JP2012178113A - Distribution system, node device, and information processing method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To acquire information on what compound contents a content constitutes without concentrating loads on a specific device.SOLUTION: One of node devices includes: first storage means for storing first identification information identifying the compound contents comprising two or more contents from the plurality of contents and second identification information identifying the contents constituting the compound contents identified by the first identification information in association with each other; reception means for receiving, from a prescribed device connected to a network, inquiry information which inquires about the contents and includes the second identification information; first determination means for determining whether or not the first identification information corresponding to the second identification information received by the reception means is stored in the first storage means; and transmission means for transmitting the first identification information determined by the determination means to the prescribed device when it is determined that the first identification information is stored in the first storage means by the first determination means.

Description

  The present invention relates to a technical field of a distribution system using an overlay network.

  Conventionally, a client server system is known as a system for distributing contents via a network. In this client-server system, server devices can be augmented with the development of technology. Thereby, the server apparatus can manage many contents. In recent years, communication systems using overlay networks have attracted attention. Specifically, a peer-to-peer communication system has attracted attention. In this peer-to-peer communication system, a plurality of contents are distributed and stored in a plurality of node devices. For example, for each content, a node device that manages information indicating the location of the node device that stores the content is defined. Accordingly, since the content management load is distributed to a plurality of node devices, a large number of contents can be managed.

  Patent Document 1 describes a technique for managing a plurality of related contents in association with content catalog information in which content attribute information is registered. Specifically, in the content attribute information, identification information of a reference content serving as a reference among a plurality of contents and related information indicating a relationship between the reference content and related content related to the reference content are set. It is assumed that after content attribute information is searched based on an input keyword, acquisition of related content is requested. Then, the identification information of the related content is generated based on the identification information of the reference content and the related information in the searched attribute information. Then, the related content is acquired based on the generated identification information.

JP 2010-237851 A

  By the way, there is a demand to create a content by combining a plurality of contents among a large number of contents distributed in the distribution system. Here, content created by combining a plurality of contents is referred to as “composite content”. The composite content is composed of a plurality of contents. In this case, there is a case where it is desired to search for a composite content configured using predetermined content from a plurality of composite content. Specifically, it is a case where one of a plurality of contents constituting the composite contents is to be stopped for distribution due to copyright infringement. In general, it is conceivable to manage posting of composite content to a network by a specific server. However, in this method, inquiries for searching complex content are concentrated on a specific server, and the processing load is concentrated on the specific server.

  The present invention has been made in view of the above points. The present invention provides a distribution system, a node device, an information processing method, and a program capable of acquiring information indicating which composite content is a component of content without concentrating the load on a specific device. With the goal.

  In order to solve the above problem, the invention according to claim 1 is a distribution system in which a plurality of contents are distributed and stored in a plurality of node devices connected to a network, and the plurality of contents are distributed. Any one of the plurality of node devices included in the distribution system includes: first identification information for identifying composite content composed of two or more contents from the plurality of contents; First storage means for storing the second identification information for identifying the content constituting the composite content identified by the first identification information, inquiry information for inquiring about the content, the second identification information And receiving means for receiving the inquiry information from a predetermined device connected to the network, and receiving by the receiving means The first determination means for determining whether or not the first identification information associated with the second identification information is stored in the first storage means, and the first determination means A transmission unit configured to transmit the first identification information determined by the determination unit to the predetermined device when it is determined to be stored in the first storage unit;

  According to this invention, the predetermined device can acquire the first identification information from any of the node devices configuring the overlay network based on the second identification information for identifying the content. Therefore, it is possible to specify which composite content is a component of the content by using the acquired first identification information without concentrating the load on a specific device.

  The invention according to claim 2 is a system in which the distribution system distributes content via an overlay network composed of the plurality of node devices, and the distribution system is one of the plurality of node devices. A first node device that stores content and a second node device that is one of the plurality of node devices and is determined for each content, and indicates a location of the first node device The second node device that manages information, and the second node device includes the first storage unit, the reception unit, the first determination unit, and the transmission unit, 1 storage means includes the second identification information of the content managed by the second node and the first identification information of the composite content including the content indicated by the second identification information. , And to store in association with.

  According to the present invention, it is possible to effectively distribute the processing load for the inquiry about the composite content to the plurality of node devices.

  According to a third aspect of the present invention, the acquisition means for acquiring the second identification information of the content instructed to stop distribution, and the inquiry information including the second identification information acquired by the acquisition means Received by the second receiving means, the second receiving means for receiving the first identification information from the node apparatus that is the destination of the inquiry information, and the second receiving means. And an information processing apparatus comprising: a stopping unit that stops distribution of the composite content identified by the first identification information.

  According to the present invention, when the distribution of a certain content is stopped, it is also possible to stop the distribution of the composite content including the content that is the target of the distribution stop.

  According to a fourth aspect of the present invention, the first storage means includes third identification information for identifying second composite content configured by a plurality of the composite contents, and the composite content that constitutes the second composite content. First identification information to be identified and stored, the reception means receives second inquiry information including the second identification information, and the first determination means is received by the reception means It is determined whether the third identification information associated with the second identification information is stored in the first storage means, and the transmission means transmits the third identification information determined by the first determination means It is characterized by doing.

  According to this invention, a certain composite content may be composed of a plurality of composite content. Also in this case, based on the first identification information for identifying the composite content, it is possible to specify which composite content is the constituent element of the composite content by the acquired third identification information.

