JP2010067072A - Storage instruction device, node device, storage instruction processing program, node processing program and storage instruction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a storage instruction device, a node device, a storage instruction processing program, a node processing program and a storage instruction method, wherein it is estimated that a node device having a short participation period in a content distribution storage system has small free recording capacity in a storage part such as an HD (a hard disk) when putting content data into the content distribution storage system and wherein storage is instructed to the node device having the short participation period. <P>SOLUTION: The storage instruction device in the content distribution storage system includes a storage instruction device, which makes the content data be stored in the node devices, for use of a plurality of pieces of the content data between the plurality of node devices communicable with each other via a network. The storage instruction device selects a first prescribed number of the node devices each having shorter participation period wherein the node device participates in the content distribution storage system, based on node information stored in a node information storage means, and sends out storage instruction information for instructing the storage of the content data. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technical field of a peer-to-peer (P2P) type communication system including a plurality of node devices that can communicate with each other via a network.

  In this type of peer-to-peer communication system, copy data (hereinafter referred to as “replica”) of a plurality of content data (content data such as movies and music) is distributed and stored (arranged) in a plurality of node devices. A distributed content storage system that makes it possible to use replicas between node devices is known, and this improves fault tolerance and access dispersibility. The location of the replicas thus distributed and stored can be efficiently searched using a distributed hash table (hereinafter referred to as DHT (Distributed Hash Table)) as disclosed in, for example, Patent Document 1.

  In such a distributed content storage system, when performing a content distribution service, access is concentrated on popular content replicas, so it is desirable to distribute and store a number of replicas corresponding to popularity in a plurality of node devices. According to Patent Document 1, each node device has an evaluation value of the content before publication (before the publication) before making a replica of the content newly input to the system available to other node devices (before publication). Compared with the evaluation value of the content replica that has already been saved), it is saved when the evaluation value of the content before publication is large, but not when it is small Yes.

As described above, when a new content replica before publication is stored in a node device in the system, a node device in the system is randomly selected or a content viewing reservation period is selected as a storage destination node device selection method. And a replica of the content is stored in the node device that has reserved viewing during the period. For example, Patent Document 2 discloses a storage instruction device that stores a replica of a new content in a node device that has reserved the purchase of the content when a replica of the new content before publication is inserted in the system. Is disclosed.
JP 2007-034630 A JP 2008-20938 A

  However, since the free recording capacity of the disk on which the replica of the content of each node device is recorded is not taken into consideration, a certain node device records no replica of the content on the disc at all, but the disk of another certain node device Is almost used and there is no free recording capacity.

  For this reason, when an instruction to save a new content replica is given to a node device whose free disk recording capacity is less than the capacity of the new content replica, the node device A situation occurs in which a replica is deleted, a recording location of a new replica is secured, and a new replica is recorded.

  The present invention has been made in view of the above-described problems. When content data is input to a content distributed storage system, a node device having a short participation period in the content distributed storage system is an HD (hard disk) or the like. Providing a storage instruction device, a node device, a storage instruction processing program, a node processing program, and a storage instruction method for storing content data for a node device with a short participation period, presuming that the storage unit has a small free recording capacity The task is to do.

  In order to solve the above-mentioned problem, the invention according to claim 1 is a storage for storing content data in a node device so that a plurality of content data can be used between a plurality of node devices that can communicate with each other via a network. The storage instruction device in the content distributed storage system including the instruction device, the node device identification information for identifying the node device, and the participation participating in the content distribution storage system in the node device of the node device identification information Acquisition means for acquiring a period, node information storage means for storing node information in which the node device identification information acquired by the acquisition means is associated with a participation period, and nodes stored in the node information storage means Selection for selecting a first predetermined number of the node devices having a shorter participation period based on information And the step, for the selected node device, a storage instruction apparatus characterized by comprising: a storage instructing means for sending a store instruction information for instructing storage of the content data.

  According to the present invention, when content data is input to the content distributed storage system, the free recording capacity for recording the content data is instructed to store the node device having a short participation period in the content distributed storage system. It is possible to instruct the node device that is estimated to have a relatively large amount of content data to be stored, and to effectively use the recording capacity of the recording unit for recording the content data of each node device in a balanced manner. It is possible to realize a distributed content storage system capable of

  In order to solve the above problem, the invention according to claim 2 is the storage instruction device according to claim 1, wherein the acquisition unit is configured to receive the first predetermined period from the other device with the shorter participation period. A second predetermined number of node information greater than the number is acquired, the node information storage means stores the acquired second predetermined number of node information, and the selection means stores the node information in the node information storage means The first predetermined number of node devices are selected from the stored second predetermined number of node information, and the save instruction means sends the node information and the save instruction information to the selected node device. This is a storage instruction device.

