JP2007034545A - Management device, node device, content information management processing program, confirmation request processing program, information distribution system and information distribution method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an information distribution method for efficiently controlling the reduction of a replica arranged in a system. <P>SOLUTION: A management device which is used for an information distribution system equipped with a plurality of nodes connected to each other constructing an overlay network, and configured to manage all content information is provided with a management information recording means which records management information for managing content information to be shared in the information distribution system, a confirmation request receiving means for receiving a confirmation request to confirm whether or not the content information recorded in the node devices is information to be shared by the information distribution system from the node devices, a confirmation request processing means for processing the confirmation request received by the conformation request receiving means based on the management information recorded in the management information recording means and a confirmation request processing result transmitting means for transmitting the processing result by the confirmation request processing means to the node device which has transmitted the confirmation request. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a technical field such as an information distribution system including a plurality of node devices connected to each other by constructing an overlay network.

  In recent years, so-called content distribution in which a terminal device accesses a server or the like storing the above content via a network such as the Internet, and distributes the content desired to be viewed on the terminal device to the terminal device. Research and development on the distribution system that performs is active.

  As one of the distribution systems, a distribution system in which the content is directly exchanged between terminal devices belonging to the network (in other words, a distribution system that distributes and shares each content among a plurality of terminal devices) There is a P2P (Pear to Pear) type distribution system. This P2P type distribution system is attracting attention as a technique for solving concentration of access to servers and high management costs, which are disadvantages of a conventional client / server model.

  Also, in this field of research, as one of the P2P type distribution systems, a plurality of replicas (hereinafter simply referred to as replicas) are prepared for one content to be shared and participate in the system. A “distributed storage system”, which is a technique for improving fault tolerance and access dispersibility by distributing and arranging (distributed storage) in a plurality of node devices, has been proposed.

  Here, as a proposal regarding the creation and arrangement of the replica in the related art, for example, there is one described in Patent Document 1 below.

According to Patent Document 1, referring to the total size (total information amount) and the number of replicas existing in each terminal device connected in a service group on the network, the network in the service group A method for creating and arranging replicas in a balanced manner as a whole has been proposed.
JP 2003-99337 A

  By the way, in such a distributed storage system, when such autonomous replica placement is realized, it is desired to completely delete specific contents from the system (in other words, node devices participating in the system) or 1 There is a request from, for example, the system operator or the content author, who wants to delete only one, but it is difficult to perform such content deletion control efficiently in conventional systems. It was. One reason for this is that in a P2P type distribution system, each node device can freely participate in or leave the system (for example, power ON / OFF), and therefore a time lag occurs in the participation and withdrawal. Is mentioned.

  Therefore, the present invention has been made in view of the above problems, and an example of the purpose thereof is a management apparatus, a node apparatus, and a content capable of performing deletion control of content arranged in the system more efficiently. An object is to provide an information management processing program, a confirmation request processing program, an information distribution system, and an information distribution method.

  In order to solve the above-mentioned problem, the invention described in claim 1 is a management device that manages all content information used in an information distribution system including a plurality of node devices connected to each other by constructing an overlay network. Management information recording means for recording management information for managing the content information to be shared in the information distribution system, and information in which the content information recorded in the node device is shared in the information distribution system Confirmation request for confirming whether or not the confirmation request is received from the node device, and for the confirmation request received by the confirmation request receiving means, the management information recorded in the management information recording means Confirmation request processing means for processing based on the confirmation request processing means for the node device that has transmitted the confirmation request. Characterized in that it and a confirmation request processing result transmitting means for transmitting a processing result by.

  According to this invention, the management device records management information for managing the content information to be shared, and the content information recorded in the node device is information shared in the information distribution system. A confirmation request for confirming whether the confirmation request is received from the node device, the confirmation request is processed based on the recorded management information, and the processing result is transmitted to the node device that has transmitted the confirmation request. Therefore, the node device can appropriately confirm whether the content information recorded by the node device is information shared in the information distribution system by a confirmation request. According to the confirmation, it can be determined whether or not to delete the content information (that is, the replica). Therefore, it becomes possible to perform deletion control of replicas arranged in the system more efficiently.

  According to a second aspect of the present invention, in the management device according to the first aspect, the confirmation request receiving means includes confirmation including content recording information relating to content information recorded by a node device that has transmitted the confirmation request. Receiving the request, the confirmation request processing means determines whether or not the content recording information included in the confirmation request is recorded in the management information of the management information recording means, and the confirmation request processing result transmitting means is The determination result by the confirmation request processing means is transmitted to the node device that has transmitted the confirmation request.

  According to the present invention, the node device can appropriately confirm whether or not the content information recorded by itself is recorded in the management information, and deletes the content information according to the confirmation. Or not. Therefore, it becomes possible to perform deletion control of replicas arranged in the system more efficiently.

  According to a third aspect of the present invention, in the management device according to the first aspect, the confirmation request receiving means includes a confirmation including content recording information relating to content information recorded by the node device that has transmitted the confirmation request. Receiving the request, the confirmation request processing means determines whether or not the content recording information included in the confirmation request is recorded in the management information of the management information recording means, and the confirmation request processing result transmitting means is If the content recording information included in the confirmation request is not recorded in the management information of the management information recording unit as a result of the determination by the confirmation request processing unit, the content information is deleted from the node device. It is characterized by transmitting a deletion request for requesting this.

  According to the present invention, the node device appropriately confirms whether or not the content information recorded by itself is recorded in the management information by the confirmation request, and if the content information is not recorded in the management information, Since the information is deleted from the node device, it is possible to perform the deletion control of the replica arranged in the system more efficiently.

  According to a fourth aspect of the present invention, in the management device according to the first aspect, the confirmation request receiving means includes a confirmation including content recording information relating to content information recorded by a node device that has transmitted the confirmation request. Receiving the request, the confirmation request processing means determines whether or not the content recording information included in the confirmation request is recorded in the management information of the management information recording means, and the confirmation request processing result transmitting means is When the content recording information included in the confirmation request is recorded in the management information of the management information recording unit as a result of the determination by the confirmation request processing unit, the content information is held in the node device. It is characterized by transmitting a holding request for requesting this.

  According to the present invention, the node device appropriately confirms whether or not the content information recorded by itself is recorded in the management information by a confirmation request. Then, the management device transmits the content information managed by the management device and managed by the node device to the node device as a retention request message. Since the node device deletes the content information not included in the holding request message from the node device, it is possible to more efficiently perform the deletion control of the replica arranged in the system.

  Further, the invention according to claim 5 is the management device according to claim 1, wherein the confirmation request processing means reads management information recorded in the management information recording means, and the confirmation request processing result transmission means. Transmits the management information read by the confirmation request processing means to the node device that has transmitted the confirmation request.

  According to the present invention, since the node device can acquire the management information from the management device, the node device can determine whether to delete the content information according to the management information. Therefore, it becomes possible to perform deletion control of replicas arranged in the system more efficiently. In addition, the processing load on the management apparatus can be reduced.

  The invention according to claim 6 is the management recorded in the management information recording means in the management device according to claim 1, when the content information to be shared in the information distribution system is changed. Update means for updating information, and when the management information recorded in the management information recording means is updated by the update means, the updated management information is sent to the node devices participating in the information distribution system. Management information transmitting means for transmitting.

  According to the present invention, when the management apparatus updates the management information by changing the content information to be shared in the information distribution system, the management apparatus applies to the node apparatuses participating in the information distribution system, Since the updated management information is configured to be transmitted, the node device can always determine whether to delete the content information according to the latest management information. Therefore, it becomes possible to perform deletion control of replicas arranged in the system more efficiently.

  The invention according to claim 7 is a node device included in an information distribution system including a plurality of node devices connected to each other by constructing an overlay network, and content information used in the information distribution system is stored in the node device. A confirmation request for transmitting a confirmation request for confirming whether or not the content information recorded in the recording means is managed to a recording means for recording and a management apparatus for managing all the content information used in the information distribution system A transmission means; a confirmation request processing result receiving means for receiving a confirmation request processing result for the confirmation request by the management apparatus from the management apparatus; and a processing means for performing processing based on the confirmation request processing result. And

  According to this invention, the node device transmits a confirmation request for confirming whether or not the recorded content information is managed to a management device that manages all the content information used in the information distribution system, Since the confirmation request processing result for the confirmation request is received from the management device and the processing based on the confirmation request processing result is performed, the node device appropriately stores the content information recorded by itself in the management device. It is possible to confirm whether or not it is managed by a confirmation request, and it is possible to determine whether or not to delete content information (that is, a replica) according to the confirmation. Therefore, it becomes possible to perform deletion control of replicas arranged in the system more efficiently.

  The invention according to claim 8 is the node device according to claim 7, wherein the confirmation request transmission unit transmits a confirmation request including content recording information related to the content information recorded in the recording unit, The confirmation request processing result receiving unit receives a determination result for determining whether or not the content recording information included in the confirmation request is managed by the management device, and the processing unit is configured to receive the determination result according to the received determination result. When it is determined that the content information recorded by the recording unit is not managed by the management device, the content information not managed by the recording unit is deleted.

  According to the present invention, the node device can appropriately confirm whether or not the content information recorded by the node device is managed in the management device by the confirmation request. Since the content information is deleted from the node device, it is possible to more efficiently perform deletion control of replicas arranged in the system.

  The invention according to claim 9 is the node device according to claim 7, wherein the confirmation request transmission unit transmits a confirmation request including content recording information related to the content information recorded in the recording unit, The confirmation request processing result receiving means determines whether the content information recorded by the recording means is based on a determination result of whether or not the content recording information included in the confirmation request is managed by the management device. When it is determined that the information is not managed by a management device, a deletion request for deleting the content information not managed from the recording unit is received, and the processing unit records the content information corresponding to the deletion request. It is characterized by deleting from the means.

  According to the present invention, the node device can appropriately confirm whether or not the content information recorded by the node device is managed in the management device by the confirmation request. Since the content information is deleted from the node device, it is possible to more efficiently perform deletion control of replicas arranged in the system.

  The invention according to claim 10 is the node device according to claim 7, wherein the confirmation request transmitting unit transmits a confirmation request including content recording information related to the content information recorded in the recording unit, The confirmation request processing result receiving means determines whether the content information recorded by the recording means is based on a determination result of whether or not the content recording information included in the confirmation request is managed by the management device. When it is determined that the content is managed by the management device, the retention request for retaining the content information managed from the management device is received, and the processing means records the content information corresponding to the retention request. The content information that is not stored in the storage unit and is not instructed to hold is deleted from the recording unit.