  According to a fifth aspect of the present invention, the first node device stores a second acquisition unit that acquires any one of the composite contents from the overlay network, and the composite content acquired by the second acquisition unit. Content that constitutes the composite content includes second storage means, the first identification information of the composite content stored in the second storage means, and the second identification information of the content that constitutes the composite content. Third transmission means for transmitting to the second node device managing the location information of the first node device to be stored, wherein the second node device transmits the first transmitted from the first node device. The apparatus further comprises third receiving means for receiving identification information and the second identification information, wherein the first storage means receives the first identification received by the third receiving means. And to store in association with said boric second identification information.

  According to this invention, the second node device can acquire the first identification information and the second identification information stored in association with each other from the first node device storing the composite content.

  The invention according to claim 6 is any one of the plurality of node devices included in a distribution system in which a plurality of contents are distributed and stored in a plurality of node devices connected to a network, and the plurality of contents are distributed. A first identification information for identifying composite content composed of two or more contents, and the composite content identified by the first identification information. A first storage means for storing the second identification information for identifying the contents in association with each other; and inquiry information for inquiring about the contents, the inquiry information including the second identification information being connected to a network. Receiving means for receiving from the device, and the first associated with the second identification information received by the receiving means When it is determined by the first determination unit that determines whether other information is stored in the first storage unit, and the first determination unit that the first identification information is stored in the first storage unit And transmitting means for transmitting the first identification information determined by the determining means to the predetermined device.

  The invention according to claim 7 is an information processing method in a distribution system in which a plurality of contents are distributed and stored in a plurality of node devices connected to a network, and the plurality of contents are distributed. Any one of the plurality of node devices included in the information is inquiry information for inquiring about the content, and the content constituting the composite content composed of two or more contents is selected from the plurality of contents. A reception step for receiving the inquiry information including the second identification information to be identified from a predetermined device connected to the network; and a first identification information associated with the second identification information received in the reception step. And first identification information for identifying the composite content identifies the composite content It is determined whether the first identification information and the second identification information for identifying the content constituting the composite content identified by the first identification information are stored in association with each other and stored. And determining in the determination step that the first identification information determined in the determination step is the predetermined device when it is determined that the first identification information is stored in the first storage means. And a transmission step of transmitting to.

  The invention according to claim 8 is any one of the plurality of node devices included in a distribution system in which a plurality of contents are distributed and stored in a plurality of node devices connected to a network, and the plurality of contents are distributed. Inquiry information for inquiring the content to the computer included in the node device, wherein the second identification information for identifying the content constituting the composite content composed of two or more content among the plurality of content A receiving step for receiving the inquiry information from a predetermined device connected to the network, and first identification information associated with the second identification information received in the receiving step, and identifying the composite content First identification information for identifying the composite content, A determination step for determining whether or not the second identification information for identifying the content constituting the composite content identified by the first identification information is stored in association with the first storage means; and the determination step When the first identification information is determined to be stored in the first storage means, a transmission step of transmitting the first identification information determined in the determination step to the predetermined device, and It is made to perform.

  According to the present invention, the predetermined device can acquire the first identification information from any node device configuring the overlay network based on the second identification information for identifying the content. Therefore, it is possible to specify which composite content is a component of the content by using the acquired first identification information without concentrating the load on a specific device.

It is a figure showing an example of outline composition of a distribution system of one embodiment. (A) is a figure which shows the operation | movement outline | summary at the time of the injection | throwing-in of the composite content of the delivery system S of this embodiment, and the confirmation of the composite content using a content, (B) is a figure of the delivery system S of this embodiment. It is a figure which shows the operation | movement outline | summary at the time of the delivery stop of content. (A) is a block diagram showing a schematic configuration example of the center server SS, (B) is a block diagram showing a schematic configuration example of a node. It is a flowchart which shows the process example of the control part 1 of center server SS of one Embodiment. It is a flowchart which shows the process example of the control part 11 of the node of one Embodiment. It is a flowchart which shows the process example of the message reception process of the control part 11 of the node of one Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiment described below is an embodiment when the present invention is applied to a distribution system.

[1. Overview of distribution system configuration and operation]
First, the configuration and operation outline of the distribution system of the present embodiment will be described with reference to FIG. FIG. 1 is a diagram illustrating a schematic configuration example of a distribution system according to the present embodiment. As shown in FIG. 1, the distribution system S of the present embodiment includes a center server SS, node devices Nn (n = 1, 2, 3... K), and the like. The node device Nn is hereinafter referred to as “node”. The center server SS and the node are connected to the network NW. The network NW is composed of the Internet or the like.

  As shown in FIG. 1, in the distribution system S, a base network NLn is constructed for each of a plurality of bases Pn. Examples of the base include a karaoke store, a school, a company, a house, and other facilities. The base network NLn is a private network such as a LAN (Local Area Network) as a communication means.

  Each base network NLn is connected to a node and a plurality of base terminals Tn-l (l = 1, 2, 3,... J). The node has a function as an edge server that provides content to the base terminal Tn-l connected to the same base network NLn. On the other hand, the base terminal Tn-l has a function of reproducing content. For example, when the base Pn is a karaoke store, the base terminal Tn-l is a commander that plays content for karaoke. For example, when the base Pn is a school, it is a viewing terminal that reproduces content for teaching materials. For example, when the base Pn is a company, it is a viewing terminal that reproduces content for training. For example, when the base Pn is a house, it is a set-top box that reproduces content for a broadcast program.