  According to the present invention, the second predetermined number of node information larger than the first predetermined number having a shorter participation period in the content distributed storage system is acquired and stored, and the stored second predetermined number of node information is stored. A first predetermined number of node devices can be selected from among them to instruct storage of content data.

  In order to solve the above-mentioned problem, a third aspect of the present invention is the storage instruction apparatus according to the second aspect, wherein the first predetermined number of node devices can be selected based on the node information. A determination unit that determines whether the selection unit is selectable by the determination unit, the selection unit selects the first predetermined number of node devices and cannot be selected by the determination unit. A node device identified by the generated node device identification information, comprising: identification information generating means for generating the first predetermined number of the node device identification information if determined to be present; The storage instruction device sends the storage instruction information to the storage device.

  According to the present invention, when the first predetermined number of node devices cannot be selected, node device identification information such as a node ID is generated and specified by the node device identification information based on the node device identification information. Since a message instructing storage of content data can be sent to the node device to be operated, even if the first predetermined number of node devices cannot be selected from the node information stored in the node information storage means The node device identification information such as the node ID can be generated and the other node devices can be instructed to store the content data reliably according to the node ID.

  In order to solve the above-mentioned problem, the invention according to claim 4 is the node device functioning as the storage instruction device according to claim 2, wherein the node information stored in the node information storage means is used. Of the second predetermined number of specified node devices, a third predetermined number of node devices are extracted to generate divided node information, and node information stored in the node information storage unit is extracted. , Updating means for updating the node information storage means excluding the divided node information from the second predetermined number of node devices, wherein the selection means is the node information updated by the updating means The node device is characterized in that the first predetermined number of node devices are selected from the node information of the storage means.

  According to the present invention, the node device instructed to store the content data from another node device or the content input server is divided node information extracted and divided from the node information stored in the node information storage means. A first predetermined number of node devices can be selected from the node information excluding.

  In order to solve the above-mentioned problem, the invention according to claim 5 is the node device according to claim 4, wherein the save instructing unit is configured to provide the node device selected by the selecting unit with respect to the node device. The node device is characterized in that it transmits split node information and the save instruction information.

  According to the present invention, when the node device instructs the other node devices participating in the distributed content storage system to store, the divided node information is transmitted and the storage is instructed. The instructed other node device can select the first predetermined number of node devices based on the acquired divided node information, and instruct the selected node device to save the content data.

  In order to solve the above problem, the invention according to claim 6 is the node device according to claim 4 or claim 5, wherein the selection means and the save instruction means are configured such that the content data includes the plurality of contents data. The node device is characterized in that selection of the first predetermined number of node devices and transmission of the storage instruction information to the selected node devices are repeatedly performed until the release date and time that can be used between the node devices.

  According to the present invention, the storage instruction can be repeatedly performed until the content publication date and time, and the content data can be pre-distributed to the node devices participating in the distributed content storage system until the content publication date and time.

  In order to solve the above-mentioned problem, the invention according to claim 7 is the node device according to claim 4 to claim 6, wherein the update unit is a node device already selected by the selection unit. Node information is updated by removing node information from the node information storage means.

  According to the present invention, it is possible to prevent the same node device from being instructed to store content data repeatedly.

  In order to solve the above-mentioned problem, the invention described in claim 8 is the node device according to claim 6 or 7, wherein storage instruction information receiving means for receiving the storage instruction information from another device is provided. And when the storage instruction information receiving means receives the storage instruction information, the acquisition means acquires the node device identification information and a participation period from the other device, and the node information storage means Storing the node information in which the acquired node device identification information and the participation period are associated with each other, and the selection unit is configured to store the node having a shorter participation period based on the node information stored in the node information storage unit. One node device is selected, and the save instruction means sends the save instruction information to the selected node device.

  According to this invention, when the node device receives the save instruction information from another device such as the content input server or another node device and receives the save instruction, the other device has transmitted the save instruction information. The node device identification information and the participation period can be acquired from the node information and stored in the node information storage means, and the save instruction information can be transmitted to the node device selected based on the stored node information.

  In order to solve the above-mentioned problem, the invention according to claim 9 is the node device according to claim 8, wherein the disclosure date and time of the content data is received from the other device that has transmitted the storage instruction information. It is a node device characterized by having disclosure date information acquisition means for acquiring the disclosure date information shown.

  According to the present invention, a node device that has received an instruction to save content data can easily acquire and grasp the disclosure date and time of the content data.