  According to the present invention, the node device appropriately confirms whether or not the content information recorded by itself is recorded in the management information by a confirmation request. Then, the management device transmits the content information managed by the management device and managed by the node device to the node device as a retention request message. Since the node device deletes the content information not included in the holding request message from the node device, it is possible to more efficiently perform the deletion control of the replica arranged in the system.

  The invention according to claim 11 is the node device according to claim 7, wherein the confirmation request processing result receiving means receives management information indicating content information managed by the management device, and The means compares the management information with the content information recorded by the recording means, determines whether or not the management information is recorded by the recording means, and is not managed If it is determined, the content information that is not managed is deleted from the recording means.

  According to the present invention, the node device can appropriately check whether the content information recorded by the node device is managed by the management information based on the received management information. Deletes the content information from the node device, so that the deletion control of the replicas arranged in the system can be performed more efficiently. In addition, the processing load on the management apparatus can be reduced.

  The invention according to claim 12 is the node device according to claim 7, further comprising management information recording means for recording management information for managing all content information used in the information distribution system, wherein the confirmation request The transmission means transmits information requesting the management information recorded by the management apparatus as the confirmation request, and the confirmation request processing result reception means receives management information indicating content information managed by the management apparatus. The processing means updates the management information recorded in the management information recording means to the received management information, compares the updated management information with the content information recorded in the recording means, and It is determined whether or not the information is managed by the management information recorded by the recording means. If it is determined that the information is not managed, the information is managed from the recording means. And deletes the have the content information.

  According to the present invention, the node device can appropriately check whether the content information recorded by the node device is managed by the management information based on the updated management information. Deletes the content information from the node device, so that the deletion control of the replicas arranged in the system can be performed more efficiently.

  Further, the invention according to claim 13 is the node device according to any one of claims 7 to 12, wherein the confirmation request transmitting means is configured such that when the node device participates in the information distribution system, A confirmation request is transmitted to the management apparatus.

  According to the present invention, when the node device participates in the system, the confirmation request is transmitted to the management device. Therefore, it is possible to perform the deletion control of the replica arranged in the system more efficiently without omission. Become.

  The invention according to claim 14 is the node device according to any one of claims 7 to 13, further comprising content information requesting means for requesting content information used in the information distribution system, The confirmation request transmitting means transmits the confirmation request to the management apparatus when requesting the content information used in the information distribution system.

  According to the present invention, when the content information used in the information distribution system is requested, the confirmation request is transmitted to the management apparatus, so that the deletion control of the replica arranged in the system is not leaked, and the efficiency is improved. It can be done well.

  The invention described in claim 15 is the node device according to any one of claims 7 to 14, further comprising determination means for determining whether or not a predetermined time has elapsed, wherein the confirmation request transmitting means comprises: The confirmation request is transmitted to the management device every time a predetermined time elapses.

  According to the present invention, since the confirmation request is transmitted to the management device every time a predetermined time elapses, it is possible to perform the deletion control of the replicas arranged in the system more efficiently without omission.

  The invention described in claim 16 is the node device according to any one of claims 7 to 14, wherein the content information requesting means for requesting content information used in the information distribution system, and the request In order to record the recorded content information in the recording means, it is necessary to delete whether or not other content information already recorded in the recording means needs to be deleted; A recording presence / absence determining means for determining whether or not the other content information is recorded in another node device when the determining means determines that the other content information needs to be deleted; And the confirmation request transmitting means determines that the confirmation request transmitting means determines that the other content information is not recorded in another node device when the recording presence / absence determining means is not recorded. The request and transmits to the management apparatus.

  According to the present invention, if the other content information already recorded in the recording unit is not recorded in another node device, whether or not the confirmation request is transmitted to the management device and managed. Therefore, for example, it is possible to control so that only one piece of content information to be managed remains in the system.

  The invention according to claim 17 is the node device according to any one of claims 7 to 14, wherein the content information requesting means for requesting content information used in the information distribution system, and the request In order to record the recorded content information in the recording means, it is necessary to delete whether or not other content information already recorded in the recording means needs to be deleted; When it is determined by the determining means that the other content information needs to be deleted, a recording presence / absence determining means for determining whether or not the other content information is recorded in another node device; and the recording When it is determined by the presence / absence determining unit that the other content information is recorded in another node device, the other content information is deleted from the recording unit. A deleting unit that, and further comprising a.

  According to the present invention, when the other content information already recorded in the recording unit is recorded in another node device, the other content information is deleted from the recording unit. Therefore, it is possible to perform deletion control of replicas arranged in the system more efficiently.

  The content information management processing program according to claim 18 is a computer that manages all content information used in an information distribution system including a plurality of node devices connected to each other by constructing an overlay network. Management information recording means for recording management information for managing the content information to be shared in the distribution system, whether or not the content information recorded in the node device is information shared in the information distribution system Confirmation request processing for confirming the confirmation request received from the node device, confirmation request processing for processing the confirmation request received by the confirmation request receiving unit based on the management information recorded in the management information recording unit And the confirmation request to the node device that has transmitted the confirmation request. It is made to function as a confirmation request processing result transmitting means for transmitting a processing result by the processing means, characterized in.

  According to a nineteenth aspect of the present invention, there is provided a confirmation request processing program comprising: a computer included in an information distribution system including a plurality of node devices connected to each other by constructing an overlay network; content information used in the information distribution system A confirmation request for confirming whether or not the content information recorded in the recording unit is managed is transmitted to the management unit that manages the recording unit for recording and all the content information used in the information distribution system. A confirmation request transmitting means; a confirmation request processing result receiving means for receiving a confirmation request processing result for the confirmation request by the management apparatus from the management apparatus; and a processing means for performing a process based on the confirmation request processing result. And

  The invention according to claim 20 is an information distribution system comprising a plurality of node devices connected to each other by constructing an overlay network, and management information for managing the content information to be shared in the information distribution system Management information recording means for recording and a confirmation request reception for receiving from the node device a confirmation request for confirming whether the content information recorded in the node device is information shared in the information distribution system A confirmation request processing means for processing the confirmation request received by the confirmation request receiving means based on the management information recorded in the management information recording means, and a node device that has transmitted the confirmation request. And a confirmation request processing result transmission means for transmitting a processing result by the confirmation request processing means. Whether the content information recorded in the recording means is managed by the recording means for recording the content information used in the information distribution system and the management apparatus for managing all the content information used in the information distribution system. A confirmation request transmitting means for transmitting a confirmation request to confirm to the management apparatus, a confirmation request processing result receiving means for receiving a confirmation request processing result for the confirmation request by the management apparatus from the management apparatus, and the confirmation request processing And a node device including a processing unit that performs processing based on the result.

  The invention according to claim 21 is an information distribution system comprising a plurality of node devices connected to each other by constructing an overlay network, and management information for managing the content information to be shared in the information distribution system Management information recording step for recording information, and reception of a confirmation request for receiving, from the node device, a confirmation request for confirming whether the content information recorded in the node device is information shared in the information distribution system A confirmation request processing step for processing the confirmation request received in the confirmation request receiving step based on management information recorded in the management information record, and the node device that has transmitted the confirmation request. A confirmation request processing result transmission step for transmitting a processing result in the confirmation request processing step. A management method in the management apparatus, a recording step for recording content information used in the information distribution system, and a confirmation request for confirming whether the content information recorded in the recording step is managed in the management method A confirmation request transmitting step, a confirmation request processing result receiving step for receiving a confirmation request processing result for the confirmation request in the management method from the management step, and a processing step for performing a process based on the confirmation request processing result. And a node device processing method.

  According to the present invention, management information for managing the content information to be shared is recorded, and whether or not the content information recorded in the node device is information shared in the information distribution system. A confirmation request to be confirmed is received from the node device, the confirmation request is processed based on the recorded management information, and the processing result is transmitted to the node device that has transmitted the confirmation request. Therefore, the node device can appropriately confirm whether or not the content information recorded by the node device is information shared in the information distribution system by the confirmation request, and the content according to the confirmation. It can be determined whether to delete information (ie, replica). Therefore, it becomes possible to perform deletion control of replicas arranged in the system more efficiently.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, the best embodiment of the invention will be described based on the drawings. The embodiment described below is an embodiment when the present invention is applied to a content distribution system.

  First, a configuration of a content distribution system according to the present embodiment and an algorithm using a distributed hash table (hereinafter referred to as DHT (Distributed Hash Table)) will be described. Next, an operation of creating a replica that is a copy of the content for the node device that has made the content distribution request will be described.

  Thereafter, an embodiment of the present invention will be described.

[1. Content distribution system configuration]
First, with reference to FIG. 1, a schematic configuration and the like of a content distribution system as an information distribution system will be described.

  FIG. 1 is a diagram illustrating an example of a connection mode of each node device in the content distribution system according to the present embodiment.

  As shown in the lower frame 101 of FIG. 1, IX (Internet eXchange) 3, ISP (Internet Service Provider) 4, DSL (Digital Subscriber Line) line operator (device) 5, FTTH (Fiber To The Home) line A network (real-world network) 8 such as the Internet is constructed by an operator (device) 6 and a communication line (for example, a telephone line or an optical cable) 7.

  The content distribution system S is configured to include a plurality of node devices 1a, 1b, 1c,... 1x, 1y, 1z,. Network system. Each node device 1a, 1b, 1c... 1x, 1y, 1z... Is assigned a unique manufacturing number and IP (Internet Protocol) address as information (node information) indicating the node device. Note that the serial number and IP address are not duplicated among the plurality of node devices 1. In the following description, when any one of the node devices 1a, 1b, 1c... 1x, 1y, 1z.

[1-1. Outline of DHT]
Hereinafter, an algorithm using a distributed hash table (hereinafter referred to as DHT (Distributed Hash Table)) according to the present embodiment will be described.

  In the content distribution system S described above, when the node device 1 accesses information held by another node device 1, the node device 1 must know the IP address as node information of the node device 1 having the information.

  For example, in a system that shares content with each other, each node device 1 participating in the system knows the IP addresses of all the node devices 1 participating in the system and an index of information held by each device. Although it is a simple method, when the number of devices becomes as large as tens of thousands, it is not realistic to remember the IP addresses of all the node devices 1. Further, when the power of any node device 1 is turned on or off, the IP address of the arbitrary node device stored in each node device 1 is frequently updated, which makes operation difficult.

  Therefore, in one node device 1, only the minimum necessary IP address of the node device 1 among all the node devices 1 participating in the system is memorized (stored), and the IP address is known. For node devices 1 that are not (not stored), a system has been devised in which information is transferred between each node device 1 and delivered.

  As an example of such a system, an overlay network 9 as shown in the upper frame 100 of FIG. 1 is constructed by an algorithm using DHT. That is, the overlay network 9 means a network that forms a virtual link formed using the existing network 8.