  Further, as shown in FIG. 1, in the distribution system S, an overlay network ON is configured by participation of a plurality of nodes that can communicate with each other via a network NW. The overlay network ON is a logical network that forms a virtual link. The overlay network ON is realized by a specific algorithm, for example, an algorithm using a distributed hash table. The distributed hash table is hereinafter referred to as “DHT (Distributed Hash Table)”. Here, participating in the overlay network ON means operating in a state in which various messages can be transmitted to and received from other nodes via the overlay network ON based on a routing table using DHT. Note that a routing table using DHT is known in Japanese Patent Application Laid-Open No. 2006-197400 and the like, and thus detailed description thereof is omitted. A node ID is assigned to each node participating in the overlay network ON. This node ID is unique identification information for identifying a node among nodes participating in the overlay network ON.

  In the distribution system S, various contents are distributed and stored in a plurality of nodes. A node that stores content is referred to as a “holding node”. The holding node is an example of the first node device in the present invention. Each content is given a content ID. The content ID is unique identification information for identifying the content from the content stored in the overlay network ON. The center server SS inputs content into the overlay network ON. The input of content means that the content is stored in any node and the stored content can be acquired from the overlay network ON by each node. Attribute information such as content ID and title of each content is described in the content catalog information. The content catalog information is created by the center server SS. Then, the center server SS distributes the content catalog information to all nodes. Each node distributes the received content catalog information to all base terminals Tn-l connected to the same base Pn.

  Further, in the distribution system S, composite content composed of a plurality of contents may be input. In addition, content that is not composite content is normal content. For example, when the base Pn is a karaoke store, the composite content includes karaoke content. The content for karaoke is composed of normal content such as music data, video data, and lyrics data, for example. In addition, content posted by the user of the base terminal Tn-l may be used as a component of composite content. For example, content for karaoke is created from music data and lyrics data of a certain piece of music and video data posted by a user. Thereby, the user can enjoy karaoke while playing the video posted by himself or the video posted by others on the base terminal Tn-1. The content posted by the user is referred to as “posted content”.

  The content ID of each content constituting the composite content is described in the meta file of the composite content. The metafile of composite content is a file for searching for each content constituting the composite content. The content ID of the composite content is assigned to the metafile of the composite content. The meta file of the composite content to which the content ID is assigned is input to the overlay network ON as with the normal content. Note that composite content including a plurality of composite contents may be input to the overlay network ON. In this case, the content ID of each composite content constituting the composite content is described in the composite content metafile. Note that the content ID of the composite content is an example of first identification information in the present invention. Further, the content ID of the normal content is an example of second identification information in the present invention.

  The location of the content distributed and stored in a plurality of nodes is stored as index information by the node that manages the location of the content. A node that manages the location of content is called a “root node”. The index information includes a set of node information of the node storing the content and the content ID of the content. For example, the root node is determined to be a node to which a node ID closest to the content ID is assigned. The node ID closest to the content ID is, for example, the node ID with the highest number of upper digits that match. The root node is an example of a second node device in the present invention.

  When the node acquires a certain content from the overlay network ON, the node searches for the acquired content. The node that acquires the content is hereinafter referred to as a “user node”. Specifically, the user node transmits a search message. The search message is a message for inquiring about the location of the content to be acquired to the root node of the content. The search message includes the content ID of the content to be acquired. The search message is transferred to the root node by routing using DHT. The root node acquires index information corresponding to the content ID included in the received search message from the index information cache. The root node returns the acquired index information to the user node that is the source of the search message. Thereby, the user node receives the IP address and the like of the holding node from the root node. Then, the user node accesses the holding node and downloads the content. Note that the process of inquiring the location of the content to the root node is well known in, for example, Japanese Patent Application Laid-Open No. 2007-053662, and detailed description thereof is omitted.

  When the user node acquires content from the holding node, the user node publishes the content. The disclosure of content means that the content acquired by the user node can be acquired from the overlay network ON. Specifically, the user node stores the acquired content. Then, the user node transmits a publish message to the root node. The publish message is a message for notifying the root node that the content has been saved. The publish message includes the content ID of the saved content and the node information of the user node that saved the content. The root node stores index information including a set of content ID and node information included in the received publish message in the index information cache. In this way, the user node becomes a new holding node for storing content.

  When a user node acquires composite content, it first acquires a meta file of the composite content. The metafile acquisition method is the same as the content acquisition method. Next, the user node acquires the content ID of each content constituting the composite content from the metafile. And a user node acquires each content which comprises composite content based on acquired content ID.

  By the way, there is a case where it is desired to search for a composite content having a certain content as a constituent element from the composite content input to the overlay network ON. For example, when a certain content is a content that violates copyright, it is necessary to specify a composite content that uses the content. In other words, it is necessary to stop the distribution of content that violates copyright. At the same time, distribution of composite content that uses content that violates copyright must also be stopped. Further, for example, there is a case where it is desired to know the number of composite contents that use a certain content. The number of composite contents that use a certain content is called “number of uses”. For example, each posted content is ranked according to the number of usages by the composite content. Then, the ranking information is provided to the user. Further, for example, there are cases where the user wants to know which composite content the content posted by himself / herself is used. In order to specify the composite content that uses the content, for example, a management table that associates the content with the composite content is required. For example, assume that the management table is managed by the center server SS. In this case, as the number of composite contents increases, the amount of information in the management table that the center server SS should store increases.

  Therefore, in the distribution system S, the root node stores information corresponding to the management table for the content whose location is managed. Information corresponding to this management table is referred to as “composite content index information”. The composite content index information includes a content ID of the content and a content ID of the composite content having the content as a constituent element.

  FIG. 2A is a diagram showing an outline of the operation of the distribution system S according to the present embodiment when the composite content is input and when the composite content using the content is confirmed. As shown in FIG. 2A, the node N3 is the root node of the content A. Content A is content posted by the user. The node N4 is a root node for the content B.