  In order to solve the above problem, an invention according to claim 10 is a storage instruction processing program that causes a computer to function as the storage instruction device according to any one of claims 1 to 3. .

  In order to solve the above problem, an invention according to claim 11 is a node processing program that causes a computer to function as the node device according to any one of claims 4 to 9.

  In order to solve the above-described problem, the invention according to claim 12 is a storage for storing content data in a node device so that the plurality of content data can be used among a plurality of node devices that can communicate with each other via a network. A storage instruction method in a content distribution storage system including an instruction device, wherein the storage instruction device includes node device identification information for identifying the node device, and the content distribution storage system in the node device of the node device identification information. A step of acquiring a participating participation period and storing it as node information in association with the node information storage means, and the saving instruction device is configured to perform the participation based on the node information stored in the node information storage means. A first predetermined number of the node devices having a shorter period are selected, and the selected node devices are copied. A step of sending the store instruction information for instructing storage of Ceiling data, a saving instruction method characterized by having a.

  According to the present invention, when content data is input to the content distributed storage system, the node device having a short participation period in the content distributed storage system is instructed to store the content data of the node device. It becomes possible to instruct storage of content data to a node device that is estimated to have a relatively large free recording capacity, and the recording capacity of the recording unit for recording the content data of each node device is effectively balanced. A distributed content storage system that can be used can be realized.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, the best embodiment of the invention will be described with reference to the drawings.

[1. Configuration of distributed content storage system]
First, with reference to FIG. 1 and the like, a schematic configuration and the like of the content distributed storage system according to the present embodiment will be described.

  FIG. 1 is a diagram showing an example of a connection mode of each node device in the distributed content storage system according to this embodiment.

  As shown in the lower frame 101 of FIG. 1, IX (Internet eXchange) 3, ISP (Internet Service Provider) 4a, 4b, DSL (Digital Subscriber Line) line operators (devices) 5a, 5b, FTTH (Fiber To A network (real-world communication network) 8 such as the Internet is constructed by a line provider (device) 6 and a communication line (for example, a telephone line or an optical cable) 7. Note that a router for transferring data (packets) is appropriately inserted into the network 8 in the example of FIG.

  A plurality of node devices (hereinafter referred to as “nodes”) Nn (n = 1, 2, 3,...) Are connected to such a network 8 via a router. Each node Nn is assigned a unique manufacturing number and an IP (Internet Protocol) address. The content distributed storage system S according to the present embodiment is a peer-to-peer network system formed by participation of any of a plurality of nodes Nn, as shown in the upper frame 100 of FIG. It has become.

  A network 9 shown in the upper frame 100 of FIG. 1 is a P2P network (overlay network, logical network) 9 constituting a virtual link formed using the existing network 8. Such a P2P network 9 is realized by a specific algorithm, for example, an algorithm using DHT.

  Each node Nn participating in the distributed content storage system S (in other words, the P2P network 9) is assigned a node ID that is unique identification information having a predetermined number of digits. The node ID is, for example, a value (for example, the bit length is 160 bits) obtained by hashing an IP address or a manufacturing number individually assigned to each node Nn with a common hash function (for example, SHA-1). Yes, it will be distributed in one ID space without any bias.

  Furthermore, the content distributed storage system S is a content input server CS as an example of the storage instruction device of the present invention that inputs new content into the content distributed storage system S, and the node Nn joins the content distributed storage system S. And a database server DS that manages and stores the registration date and time of each node Nn in the content distributed storage system S, the IP address of each node Nn, the node ID, and the like as node information.

  The participation in the content distributed storage system S is such that the non-participating node Nn (for example, the node N25) receives its IP address information and the node from the authentication server AS in order to receive permission to participate in the system S. This is performed by requesting system use registration (registration request) together with the ID and allowing the authentication server AS to participate in the distributed content storage system S.

  When a new node Nn (new participation node Nn) accesses the authentication system AS and performs system use registration, the authentication server AS makes an IP address and a node ID (node ID) of the new participation node Nn to the database server DS. An example of device identification information) and registration date / time are notified, and the database server DS stores (registers) them in association with each other.

  On the other hand, the new participation node Nn permitted to participate participates in the system S with respect to any node Nn that has already participated in the system S (for example, a contact node that always participates in the system S). Participating in the content distributed storage system S by transmitting a participation message indicating that it has been done.

  Each node Nn participating in the distributed content storage system S holds a routing table using DHT. Therefore, the node Nn (contact node or the like) that has received the participation message from the new participation node Nn copies the routing table held by itself and sends it to the new participation node Nn.

