source apparatus that communicates with a plurality of auxiliary apparatuses. The request source apparatus includes an auxiliary request transmission unit, an auxiliary response reception unit, and a central request. It has a transmission unit, a central response reception unit, and a restoration unit, and includes an auxiliary request transmission step, an auxiliary response reception step, a central request transmission step, a central response reception step, and a restoration step, and is configured as follows.

  That is, in the auxiliary request transmitting step, the auxiliary request transmitting unit transmits an auxiliary request designating an identifier of desired data to an auxiliary device that is communicably connected to the request source device among a plurality of auxiliary devices.

  On the other hand, in the auxiliary response receiving step, the auxiliary response receiving unit receives an auxiliary response transmitted from any of the plurality of auxiliary devices.

  Further, in the central request transmission step, if there is a fragment that is insufficient for the central request transmission unit to restore the desired data from the fragment specified in the received auxiliary response and the arrangement position, the identifier of the desired data And a central request designating the location of the missing fragment is transmitted to the central unit.

  In the central response receiving step, the central response receiving unit receives the central response transmitted from the central device.

  On the other hand, in the restoration step, the restoration unit designates the fragment specified in the received central response and the arrangement position specified in the central request, and the fragment specified in the received auxiliary response when the central request is transmitted. Then, the desired data is restored from the arrangement position.

A program according to another aspect of the present invention causes a computer to function as a central device, an auxiliary device, or a request source device, or causes a computer to execute a central service method, an auxiliary service method, or a request source method. Constitute.
The program of the present invention can be recorded on a computer-readable information storage medium such as a compact disk, flexible disk, hard disk, magneto-optical disk, digital video disk, magnetic tape, and semiconductor memory.
The above program can be distributed and sold via a computer communication network independently of the computer on which the program is executed. The information storage medium can be distributed and sold independently from the computer.

  According to the present invention, a data processing system, a central device, an auxiliary device, a request source device, and a central service method suitable for preventing the concentration of access to one device as much as possible when acquiring data via a network. Further, it is possible to provide an auxiliary service method, a request source method, and a program that realizes these on a computer.

  Embodiments of the present invention will be described below. In the following, for ease of understanding, an embodiment in which the present invention is applied to various devices in the Internet will be described. However, the same applies to information processing devices such as various computers, PDAs (Personal Data Assistants), and mobile phones. The present invention can be applied to. That is, the embodiment described below is for explanation, and does not limit the scope of the present invention. Therefore, those skilled in the art can employ embodiments in which each or all of these elements are replaced with equivalent ones, and these embodiments are also included in the scope of the present invention.

(Data processing system configuration)
FIG. 1 is an explanatory diagram showing a schematic configuration of a data processing system according to one embodiment of the present invention. Hereinafter, a description will be given with reference to FIG.

  The data processing system 101 includes a central device 102, a plurality of auxiliary devices 103, and a request source device 104. Typically, the central device 102 and the plurality of auxiliary devices 103 are data server devices that are maintained and managed by a data provider, and the request source device 104 is a terminal device that is maintained and managed by a data user. As the plurality of auxiliary devices 103, it is possible to use terminal devices maintained and managed by data users, and to further manage data distribution. In this case, one terminal device functions as both the auxiliary device 103 and the request source device 104.

These central device 102, auxiliary device 103, and request source device 104 are connected via the Internet 105.
Further, as shown in the figure, there are generally a plurality of request source devices 104, but the number is not limited.

  FIG. 2 is a sequence diagram showing how various communications are exchanged in the present embodiment. Hereinafter, a description will be given with reference to FIG.

  First, the central device 102 for storing the data to be provided divides the data into a plurality of fragments, and each auxiliary device has a triplet of each fragment, the identifier of the data, and the position of the fragment in the data as much as possible. Deliver to equalize 103 (201). Each auxiliary device 103 receives and stores the delivered triplet. Thus, preparation for data provision is completed.

  The data is most often provided in a format called “file”, but any data may be used as long as it is configured as a so-called byte string or bit string. As the “identifier”, a file name is most commonly used. When data constitutes a part of certain large data (for example, in the case of an overlay module in a program), the combination of the position information and the size information of the data in the large data becomes the “identifier”. Further, when the result searched by the database is “data”, a search expression (SQL expression or the like) used for the search may be “identifier”.

  When the request source device 104 tries to receive the provision of data at some opportunity, the request source device 104 transmits an auxiliary request designating the identifier to the auxiliary device 103 known by the request source device 104 (202).

  The auxiliary device 103 that has received the auxiliary request compares the identifier of the fragment held by the auxiliary device 103 with the identifier specified in the auxiliary request, and if there is a matching fragment, the auxiliary device 103 specifies the fragment and the position of the fragment. Is transmitted to the request source apparatus 104 (203).

  Also, the auxiliary response is transferred to another auxiliary device 103 as appropriate (204). If there is a matching fragment, the transferred auxiliary device 103 similarly transmits an auxiliary response to the request source device 104 (203).

  The request source device 104 receives the auxiliary response transmitted from each auxiliary device 103 and accumulates the fragments. The auxiliary response from the auxiliary device 103 is continuously received until a predetermined condition is satisfied, for example, all fragments are accumulated or a predetermined time elapses.

  Next, if a predetermined condition is satisfied, it is determined from the fragment position whether all fragments necessary for data restoration have been obtained. If not, the central device 102 lacks an identifier. A central request designating the location information of the fragment is sent (205).

  In this case, the central device 102 that has received the central request transmits a central response designating the required fragment to the requesting device 104 (206).

  If all the fragments are already in the request source device 104 or if the central response transmitted by the central device 102 is received, the request source device 104 restores the original data from the fragments.

  By such a processing procedure, the request source apparatus 104 receives provision of data from the central apparatus 102. In this case, if there are a sufficient number of auxiliary devices 103 as compared with the number of pieces into which data is divided, concentration of access to the central device 102 can be prevented.

  Also, if the same piece is stored in a plurality of auxiliary devices 103, there is no room in the communication band, and communication with a certain auxiliary device 103 becomes temporarily unreachable, or the computational load of a certain auxiliary device 103 Even if a communication protocol capable of high-speed communication, for example, UDP (User Datagram Protocol) is employed, it is not determined whether or not the response is high or the destination has been reached. Can be expected from

  UDP is a protocol that performs best-effort datagram-oriented communication between two devices, and is a protocol that allows an IP (Internet Protocol) packet to be directly used by an application.

  Therefore, there is no guarantee that the packet will surely arrive at the other party, and retransmission, reception confirmation response, flow control, large data division and recombination (fragmentation) must all be controlled by the application side. The present invention relates to a technique for performing this control.

  On the other hand, UDP is characterized by simple processing and high-speed communication, and is suitable for data processing as in this embodiment.