  In the present embodiment, an overlay network 9 constructed by an algorithm using DHT is assumed, and a node device 1 arranged on the overlay network 9 participates in the content distribution system S (in other words, the overlay network 9 The node device 1 participating in the network. Participation in the content distribution system S is performed when a node device that has not yet participated sends a participation request to an arbitrary node device 1 that has already participated.

  The node ID of each node device 1 participating in the content distribution system S is given a unique number for each node device. This number needs to have a number of bits that can accommodate the maximum number of nodes that can be operated. For example, if the number is 128 bits, 2 ^ 128≈340 * 10 ^ 36 node devices can be operated.

  More specifically, the node ID of each node device 1 is obtained by hashing a unique value for each node device such as the IP address or serial number of each node device using a common hash function (hash algorithm). It is a hash value and is distributed and distributed in one ID space without deviation. Thus, the node ID obtained (hashed) by the common hash function has a very low probability of having the same value if the IP address or the manufacturing number is different. Since the hash function is publicly known, detailed description thereof is omitted. In the present embodiment, a node ID is a value obtained by hashing an IP address (global IP address) with a common hash function.

  Further, content (for example, movies, music, etc.) data (content information) to be shared in the content distribution system S is distributed (saved) to the plurality of node devices 1 participating in the content distribution system S. However, a unique number (hereinafter referred to as a content ID) is assigned to each content data. The content data distributed and stored in the plurality of node devices 1 in this way is a replica in which the master (large source) content data is duplicated.

  The content ID has the same length as the node ID (for example, 128 bits). For example, when a keyword such as a content name (content title) or content outline information (synopsis) obtains the node ID. And the node ID that is hashed by a common hash function (that is, placed in the same ID space as the hash value of the IP address of the node device 1) and closest to the hash value (for example, the higher-order digits match more). The node device 1 having the content stores a replica of the content data or manages its location information. As a result, the content data can be distributed on the content distribution system S without any bias. Note that even if the content data is different, it is assumed that the same keyword (for example, the name of the content) is used. In this case, the hash value is the same to avoid the same hash value. The keyword may be, for example, a combination of content name and copyright information (for example, performer name, director name, original author name, singer name, composer name, or songwriter name).

  As described above, since the node ID and the content ID assigned to each node device 1 and each content data are generated by a common hash function, as shown in FIG. Can be thought of as being scattered and present. This figure shows a node ID and content ID assigned with 32 bits. In the figure, a black dot indicates a node ID, a black diamond indicates a content ID, and the ID increases counterclockwise.

  Next, which content data is managed by which node device 1 is determined under a certain rule. In the present embodiment, the rule is that “a node device that manages content data having a certain content ID is a node device 1 having a node ID close to that content ID”. Here, the definition of “close” does not exceed the content ID, and the difference between the content ID and the node ID is the smallest. In practice, each content data is managed by each node device 1. It is only necessary to be consistent when allocating. In the example shown in the figure, based on this definition, the content data having the content IDa is managed by the node device having the node IDa, and the content data having the content IDb is managed by the node device having the node IDb. The content data having IDc is managed by the node device 1 having node IDc. A certain node device may manage a plurality of different content data.

  Here, “management” does not mean that the content data is stored / held, but “which node device 1 stores the content data, that is, the location of the content data. I know. " That is, in FIG. 2, the node device 1 having the node IDa knows in which node device 1 the content data having the content IDa is stored, and the node device 1 having the node IDb and the node having the node IDc Similarly, the device 1 knows in which node device 1 the content data having the content IDb and the content data having the content IDc are stored. Thus, a node device that knows in which node device 1 certain content data is stored is called a root node of the content data. That is, the node device 1 having the node IDa is the root node of the content data having the content IDa, and the node device 1 having the node IDb is the root node of the content data having the content IDb and has the node IDc. The node device 1 is a root node of content data having a content IDc.

  In addition, the content distribution system S according to the present embodiment, in addition to each root node that knows the location of each content data (for example, the IP address of the node device 1 that stores the content data). An administrator terminal 2 that holds (records) a management data list as management information for managing content data to be shared in the entire distribution system S is provided. In the management data list, unique information (for example, content title, content ID, or sequence number) for specifying the managed content data is registered (description). Then, the unique information of the content data that should no longer be shared in the content distribution system S is deleted from the management data list. Thereby, each node device 1 can confirm by inquiring to the administrator terminal 2 whether or not the content data stored therein should not be shared (should be deleted).

[1-2. Create routing table]
Here, an example of a method for creating a routing table used in DHT will be described with reference to FIG.

  FIG. 3 is a diagram illustrating an example of how a routing table is created by DHT.

  First, as shown in FIG. 3A, the ID space is divided into several areas. Actually, about 16 divisions are often used, but in order to simplify the explanation, here, the division is made into four divisions, and the ID is represented by an 8-digit quaternary number with a bit length of 16 bits. An example in which the node ID of the node device 1N is “10230210” and the routing table of the node device 1N is created will be described.

(Level 1 routing)
First, assuming that the ID space is divided into four areas, each area is expressed in quaternary numbers. The four areas “0XXXXXXX”, “1XXXXXXX”, “2XXXXXXX”, “3XXXXXXX” (X is a natural number from 0 to 3, below) The same). Since the node ID of the node device 1N itself is “10230210”, the node device 1N exists in the area “1XXXXXXX” in the lower left in the figure. Then, the node device 1N selects the node device 1 that exists in an area other than the area where the node device 1 exists (that is, the “1XXXXXXX” area) (for example, when the node device 1N joins the system S, it already participates). The node device 1 is selected from the node devices 1 registered in the DHT obtained from the node device 1 and the routing of level 2 to 8 is the same), and the IP address of the node ID is stored in the level 1 table. FIG. 4A shows an example of a level 1 table. Since the second column indicates the node device 1N itself, it is not necessary to store the IP address.

(Level 2 routing)
Next, as shown in FIG. 3B, among the areas divided into four by the above routing, the area where the user exists is further divided into four, and four areas “10XXXXXX”, “11XXXXXX”, “12XXXXXX”, “13XXXXXX” ". Then, similarly to the above, the node device 1 that exists in an area other than the area in which it exists is selected, and the IP address of the node ID is stored in the level 2 table. FIG. 4B is an example of a level 2 table. Since the first column indicates the node device 1N itself, it is not necessary to store the IP address.

(Level 3 routing)
Further, as shown in FIG. 3C, among the areas divided into four by the above routing, the area where the user exists is further divided into four, and further four areas “100XXXXX”, “101XXXXX”, “102XXXXX”, “103XXXXX” And divide. Then, similarly to the above, the node device 1 existing in an area other than the area where the user exists is selected, and the IP address of the node ID is stored in the level 1 table. FIG. 4C is an example of a level 3 table. Since the third column shows the node device 1N itself, it is not necessary to store the IP address, and the second column and the fourth column are blank because there is no node device in the area. In this way, all the 16-bit IDs can be covered by creating the routing table as shown in FIG. As the level goes up, white space becomes more noticeable in the table.

  All the node devices 1 each create and own the routing table created according to the method described above.

[1-3. Content data search method]
Next, an example of a search method for the node device 1 (hereinafter referred to as “content holding node”) that is a storage source of content data in the present embodiment will be described with reference to FIG.

  FIG. 5 is a diagram illustrating an example of how a content holding node is searched by DHT.

  Here, a procedure when the node device 1a having the node ID “12003030” (hereinafter referred to as “request node”) searches for a content holding node holding content data having the content ID “31330012” will be described. As shown in the figure, the node IDs of the content holding nodes holding the content ID “31330012” are “00213000” and “02223230”.

  In FIG. 5, the path from the request node to the node device 1e (that is, the root node) that manages the content data having the content ID “31330012” is represented by a solid line arrow.

  First, the request node transmits content inquiry information (hereinafter, “content inquiry information” is referred to as “query”) to a node device having a node ID in the same area as the content ID “31330012”.

  First, the request node refers to the level 1 table of the routing table held by itself, and transmits a query to the node device having the node ID in the same area as the content ID “31330012”. That is, since the content ID “31330012” is an area of “3XXXXXXX”, the node device 1 belonging to the area of “3XXXXXXX” knows the IP address (that is, the IP address is stored in the routing table held by itself). A query is transmitted to the node device 1b (which stores the address).

  According to the example shown in FIG. 5, since the IP address of the node device 1b whose node ID is “30100000” is stored in the routing table of the request node, the request node is the node device whose node ID is “30100000”. A query is transmitted to 1b.

  Next, the node device 1b that has received the query refers to the index held by the node device 1b itself, and checks whether there is a holding node list corresponding to the content ID “31330012”. That is, the presence or absence of node information included in the holding node list is confirmed.

  FIG. 21 shows the relationship between the content ID and the holding node list in this description. FIG. 21A shows four types of content IDs. FIG. 21B shows that the content data having the uppermost content ID “cd3efb6589bb091decdf” in FIG. 21A is held (stored) in the seven node devices represented by IP addresses. . The list indicating the location (IP address) of the node device in FIG. 21B is referred to as a holding node list. The holding node list is created for each content ID. The content holding node list with the content ID “67895dfce434efb098779” in FIG. 21A is shown in FIG. 21C, and there are two node devices holding the content. Further, the content holding node list having the content ID “71253647fdef3f3f2f2d67” in FIG. 21A is shown in FIG. 21D, and the number of node devices holding the content is eight. Furthermore, the holding node list of the content whose content ID is “84defcba3234a13367890” in FIG. 21A is shown in FIG. 21E, and there are four node devices holding the content. These holding node lists are stored in predetermined node devices.

  If the node device 1b does not have a holding node list, the level 2 table of the routing table held by the node device 1b itself is referred to. Among the node devices 1 belonging to the “31XXXXXX” area, The query is transferred to the node device 1c (node ID “31012001”) that knows the IP address.

  In this way, the query is transferred to the upstream node device, that is, the node device interposed between itself and the root node, and approaches the root node in the manner of adapting the digit of the content ID in order from the top.

  Then, the node device 1c that has received the query from the node device 1b refers to the index held by the node device 1c itself, and checks whether there is a holding node list corresponding to the content ID “31330012”. If there is no node device 1c (refer to the level 3 table of the routing table held by the node device 1c itself), among the node devices 1 belonging to the area of “313XXXXX”, the node device 1d that knows the IP address ( The query is transferred to the node ID “31320100”).