  This routing table defines the transfer destinations of various messages on the content distributed storage system S, and specifically includes the node ID, IP address, port number, etc. of the node Nn that is moderately separated in the ID space. Multiple node information items are registered. The IP address and port number are examples of network address information.

  One node Nn participating in the content distributed storage system S registers the minimum necessary node information of the nodes Nn among all the nodes Nn participating in the system S in the routing table, With respect to the node Nn that does not know (store) the node information, various messages are transferred between the nodes Nn to be delivered.

  Such a routing table using DHT is well known in Japanese Patent Application Laid-Open No. 2006-197400 and the like, and will not be described in detail.

  Next, content used in each node Nn in the content distributed storage system S will be described.

  In the distributed content storage system S, content data (content replication data, hereinafter referred to as replicas) of various contents (for example, movies and music) having different contents are transmitted to a plurality of nodes Nn in a predetermined file format. It is stored (stored) in a distributed manner, and the replica can be used among the nodes Nn. For example, the node N5 stores a replica of the movie content with the title XXX, while the node N3 stores a replica of the movie content with the title YYY. (Hereinafter referred to as “content holding nodes”).

  In addition, information such as a content name (title) and a content ID (identification information unique to each content) is added to each of these content replicas. This content ID is generated, for example, by hashing the content name + arbitrary numerical value (or may be the first few bytes of the content data) with a hash function common to obtaining the node ID (node ID and Placed in the same ID space). Alternatively, the system administrator may give a unique ID value (same bit length as the node ID) for each content. In this case, the catalog in which the correspondence between the content name and the content ID is written is distributed to all the nodes Nn participating in the distributed content storage system S by the system administrator.

  When a new content is input to the content distributed storage system S by the content input server CS, the node Nn having a shorter participation period in the content distributed storage system S is instructed to store a new content replica. Is done. Specifically, the content input server CS has the IP address, node ID, etc. of the second predetermined number of nodes Nn (for example, 10, 100, etc.) that have joined the system S from the database server DS more recently. Is acquired, and a first predetermined number of nodes Nn are selected from the storage destination candidate list (for example, one is randomly selected), and the selected node Nn is selected. Send a replica of the content and instruct it to save. The node Nn that has received the content storage instruction from the content input server CS stores (records) the content replica in the cache area of its own storage unit.

  Thereafter, the node Nn notifies the node Nn that manages the location of the replica of the content (hereinafter referred to as “root node” or “root node of content data (content ID)”) that the replica is stored. Publish (registration) including the content ID of the replica and its own node information (node ID, IP address, etc.) (in order to make it public to other nodes Nn participating in the system S) Generate a message and send the publish message to the root node (addressed to the root node).

  As a result, the publish message arrives at the root node by DHT routing using the content ID as a key. Then, the root node registers (stores in the index cache) index information including a set of node information and content ID included in the received publish message. In this way, the node Nn that has received the save instruction newly becomes a content pre-holding node that holds a replica of the content.

  Note that the index information including the set of node information and content ID included in the publish message is also registered (cached) in the cache node in the transfer path to the root node.

  Then, when the new content stored in the node Nn comes to the release date, the information on the content is posted in a catalog list distributed by the system operator, and a replica of the content can be downloaded (participating in the content distributed storage system S) Can be shared among a plurality of nodes Nn). Each node Nn that desires to view the content (i) searches for the content (ii) downloads the content from the node Nn that stores the content, and views and views the content.

  In addition, the location of the replica stored in this manner, that is, a set of node information (node ID, IP address, etc.) of the node Nn storing the replica and a content ID corresponding to the replica of the content is included. Index information is stored (stored in an index cache) and managed by a root node or the like.

  That is, the node information of the content holding node that stores the content replica is managed by each root node so that it can be provided in response to an inquiry from another node Nn.

  For example, the index information about the replica of the movie content with the title XXX is managed by the node N4 which is the root node of the content (content ID), and the index information about the replica of the movie content with the title YYY is Managed by the node N7 which is the root node of the content (content ID). Further, such a root node is determined to be, for example, a node Nn having a node ID closest to the content ID (for example, the higher-order digits match more).

  When a user of a certain node Nn wants to acquire a replica of the desired content, the node Nn that desires to acquire the replica (hereinafter referred to as “user node”) determines the content ID and the self of the content selected by the user. A content location inquiry (search) message (query) including the IP address of the client is generated and sent to another node Nn according to a routing table using its own DHT. That is, the user node sends a content location inquiry (search) message to the root node (to the root node). As a result, the content location inquiry (search) message finally arrives at the root node by DHT routing using the content ID as a key, like the publish message described above.