  FIG. 3 is a schematic diagram showing a schematic configuration of an information processing apparatus suitable for realizing the central device 102, the auxiliary device 103, and the request source device 104 of the present embodiment. Hereinafter, a description will be given with reference to FIG.

  The information processing apparatus 301 includes a CPU (Central Processing Unit) 302, a ROM (Read Only Memory) 303, a RAM (Random Access Memory) 304, an input device 305 including a keyboard, a mouse, and a controller, and a display device such as a monitor. 306, an external storage device 307 such as a hard disk, a medium reading device 308 such as a CD-ROM drive, and a NIC (Network Interface Card) 309.

  Various programs for functioning as a central device are installed in the external storage device 307 from a CD-ROM or the like mounted on the medium reading device 308, and the information processing device 301 is executed by executing the server program. It functions as the central device 102 of the invention. In particular, the initialization data describing the procedure to be processed after the information processing device 301 is turned on is appropriately prepared in the external storage device 307. Various programs are executed and function as the central device 102, the auxiliary device 103, or the request source device 104 of the present invention.

The CPU 302 controls the overall operation of the information processing apparatus 301, is connected to each component, gives control signals for controlling them, and transmits and receives data to exchange information with them.
The ROM 303 records an IPL (Initial Program Loader) that is executed immediately after the power is turned on, and is recorded on a CD-ROM or the like attached to the external storage device 307 or the medium reader 308 by executing this. The program is read into the RAM 304 and execution by the CPU 302 is started.

  The RAM 304 is for temporarily storing data and programs. The RAM 304 stores programs and data recorded on a CD-ROM or the like mounted on the external storage device 307 or the medium reading device 308. In the case of functioning as the device 102 or the auxiliary device 103, it is used for temporarily storing information necessary for providing various services or recording a service providing process.

  Further, when functioning as the request source apparatus 104, it is used for temporarily storing various communication packets or temporarily using them for the restoration processing of data to be provided.

  The input device 305 is used by the administrator of the central device 102 and the auxiliary device 103 and the user of the request source device 104 to give various instructions when directly using or managing the information processing device 301. The display device 306 is for presenting various reports such as the result of the instruction to the administrator.

  Typically, these correspond to a keyboard, a mouse, a controller, and a monitor that are directly connected to the information processing apparatus 301, but other information that is connected via a NIC 309, a serial communication line, a parallel communication line, or the like. As a function of the processing device as the input device 305, an aspect in which the information processing device 301 itself does not include a keyboard, a mouse, a controller, a monitor, or the like is also widely used.

  As described above, the external storage device 307 includes various programs and setting data for the information processing device 301 to function as the central device 102, the auxiliary device 103, or the request source device 104, various data related to the provided service, It is used to record access statistics from a terminal in a nonvolatile and readable / writable manner.

  The medium reading device 308 is used to install various software in the information processing device 301 or to store data used by the information processing device 301 in order to widen the storage capacity of the external storage device 307. The An available medium is typically a CD-ROM or a DVD-ROM. Even if the medium reading device 308 is not used, various software provided from other information processing devices via the Internet or LAN is installed using the network installation technology via the NIC 309. It is possible.

  The NIC 309 is used to connect the information processing apparatus 301 to a computer communication network (not shown) such as the Internet, and is used in configuring a LAN (Local Area Network). The 10BASE-T / 100BASE-T standard is used. To connect to the Internet using an analog modem, ISDN (Integrated Services Digital Network) modem, ADSL (Asymmetric Digital Subscriber Line) modem, cable television line A cable modem or the like and an internal interface (not shown) that mediates between these and the CPU 302 are configured.

(Central device)
FIG. 4 is a schematic diagram showing a schematic configuration of the central apparatus according to the present embodiment. FIG. 5 is a flowchart showing a control flow of the divided delivery process executed by the central apparatus according to the present embodiment. Hereinafter, a description will be given with reference to FIG. In the following description, a case where the central apparatus 102 is realized on the information processing apparatus 301 will be described as an example.

  The central apparatus 102 includes a data storage unit 501, a division unit 502, a delivery unit 503, a central request reception unit 504, and a central response transmission unit 505.

  Here, the data storage unit 501 stores the data in association with the identifier. The data is data that will be downloaded to the request source apparatus 104 in the future.

  Therefore, when the central device 102 is configured by the information processing device 301, the external storage device 307 functions as the data storage unit 501.

  This process is started when the data stored in the data storage unit 501 is determined to be downloaded to the request source apparatus 104 in the future.

  First, the dividing unit 502 divides the stored data into a plurality of fragments (step S501).

  The size of each fragment is preferably a size suitable for transmission as a UDP communication packet. This varies depending on the network conditions, but the size can be statistically obtained from the past communication history.

Next, the dividing unit 502 at least for each of the divided fragments,
(A) The fragment (b) The identifier of the original data (c) A fragment packet including three types of information of the arrangement position where the fragment is arranged in the original data is generated (step S502).

  As for the arrangement position of the fragment, for example, information that the fragment is the XXth fragment counted from the top among the total number of divided fragments is designated in a predetermined format.

  The identifier of the original data may be expressed by determining an appropriate character string format, or may be expressed in an identification number format by an integer.

  When specifying the fragment itself, specify the checksum etc. together to detect that the data has been corrupted due to a communication failure in the middle of the communication path, or that the data has been altered due to interference from a third party. Also good.

  Next, each fragment packet is stored in the external storage device 307 (step S503). At this time, in addition to using the checksum as described above, by attaching an electronic signature, the auxiliary device 103 and the request source device 104 can detect data alteration.

  When the central apparatus 102 is configured using the information processing apparatus 201 described above, the CPU 302 functions as the dividing unit 502 in cooperation with the RAM 304 and the external storage device 307.

Further, the delivery unit 503 performs the following processing for all fragment packets generated as described above (step S504). That is, if processing has not been completed for all fragment packets (step S504; No), one unprocessed fragment packet is acquired (step S505), and the auxiliary device 103 that is the delivery destination of the fragment packet is determined (step S505). S506). Various techniques are conceivable as a method for determining the auxiliary device 103 as a delivery destination. For example, the following method may be used.
(1) If there are m (m ≧ 2) auxiliary devices 103 that can be delivery destinations, and the currently processed fragment packet is the n (n ≧ 0) th packet, n mod m + 1st auxiliary device 103 is the delivery destination of the nth fragment packet. It is the simplest method similar to the round robin format.
(2) When there are m auxiliary devices 103 that can be delivery destinations, a random number i from integer 1 to m is generated, and the i-th auxiliary device 103 is set as the delivery destination of the n-th fragment packet. This is a technique for equalizing the delivery destinations of fragment packets by random numbers.
(3) From the communication history of the auxiliary device 103 so far, when each of the m auxiliary devices 103 is k-th, the parameter p [k] (p [k]> 0 representing the load thereof ). This parameter is a positive numerical value. The larger the value, the greater the load, which means that there is no room in the bandwidth of the communication path used by the auxiliary device 103. Then, using a random number, the probability that the kth auxiliary device 103 is selected is, for example,
(1 / p [k]) / Σ _{i = 1} ^m (1 / p [i])
Thus, the delivery destination auxiliary device 103 is determined.