  Then, the node device 1d that has received the query from the node device 1c refers to the index held by the node device 1d itself, and checks whether there is a holding node list corresponding to the content ID “31330012”. If there is no node device 1d, the node device 1d itself knows the IP address among the node devices 1 belonging to the area "313XXXXX" by referring to the level 4 table of the routing table held by the node device 1d itself. The query is transferred to the node ID “31330000”).

  Since the node device 1e is a root node for the content ID “31330012”, the IP address list (holding node list) of the content holding node can be found.

Then, the node information (IP address, etc.) of the content holding node (node device 1f) included in the found holding node list is transmitted to the request node.
Then, the request node that has received the node information of the content holding node (node device 1f) transmits a distribution request for requesting content distribution to the content holding node (node device 1f) as indicated by a broken line arrow in FIG. . Then, the content holding node (node device 1f) that has received the distribution request distributes the content data to the request node as shown by a one-dot chain line in FIG.

[1-4. Node device configuration]
Next, the configuration and function of the node device 1 will be described with reference to FIG.

  FIG. 6 is a diagram illustrating a schematic configuration example of the node device. As shown in FIG. 6, the node device 1 includes a confirmation request transmission unit composed of a CPU having a calculation function, a working RAM (Random Access Memory), a ROM (Read Only Memory) for recording various data and programs, and the like. Confirmation request processing result receiving means, processing means, content information requesting means, content information receiving means, deletion necessity determining means, deleting means, and recording presence / absence determining means, and the content data as the content entity, A recording unit 12 as a recording means composed of an HDD (Hard Disc Drive) or the like for recording (saving) various routing data necessary for the distribution and other necessary programs, and the received content data The buffer memory 13 for temporary storage and the encoded video data included in the content data (Video information) and audio data (audio information), etc., a decoder unit 14 that decodes (data expansion, decoding, etc.), and a video that is subjected to a predetermined drawing process on the decoded video data and the like and output as a video signal A processing unit 15, a display unit 16 such as a CRT (Cathode Ray Tube) or a liquid crystal display that displays video based on the video signal output from the video processing unit 15, and the decoded audio data as an analog audio signal D / A (Digital / Analog) conversion and then amplifying this with an amplifier or the like, outputting the audio signal, the speaker 18 outputting the audio signal output from the audio processing unit 17 as a sound wave, and others via the network 8 Communication unit 20 for controlling communication of information with other node devices 1 and respective users (users) And an input unit (for example, a keyboard, a mouse, or an operation panel) 21 that receives an instruction from the control unit and outputs an instruction signal corresponding to the instruction to the control unit 11, and includes a control unit 11, a recording unit 12, The buffer memory 13, the decoder unit 14, and the communication unit 20 are connected to each other via a bus 22 so as to be able to exchange data.

  Then, when the CPU in the control unit 11 executes various programs recorded in the recording unit 12 or the like, the control unit 11 controls the overall operation of the node device 1 according to the embodiment.

  Detailed processing in the control unit 11 of the node device 1 will be described later.

[1-5. Configuration of administrator terminal]
Next, the configuration and functions of the administrator terminal 2 will be described with reference to FIG.

  FIG. 7 is a diagram illustrating a schematic configuration example of the administrator terminal 2. As shown in FIG. 7, the administrator terminal 2 includes a confirmation request receiving means composed of a CPU having a calculation function, a working RAM (Random Access Memory), a ROM (Read Only Memory) for recording various data and programs, and the like. , A confirmation request processing means, a confirmation request processing result transmission means, an update means, a control unit 35 as a management information transmission means, an HDD (Hard Disc Drive) for recording (storing) the management data list, etc. A configured recording unit 36 as management information recording means, a communication unit 37 for performing communication control of information with other node devices 1 through the network 8, and an instruction from an administrator are received and in response to the instruction An input unit (for example, a keyboard, a mouse, or an operation panel) 38 that outputs the instruction signal to the control unit 35, and a liquid crystal display for displaying various information That a display unit 39, is configured to include a control unit 35, recording unit 36, a communication unit 37, and a display unit 39, are connected so they can exchange data with one another via a bus 40.

  Then, when the CPU in the control unit 35 executes various programs recorded in the recording unit 36 or the like, the control unit 35 performs overall control of the overall operation as the administrator terminal 2 according to the embodiment.

  Detailed processing in the control unit 35 of the administrator terminal 2 will be described later.

[2. Operation of content distribution system]
Next, the operation of the content distribution system S described above will be described separately for the first embodiment and the second embodiment.

[2.1 First Embodiment]
First, the processing operation of the administrator terminal 2 and the processing operation of the node device (hereinafter simply referred to as “node”) 1 constituting the content distribution system S in the first embodiment will be described with reference to the flowcharts shown in FIGS. To do.

  FIG. 8 is a conceptual diagram showing the operation of the content distribution system S in the first embodiment. FIG. 8A shows an initial state, and in the management data list recorded in the administrator terminal 2, the content data “FILE02 (an example of content recording information related to content data unique information and content information)” is shown. (Hereinafter simply referred to as “content”) is not managed (recorded), that is, is not information shared in the content distribution system S, but the content of “FILE02” remains in the node 1b due to deletion failure. Yes. 8B and 8C show processing operations of the node 1b and the administrator terminal 2 until the content of “FILE02” remaining in the node 1b is deleted.

[2.1.1.1] Processing Operation in Administrator Terminal 2 First, processing operation performed in the administrator terminal 2 will be described with reference to FIGS. 9 to 11.

  FIG. 9 is a flowchart showing an overview of the overall operation of the administrator terminal 2. FIG. 10A is a flowchart showing details of the content input process (when the input operation is performed) to the system (content distribution system S) in step S55 shown in FIG. 9, and FIG. It is a flowchart which shows the detail of the content deletion process (when deletion operation is performed) to the system (content delivery system S) in step S55 shown in FIG. FIG. 11A is a flowchart showing the processing of the administrator terminal 2 when the disclosure confirmation request message is received (processing for each message in step S57), and FIG. 11B is the same as FIG. It is a flowchart which shows the detail of the process in step S71 shown.

  First, FIG. 9 showing an outline of the operation of the administrator terminal 2 will be described.

In step S50, when the power of the administrator terminal 2 is turned on (power is turned on) (the node list is not necessary. Delete S51 from the flow).
In step S52, the control unit 35 initializes a management data list (for example, a catalog list or the like) in which unique information of content to be managed in the content distribution system S is described, and proceeds to step S53.

  In step S53, the control unit 35 determines whether or not the administrator terminal 2 is powered off (power is turned off). If the power is not turned off, the process proceeds to step S54 (step S53: NO). On the other hand, when the power is turned off (step S53: YES), the process of the administrator terminal 2 is terminated.

  Next, in step S <b> 54, the control unit 35 determines whether there is content to be newly input to the content distribution system S and whether there is content to be deleted from the content distribution system S. The content input operation and the deletion operation are determined by whether or not a content input request or deletion request input operation has been performed by the system administrator from the input unit 38 of the administrator terminal 2.

  If a content insertion or deletion request operation has been performed (step S54: YES), the process proceeds to step S55. If the content information input or deletion request operation is not performed (step S54: NO), the process proceeds to step S56.

  In step S55, the control unit 35 performs the content input process or the deletion process determined in step S54 for the content distribution system S.

  The content input process will be described in detail with reference to FIG. The content deletion process will be described in detail with reference to FIG. When the content input process or the deletion process in step S55 ends, the process proceeds to step S53.

  Next, in step S <b> 56, the control unit 35 of the administrator terminal 2 determines whether or not the administrator terminal 2 has received a message from the node 1. When the message from the node 1 is received (step S56: YES), the process proceeds to step S57. When the message from the node 1 has not been received (step S56: NO), the process proceeds to step S53.

  Next, in step S57, processing according to the content of the message from node 1 (for example, processing shown in FIG. 11 (a) or (b)) is performed. The content of the message from the node 1 is determined by the control unit 35 of the administrator terminal 2. It progresses to step S53 after completion | finish of a process.

  Next, content input processing to the content distribution system S of the administrator terminal 2 in FIG.

  When the content input process to the content distribution system S is started, in step S61, the control unit 35 stores the specific information of the content C (add) to be input (stored) in the node 1 in the management data list of the administrator terminal 2. And proceed to step S62.

  In step S62, the control unit 35 designates an arbitrary node 1 (that is, a creation destination of a replica of the content C (add)) to store the content C (add) input to the content distribution system S as a random node ID. = Select by generating IDrandom.

  When a message is sent to IDrandom according to the DHT routing, the message arrives at the node device having the node ID closest to IDrandom. As a result, the node device is selected.

  Next, the process proceeds to step S63.

  In step S63, the control unit 35 transmits a replica creation request message to the selected node 1 using the DHT message transfer mechanism.

  Next, content deletion processing from the content distribution system S of the administrator terminal 2 in FIG.

  When the content deletion processing from the content distribution system S is started, the control unit 35 deletes the unique information of the content C (remove) to be deleted from the content distribution system S from the management data list in step S66. Proceed to S67.

  In step S <b> 67, the control unit 35 searches for the node 1 that is all content holding nodes that store the content C (remove) from which the unique information is deleted from the administrator data list. In step S68, the search is waited. For example, [1-3. The content data search method], and the control unit 35 acquires the IP address and the like of the node 1 that is the content holding node from the root node of the content C (remove).

  In step S69, the control unit 35 transmits a content deletion request message for requesting deletion of the content C (remove) based on the IP address to the searched node 1 as each content holding node. To do.

  Next, the process for each message performed in step S57 in FIG. 9 will be described.

  First, the disclosure confirmation request message reception process when the disclosure confirmation request message from the node 1 is received by the control unit 35 of the administrator terminal 2 as the confirmation request receiving means will be described with reference to FIG.

  Here, the disclosure confirmation request message is a confirmation request message for confirming whether or not the content recorded in the node 1 is information shared in the content information distribution system S.

  When it is confirmed that the received message is a disclosure confirmation request message and the disclosure confirmation request message reception process is started, the control unit 35 as a confirmation request processing means performs a management data list for the disclosure confirmation request message. Process based on. Specifically, in step S <b> 71, the control unit 35 performs an operation of comparing the possessed content list attached (included) in the disclosure confirmation request message with the management data list of the administrator terminal 2. Details will be described with reference to FIG. Here, the possessed content list is a list of unique information of content (stored as a replica) owned by the node that transmitted the disclosure confirmation request message. Next, the process proceeds to step S72.

  In step S72, the control unit 35 deletes the content list (determination result) in which unique information of content that is registered in the owned content list of the node 1 but not registered in the management data list is registered. ) Is attached as a confirmation request processing result transmission means to the node 1 that has transmitted the publication confirmation request message.

  Next, a comparison operation between the owned content list and the management data list in step S71 of FIG. 11A performed in FIG. 11B will be described.