  For example, it is assumed that the administrator of the distribution system S instructs the center server SS to create the content X as composite content composed of the content A and B. Then, the center server SS generates a metafile M of content X describing the content IDs of the content A and B. Then, the center server SS inputs the metafile M (FIGS. 2A and 1). That is, the center server SS stores the metafile M in one or more nodes. Further, the center server SS distributes the content catalog information to which the attribute information of the content X is added to all nodes.

  Next, the center server SS notifies the content root node, which is a component of the content X, that the content whose location is managed has been used. Specifically, the center server SS transmits a usage notification message (FIGS. 2A and 2). The usage notification message includes composite content index information. Since the content X is composed of two contents, two usage notification messages are transmitted. The composite content index information included in the first usage notification message includes the content ID of content A and the content ID of content X. The composite content index information included in the second usage notification message includes the content ID of content B and the content ID of content X.

  The usage notification message transmitted from the center server SS is transferred to the root node by routing using DHT. That is, the first usage notification message is transferred to the node N3 according to the content ID of the content A included in the composite content index information in the message. The second usage notification message is transferred to the node N4 according to the content ID of the content B included in the composite content index information in the message. Then, the node N3 and the node N4 each store the composite content index information included in the received usage notification message in the composite content index cache (FIGS. 2A and 3).

  Thereafter, it is assumed that the user of the base terminal T2-1 wants to know the composite content using the content A posted by himself / herself. In this case, the user designates the content A by operating the base terminal T2-1. Then, the base terminal T2-1 transmits a composite content inquiry request to the node N2 (FIGS. 2A and 4). The composite content inquiry request is a request for inquiring composite content having the specified content as a component. The composite content inquiry request includes the content ID of the content that is the target of the composite content inquiry. Upon receiving the composite content inquiry request, the node N2 transmits a composite content inquiry message (FIGS. 2A and 5). The composite content inquiry message is a message for inquiring the root node for composite content having the specified content as a constituent element. The content ID set in the composite content inquiry request is set in the composite content inquiry message. The composite content inquiry message is transferred to the node N3 by routing using DHT. The composite content inquiry message is an example of inquiry information in the present invention.

  Upon receiving the composite content inquiry message, the node N3 acquires composite content index information corresponding to the content ID of content A included in the message from the composite content index cache. Then, the node N3 transmits an inquiry response message including the acquired composite content index information to the node N2 (FIGS. 2A and 6). When the node N2 receives the inquiry response message, the node N2 acquires the complex content index information included in the message. Then, the node N2 transmits the acquired composite content index information to the base terminal T2-1 as an inquiry result (FIGS. 2A and 7).

  The base terminal T2-1 displays a list of titles of the composite content based on the content ID of the composite content included in the received composite content index information (FIGS. 2A and 8). In this case, the base terminal T2-1 displays the title of the content X.

  Since the node stores the composite content index information, the center server SS does not need to receive the composite content inquiry message. Therefore, the processing load for the composite content inquiry message is not concentrated on the center server SS. The content root node stores composite content index information. Therefore, it is possible to effectively distribute the processing load for the inquiry about the composite content to a plurality of nodes. For example, when the node N2 is the root node of the content A, the node N2 does not need to transmit the composite content inquiry message. In this case, the node N2 transmits the composite content index information stored in the composite content index cache to the base terminal T2-1. Further, when inquiring about a composite content including a plurality of composite contents, it can be performed in the same manner as in FIG.

  FIG. 2B is a diagram illustrating an outline of the operation of the distribution system S according to the present embodiment when content distribution is stopped.

  For example, assume that content B is found to be content that violates copyright. In this case, the administrator of the distribution system S instructs the center server SS to stop the distribution of the content B (FIGS. 2B and 1). For example, the administrator inputs the content ID of content B. Then, the center server SS confirms the composite content having the content B as a constituent element. Specifically, the center server SS transmits a composite content inquiry message including the content ID of the content B (FIGS. 2B and 2). Note that the center server SS does not participate in the overlay network ON. Therefore, the center server SS transmits a message to a predetermined node. A predetermined node that receives a message from the center server SS is referred to as a “supporter node”. The supporter node transfers the message received from the center server SS to another node according to routing using DHT. The center server SS sends and receives messages to and from nodes participating in the overlay network ON by way of the supporter node.

  Upon receiving the composite content inquiry message, the node N4 transmits an inquiry response message (FIGS. 2B and 3). The center server SS receives the inquiry response message. The center server SS acquires the content ID of the composite content from the composite content index information included in the inquiry response message. Here, the content ID of content X is acquired. Therefore, the center server SS deletes the attribute information of the content X from the content catalog information. Further, the center server SS deletes the attribute information of the content B from the content catalog information (FIGS. 2B and 4). Then, the center server SS distributes the content catalog information from which the attribute information of the contents B and X is deleted to all nodes.

  The content ID of content B cannot be retrieved from the new content catalog information. Also, the content ID of content X cannot be searched. Therefore, the content ID necessary for the node to acquire the contents B and X from the overlay network ON cannot be acquired. That is, the distribution of the contents B and X is stopped by deleting the attribute information from the contents catalog information. In some cases, there is a composite content whose component is a composite content whose distribution has been stopped. Even in such a case, it is possible to stop the distribution of the composite content having the composite content whose distribution is stopped as a constituent element by the same method. When ranking each posted content according to the number of uses by the composite content, the content inquiry method using the content is the same as in FIG. In this way, content distribution can be stopped without deleting content from the overlay network ON. Note that content distribution may be stopped by deleting content from the overlay network ON. For example, by transmitting a message from the center server SS to all the nodes, each node may delete the content to be stopped and the meta file of the composite content.