In calculating the probability, instead of using the reciprocal, a predetermined monotonically decreasing function f (•), that is, if x <y for any positive number x, y, f (x) ≧ f ( y)> 0
f (p [k]) / Σ _{i = 1} ^m f (p [i])
It may be determined as follows.

  Thus, for example, when the number of fragment packets is 128 and the number of auxiliary devices 103 is 512, each fragment packet is delivered to about four auxiliary devices 103, and each auxiliary device 103 is reduced to about A mode in which delivery of one fragment packet is received or each fragment packet is delivered to about six auxiliary devices 103 so that each auxiliary device receives delivery of approximately one or two fragment packets. It can be.

  That is, the number of fragment packets delivered to each auxiliary device 103 is not biased (although it may be different), and the number of auxiliary devices 103 to which each fragment packet is delivered is also biased (although it may be different). It is desirable not to do so. Further, when considering “bias” here, the bandwidth of the communication path to which the auxiliary device 103 is connected and the performance of the auxiliary device 103 itself may be considered.

  Further, when determining candidates for the auxiliary device 103, it is selected in order from the smallest number of hops closest to the network topology in the computer communication network, or a device included in a predetermined range, A method may be adopted in which the communication band is selected in ascending order of communication cost, such as selecting the communication band in descending order.

  Then, the delivery unit 503 delivers the fragment packet to the determined delivery destination auxiliary device 103 (step S507), and returns to step S504.

  On the other hand, when the delivery of all the fragment packets is completed (step S504; Yes), this process ends. As described above, the CPU 302 functions as the delivery unit 503 in cooperation with the RAM 304, the external storage device 307, and the NIC 309.

  Depending on the capacity of the external storage device 307, the fragment packet once stored may be deleted. This is because the fragment packet can be generated as needed as long as the original data is stored. Conversely, when the fragment packet remains in the external storage device 307, the original data may be deleted. This is because the original data can be restored from the fragment packet when it becomes necessary in the central apparatus 102.

  When delivering a packet, it is necessary to specify a transmission source and a transmission destination of the packet, and such information is also added to the packet. In addition, when the packet indicates that a request is made, the response destination (generally the transmission source of the packet, but when relaying or forwarding, the communication device that first issued the packet receives the response destination And is not added to or specified in the packet. Hereinafter, although the same, the description will be omitted as appropriate for easy understanding.

  Now, after the delivery of each fragmented packet, as described above, there are a sufficient number of auxiliary devices 103, and if communication between the request source device 104 and the auxiliary device 103 is successful enough, Although the processing is not necessary, in reality, the processing of the auxiliary device 103 is insufficient, and the packet may be sent so as to send the fragment directly from the requesting device 104 to the central device 102. This packet is called a “central request”. FIG. 6 is a flowchart showing the control flow of the central response process for processing the central request. Hereinafter, a description will be given with reference to FIG.

  First, the central apparatus 102 receives packets transmitted from other communication devices (including various communication devices in addition to the auxiliary device 103 and the request source terminal 104) via the NIC 309 (step S601). Then, the type of the packet is determined (step S602). If the type of the packet is not a central request (step S602; other), the corresponding processing is appropriately executed (step S603), waits for the next packet to arrive (step S604), and the packet has arrived If detected, the process returns to step S601.

  It should be noted that a time-out may be provided as appropriate for waiting for the arrival of the packet in step S604, and processing such as returning to step S604 after executing processing corresponding to the time-out may be executed. In the following, when waiting for the arrival of a packet, the same processing can be performed, but the description will be omitted as appropriate for easy understanding.

On the other hand, when the packet is a central request (step S602; central request), the NIC 309 functions as the central request receiving unit 504 in cooperation with the CPU 302. Therefore, the central request receiving unit 504 extracts (a) identifier (b) the number of required fragments and information on the arrangement position in the data of each fragment specified in the central request (step S605).

  Next, the central response transmission unit 505 determines whether or not a fragment packet corresponding to the identifier designated in the central request and the designated arrangement position can be acquired (step S606), and if possible (step S606; Yes), this is acquired (step S607). As described above, when the fragment packet stored in the external storage device 307 in step S503 remains as it is, it is only necessary to obtain a packet that satisfies the conditions as it is. Otherwise, the fragment data is re-fragmented from the original data. A packet may be generated.

  Then, a central response designating the fragment packet is transmitted to the request source terminal (step S608), and the process proceeds to step S604. A single central response may be configured to include a plurality of fragment packets. If a single central response is set to one fragment packet and a plurality of fragments are required for data restoration, a plurality of fragment packets may be included. These central responses may be sequentially transmitted to the requesting terminal 104.

  On the other hand, if it is not possible (step S606; No), an error notification is transmitted to the requesting terminal that the information specified in the central request is incorrect (step S609), and the process proceeds to step S604.

  As described above, if the information collected from the auxiliary device 103 cannot restore desired data, the request source device 104 requests the central device 102 for the shortage, and the central device 102 requests the shortage for the request source device. 104 is transmitted.

  As described above, in this embodiment, the central device 102 does not provide data alone, but distributes fragments to the auxiliary device 103 and leaves most of the provision to the auxiliary device 103. Access concentration can be prevented.

  In addition, since round robin or random numbers are used and the distribution destination of fragment packets is determined in consideration of the load in some cases, the number of fragment packets held by each auxiliary device 103 is equal or the load is equal. Therefore, it is possible to prevent adverse effects such as concentration of access only on a specific auxiliary device 103 as much as possible.

(Auxiliary device)
FIG. 7 is a schematic diagram illustrating a schematic configuration of the auxiliary device according to the present embodiment. FIG. 8 is a flowchart showing the flow of control of auxiliary response processing executed by the auxiliary device according to the present embodiment. Hereinafter, a description will be given with reference to FIG. In the following description, a case where the auxiliary device 103 is realized on the information processing device 301 will be described as an example.

  Each of the plurality of auxiliary devices 103 includes a receiving unit 701, a fragment storage unit 702, an auxiliary request receiving unit 703, and an auxiliary response transmitting unit 704. In an embodiment described later, an auxiliary request transfer unit 705 is provided, and this is also illustrated in advance in this figure.

  When this processing is started, the auxiliary device 103 includes other communication devices (including the central device 102, the other auxiliary devices 103, the request source device 104, and various communication devices) via the NIC 309. The transmitted packet is received (step S801), and the type of the packet is examined (step S802).