  In step S74, the control unit 35 initializes a deleted content list that lists contents to be deleted. At this stage, no content is registered in the deleted content list. Next, the process proceeds to step S75.

  In step S75, the control unit 35 initializes i, which is a variable in the storage area, to “0”, and proceeds to step S76.

  In step S76, when the size of the owned content list is smaller than the variable i, the control unit 35 proceeds to step S77 (step S76: YES). When the size of the retained content list is larger than the variable i (step S76: NO), the comparison is completed.

  In step S77, the control unit 35 determines whether or not the held content information (i) is included in the management data list. That is, the control unit 35, as a confirmation request processing unit, determines whether or not content-specific information included in the disclosure confirmation request message is recorded in the management data list. The owned content information (i) means unique information of the content registered in the i-th content list (for example, “FILE... Shown in FIG. 8A)”. If the owned content information (i) is included in the management data list (step S77: YES), the process proceeds to step S79. On the other hand, if the owned content information (i) is not included in the management data list (step S77: NO), the process proceeds to step S78.

  In step S78, the control unit 35 registers the specific information of the content corresponding to the retained content information (i) in the deleted content list as the processing result judgment result (processing result) by the confirmation request processing means. Then, the process proceeds to step S79.

  In this way, when the unique information of the content included in the owned content list is not recorded in the management data list (that is, should not be shared in the entire content distribution system S), the unique content of the content is included in the deleted content list. As a delete request for requesting that the content registered in the deleted content list be deleted from the node 1, the disclosure confirmation result message to which information is registered and the deleted content list is attached (included) In step S72, it is transmitted to the node 1.

  In step S79, the control unit 35 increments the variable i by one, and proceeds to step S76.

[2.1.1.2] Modified Example of Processing Operation in Administrator Terminal 2 Next, a modified example of the processing operation performed in the administrator terminal 2 will be described with reference to FIG.

  FIG. 22A and FIG. 22B are modified examples of the flowchart showing the processing of the administrator terminal 2 when the disclosure confirmation request message is received (processing for each message in step S57).

  First, in FIG. 22A, it is confirmed that the message received by the control unit 35 of the administrator terminal 2 as the confirmation request receiving means is the disclosure confirmation request message, and the disclosure confirmation request message reception process is started. Then, the control unit 35 processes the disclosure confirmation request message based on the management data list. Specifically, in step S140, the control unit 35 performs an operation of comparing the possessed content list attached (included) in the disclosure confirmation request message with the management data list of the administrator terminal 2. Details have been described with reference to FIG. Here, the possessed content list is a list of unique information of content (stored as a replica) owned by the node that transmitted the disclosure confirmation request message. Next, the process proceeds to step S141.

  In step S141, the control unit 35 confirms a content deletion request message for requesting deletion of content that is registered in the content list owned by the node 1 but not registered in the management data list. As a request processing result transmission means, it transmits to the node 1 that has transmitted the disclosure confirmation request message.

  Thereafter, content deletion processing is performed in the node 1 in accordance with the flowchart shown in FIG.

  Next, the operation of the node 1 that has received the content deletion request message in step S141 will be described below with reference to FIG.

  When the content holding request message reception process is started in step S87, the control unit 11 of the node device 1 analyzes the content deletion request message and specifies the content C (i) to be deleted in step S148. Then, the control unit 11 of the node device 1 deletes the specified content C (i) from the recording unit 12 of the node device 1.

  Next, FIG. 22B, which is another modification, will be described. In FIG. 22B, when it is confirmed that the message received by the control unit 35 of the administrator terminal 2 as the confirmation request receiving means is the disclosure confirmation request message, and the disclosure confirmation request message reception process is started, the control is performed. The unit 35 processes the disclosure confirmation request message based on the management data list. Specifically, in step S143, the control unit 35 performs an operation of comparing the held content list attached to (included in) the disclosure confirmation request message and the management data list of the administrator terminal 2. Details have been described with reference to FIG. Next, the process proceeds to step S144.

  In step S144, the control unit 35 sends a content holding request message requesting holding of the content registered in the owned content list of the node 1 and also registered in the management data list to the confirmation request processing result. As a transmission means, the information is transmitted to the node 1 that has transmitted the disclosure confirmation request message.

  Next, the operation of the node 1 that has received the content holding request message in step S144 will be described below with reference to FIG.

  When the content holding request message reception process is started in step S87, the control unit 11 of the node device 1 analyzes the content holding request message and specifies the content C (i) to be held in step S148. Thereafter, the identified content C (i) is compared with the content list owned by the node device 1. The control unit 11 of the node device 1 deletes the content not registered in the owned content list from the recording unit 12 of the node device 1.

  Further, as a modification of FIG. 22A, the deleted content list may be transmitted to the request source as a deletion request only when at least one item exists in the deleted content list.

  Furthermore, in the comparison result between the owned content list and the management data list, not only the content to be deleted but also the content that does not need to be deleted may be created and sent to the request source, that is, all comparisons The result may be sent to the requester.

[2.1.2] Processing Operation at Node 1 Next, processing operation performed at the node 1 will be described with reference to FIGS.

  FIG. 12A is a flowchart showing an outline of the operation for the node 1 in the first embodiment. FIG. 12B is a flowchart showing details of the disclosure confirmation request processing in step S81 and the like shown in FIG. 12A, and FIG. 12C shows the processing of the node 1 when the disclosure confirmation result message is received. FIG. 12D is a flowchart showing processing when the disclosure confirmation request event timer set in step S82 shown in FIG. 12A is started. It is. FIG. 13 is a flowchart showing details of the content request processing in step S85 shown in FIG. FIG. 14A is a flowchart showing details of the replica storage area securing process in step S98 and the like shown in FIG. 13, and FIG. 14B is a process for deleting the content C (i) shown in FIG. It is a flowchart which shows the detail of. FIG. 15A is a flowchart showing the process of node 1 when a replica creation request message is received (process for each message in step S87), and FIG. 15B is the case when a content deletion request message is received 5 is a flowchart showing (processing for each message in step S87).

  First, FIG. 12A showing an outline of the operation of the node 1 will be described.

  In step S80, when the power of the node 1 is turned on (power ON), the control unit 11 performs a disclosure confirmation request process in step S81. Details will be described with reference to FIG. Next, the process proceeds to step S82.

  In step S82, in order to perform the operation of the disclosure confirmation request process not only when the node 1 is turned on but also every time a predetermined time (for example, 1 hour) elapses, the control unit 11 performs a timer at the predetermined time interval. Set the timer to start. Then, a timer (an example of a determination unit that determines whether or not a predetermined time has elapsed) at a set time interval requests the CPU existing in the control unit 11 to perform interrupt processing. The disclosure confirmation request process is performed at the timing when the process occurs. The processing operation when an event occurs will be described with reference to FIG. Next, the process proceeds to step S83.

  Next, in step S83, the control unit 11 determines whether or not the power of the node 1 is turned off (power is turned off). If the power is not turned off, the process proceeds to step S84 (step S83: NO). On the other hand, when the power is turned off (step S83: YES), the processing of the node 1 is terminated.

  Next, in step S <b> 84, the control unit 11 determines whether or not there has been a content request operation on the input unit 21 by the user. Such a request operation is performed by inputting information for specifying unique information such as a title of content that the user desires to view from the input unit 12 of the node 1.

  If a content request operation has been performed (step S84: YES), the process proceeds to step S85. If the content request operation has not been performed (step S84: NO), the process proceeds to step S86.

  Next, in step S85, the control unit 11 performs a request process for the content specified by the request operation. Details will be described later. After the content request process is performed, the process proceeds to step S83.

  Next, in step S86, the control unit 11 determines whether or not a message from the administrator terminal 2 or another node 1 has been received. If a message has been received (step S86: YES), the process proceeds to step S87. If no message has been received (step S86: NO), the process proceeds to step S83.

  Next, in step S87, processing according to the content of the received message (for example, processing shown in FIGS. 15A and 15B) is performed. The content of the message is determined by the control unit 11 of the node 1. It progresses to step S83 after the said process is complete | finished.

  Next, with reference to FIG. 12B, the disclosure confirmation request process performed in step S81 shown in FIG.

  When the public confirmation request process is started, in step S89, the control unit 11 as the confirmation request transmission unit receives from the recording unit 12 a stored content list in which the unique information of the content recorded and stored by the node 1 is registered. This is read and attached to the disclosure confirmation request message, and the disclosure confirmation request message is transmitted to the administrator terminal 2 as a confirmation request for confirming whether or not the content recorded in the recording unit 12 is managed. .

  As described above, the transmission confirmation request message thus transmitted is received and processed by the administrator terminal 2 (FIG. 11A), and then the confirmation request processing result for the confirmation request is received from the administrator terminal 2. Is sent as a confirmation result message (attached to the deleted content list as a determination result of determining whether or not the specific information of the content included in the owned content list is managed by the administrator terminal 2: deletion request) , Received by the node 1 (confirmation request processing result receiving means). Thereby, the disclosure confirmation result message reception process shown in FIG. 12C is started, and the control unit 11 as a processing unit performs a process based on the confirmation request process result.

  Specifically, first, in step S136, the control unit 11 initializes the variable i and sets the value to “0”.

  Next, in step S137, the control unit 11 determines that the size of the deleted content list attached to the disclosure confirmation result message is larger than the variable i (that is, if there is content to be deleted from the retained content list). In the case of (step S137: YES), the process proceeds to step S138. On the other hand, if the value of the size of the deleted content list is not greater than (becomes equal to) the variable i (step S137: NO), the disclosure confirmation result message reception process ends.

  In step S138, the control unit 11 as a processing unit records content corresponding to the deleted content list (i) (that is, content not managed by the administrator terminal 2 and corresponding to the deletion request). Delete from the section 12. Furthermore, the unique information of the content corresponding to the deleted content list (i) is deleted from the held content list. In step S139, the value of the variable i is incremented by one, and the process proceeds to step S137. As a result, all the contents registered in the deleted content list are deleted from the node 1.

  Next, in FIG. 12 (d), processing of a disclosure confirmation request event when the timer set in step S82 of FIG. 12 (a) is started will be described.

  When the publication confirmation request event process is started, in step S211, the control unit 11 performs the publication confirmation request process (refer to FIG. 12B for details) similarly to step S81, and then, step S212. In step S82, a timer setting process is performed so that the timer is started at the predetermined time interval as in step S82. Thereby, after a predetermined time elapses, the disclosure confirmation request event process is performed again.

  Next, the content request process shown in step S85 of FIG. 12A will be described using FIG.