[2. Configuration of center server]
Next, the configuration of the center server SS will be described with reference to FIG. FIG. 3A is a block diagram illustrating a schematic configuration example of the center server SS. As illustrated in FIG. 3A, the center server SS includes a control unit 1, a storage unit 2, a communication unit 3, and the like. The control unit 1, the storage unit 2, and the communication unit 3 are connected to each other via a bus 4.

  The storage unit 2 is composed of, for example, a hard disk drive. The storage unit 2 stores an operating system, various control programs, and the like. Further, the storage unit 2 stores the original of each content and the metafile of each composite content. The storage unit 2 stores content catalog information. The storage unit 2 stores node information of supporter nodes.

  The communication unit 3 performs communication control with a node or the like through the network NW. The control unit 1 includes a CPU having a calculation function, a working RAM, a ROM, and the like. The control unit 1 performs overall control of the entire center server SS when the CPU reads and executes a program stored in the storage unit 2 or the like.

[3. Node configuration]
Next, the configuration and function of the node will be described with reference to FIG. FIG. 3B is a block diagram illustrating a schematic configuration example of a node. As shown in FIG. 3B, the node includes a control unit 11, a storage unit 12, a communication unit 13a, a communication unit 13b, a buffer memory 14, and the like. The control unit 11, the storage unit 12, the communication unit 13 a, the communication unit 13 b, and the buffer memory 14 are connected to each other via a bus 15.

  In the present embodiment, the node is a relay device that relays an IP (Internet Protocol) packet between the network NW and the base network NLn. This relay device is, for example, a router or an L3 switching hub. The node may be a terminal device used by the user. In addition, the node may basically be a device such as a gateway that is regularly connected to the network NW.

  The storage unit 12 is composed of, for example, a hard disk drive. The storage unit 12 stores an operating system, a P2P program, and the like. The P2P program is a program for communicating with other nodes using a routing table. Note that the P2P program or the like may be downloaded from a predetermined server connected to the network NW, for example. Alternatively, the P2P program or the like may be recorded on a recording medium such as a DVD and read via a drive of the recording medium.

  In addition, the storage unit 12 stores a routing table using DHT used for overlay network ON. The storage unit 12 stores content catalog information distributed from the center server SS. The storage unit 12 stores content and metafiles acquired from the overlay network ON in association with content IDs. The storage unit 12 stores index information and composite content index information. The storage unit 12 stores the IP address and port number of the center server SS.

  The communication unit 13a performs communication control with other nodes, the center server SS, and the like through the network NW. The communication unit 13b performs communication control with the base terminal Tn-l through the base network NLn. Further, the buffer memory 14 temporarily accumulates the content received via the communication unit 13a.

  The control unit 11 includes a CPU having a calculation function, a working RAM, a ROM, and the like. The control unit 11 has a clock function and a timer function. The control unit 11 reads and executes the program stored in the storage unit 12 or the like by the CPU, so that the reception unit, the first determination unit, the transmission unit, the second transmission unit, the second reception unit in the present invention, Functions as stop means, acquisition means, second acquisition means, third transmission means, and third reception means.

[4. Operation of distribution system]
Next, the operation of the distribution system S of the present embodiment will be described with reference to FIGS. FIG. 4 is a flowchart illustrating a processing example of the control unit 1 of the center server SS of the present embodiment.

  The process illustrated in FIG. 4 is started, for example, when the center server SS is powered on. First, the control unit 1 determines whether or not the power supply OFF is requested by the administrator of the distribution system S (step S1). At this time, when it is determined that the power-off is not requested (step S1: NO), the control unit 1 determines whether or not the administrator has instructed to input the normal content (step S2). At this time, when it is determined that the input of the normal content is instructed (step S2: YES), the control unit 1 inputs the normal content (step S3). Specifically, the control unit 1 assigns a new content ID to the normal content to be input. Next, the control unit 1 causes the node to save the normal content by transmitting the normal content to be input to one or more nodes. Next, the control unit 1 adds the attribute information of the normal content to be input to the content catalog information. Then, the control unit 1 distributes content catalog information. After finishing the process of step S3, the control part 1 transfers to step S1.

  In step S2, when it is determined that the input of normal content is not instructed (step S2: NO), the control unit 1 determines whether or not the input of composite content is instructed by the administrator (step S4). ). At this time, if the control unit 1 determines that the input of the composite content has been instructed (step S4: YES), the control unit 1 generates a metafile of the composite content to be input (step S5). Next, the control unit 1 inputs the generated metafile (step S6). Specifically, the control unit 1 assigns a new content ID to the input metafile. Next, the control unit 1 transmits the input metafile to one or more nodes, thereby causing the nodes to store the metafile. Next, the control unit 1 adds the attribute information of the input metafile to the content catalog information. Then, the control unit 1 distributes content catalog information.

  Next, the control unit 1 transmits a usage notification message (step S7). Specifically, the control unit 1 generates composite content index information including the content ID of the content constituting the composite content and the content ID of the composite content to be input. The composite content index information is generated for each content constituting the composite content. Then, the control unit 1 transmits a usage notification message including the composite content index information. The usage notification message is transmitted for each generated composite content index information. After finishing the process of step S7, the control part 1 transfers to step S1.

  In step S4, when it is determined that the complex content input is not instructed (step S4: NO), the control unit 1 determines whether or not the administrator has instructed the content distribution stop (step S8). ). At this time, if the control unit 1 determines that an instruction to stop content distribution has been given (step S8: YES), the control unit 1 transmits a composite content inquiry message (step S9). Specifically, the control unit 1 acquires the content ID of the content to be distributed that has been input by the administrator. Then, the control unit 1 transmits a composite content inquiry message including the acquired content ID.