  When the packet is a fragment packet transmitted from the central apparatus 102 (step S802; fragment packet), the NIC 309 functions as the reception unit 701 in cooperation with the CPU 302, the RAM 304, and the like. Then, the fragment packet is stored in the external storage device 307 (step S803), waits until the next packet arrives (step S804), and returns to step S801 when arrival is detected.

  If an electronic signature is attached to the fragment packet, the electronic signature is confirmed in step S803, and the fragment packet is stored in the external storage device 307 only when the electronic signature is approved. Also good.

  When storing the fragment packet, various techniques for deleting unnecessary information or for speeding up information retrieval may be applied. Therefore, the external storage device 307 functions as the fragment storage unit 702 in cooperation with the CPU 302 and the like. As described above, the number of fragment packets delivered from the central apparatus 102 is not necessarily one, and may be plural. As a result, when there is a request from the request source apparatus 104 in the future, preparations are made for responding the information contained in this fragment packet.

  On the other hand, when the packet is an auxiliary request transmitted from the request source apparatus 104 (step S802; auxiliary request), the NIC 309 functions as the auxiliary request receiving unit 703 in cooperation with the CPU 302, the RAM 304, and the like. Thus, the auxiliary request receiving unit 703 determines whether or not the fragment packet stored in the fragment storage unit 702 can be obtained with the identifier specified in the received auxiliary request (step S805). If this is acquired (step S805; Yes), this is acquired (step S806), an auxiliary response designating the fragment packet is transmitted to the request source apparatus 104 (step S807), and the process proceeds to step S804.

  That is, when an auxiliary request is transmitted / received from the request source apparatus 104 to the auxiliary apparatus 103, each auxiliary apparatus 103 looks at the item of the identifier of the fragment packet stored in itself, and the request source apparatus 104 requests It is determined whether or not it has a fragment of the data that is being processed, and if so, the contents of the stored fragment and the arrangement position of the fragment in the original data are transmitted to the request source apparatus 104. . As a result, the request source apparatus 104 can restore the desired data.

  On the other hand, if it is not possible (step S805; No), it will progress to step S804. That is, in the present invention, the notification that there is no fragment packet is not sent from the auxiliary device 103 to the request source device 104. This is because an auxiliary request is sent to a plurality of auxiliary devices 103, and it is sufficient to return an auxiliary response only when a fragment packet can be returned.

  On the other hand, when the packet is another type of packet (step S802; other), the auxiliary device 103 executes a corresponding process (step S808) and proceeds to step S804.

  In this way, in this embodiment, the auxiliary device 103 “caches” the fragment distributed from the central device 102 and provides the fragment in response to a request for data from the requesting device 104. Load concentration can be prevented.

  As described above, when an auxiliary response is transmitted and received by a protocol without arrival confirmation, for example, UDP communication, the load on the CPU 302 of the auxiliary device 103 itself and the bandwidth of the communication path connected to the NIC 309 The process of steps S805 to S807 may be executed only when the margin is detected after step S802 and the load does not exceed a certain threshold.

(Requesting device)
FIG. 9 is a schematic diagram illustrating a schematic configuration of the request source apparatus according to the present embodiment. FIG. 10 is a flowchart showing the flow of control of a file (data) acquisition process executed by the request source apparatus. Hereinafter, a description will be given with reference to FIG. In the following description, a case where the request source device 104 is realized on the information processing device 301 will be described as an example.

  The request source device 104 includes an auxiliary request transmission unit 901, an auxiliary response reception unit 902, a central request transmission unit 903, a central response reception unit 904, and a restoration unit 905.

  First, the auxiliary request transmission unit 901 transmits an auxiliary request designating an identifier of desired data to the auxiliary device 103 that is communicably connected to the request source device 104 among the plurality of auxiliary devices 103 (step S1001). ). In the auxiliary request packet, the request source apparatus 104 is designated as a response destination of the request. Therefore, the CPU 302 functions as the auxiliary request transmission unit 901 in cooperation with the NIC 309 and the like.

  For example, when the central device 102, the auxiliary device 103, and the request source device 104 are arranged in the Internet, all devices can theoretically communicate with each other, but in practice, the request source device 104 is In many cases, communication is possible only with some auxiliary devices 103. This limitation is due to the fact that the IP address and port number that are the preconditions for communicating with the auxiliary device 103 may not be known in addition to the communication path capacity.

  In the case of a competitive network game, each player may first access a server called a lobby using his / her terminal and play a battle between the terminals introduced to this server. For example, information such as the IP address and port number of (a part of) the auxiliary device 103 is provided at the stage of such introduction.

  In addition, it is also possible to select another communication device that the request source apparatus 104 has communicated with when using the service in the past as the auxiliary apparatus 103 that is the transmission destination of the auxiliary request.

  Further, when broadcast-type broadcast communication is possible according to the protocol, the auxiliary request can be sent to the auxiliary device 103 that can respond by making the auxiliary request in this format.

  Thereafter, the request source device 104 receives the packet (step S1002) and checks the type of the packet (step S1003). When the type of this packet is an auxiliary response (step S1003; auxiliary response), it is checked whether or not the fragment arrangement position of the fragment packet specified in the auxiliary response has already been received (step S1004). If it has not been received (step S1004; No), the fragment packet is stored in a temporary storage device such as the RAM 304 or the external storage device 307 (step S1005).

  Then, it is determined whether or not to wait further for an auxiliary response from the auxiliary device 103 (step S1006). When waiting further (step S1007; Yes), after waiting until the next packet is detected (step S1007), the process proceeds to step S1002. Return.

Although it is determined whether or not to wait for an auxiliary response, if all the fragment packets necessary for data restoration are prepared, there is no need to wait for an additional response. If this is still insufficient, the following criteria can be set for judgment.
(A) Whether or not a predetermined time has passed since the auxiliary request was transmitted.
(B) After transmitting the auxiliary request, the time interval at which the auxiliary responses are sequentially received is checked, and whether or not the time interval has become longer than a predetermined threshold value.
(C) From the history of time intervals in which auxiliary responses are sequentially received after the transmission of the auxiliary request, the expected value of the next time interval is estimated by various extrapolation techniques, and the estimated time interval is a predetermined value. Whether it has become longer than the threshold.

  On the other hand, if the packet is other than that (step S1003; other), the process corresponding to the packet is executed (step S1008), and the process proceeds to step S1007.

  If an electronic signature is attached to the fragment packet, it is determined in step S1005 whether or not the fragment packet is valid as viewed from the electronic signature, and only when the fragment packet is authenticated, the external storage device 307 stores the fragment packet. The fragment packet may be saved. The same applies hereinafter.

  As described above, the CPU 302 functions as the auxiliary response receiving unit 902 in cooperation with the RAM 304, the external storage device 307, the NIC 309, and the like.