  When the content request process is started, in step S92, the control unit 11 performs a disclosure confirmation request process in the same manner as in step S81 (see FIG. 12B for details). That is, the control unit 11 transmits a public confirmation request message to the administrator terminal 2 when requesting content used in the content information distribution system S as content information requesting means.

  Next, in step S93, the control unit 11 inputs the specific information of the requested content C (request) requested (desired to be viewed) in step S84.

  Next, in step S94, the control unit 11 determines whether or not the requested content C (request) is recorded (possessed) in its own recording unit 12. When the content C (request) is recorded in its own recording unit 12 (step S94: YES), the process proceeds to step 103. On the other hand, when the content C (request) is not recorded in its own recording unit 12 (step S94: NO), the process proceeds to step 95.

  Next, in step S95, an operation of searching for the node 1 storing the content C (request) is performed (similar to the above step S67, the above-described [1-3. Content Data Search Method] is performed. ), The controller 11 waits until a search result is obtained (step S96).

  Next, in step S97, the control unit 11 determines whether or not the content C (request) has been found, that is, whether or not the IP address or the like of the node storing the content C (request) has been acquired (received). Judging. When the content C (request) is found (a holding node list in which the IP address of the content holding node storing the content C (request) is registered can be acquired) (step S97: YES), Proceed to step S98. On the other hand, when the content C (request) is not found (the holding node list cannot be acquired) (step S97: NO), the content request processing is terminated.

  Next, in step S98, the control unit 11 secures a replica storage area for providing a free space necessary for copying the content C (request) to the recording unit 12 of the node 1 (creating a replica). I do. Details will be described later with reference to FIG.

  Next, in step S99, the control unit 11 has a free capacity for recording a replica of the content C (request) in the recording unit 12 of the node 1 by the replica storage area securing process performed in step S98. It is determined whether or not it has been secured. If an area for storing the replica can be secured (step S99: YES), the process proceeds to step S100. On the other hand, when an area for storing the replica cannot be secured (step S99: NO), the content request process is terminated.

  Next, in step S100, the control unit 11 records the content C (request) found in step S97 (the retention node list has been acquired from the root node of the content C (request)) node 1 (content retention node) In order to record the content C (request) as a replica, a download request message is transmitted.

  Next, in step S101, the control unit 11 determines whether or not a content non-ownership notification message has been received from the node 1 that has transmitted the download request message in step S100. If a content non-possession notification message is received (step S101: YES), the process proceeds to step S104. On the other hand, when the content non-possession notification message is not received (step S101: NO), the process proceeds to step S102.

  Next, in Step S102, since the recording unit 12 of the node 1 that has requested the content C (request) has been confirmed to have enough free space to record the content C (request) as a replica, the control unit 11 Downloads the content C (request) from the node 1 (content holding node) that records the content C (request), and records the content C (request) in its own recording unit 12.

  Next, in step S103, the control unit 11 performs playback control of the content C (request) downloaded in step S102 in accordance with the playback operation of the input unit 12 from the user. Thereby, the content C (request) is reproduced, and the user can enjoy the content by viewing it.

  Next, in step S104, the control unit 11 sets the IP address or the like of the node 1 that transmitted the content non-possession notification message even though the IP address or the like is registered as the content holding node in the acquired holding node list. Delete from the holding node list. The node 1 may transmit a request message for deleting the IP address or the like of the node 1 that transmitted the content non-possession notification message from the holding node list to the root node of the content C (request). As a result, the holding node list managed in the root node can be updated to the latest state.

  Next, the replica storage area securing process shown in step S98 of FIG. 13 will be described with reference to FIG.

  When the replica storage area securing process is started, in step S106, the control unit 11 initializes the variable i to “0”, and the capacity of the current free area in the recording unit 12 of the own node 1 (current free capacity). Check out. Next, the control unit 11 checks the capacity of the content to be downloaded (for example, checks from the electronic catalog or the like in which the specific information or capacity of the content is registered), and checks the free capacity necessary for recording the content. . Then, the control unit 11 subtracts the current free space from the necessary free space, and substitutes the value for the variable S.

  In step S107, the control unit 11 determines whether or not the variable S is “0” or less. That is, the control unit 11 as a deletion necessity determination unit determines whether or not it is necessary to delete other content already recorded in the recording unit 12 in order to record the requested content in the recording unit 12. Determine.

  Then, the control unit 11 can record the content desired to be viewed in the recording unit 12 of the own node 1 when the variable S is “0” or less (that is, when the current free space is larger than the required free space). If it is determined that there is no need to delete other contents (step S107: YES), the replica storage area securing process is terminated. On the other hand, when the variable S is not “0” or less (that is, when the current available capacity is less than the required available capacity), that is, the content desired to be viewed can be recorded in the recording unit 12 of the own node 1. If it is determined that other content needs to be deleted (step S107: NO), the process proceeds to step S108.

  In step S108, the control unit 11 determines whether or not the possessed content number is larger than the variable i. If not, for example, if there is no content recorded in the recording unit 12 of the own node 1 (step S108). In S108: NO), the replica storage area securing process is terminated. On the other hand, when the number of possessed contents is larger than the variable i (step S173: YES), the control unit 11 proceeds to step S109.

  In step 109, the control unit 11 performs a process for deleting any content C (i) recorded in the recording unit 12. Details will be described later with reference to FIG.

  Next, in step S110, the control unit 11 determines whether or not the content C (i) can be deleted. If the content C (i) cannot be deleted (step S110: NO), the process proceeds to step S112. On the other hand, when the content C (i) can be deleted (step S110: YES), the process proceeds to step S111.

  In step S111, the control unit 11 substitutes a value obtained by subtracting the data capacity of the deleted content C (i) from the variable S into the variable S again.

  Next, in step 112, the variable i is incremented by “1”, and the process proceeds to step S107. Thus, the replica storage area is secured by the replica storage area securing process.

  Next, the content C (i) deletion process shown in step S109 of FIG. 14A will be described with reference to FIG.

  When the deletion process of the content C (i) as another content is started, an operation of searching for the node 1 storing the content C (i) to be deleted is performed in step S311 (step S67 above). The control unit 11 waits until a search result is obtained (step S312).

  Next, the control unit 11 as a recording presence / absence determination unit determines whether or not the content C (i) has been searched in step S313, that is, whether or not the content C (i) is recorded in another node 1. To do. If the content C (i) can be searched (a holding node list in which the IP address of the content holding node storing the content C (i) is registered can be acquired) (step S313: YES), the control unit 11 as the deletion unit deletes the content C (i) from the recording unit 12 (step S317). On the other hand, when the content C (i) cannot be searched (step S313: NO), that is, when the content C (i) is not recorded in another node 1, the same as step S89 shown in FIG. As described above, the control unit 11 as the confirmation request transmission unit attaches the unique information of the content C (i) to the disclosure confirmation request message, and transmits the disclosure confirmation request message to the administrator terminal 2 as a confirmation request. (Step S314) and waits for a response (Step S315).

  As described above, the transmission confirmation request message transmitted in this way is received by the administrator terminal 2, and it is determined whether or not the unique information of the content C (i) is registered in the management data list. A public confirmation result message including “” is returned to the node 1.

  When receiving the disclosure confirmation result message, the control unit 11 determines whether or not the unique information of the content C (i) is registered in the management data list based on the determination result in step S316. If not (step S316: NO), the content C (i) is deleted from the recording unit 12 because the content is not managed by the administrator terminal 2 (step S317).

  On the other hand, when the unique information of the content C (i) is registered in the management data list (step S316: YES), the control unit 11 is the content managed in the administrator terminal 2, and therefore the content C ( The deletion process of the content C (i) is terminated without deleting i) from the recording unit 12. Thereby, it is possible to control the system S so that, for example, only one content C (i) to be managed is left.

  Next, the process for each message performed in step S87 in FIG.

  First, a replica creation request message reception process when the node 1 receives a replica creation request message from the administrator terminal 2 will be described with reference to FIG.

  When the replica creation request message reception process is started, the control unit 11 performs a replica storage area securing process in step S121 (the process shown in FIG. Is omitted).

  Next, in step S122, the control unit 11 determines whether or not a free capacity for recording the replica in the recording unit 12 of the own node 1 has been secured by the replica storage area securing process performed in step S121. to decide. If an area for storing the replica can be secured (step S122: YES), the process proceeds to step S123. On the other hand, when the area for storing the replica cannot be secured (step S122: NO), the process proceeds to step S125.

  In step S123, the control unit 11 transmits a download request message to the administrator terminal 2 that has transmitted the replica creation request message. In step S124, the control unit 11 downloads the content C (add) from the administrator terminal 2. The data is recorded in the recording unit 12, and the replica creation request message reception process ends.

  On the other hand, in step S125, the control unit 11 transmits an area allocation failure notification message to the administrator terminal 2, and ends the replica creation request message reception process. The administrator terminal 2 that has received the area allocation failure notification message newly selects the node 1 and transmits a replica creation request message to the node 1.

  Next, content deletion request message reception processing when the node 1 receives a content deletion request message from the administrator terminal 2 will be described with reference to FIG.

  When the content deletion request message reception process is started in step S130, the control unit 11 analyzes the content deletion request message in the control unit 11 in step S131, and determines the content C (i) to be deleted. The specified content C (i) is deleted from the recording unit 12, and the content deletion request message receiving process is terminated.

  As described above, according to the first embodiment, the administrator terminal 2 records a management data list for managing content to be shared in the content distribution system S, and the node 1 records itself ( A confirmation request for confirming whether a stored replica of the content is information shared in the content distribution system S is sent to the administrator terminal at a predetermined timing such as at power-on, when searching for other content, or at regular intervals. In response to the confirmation request, the administrator terminal 2 stores in the management data list whether or not the content replica recorded in the node 1 is information shared in the content distribution system S. Since the determination result is transmitted to the node 1, the node 1 appropriately records the record recorded by itself. Replica Ceiling becomes possible to check whether the information shared in the content distribution system S, it is possible to determine whether to delete a replica of content according to the confirmation. Therefore, even in the case of the P2P type content distribution system S in which each node 1 can frequently participate and withdraw (for example, power ON / OFF), a replica of the content arranged in the system S Deletion control can be performed more efficiently.

  In addition, the administrator terminal 2 can centrally manage content replicas, and a specific content replica can be completely deleted from the system S in response to a request from the system operator or content author. Is copyright information, copyright protection can be performed more efficiently.

  In addition, when the node 1 records a replica of the content, if it is necessary to delete the replica of the other content in order to secure the recording capacity, the replica of the other content is recorded in the other node 1. In this case, since the other content replica is deleted for the first time, it is possible to leave only one content replica from the content distribution system S instead of deleting it completely. Deletion control of the placed content replicas can be performed more efficiently. In other words, if you delete the replica in order to secure the recording capacity, this content may be lost from the system at all times. However, after preventing this, the administrator wants to delete the content. Can be surely deleted from the system.