  Next, the control unit 1 receives an inquiry response message from the root node of the content to be stopped (Step S10). Next, the control unit 1 determines whether there is composite content including the content to be stopped as a component (step S11). At this time, if the received inquiry response message includes complex content index information, the control unit 1 determines that there is complex content having the content to be distributed as a constituent element (step S11: YES). . In this case, the control unit 1 stops the distribution of the composite content having the content to be stopped as a constituent element (step S12). Specifically, the control unit 1 acquires the content ID of the composite content from the composite content index information included in the inquiry response message. Next, the control unit 1 searches for attribute information from the content catalog information with the acquired content ID. Then, the control unit 1 deletes the searched attribute information from the catalog information. The control unit 1 performs these processes for each composite content index information acquired from the inquiry response message. That is, the control unit 1 performs these processes for each composite content whose content is the content to be stopped.

  Next, the control unit 1 stops the distribution of the content to be distributed (step S13). Specifically, the control unit 1 searches the attribute information from the content catalog information with the content ID of the content to be distributed. Next, the control unit 1 deletes the searched attribute information from the catalog information. Then, the control unit 1 distributes the content catalog information to all nodes. After finishing the process of step S13, the control part 1 transfers to step S1.

  In step S11, if the received inquiry response message does not include the composite content index information, the control unit 1 determines that there is no composite content including the content to be stopped (step S11: YES). ). In this case, the control unit 1 stops the distribution of the content to be distributed (step S13).

  Note that there are cases where the composite content having the content to be distributed as a constituent element is a constituent element of another composite content. In this case, the control unit 1 stops the distribution of other composite contents. Specifically, the control unit 1 transmits a composite content inquiry message including the content ID of the composite content having the content to be stopped as a constituent element. Then, the control unit 1 receives an inquiry response message from the root node of the composite content. The subsequent processing is the same as steps S11 to S13.

  In step S8, when it is determined that the distribution stop is not instructed (step S8: NO), the control unit 1 determines whether or not the administrator has instructed the inquiry about the composite content using the content. (Step S14). The composite content inquiry instruction is performed, for example, when ranking the posted content based on the number of uses by the composite content. At this time, when it is determined that the inquiry about the composite content is instructed (step S14: YES), the control unit 1 transmits a composite content inquiry message (step S15). Specifically, the control unit 1 acquires the content ID of the content that is the target of the inquiry input from the administrator. Then, the control unit 1 transmits a composite content inquiry message including the acquired content ID.

  Next, the control unit 1 receives an inquiry response message from the root node of the content to be stopped (Step S16). Next, the control unit 1 displays the inquiry result on, for example, a terminal device used by the administrator (step S17). For example, the control unit 1 acquires the content ID of the composite content from the composite content index information included in the inquiry response message. Next, the control unit 1 causes the terminal device to display information such as the acquired content ID, the title of the composite content corresponding to the acquired content ID, and the number of uses. After finishing the process of step S17, the control part 1 transfers to step S1.

  In step S14, when it is determined that the inquiry about the composite content is not instructed (step S14: NO), the control unit 1 proceeds to step S1. In step S1, if the control unit 1 determines that the power-off is requested (step S1: YES), the control unit 1 ends the process shown in FIG.

  FIG. 5 is a flowchart illustrating a processing example of the control unit 11 of the node according to the present embodiment. The process shown in FIG. 5 is started, for example, when the power of the node is turned on. First, the control unit 11 determines whether or not the administrator of the site Pn has requested power OFF (step S31). At this time, when it is determined that the power supply OFF is not requested (step S31: NO), the control unit 11 determines whether a normal content request is received from the base terminal Tn-1 (step S32). . The normal content request is a request for requesting normal content. The normal content request includes the content ID of the requested normal content. At this time, when it is determined that the normal content request has been received (step S32: YES), the control unit 11 acquires the requested normal content from the overlay network ON (step S33). In addition, description of the specific processing content is abbreviate | omitted. Next, the control unit 11 transmits a publish message including the content ID of the acquired normal content (step S34). Next, the control unit 11 uploads the acquired content to the base terminal Tn-1 that is the transmission source of the normal content request (step S35). After finishing the process of step S35, the control part 11 transfers to step S31.

  If it is determined in step S32 that the normal content request has not been received (step S32: NO), the control unit 11 determines whether or not the composite content request has been received from the base terminal Tn-1 (step S32). S36). The composite content request is a request for requesting normal content. The composite content request includes the content ID of the requested composite content. At this time, if it is determined that the composite content request has been received (step S36: YES), the control unit 11 acquires the requested composite content metafile from the overlay network ON (step S37). Next, the control unit 11 transmits a publish message including the content ID of the acquired metafile (step S38). Next, the control unit 11 acquires each content constituting the composite content from the overlay network ON based on the content ID described in the acquired metafile. (Step S39). Next, the control unit 11 transmits a publish message including the content ID of each acquired content (step S40). Next, the control unit 11 transmits each acquired content to the base terminal Tn-1 that is the transmission source of the normal content request (step S41). When the control section 11 finishes the process of step S41, the control section 11 proceeds to step S31.