  If it is decided not to wait for an auxiliary response (step S1006; No), the request source apparatus 104 determines whether all the fragment packets necessary for data restoration are prepared (step S1009). If this is the case (step S1009; No), the arrangement position where the fragment packet is insufficient is acquired (step S1010), and a central request for designating the identifier and the arrangement position of the insufficient fragment is sent to the central apparatus 102. Transmit (step S1011).

  Therefore, the CPU 302 functions as the central request transmission unit 903 in cooperation with the RAM 304, the external storage device 307, the NIC 309, and the like.

  Thereafter, the request source apparatus 104 receives the packet (step S1012), and checks the type of the packet (step S1013). If this packet type is a central response or an auxiliary response (step S1013; central response / auxiliary response), whether the fragment arrangement position of the fragment packet specified in the central response / auxiliary response has already been received. If it has not been received (step S1014; No), the fragment packet is stored in a temporary storage device such as the RAM 304 or the external storage device 307 (step S1015).

  Then, it is determined whether or not to wait for a central response / auxiliary response from the central device 102 or the auxiliary device 103 (step S1016), and when waiting further (step S1016; Yes), after waiting until the next packet is detected ( Step S1017) and return to Step S1012.

  Here, not only the central response but also the auxiliary response is considered because the auxiliary response can arrive with such a delay depending on the topological position of the auxiliary device 103 in the communication network and the condition of the bandwidth of the communication path. Because there is sex.

  Therefore, the CPU 302 functions as the central response receiving unit 904 in cooperation with the RAM 304, the external storage device 307, the NIC 309, and the like.

  Here, the criteria for whether to wait for the central response / auxiliary response may be considered in the same manner as in the case of the auxiliary response in step S1007.

  On the other hand, if it is an error notification indicating that data whose packet type does not exist is requested (step S1013; error notification), that fact is reported (step S1018), and this processing ends.

  If the packet type is other than this (step S1013; other), the process corresponding to the packet is executed (step S1019), and the process proceeds to step S1017.

  When the central response / auxiliary response is not waited (step S1016; No), it is determined whether all fragment packets necessary for data restoration are prepared (step S1020). ) To that effect (step S1021), and this processing is terminated.

  On the other hand, if all the necessary fragment packets are available (step S1009; Yes, step S1020; Yes), the desired data is restored by acquiring and concatenating the fragments from the fragment packets in the order of arrangement positions ( Step S1022), the process is terminated.

  Therefore, the CPU 302 functions as the restoration unit 905 in cooperation with the RAM 304, the external storage device 307, and the like.

  As described above, the request source device 104 of the present embodiment restores the original data from the information about the fragments collected from the auxiliary device 103 and the information about the fragments acquired from the central device 102 if it is not enough. To do.

  As described above, according to the present embodiment, when the request source device 104 wishes to acquire certain data, the access to the central device 102 is reduced as much as possible, and the stored data distributed to the auxiliary device 103 is stored. By collecting fragments, it is possible to provide a data processing system that restores desired data.

  In the above embodiment, the central response includes a data fragment. However, the central device 102 specifies mediation information for specifying the auxiliary device 103 that owns the necessary data fragment instead of the data fragment. It may be included in the central response, and the request source device 104 that has received the central response may issue an auxiliary request to the auxiliary device 103 specified in the mediation information in the central response. In general, since the size of the information specifying the auxiliary device 103 is overwhelmingly smaller than the size of the data fragment, by adopting this embodiment, the load of the central device 102 can be distributed to the auxiliary device 103. become able to.

  Further, a combination of a file name and a version number can be used as the “identifier”. If only the file name is specified in the data specification, it is treated as if the latest file was specified, and if the version number is also specified, the file of that version is handled as specified.

  As the “identifier”, “any version after the version XX in the file XX” or the like may be used. In this case, when multiple versions of fragments are collected in the auxiliary response, the request source apparatus 104 adopts the latest version, or adopts a version in which all the fragments are prepared first, for example. Can be adopted.

  As described above, since the present embodiment can be distributed and arranged in various auxiliary devices 103, it is suitable for load distribution and even when there are a plurality of frequently used versions, It is also suitable for performing version management appropriately.

  In the above-described embodiment, the auxiliary request transmitted from the request source apparatus 104 is processed only by the auxiliary apparatus 103 that directly receives the auxiliary request, and the auxiliary packet that is not stored is not directly communicated with the request source apparatus 104. Even when the device 103 is owned, transmission of the central request to the central device 102 has occurred. In this embodiment, even in such a case, the central request is made as little as possible.

That is, in the request source device 104, the auxiliary request transmission unit 901 adds the following information to the auxiliary request fragment packet.
(A) Identifier not duplicated with other auxiliary requests (b) Lifetime of the request

  By using this identifier and life information, the auxiliary request is propagated in the network as will be described later. The lifetime information is typically an integer greater than or equal to 0 and corresponds to the so-called longest hop count.

  And in the response process in said auxiliary | assistant apparatus 103, a process is added suitably. FIG. 11 is a portion showing a difference from the above-described embodiment in a flowchart showing a control flow of response processing in the present embodiment.

  That is, the auxiliary device 103 performs the following processing between step S802 and step S805 of the above embodiment.

  First, it is determined whether the identifier specified in the received auxiliary request is different from any of the identifiers specified in the previously received auxiliary requests (step S851). If they are different from each other (step S851; Yes), the life specified in the received auxiliary request is reduced (step S852), it is determined whether or not the life is exhausted (step S853), and if not (step S853). No), the auxiliary request designating the reduced lifetime is transferred to the other auxiliary device 103 (step S854), and the process proceeds to step S805.

  At the time of transfer, it is determined whether the auxiliary request is received from the request source apparatus 104 or relayed by another auxiliary apparatus 103. 103 does not need to be transferred in step S854.

  In addition, during transfer, information on the response destination of the auxiliary request is maintained, and when the auxiliary device 103 at the transfer destination returns an auxiliary response, it can be directly returned to the request source device 104. Keep it.

  In addition, as described above, since the life is typically expressed as an integer, 1 is subtracted to reduce the life, and whether or not the life is exhausted is a value of 0 or less (less than 0). You can judge it.

  On the other hand, when there is an identifier that matches the identifier specified in the auxiliary request received in the past (step S851; No), or when the lifetime is exhausted (step S853; Yes), the process proceeds to step S805 without performing the transfer. .

  Note that the lifetime may be reduced only when the fragment associated with the identifier specified in the received auxiliary request is not stored in the fragment storage unit 702. In this case, the lifetime means the maximum number of hops limited to the auxiliary device 103 storing the fragment.

  Further, whether or not an auxiliary request has been transferred in the past is determined by an identifier (so-called “message ID”) specified in the auxiliary request.