[2.2 Second Embodiment]
Next, the processing operation of the administrator terminal 2 and the processing operation of the node 1 constituting the content distribution system S in the second embodiment will be described with reference to the flowcharts shown in FIGS. Note that in the second embodiment, overlapping description of the same contents as in the first embodiment is omitted.

  In the second embodiment, the management data list is recorded also in the node 1, and the management data list recorded in the administrator terminal 2 is compared with the management data list of the node 1 using an arbitrary operation as a trigger. Do things. As a result of the comparison, the content is registered in the management data list of the node 1 but not registered in the management data list of the administrator terminal 2.

  FIG. 16 is a conceptual diagram showing the operation of the content distribution system S in the second embodiment. FIG. 16A shows an initial state, in which a management data list is recorded in both the node 1 and the administrator terminal 2. In the management data list recorded in the administrator terminal 2, “FILE02 Is not managed (recorded), but the content of “FILE02” remains in the node 1b due to the deletion failure. 16B and 16C show the processing of the node 1b and the administrator terminal 2 until the management data list is updated in the node 1b, and the content of “FILE02” remaining in the node 1b is deleted. The operation is shown.

  FIG. 17A is a flowchart showing an outline of the operation of the node 1 in the second embodiment, and corresponds to FIG. The process of the administrator terminal 2 in the second embodiment is as shown in FIG. 9 as in the first embodiment (however, the details of the process in step S57 shown in FIG. There are different parts to do).

  In step S190, when the power of the node 1 is turned on (power ON), the control unit 11 performs a management data list request process in step S191. Details will be described with reference to FIG. Next, the process proceeds to step S192.

  In step S192, the control unit 11 performs the management data list request processing operation not only when the node 1 is turned on but also every time a predetermined time (for example, 1 hour) elapses. Set the timer so that the timer starts. Then, since the timer requests the CPU existing in the control unit 11 at the set time interval to perform the interrupt process, the management data list request process is performed at the timing when the interrupt process occurs. Become. The processing operation when an event occurs will be described with reference to FIG.

  Note that the processing from step S193 to S197 shown in FIG. 17A is basically the same as the processing from step S83 to S87 shown in FIG. 12A, but the processing shown in step S195 and step S197. There are different details.

  FIG. 17B is a flowchart showing details of the management data list request processing in step S191 shown in FIG.

  When the management data list request process is started, in step S201, the control unit 11 checks whether the management data list recorded by the node 1 matches the management data list recorded by the administrator terminal 2. The management data list request message is transmitted to the administrator terminal 2 as a confirmation request for confirming whether or not the content recorded in the recording unit 12 is managed.

  FIG. 17C is a flowchart showing processing when the management data list request event timer set in step S192 shown in FIG.

  When the management data list request event process is started, in step S203, the control unit 11 performs the management data list request process (see FIG. 17B for details) in the same manner as in step S191. In step S204, similarly to step S192, a timer setting process is performed so that the timer is started at the predetermined time interval. As a result, the management data list request event process is performed again after a predetermined time has elapsed.

  Next, FIG. 18A is a flowchart showing processing of the administrator terminal 2 when the management data list request message is received (processing for each message in step S57 shown in FIG. 9), and FIG. These are flowcharts which show the process of the node 1 when the management data list message is received (the process for each message in step S197 shown in FIG. 17A).

  When it is confirmed that the message received at the administrator terminal 2 is a management data list request message and the management data list request message reception process is started, the control unit 35 stores the management data list recorded in the recording unit 36. And the management data list message with the management data list attached is transmitted to the node 1 that transmitted the management data list request message.

  On the other hand, when it is confirmed that the message received at the node 1 is a management data list message, and the management data list message reception process is started, the control unit 11 stores the management data list recorded in the recording unit 12. Is updated to the management data list attached to the received management data list message (step S171).

  Next, in step S172, the control unit 11 initializes the variable i to “0”.

  Next, in step S173, the control unit 11 determines whether or not the possessed content number is larger than the variable i. If not, for example, if there is no content recorded in the recording unit 12 of the node 1 itself. In (Step S173: NO), the management data list message reception process is terminated.

  On the other hand, when the number of possessed contents is larger than the variable i (step S173: YES), the control unit 11 proceeds to step S174.

  In step S174, the control unit 11 compares the management data list updated in step S171 with the content (unique information) recorded by the recording unit 12, and manages the unique information of the content C (i). It is determined whether it is registered (managed) in the data list. When the unique information of the content C (i) is not registered in the management data list (step S174: NO), the control unit 11 performs a process of deleting the content (i) from the recording unit 12 (step S174). S175).

  On the other hand, if the unique information of the content C (i) is registered in the management data list (step S174: YES), the variable i is incremented by “1” in step S176, and the process proceeds to step S173.

  Next, FIG. 19 is a flowchart showing details of the content request processing in step S195 shown in FIG.

  When the content request process is started, in step S151, the control unit 11 performs a management data list request process in the same manner as in step S191 (see FIG. 17B for details). Thus, when the management data list message transmitted from the administrator terminal 2 is received, the control unit 11 converts the management data list recorded in the recording unit 12 to the management data attached to the received management data list message. The list is updated (step S152).

  The processing from step S153 to S164 shown in FIG. 19 is the same as the processing from step S94 to S104 shown in FIG. 13, and the replica storage area securing processing in step S158 shown in FIG. 19 is the same as that in the first embodiment. Similarly, this is as shown in FIG. However, the content C (i) deletion process shown in step S109 shown in FIG. 14A in this case is as shown in FIG.

  When the deletion process of the content C (i) shown in FIG. 20 is started, an operation for searching for the node 1 storing the content C (i) to be deleted is performed in step S411 (the above-described step S311 and Similarly, the control unit 11 waits until a search result is obtained (step S412).

  Next, in step S413, the control unit 11 determines whether or not the content C (i) has been searched, that is, whether or not the content C (i) is recorded in another node 1. When the content C (i) can be searched (step S413: YES), the control unit 11 deletes the content C (i) from the recording unit 12 (step S416). On the other hand, when the content C (i) cannot be searched (step S413: NO), that is, when the content C (i) is not recorded in another node 1, the control unit 11 performs the content C (i). It is confirmed whether or not the unique information is registered in the management data list recorded in its own recording unit 12 (step S414). If registered in the management data list (step S415: YES), the content C (i) deletion process is terminated without deleting the content C (i). On the other hand, when the unique information of the content C (i) is not registered in the management data list recorded in its own recording unit 12 (step S415: NO), the control unit 11 determines that the content C (i ) Is deleted from the recording unit 12.

  As described above, according to the second embodiment, the node 1 makes a confirmation request to the administrator terminal 2 at a predetermined timing such as at power-on, when searching for other contents, at regular intervals, In response to the confirmation request, the administrator terminal 2 transmits the management data list to the node 1, and the node 1 has a replica of the content recorded (stored) by itself based on the management data list. Since it is determined whether or not the information is shared in the content distribution system S, it is possible to determine whether the replica is information shared in the content distribution system S in addition to the effects of the first embodiment. Can be distributed to each node 1 and the processing load on the administrator terminal 2 can be reduced.

  In the first and second embodiments, the confirmation request as to whether or not the replica of the content recorded (stored) by itself is information shared in the content distribution system S is made when the power is turned on. However, the present invention is not limited to this, but when the node 1 participates in the content distribution system S (for example, the node 1 is connected to an arbitrary node 1). When the participation request is transmitted, the confirmation request may be transmitted to the administrator terminal 2. Further, the administrator terminal 2 updates the management data list as an update unit when the content to be shared in the content distribution system S is changed, and participates in the content distribution system S at the time of the update. An updated management data list may be transmitted (broadcast) to the existing node 1.

  With this configuration, it is possible to perform the deletion control of the replicas arranged in the system S more efficiently without omission.

  In addition, the computer program that functions as the node 1 and the administrator terminal 2 in the first and second embodiments may be recorded in advance, or provided by being recorded on a recording medium such as a CD-ROM. It may be read through a drive. Further, it may be downloaded from a predetermined server connected to the Internet.

  As described above, the present invention can be used in the field of content distribution via a network, and particularly when applied to the field of content distribution in a download format, a particularly remarkable effect can be obtained.

It is a figure which shows an example of the connection aspect of each node apparatus in the content delivery system which concerns on this embodiment. It is explanatory drawing of ID space. It is a figure which shows an example of a mode that a routing table is produced by DHT. (A) An example of a level 1 table. (B) An example of a level 2 table. (C) An example of a level 3 table. (D) An example of a completed routing table. It is a figure which shows an example of a mode that the node apparatus 1 which is a preservation | save source of content data is searched by DHT in this embodiment. It is a figure which shows the example of a schematic structure of a node apparatus. It is a figure which shows the example of a schematic structure of an administrator terminal. It is a conceptual diagram which shows operation | movement of the content delivery system S in 1st Embodiment. The overall operation outline of the administrator terminal 2 is represented by a flowchart. FIG. 9A is a flowchart showing details of content input processing to the system S in step S55 shown in FIG. 9, and FIG. 9B shows details of content deletion processing to the system S in step S55 shown in FIG. It is a flowchart. (A) is a flowchart which shows the process of the administrator terminal 2 when a public confirmation request message is received, (b) is a flowchart which shows the detail of the process in step S71 shown to (a). (A) is a flowchart showing an outline of the operation of the node 1 in the first embodiment, and (b) is a flowchart showing details of the disclosure confirmation request process in step S81 shown in (a). (C) is a flowchart showing the processing of node 1 when a disclosure confirmation result message is received. (D) is a disclosure confirmation request event timer set in step S82 shown in (a). It is a flowchart which shows the process at the time. It is a flowchart which shows the detail of the content request | requirement process in step S85 shown to Fig.12 (a). (A) is a flowchart showing details of the replica storage area securing process in step S98 and the like shown in FIG. 13, and (b) is a flowchart showing details of the deletion process of the content C (i) shown in (a). is there. (A) is a flowchart which shows the process of the node 1 when a replica creation request message is received, (b) is a flowchart which shows the process of the node 1 when a content deletion request message is received. It is a conceptual diagram which shows operation | movement of the content delivery system S in 2nd Embodiment. (A) is a flowchart showing an outline of the operation of the node 1 in the second embodiment, and (b) is a flowchart showing details of the management data list request process in step S191 shown in (a). Yes, (c) is a flowchart showing processing when the management data list request event timer set in step S192 shown in (a) is started. (A) is a flowchart which shows the process of the administrator terminal 2 when a management data list request message is received, (b) is a flowchart which shows the process of the node 1 when a management data list message is received. . It is a flowchart which shows the detail of the content request | requirement process in step S195 shown to Fig.17 (a). It is a flowchart which shows the detail of content C (i) deletion process shown to step S109 shown to Fig.14 (a) in 2nd Embodiment. It is a figure which shows the relationship between content ID and a holding | maintenance node list. It is a flowchart which shows the modification in 1st Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Node apparatus 2 Manager terminal 11 Control part 12 Recording part 13 Buffer memory 14 Decoder part 15 Image | video processing part 16 Display part 17 Audio | voice processing part 18 Speaker 20 Communication part 21 Input part 22 Bus 35 Control part 36 Recording part 37 Communication part 38 Input unit 39 Display unit 40 Bus S Content distribution system