  In step S36, when it is determined that the composite content request has not been received (step S36: NO), the control unit 11 determines whether a composite content inquiry request has been received from the base terminal Tn-1 ( Step S42). At this time, if it is determined that the composite content inquiry request has been received (step S42: YES), the control unit 11 transmits a composite content inquiry message (step S43). Specifically, the control unit 11 acquires a content ID from the composite content inquiry request. Then, the control unit 11 transmits a composite content inquiry message including the acquired content ID. Next, the control unit 1 receives an inquiry response message from the root node of the content whose distribution is to be stopped (step S44). Next, the control unit 1 transmits the inquiry result to the base terminal Tn-1 that is the transmission source of the composite content inquiry request (step S45). Specifically, the control unit 11 acquires composite content index information from the inquiry response message. Next, the control unit 11 transmits the acquired composite content index information as an inquiry result. When the control section 11 finishes the process step of step S45, the control section 11 proceeds to step S31.

  In step S42, when it is determined that the complex content inquiry request has not been received (step S42: NO), the control unit 11 executes a message reception process described later, and proceeds to step S31. In step S31, when it is determined that the power-off is requested (step S31: YES), the control unit 1 ends the process illustrated in FIG.

  FIG. 6 is a flowchart illustrating a processing example of message reception processing of the control unit 11 of the node according to the present exemplary embodiment. First, it is determined whether or not a message from another node to the root node has been received (step S61). Examples of the message to the root node include a publish message, a complex content inquiry message, a usage notification message, and the like. At this time, when it is determined that the message to the root node has not been received (step S61: NO), the control unit 11 ends the message reception process. On the other hand, when it is determined that the message to the root node has been received (step S61: YES), the control unit 11 determines whether or not the node itself that has received the message is the root node (step S62). Specifically, the control unit 11 acquires a content ID from the received message. In addition, the control unit 11 acquires the node ID of the node that has received the message from the storage unit 12. Further, the control unit 11 acquires a node ID closest to the content ID acquired from the message among the node IDs registered in the routing table. Next, the control unit 11 determines which of the node ID of the node that has received the message and the node ID acquired from the routing table is the node ID closer to the content ID acquired from the message. . At this time, if the control unit 11 determines that the node ID acquired from the routing table is closer to the content ID, the control unit 11 determines that the node that has received the message is not the root node (step S62: NO). In this case, the control unit 11 transfers the received message to another node based on the routing table (step S63). When the control unit 11 finishes the process of step S63, the control unit 11 ends the message reception process.

  On the other hand, if the control unit 11 determines that the node ID of the node that has received the message is closer to the content ID, the control unit 11 determines that the node that has received the message is the root node (step S62: YES). . In this case, the control unit 11 determines whether or not the received message is a publish message (step S64). At this time, if the control unit 11 determines that the message is a publish message (step S64: YES), the control unit 11 stores the index information included in the publish message in the index information cache (step S65). The control part 11 complete | finishes a message reception process, after finishing the process of step S65.

  In step S64, when the control unit 11 determines that the received message is not a publish message (step S64: NO), the control unit 11 determines whether the received message is a complex content inquiry message (step S66). . At this time, if the control unit 11 determines that the message is a composite content inquiry message (step S66: YES), the control unit 11 acquires a content ID included in the composite content inquiry message. Then, the control unit 11 determines whether or not the composite content index information corresponding to the acquired content ID is stored in the composite content index cache (step S67).

  At this time, when it is determined that the composite content index information is stored (step S67: YES), the control unit 11 acquires the composite content index information corresponding to the acquired content ID from the composite content index cache. . Then, the control unit 11 transmits an inquiry response message including the acquired composite content index information to the node that has transmitted the composite content inquiry message (step S68). On the other hand, when the control 11 determines that the composite content index information is not stored (step S67: NO), the control response message indicating that there is no composite content is sent to the node that sent the composite content inquiry message. Transmit (step S69). When finishing the process of step S68 or S69, the control unit 11 ends the message reception process.

  In step S66, when it is determined that the received message is not a complex content inquiry message (step S66: NO), the control unit 11 determines whether the received message is a usage notification message (step S70). ). At this time, if the control unit 11 determines that the message is a usage notification message (step S70: YES), the control unit 11 stores the composite content index information included in the usage notification message in the composite content index information cache (step S71). . The control part 11 complete | finishes a message reception process, after complete | finishing the process of step S71.

  In step S70, when it is determined that the received message is not a usage notification message (step S70: NO), the control unit 11 executes processing according to the received message and ends the message reception processing.

  In the above embodiment, the peer-to-peer network using DHT is applied to the overlay network, but the present invention is not limited to this. For example, another peer-to-peer system or a system using an overlay network may be applied. As an overlay network that does not use DHT, for example, there is a hybrid peer-to-peer network system.

  In the above embodiment, the node that stores the composite content index information is defined as the root node of the content that constitutes the composite content. However, for example, a predetermined node may store the composite content index information. As the predetermined node, for example, there is a node that is steadily connected to the network NW.

  Also, some or all of the base terminals Tn-l may be node devices in the present invention. In this case, it is assumed that the user operates the base terminal Tn-l and designates the content for which a complex content inquiry is to be made. Then, the base terminal Tn-1 as the node device transmits a composite content inquiry message including the content ID of the designated content to the root node of the designated content. Further, the processing content when the base terminal Tn-l receives the usage notification message from the center server SS is the same as in the above-described embodiment. The processing contents when the base terminal Tn-l receives the composite content inquiry message from another node device are the same as those in the above-described embodiment.

  In the above embodiment, the root node acquires the composite content index information by receiving a usage notification message from the center server SS when the composite content is input. However, the root node may acquire the composite content index information from the holding node that acquired the composite content from the overlay network ON. When acquiring the composite content, the node acquires the content ID of the composite content from the content catalog information. Then, the node acquires a meta file of the composite content. The content ID of the content constituting the composite content is described in the composite content metafile. Accordingly, the node that acquired the composite content acquires the content ID of the composite content and the content ID of the content that constitutes the composite content. That is, the node that acquired the composite content acquires the composite content index information. Therefore, the node that acquired the composite content can include the composite content index information in the publish message that is transmitted to the root node of the content constituting the composite content. The root node can acquire the composite content index information by receiving the publish message. Then, the root node stores the composite content index information in the composite content index cache.