  Now, after appropriately transferring, the received auxiliary request is examined. In this embodiment, the immediate transmission source of the received auxiliary request is the request source apparatus 104 and other auxiliary requests. It is conceivable that the device 103 is used. However, as described above, even when the auxiliary request is transferred, the information specifying the auxiliary response transmission destination, that is, the original request source apparatus 104 is maintained as it is. An auxiliary response designating the fragment packet is transmitted to the request source apparatus 104.

  According to the present invention, even when the request source device 104 is the auxiliary device 103 that does not directly know the location, if there is a route with a predetermined number of hops or less that reaches the auxiliary device 103, the auxiliary device 103 The fragment can be provided from 103 as well.

  The request source apparatus 104 of the above embodiment is expected to collect all pieces of desired data fragment packets. Therefore, it is possible to store a part of the fragment packet in the external storage device 307 and cause the information processing device 301 in which the request source device 104 is realized to function as the auxiliary device 103.

  In this case, the fragment packet is not directly transmitted from the central apparatus 102, but is a packet received by another auxiliary apparatus in the past in an attempt to restore data.

Which fragment packet is used to function as the auxiliary device 103, the fragment packet to be left can be selected based on the following criteria.
(A) A random number is generated and selected randomly based on the random number. It is the easiest selection method.
(B) Select the fragment packet provided by the central response from the central device 102. When there are a plurality, they are selected at random as appropriate.
(C) Of the fragment packets provided by the auxiliary response from the auxiliary device 103, the packet that has arrived last is selected. You may select at random suitably from multiple things which arrived later.
(D) Either or both of the above (b) and (c) are used. For example, (c) when a central request is not issued, (b) when a central request is issued, and so on. Moreover, it is good also as employ | adopting what was selected by both (b) and (c).

  According to the above (b) to (d), it is expected that the peripheral devices of the information processing apparatus 301 have no or few auxiliary devices 103 holding the fragment packets. It is expected that the distribution of packets will be unbalanced, which can contribute to improving the performance of the entire data processing system 101.

  In addition, as can be seen from the above embodiment, another information processing apparatus that relays the transmission / reception of the fragment packet among the request source apparatus 104, the auxiliary apparatus 103, and the central apparatus 102, It is also possible to check whether or not the packet is necessary, and if it is necessary, it is possible to use the fragment packet to be relayed by itself without sending the request packet. With this configuration, it is possible to reduce the overall packet distribution amount and contribute to improving the performance of the entire data processing system 101.

  In addition, if a device that has passed in the past is recorded in an auxiliary request, a central request, or a fragment packet, route search information can be collected, and transmission to a device that has passed in the past is not performed and an unpassed It becomes possible to transmit only to the device. As a result, useless packet transmission / reception can be prevented, which contributes to an improvement in the performance of the entire data processing system 101.

  As described above, according to the present invention, when acquiring data via a network, a data processing system, a central device, an auxiliary device, and a request suitable for preventing as much access as possible from being concentrated on one device. An original apparatus, a central service method, an auxiliary service method, a request source method, and a program for realizing them on a computer can be provided, and can be applied to various data distribution techniques.

It is explanatory drawing which shows schematic structure of the data processing system which concerns on one of embodiment of this invention. It is a sequence diagram which shows the mode of communication in this embodiment. It is a mimetic diagram showing an outline composition of an information processor with which a central device, an auxiliary device, or a request origin device in this embodiment is realized. It is a mimetic diagram showing an outline composition of a central device concerning this embodiment. It is a flowchart which shows the flow of control of the division delivery process performed with the central apparatus which concerns on this embodiment. It is a flowchart which shows the flow of control of the central response process performed with the central apparatus which concerns on this embodiment. It is a mimetic diagram showing an outline composition of an auxiliary device concerning this embodiment. It is a flowchart which shows the flow of control of the auxiliary | assistant response process performed with the auxiliary | assistant apparatus which concerns on this embodiment. It is a schematic diagram which shows schematic structure of the request origin apparatus which concerns on this embodiment. It is a flowchart which shows the flow of control of the file (data) acquisition process performed with the said request origin apparatus. It is a flowchart which shows a difference with the above-mentioned embodiment among the control flow of the response process in other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Data processing system 102 Central apparatus 103 Auxiliary apparatus 104 Request origin apparatus 105 Internet 301 Information processing apparatus 302 CPU
303 ROM
304 RAM
305 Input device 306 Display device 307 External storage device 308 Medium reader 309 NIC
501 Data storage unit 502 Division unit 503 Delivery unit 504 Central request reception unit 505 Central response transmission unit 701 Reception unit 702 Fragment storage unit 703 Auxiliary request reception unit 704 Auxiliary response transmission unit 705 Auxiliary request transfer unit 901 Auxiliary request transmission unit 902 Auxiliary response Reception unit 903 Central request transmission unit 904 Central response reception unit 905 Restoration unit

Claims (11)