Claims (21)

A management device that manages all content information used in an information distribution system including a plurality of node devices connected to each other by constructing an overlay network,
Management information recording means for recording management information for managing the content information to be shared in the information distribution system;
Confirmation request receiving means for receiving from the node device a confirmation request for confirming whether the content information recorded in the node device is information shared in the information distribution system;
Confirmation request processing means for processing the confirmation request received by the confirmation request receiving means based on the management information recorded in the management information recording means;
Confirmation request processing result transmission means for transmitting a processing result by the confirmation request processing means to the node device that has transmitted the confirmation request;
A management apparatus comprising: The confirmation request receiving means receives a confirmation request including content recording information related to content information recorded by a node device that has transmitted the confirmation request;
The confirmation request processing means determines whether the content recording information included in the confirmation request is recorded in the management information of the management information recording means;
The management apparatus according to claim 1, wherein the confirmation request processing result transmission unit transmits a determination result by the confirmation request processing unit to a node apparatus that has transmitted the confirmation request. The confirmation request receiving means receives a confirmation request including content recording information related to content information recorded by a node device that has transmitted the confirmation request;
The confirmation request processing means determines whether the content recording information included in the confirmation request is recorded in the management information of the management information recording means;
The confirmation request processing result transmission means, when the content recording information included in the confirmation request is not recorded in the management information of the management information recording means as a result of the determination by the confirmation request processing means, The management apparatus according to claim 1, further comprising: transmitting a deletion request for requesting deletion from the node apparatus. The confirmation request receiving means receives a confirmation request including content recording information related to content information recorded by a node device that has transmitted the confirmation request;
The confirmation request processing means determines whether the content recording information included in the confirmation request is recorded in the management information of the management information recording means;
The confirmation request processing result transmission means, if the content recording information included in the confirmation request is recorded in the management information of the management information recording means as a result of the determination by the confirmation request processing means, The management apparatus according to claim 1, wherein the management apparatus transmits a holding request that requests the node apparatus to hold the request. The confirmation request processing means reads management information recorded in the management information recording means,
The management apparatus according to claim 1, wherein the confirmation request processing result transmission unit transmits the management information read by the confirmation request processing unit to the node device that transmitted the confirmation request. Updating means for updating management information recorded in the management information recording means when the content information to be shared in the information distribution system is changed;
Management information transmitting means for transmitting the updated management information to the node devices participating in the information distribution system when the management information recorded in the management information recording means is updated by the updating means. The management apparatus according to claim 1, further comprising: A node device included in an information distribution system including a plurality of node devices connected to each other by constructing an overlay network,
Recording means for recording content information used in the information distribution system;
Confirmation request transmitting means for transmitting a confirmation request for confirming whether or not the content information recorded in the recording means is managed to a management apparatus that manages all content information used in the information distribution system;
Confirmation request processing result receiving means for receiving a confirmation request processing result for the confirmation request by the management device from the management device;
Processing means for performing processing based on the confirmation request processing result;
A node device comprising: The confirmation request transmitting means transmits a confirmation request including content recording information related to the content information recorded in the recording means;
The confirmation request processing result receiving means receives a determination result of determining whether or not the content recording information included in the confirmation request is managed by the management device;
If the content information recorded by the recording unit is not managed by the management device based on the received determination result, the processing unit does not manage the content managed by the recording unit. The node device according to claim 7, wherein information is deleted. The confirmation request transmitting means transmits a confirmation request including content recording information related to the content information recorded in the recording means;
The confirmation request processing result receiving means determines whether the content information recorded by the recording means is based on a determination result of whether or not the content recording information included in the confirmation request is managed by the management device. Receiving a deletion request to delete the content information that is not managed from the management device when it is determined that the content is not managed by the management device;
The node device according to claim 7, wherein the processing unit deletes content information corresponding to the deletion request from the recording unit. The confirmation request transmitting means transmits a confirmation request including content recording information related to the content information recorded in the recording means;
The confirmation request processing result receiving means determines whether the content information recorded by the recording means is based on a determination result of whether or not the content recording information included in the confirmation request is managed by the management device. When it is determined that it is managed by the management device, a holding request for holding the content information managed from the management device is received,
The node according to claim 7, wherein the processing unit causes the recording unit to retain content information corresponding to the holding request, and deletes the content information for which the holding request has not been instructed from the recording unit. apparatus. The confirmation request processing result receiving means receives management information indicating content information managed by the management device;
The processing means compares the management information with the content information recorded by the recording means to determine whether or not the management information is recorded by the recording means and is managed. The node device according to claim 7, wherein if it is determined that the content information is not managed, the content information that is not managed is deleted from the recording unit. Management information recording means for recording management information for managing all content information used in the information distribution system,
The confirmation request transmitting means transmits information requesting the management information recorded by the management device as the confirmation request,
The confirmation request processing result receiving means receives management information indicating content information managed by the management device;
The processing means updates the management information recorded in the management information recording means to the received management information, compares the updated management information with the content information recorded in the recording means, and records the recording information. It is determined whether or not the information is managed by the management information recorded by the means. If it is determined that the information is not managed, the content information that is not managed is deleted from the recording means. The node device according to claim 7.   The node according to any one of claims 7 to 12, wherein the confirmation request transmission unit transmits the confirmation request to the management device when the node device participates in the information distribution system. apparatus. Content information requesting means for requesting content information used in the information distribution system,
The said confirmation request transmission means transmits the said confirmation request to the said management apparatus, when requesting | requiring the content information used for the said information delivery system, It is any one of Claims 7-13 characterized by the above-mentioned. The described node equipment. A determination means for determining whether or not a predetermined time has elapsed;
The node device according to claim 7, wherein the confirmation request transmission unit transmits the confirmation request to the management device every time a predetermined time elapses. Content information requesting means for requesting content information used in the information distribution system;
Deletion necessity determining means for determining whether it is necessary to delete other content information already recorded in the recording means in order to record the requested content information in the recording means;
Recording presence / absence discriminating means for discriminating whether or not the other content information is recorded in another node device when it is determined by the deletion necessity determining means that the other content information needs to be deleted. And further comprising
The confirmation request transmitting unit transmits the confirmation request to the management device when the recording presence / absence determining unit determines that the other content information is not recorded in another node device. The node device according to any one of claims 7 to 14. Content information requesting means for requesting content information used in the information distribution system;
Deletion necessity determining means for determining whether it is necessary to delete other content information already recorded in the recording means in order to record the requested content information in the recording means;
Recording presence / absence discriminating means for discriminating whether or not the other content information is recorded in another node device when it is determined by the deletion necessity determining means that the other content information needs to be deleted. When,
And a deletion unit that deletes the other content information from the recording unit when the recording presence / absence determination unit determines that the other content information is recorded in another node device. The node device according to claim 7, wherein: A computer that manages all content information used in an information distribution system including a plurality of node devices connected to each other by constructing an overlay network,
Management information recording means for recording management information for managing the content information to be shared in the information distribution system;
Confirmation request receiving means for receiving from the node device a confirmation request for confirming whether the content information recorded in the node device is information shared in the information distribution system;
Confirmation request processing means for processing the confirmation request received by the confirmation request receiving means based on the management information recorded in the management information recording means; and
A content information management processing program that causes a node device that has transmitted the confirmation request to function as a confirmation request processing result transmission unit that transmits a processing result by the confirmation request processing unit. A computer included in an information distribution system including a plurality of node devices connected to each other by constructing an overlay network,
Recording means for recording content information used in the information distribution system;
Confirmation request transmitting means for transmitting to the management apparatus a confirmation request for confirming whether or not the content information recorded in the recording means is managed by the management apparatus that manages all content information used in the information distribution system;
Confirmation request processing characterized by functioning as confirmation request processing result receiving means for receiving a confirmation request processing result for the confirmation request from the management apparatus, and processing means for performing processing based on the confirmation request processing result. program. In an information distribution system comprising a plurality of node devices connected to each other by constructing an overlay network,
Management information recording means for recording management information for managing the content information to be shared in the information distribution system;
Confirmation request receiving means for receiving from the node device a confirmation request for confirming whether the content information recorded in the node device is information shared in the information distribution system;
Confirmation request processing means for processing the confirmation request received by the confirmation request receiving means based on the management information recorded in the management information recording means;
Confirmation request processing result transmission means for transmitting a processing result by the confirmation request processing means to the node device that has transmitted the confirmation request;
A management device comprising:
Recording means for recording content information used in the information distribution system;
Confirmation request transmitting means for transmitting to the management apparatus a confirmation request for confirming whether or not the content information recorded in the recording means is managed by the management apparatus that manages all content information used in the information distribution system; ,
Confirmation request processing result receiving means for receiving a confirmation request processing result for the confirmation request by the management device from the management device;
Processing means for performing processing based on the confirmation request processing result;
A node device comprising:
An information distribution system comprising: In an information distribution system comprising a plurality of node devices connected to each other by constructing an overlay network,
A management information recording step for recording management information for managing the content information to be shared in the information distribution system;
A confirmation request receiving step for receiving, from the node device, a confirmation request for confirming whether the content information recorded in the node device is information shared in the information distribution system;
A confirmation request processing step for processing the confirmation request received in the confirmation request receiving step based on management information recorded in the management information record;
A confirmation request processing result transmission step for transmitting a processing result in the confirmation request processing step to the node device that has transmitted the confirmation request;
A management method in a management device comprising:
A recording step of recording content information used in the information distribution system;
A confirmation request transmitting step of transmitting a confirmation request for confirming whether or not the content information recorded in the recording step is managed in the management method;
A confirmation request processing result receiving step for receiving a confirmation request processing result for the confirmation request in the management method from the management step;
A processing step for performing processing based on the confirmation request processing result;
A node device processing method comprising:
An information delivery method characterized by comprising:

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