DESCRIPTION OF SYMBOLS 1,11 Control part 2,12 Storage part 3,13a, 13b Communication part SS Center server Nn node NW network ON Overlay network S Distribution system

Claims (8)

A distribution system in which a plurality of contents are distributed and stored in a plurality of node devices connected to a network and distributes the plurality of contents,
Any one of the plurality of node devices included in the distribution system,
First identification information for identifying composite content composed of two or more contents from among the plurality of contents, and second identification for identifying content constituting the composite content identified by the first identification information First storage means for storing information in association with each other;
Inquiry information for inquiring about the content, wherein the inquiry information including the second identification information is received from a predetermined device connected to a network;
First determination means for determining whether the first identification information associated with the second identification information received by the reception means is stored in the first storage means;
When it is determined by the first determination unit that the first identification information is stored in the first storage unit, the first identification information determined by the determination unit is transmitted to the predetermined device. A transmission means;
A distribution system comprising: The distribution system is a system in which content is distributed via an overlay network composed of the plurality of node devices.
The distribution system includes:
A first node device that stores any of the plurality of node devices;
A second node device that is one of the plurality of node devices and is determined for each content, and manages the location information indicating the location of the first node device;
With
The second node device is
The first storage means;
The receiving means;
The first determination means;
The transmission means,
The first storage unit stores the second identification information of the content managed by the second node in association with the first identification information of the composite content including the content indicated by the second identification information. The distribution system according to claim 1. Obtaining means for obtaining the second identification information of the content instructed to stop distribution;
Second transmission means for transmitting the inquiry information including the second identification information acquired by the acquisition means to any one of the plurality of node devices;
Second receiving means for receiving the first identification information from a node device to which the inquiry information is transmitted;
Stop means for stopping delivery of the composite content identified by the first identification information received by the second receiving means;
The distribution system according to claim 1, further comprising an information processing apparatus including the information processing apparatus. The first storage means includes third identification information for identifying second complex content configured by a plurality of the complex contents, and first identification information for identifying the complex contents constituting the second complex content. Memorize it,
The receiving means receives second inquiry information including the second identification information;
The first determination unit determines whether the third identification information associated with the second identification information received by the reception unit is stored in the first storage unit;
4. The distribution system according to claim 1, wherein the transmission unit transmits the third identification information determined by the first determination unit. 5. The first node device is
Second acquisition means for acquiring any of the composite contents from the overlay network;
Second storage means for storing the composite content acquired by the second acquisition means;
The first node that stores the content constituting the composite content, the first identification information of the composite content stored in the second storage means, and the second identification information of the content constituting the composite content. Third transmission means for transmitting to the second node device managing the location information of the device;
With
The second node device is
A third receiving means for receiving the first identification information and the second identification information transmitted from the first node device;
The distribution system according to claim 2, wherein the first storage unit stores the first identification information and the second identification information received by the third reception unit in association with each other. A plurality of node devices connected to a network, wherein a plurality of contents are distributed and stored, and the node device is one of the plurality of node devices included in a distribution system that distributes the plurality of contents;
First identification information for identifying composite content composed of two or more contents from among the plurality of contents, and second identification for identifying content constituting the composite content identified by the first identification information First storage means for storing information in association with each other;
Inquiry information for inquiring about the content, wherein the inquiry information including the second identification information is received from a predetermined device connected to a network;
First determination means for determining whether the first identification information associated with the second identification information received by the reception means is stored in the first storage means;
When it is determined by the first determination unit that the first identification information is stored in the first storage unit, the first identification information determined by the determination unit is transmitted to the predetermined device. A transmission means;
A node device comprising: An information processing method in a distribution system in which a plurality of contents are distributed and stored in a plurality of node devices connected to a network, and the plurality of contents are distributed,
Any one of the plurality of node devices included in the distribution system,
Inquiry information for inquiring about the content, wherein the inquiry information including second identification information for identifying content constituting composite content composed of two or more contents from the plurality of contents is connected to a network Receiving from a predetermined device to be received;
The first identification information associated with the second identification information received in the receiving step, wherein the first identification information for identifying the composite content is the first identification information for identifying the composite content, A determination step of determining whether or not the second identification information for identifying the content constituting the composite content identified by the first identification information is stored in the first storage unit that associates and stores the second identification information;
In the determination step, when it is determined that the first identification information is stored in the first storage unit, a transmission step of transmitting the first identification information determined in the determination step to the predetermined device When,
An information processing method comprising: In a plurality of node devices connected to a network, a plurality of contents are distributed and stored, and a computer included in any one of the plurality of node devices included in a distribution system that distributes the plurality of contents,
Inquiry information for inquiring about the content, wherein the inquiry information including second identification information for identifying content constituting composite content composed of two or more contents from the plurality of contents is connected to a network Receiving from a predetermined device to be received;
The first identification information associated with the second identification information received in the receiving step, wherein the first identification information for identifying the composite content is the first identification information for identifying the composite content, A determination step of determining whether or not the second identification information for identifying the content constituting the composite content identified by the first identification information is stored in the first storage unit that associates and stores the second identification information;
In the determination step, when it is determined that the first identification information is stored in the first storage unit, a transmission step of transmitting the first identification information determined in the determination step to the predetermined device When,
A program characterized by having executed.

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