A data processing system comprising a central device, a plurality of auxiliary devices, and a plurality of requesting devices,
(A) The central device is
A data storage unit for storing data in association with an identifier;
A dividing unit for dividing the stored data into a plurality of fragments;
For each of the plurality of divided fragments, a triplet of the fragment, the identifier of the data, and a position where the fragment is arranged in the data (hereinafter referred to as “arrangement position”) A delivery unit that delivers to at least one of the
(B) Each of the plurality of auxiliary devices is
A reception unit that receives a triplet of a fragment, an identifier, and an arrangement position delivered from the central device;
A fragment storage unit that stores the received fragment, the identifier, and the arrangement position in association with each other;
(C) Each of the plurality of request source devices
An auxiliary request designating an identifier of desired data has been communicated in the past among the plurality of auxiliary devices, the auxiliary device communicatively connected to the request source device, and the plurality of request source devices. An auxiliary request transmitter for transmitting to other request source devices
(D) Each of the plurality of auxiliary devices is
An auxiliary request receiving unit that receives an auxiliary request transmitted from any of the plurality of request source devices;
Of the fragments stored in the fragment storage unit, an auxiliary response that specifies a fragment stored in association with the identifier specified in the received auxiliary request and an arrangement position stored in association with the fragment , Further comprising an auxiliary response transmission unit that transmits the auxiliary request to the request source device.
(E) Each of the plurality of request source devices includes:
An auxiliary response receiving unit for receiving an auxiliary response transmitted from any one of the transmission destinations of the auxiliary request;
If there is a fragment that is insufficient to restore the desired data from the fragment and arrangement position specified in the received auxiliary response, the center that specifies the identifier of the desired data and the arrangement position of the insufficient fragment A central request transmitter for transmitting a request to the central device;
(F) The central device is
A central request receiving unit that receives a central request designating an identifier and an arrangement position from any of the plurality of request source devices;
A central response that designates one of the divided pieces to be arranged at the designated arrangement position in the data of the identifier designated in the received central request is transmitted to the request source apparatus that has transmitted the central request. Further comprising a central response transmission unit,
(G) Each of the plurality of request source devices includes:
A central response receiver for receiving a central response transmitted from the central device;
The fragment and location specified in the received auxiliary response, and the fragment specified in the received central response and the location specified in the central request when the central request is transmitted, A restoration unit for restoring desired data;
When the central request is transmitted, it accepts a triple of the fragment specified in the received central response, the identifier specified in the central request, and the placement position specified in the central request, and transmits the central request. If not, the fragment specified in the last received auxiliary response among the received auxiliary responses, the identifier specified in the auxiliary request for the last received auxiliary response, and the last received auxiliary response A reception unit that accepts a triple with the arrangement position specified in the auxiliary request for
A fragment storage unit that stores the received fragment, the identifier, and the arrangement position in association with each other;
An auxiliary request receiving unit that receives an auxiliary request transmitted from any of the other request source devices among the plurality of request source devices,
Of the fragments stored in the fragment storage unit, an auxiliary response that specifies a fragment stored in association with the identifier specified in the received auxiliary request and an arrangement position stored in association with the fragment A data processing system further comprising: an auxiliary response transmission unit that transmits the auxiliary request to the request source apparatus that has transmitted the auxiliary request. A data processing system according to claim 1,
In the request source device, the auxiliary request transmission unit specifies an identifier that does not overlap with other auxiliary requests and transmits the lifetime of the request by designating the auxiliary request,
Each of the plurality of auxiliary devices and the plurality of requesting devices is received when the identifier specified in the received auxiliary request is different from any of the identifiers specified in the previously received auxiliary requests. If the life specified in the auxiliary request is reduced and the life is not exhausted, the auxiliary request with reduced life is communicated in the past among the other auxiliary devices of the plurality of auxiliary devices and the plurality of requesting devices. An auxiliary request transfer unit that transfers the received auxiliary request to those that have not been transferred to itself among other request source devices that have been
In each of the plurality of auxiliary devices and the plurality of request source devices, the auxiliary request receiving unit may have communicated in the past among other auxiliary devices of the plurality of auxiliary devices and the plurality of request source devices. A data processing system, further receiving an auxiliary request transferred from another request source device. A data processing system according to claim 1 or 2,
The request source device includes an auxiliary device that is communicably connected to the request source device among the plurality of auxiliary devices from a predetermined lobby server, and another request device that communicates with the request source device among the plurality of request source devices. A data processing system characterized by acquiring address information of a request source device. The data processing system according to any one of claims 1 to 3,
In the central device, the delivery unit delivers each of the triplets to a device selected at random from the plurality of auxiliary devices or a device having the lowest delivery cost. A data processing system according to any one of claims 1 to 4,
The accepting unit of the request source device replaces the triple with the received central response and a fragment specified in a randomly selected response from the received auxiliary response and a central request or auxiliary request for the response. A data processing system that accepts a triple of a specified identifier and an arrangement position specified in a central request or an auxiliary request for the response. A request source device in a data processing system comprising a central device, a plurality of auxiliary devices, and a plurality of request source devices,
An auxiliary request designating an identifier of desired data has been communicated in the past among the plurality of auxiliary devices, the auxiliary device communicatively connected to the request source device, and the plurality of request source devices. Auxiliary request transmitter that transmits to other request source device,
An auxiliary response receiving unit for receiving an auxiliary response transmitted from any one of the transmission destinations of the auxiliary request;
If there is a fragment that is insufficient to restore the desired data from the fragment and arrangement position specified in the received auxiliary response, the center that specifies the identifier of the desired data and the arrangement position of the insufficient fragment A central request transmitter for transmitting a request to the central device;
A central response receiver for receiving a central response transmitted from the central device;
The fragment and location specified in the received auxiliary response, and the fragment specified in the received central response and the location specified in the central request when the central request is transmitted, A restoration unit for restoring desired data;
When the central request is transmitted, it accepts a triple of the fragment specified in the received central response, the identifier specified in the central request, and the placement position specified in the central request, and transmits the central request. If not, the fragment specified in the last received auxiliary response among the received auxiliary responses, the identifier specified in the auxiliary request for the last received auxiliary response, and the last received auxiliary response A reception unit that accepts a triple with the arrangement position specified in the auxiliary request for
A fragment storage unit that stores the received fragment, the identifier, and the arrangement position in association with each other;
An auxiliary request receiving unit that receives an auxiliary request transmitted from any of the other request source devices among the plurality of request source devices,
Of the fragments stored in the fragment storage unit, an auxiliary response that specifies a fragment stored in association with the identifier specified in the received auxiliary request and an arrangement position stored in association with the fragment A request source apparatus comprising: an auxiliary response transmission unit that transmits the auxiliary request to the request source apparatus that has transmitted the auxiliary request. The request source device according to claim 6,
Of the plurality of auxiliary devices, the auxiliary device connected to the request source device in a communicable manner from the predetermined lobby server and the addresses of other request source devices communicating with the request source device among the plurality of request source devices. A request source device characterized by acquiring information. The request source device according to claim 6 or 7,
The reception unit replaces the triple with the received central response and a fragment specified in a randomly selected response from the received auxiliary response and an identifier specified in the central request or auxiliary request for the response A request source apparatus that accepts a triple of a central request for the response and an arrangement position specified in an auxiliary request. A data processing method executed by a central device, a plurality of auxiliary devices, and a plurality of request source devices,
The central device has a data storage unit, a division unit, a delivery unit, a central request reception unit, a central response transmission unit,
Each of the plurality of auxiliary devices has a reception unit, a fragment storage unit, an auxiliary request reception unit, an auxiliary response transmission unit,
Each of the plurality of request source devices includes an auxiliary request transmission unit, an auxiliary response reception unit, a central request transmission unit, a central response reception unit, a restoration unit, a reception unit, a fragment storage unit, an auxiliary request reception unit, and an auxiliary response transmission unit. Have
(A) In the central device, the data storage unit stores data in association with an identifier,
A dividing step in which the dividing unit divides the stored data into a plurality of pieces;
The delivery unit, for each of the plurality of divided fragments, includes a triplet of the fragment, an identifier of the data, and a position where the fragment is disposed in the data (hereinafter referred to as “arrangement position”). A delivery process for delivering to at least one of the plurality of auxiliary devices;
(B) In each of the plurality of auxiliary devices,
A receiving step in which the receiving unit receives a triplet of a fragment, an identifier, and an arrangement position delivered from the central device;
A fragment storage step of storing the received fragment, the identifier, and the arrangement position in association with each other in the fragment storage unit;
(C) In each of the plurality of request source devices,
The auxiliary request transmitting unit transmits an auxiliary request designating an identifier of desired data among the plurality of auxiliary devices so as to be communicably connected to the request source device, and the plurality of request source devices. Among them, it has an auxiliary request transmission step for transmitting to other request source devices that have communicated in the past,
(D) In each of the plurality of auxiliary devices,
An auxiliary request receiving step in which the auxiliary request receiving unit receives an auxiliary request transmitted from any of the plurality of request source devices;
Of the fragments stored in the fragment storage unit, the auxiliary response transmission unit stores a fragment stored in association with the identifier specified in the received auxiliary request and an arrangement position stored in association with the fragment. Further comprising an auxiliary response transmission step of transmitting an auxiliary response designating the request to the requesting device that has transmitted the auxiliary request,
(E) In each of the plurality of request source devices,
An auxiliary response receiving step in which the auxiliary response receiving unit receives an auxiliary response transmitted from any of the transmission destinations of the auxiliary request;
If there is a fragment that is insufficient for the central request transmission unit to restore the desired data from the fragment specified in the received auxiliary response and the arrangement position, the identifier of the desired data and the missing fragment A central request transmitting step of transmitting a central request designating a placement position to the central device;
(F) In the central device,
A central request receiving step in which the central request receiving unit receives a central request designating an identifier and an arrangement position from any of the plurality of request source devices;
The central response transmission unit sends a central response that designates one of the divided fragments to be arranged at the designated arrangement position in the data of the identifier designated in the received central request to the central request. Further comprising a central response transmission step of transmitting to the transmitted requesting device;
(G) In each of the plurality of request source devices,
A central response receiving step in which the central response receiving unit receives a central response transmitted from the central device;
The fragment and arrangement position specified in the received auxiliary response by the restoration unit, and the fragment specified in the received central response and the arrangement position specified in the central request when the central request is transmitted. And a restoration process for restoring the desired data from
When the reception unit has transmitted the central request, it accepts a triple of the fragment specified in the received central response, the identifier specified in the central request, and the placement position specified in the central request, If the central request is not transmitted, the fragment specified in the last received auxiliary response among the received auxiliary responses, the identifier specified in the auxiliary request for the last received auxiliary response, and the last An accepting step of accepting a triple with the arrangement position designated in the auxiliary request for the received auxiliary response;
A fragment storage step of storing the received fragment, identifier, and arrangement position in association with each other in the fragment storage unit,
An auxiliary request receiving step in which the auxiliary request receiving unit receives an auxiliary request transmitted from any of the other request source devices among the plurality of request source devices.
Of the fragments stored in the fragment storage unit, the auxiliary response transmission unit stores a fragment stored in association with the identifier specified in the received auxiliary request and an arrangement position stored in association with the fragment. A data processing method, further comprising: an auxiliary response transmission step of transmitting an auxiliary response that designates to the request source device that has transmitted the auxiliary request. A control method for controlling a request source device in a data processing system having a central device, a plurality of auxiliary devices, and a plurality of request source devices,
The request source device has an auxiliary request transmission unit, an auxiliary response reception unit, a central request transmission unit, a central response reception unit, a restoration unit, a reception unit, a fragment storage unit, an auxiliary request reception unit, an auxiliary response transmission unit,
The auxiliary request transmitting unit transmits an auxiliary request designating an identifier of desired data among the plurality of auxiliary devices so as to be communicably connected to the request source device, and the plurality of request source devices. Among them, an auxiliary request transmission step for transmitting to other request source devices that have communicated in the past,
An auxiliary response receiving step in which the auxiliary response receiving unit receives an auxiliary response transmitted from any of the transmission destinations of the auxiliary request;
If there is a fragment that is insufficient for the central request transmission unit to restore the desired data from the fragment specified in the received auxiliary response and the arrangement position, the identifier of the desired data and the missing fragment A central request transmission step of transmitting a central request designating a placement position to the central device;
A central response receiving step in which the central response receiving unit receives a central response transmitted from the central device;
The fragment and arrangement position specified in the received auxiliary response by the restoration unit, and the fragment specified in the received central response and the arrangement position specified in the central request when the central request is transmitted. And a restoration process for restoring the desired data from
When the reception unit has transmitted the central request, it accepts a triple of the fragment specified in the received central response, the identifier specified in the central request, and the placement position specified in the central request, If the central request is not transmitted, the fragment specified in the last received auxiliary response among the received auxiliary responses, the identifier specified in the auxiliary request for the last received auxiliary response, and the last An accepting step of accepting a triple with the arrangement position designated in the auxiliary request for the received auxiliary response;
A fragment storage step of storing the received fragment, identifier, and arrangement position in association with each other in the fragment storage unit,
An auxiliary request receiving step in which the auxiliary request receiving unit receives an auxiliary request transmitted from any of the other request source devices among the plurality of request source devices.
Of the fragments stored in the fragment storage unit by the auxiliary response transmission unit, a fragment stored in association with the identifier specified in the received auxiliary request, and an arrangement position stored in association with the fragment A control method comprising: an auxiliary response transmission step of transmitting an auxiliary response that designates the request to the request source device that has transmitted the auxiliary request. A program that causes a computer to function as a request source device in a data processing system that includes a central device, a plurality of auxiliary devices, and a plurality of request source devices, the program comprising:
  An auxiliary request designating an identifier of desired data has been communicated in the past among the plurality of auxiliary devices, the auxiliary device communicatively connected to the request source device, and the plurality of request source devices. Auxiliary request transmitter that transmits to other request source device,
  An auxiliary response receiving unit for receiving an auxiliary response transmitted from any one of the transmission destinations of the auxiliary request;
  If there is a fragment that is insufficient to restore the desired data from the fragment and arrangement position specified in the received auxiliary response, the center that specifies the identifier of the desired data and the arrangement position of the insufficient fragment A central request transmitter for transmitting a request to the central device;
  A central response receiver for receiving a central response transmitted from the central device;
  The fragment and location specified in the received auxiliary response, and the fragment specified in the received central response and the location specified in the central request when the central request is transmitted, A restoration unit for restoring desired data;
  When the central request is transmitted, it accepts a triple of the fragment specified in the received central response, the identifier specified in the central request, and the placement position specified in the central request, and transmits the central request. If not, the fragment specified in the last received auxiliary response among the received auxiliary responses, the identifier specified in the auxiliary request for the last received auxiliary response, and the last received auxiliary response A reception unit that accepts a triple with the arrangement position specified in the auxiliary request for
  A fragment storage unit that stores the received fragment, the identifier, and the arrangement position in association with each other;
  An auxiliary request receiving unit that receives an auxiliary request transmitted from any of the other request source devices among the plurality of request source devices,
  Of the fragments stored in the fragment storage unit, an auxiliary response that specifies a fragment stored in association with the identifier specified in the received auxiliary request and an arrangement position stored in association with the fragment And function as an auxiliary response transmission unit that transmits the auxiliary request to the request source apparatus that has transmitted the auxiliary request.
  A program characterized by that.

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