  Note that attribute information such as the content name and content ID of the content to be selected by the user at each node Nn is described in the content catalog list. The content ID included in the content location inquiry (search) message may be generated by the user node by hashing the content name with the common hash function. The DHT routing is known in Japanese Patent Application Laid-Open No. 2006-197400 and the like, and thus detailed description thereof is omitted.

  The root node that receives the content location inquiry (search) message acquires index information corresponding to the content ID included in the content node from the index cache, and uses the index information as a user who is the transmission source of the content location inquiry message. Reply to the node. The user node that has acquired the index information in this way connects to the content holding node based on the IP address of the content holding node included in the index information, transmits a content transmission request message, and then creates a replica of the content from there. It becomes possible to acquire. Note that the index information may include, for example, node information of a plurality of content holding nodes (when replicas of the same content are stored in a plurality of content holding nodes). In such a case, the user node can select one content holding node from among the plurality of content holding nodes and connect to the selected content holding node to obtain a content replica.

  The root node transmits a content transmission request message to the content holding node indicated by the IP address or the like included in the index information, whereby the user node acquires the replica from the content holding node. You can also The user node can also acquire the index information from a cache node that caches the same index information as the root node until the content location inquiry message reaches the root node.

  In addition, the user node that stored the replica of the content acquired from the content holding node sends the above-described publish message to the root node (to the root node) to notify the root node that the replica has been stored. Then, it becomes a content holding node that holds a replica of the content.

  In the content distributed storage system S described above, before a newly entered content replica becomes available in the system S (before publication), any content from the content input server CS as an example of a storage instruction device Is distributed to some nodes Nn (content pre-retention nodes) by further transmitting the replica to other nodes Nn and instructing the storage to be transmitted. To be saved. This is to avoid concentration of access to the replica of the content after the newly input content is disclosed.

  At this time, the content input server CS receives a second predetermined number with a shorter participation period from the database server DS that registers the participation period of all nodes Nn participating in the content distributed storage system S in the system S. Is obtained, and a first predetermined number (first predetermined number <second predetermined number) of nodes Nn is randomly selected and the selected node is obtained. Instruct Nn to store a replica of the new content. Further, the node Nn that is instructed to store is also configured as a storage instructing device, and selects a node Nn having a shorter participation period based on the storage destination candidate list and instructs to store a replica of the newly input content. To do.

  As a result, it is estimated that the recording capacity of the cache area of the storage unit for storing (recording) the replica has a margin (estimated that the free recording capacity is relatively large), and the node Nn having a short participation period is stored in the content. It can be a pre-holding node.

[2. Configuration and function of each device]
[2-1. Configuration and function of node Nn]
Next, the configuration and function of the node Nn will be described with reference to FIG.

  FIG. 2 is a diagram illustrating a schematic configuration example of the node Nn.

  As shown in FIG. 2, each node Nn includes a control unit 11 as a computer composed of a CPU having a calculation function, a working RAM, a ROM for storing various data and programs, and various data (for example, content data). Storage unit 12 as node information storage means configured to store and store (store) various programs, etc., and a replica of the storage destination candidate list, index information, DHT, etc. A buffer memory 13 that temporarily stores a replica of content data and a decoder that decodes (data decompression, decoding, etc.) encoded video data (video information) and audio data (audio information) included in the content data replica Unit 14 and the decoded video data, etc. A video processing unit 15 that performs a predetermined rendering process and outputs the video signal; a display unit 16 such as a CRT 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 Is converted into an analog audio signal by D (Digital) / A (Analog) conversion and then amplified and output by an amplifier, and a speaker 18 outputs the audio signal output from the audio processing unit 17 as a sound wave. And the communication unit 20 for controlling communication of information among the other nodes Nn, the content input server CS, the database server DS, the authentication server AS, and the like through the network 8, and an instruction according to the instruction received from the user An input unit for supplying a signal to the control unit 11 (for example, a keyboard, a mouse, or an operation A channel, etc.) 21, is configured to include a control unit 11, storage unit 12, a buffer memory 13, decoder unit 14, a communication unit 20, and the input unit 21 are connected to each other via a bus 22. As the node Nn, a personal computer, an STB (Set Top Box), a TV receiver, or the like can be applied.

  When the content distributed storage system S includes a contact node that is an access destination when participating in the system S, the storage unit 12 stores the IP address and port number of the contact node. Yes. Further, the storage unit 12 stores a stored content management table for registering information (title, content ID, etc.) related to the replica of the content stored (recorded) in the cache area.

  In such a configuration, the control unit 11 performs overall control by reading and executing a program (including the storage instruction processing program and the node processing program of the present invention) stored in the storage unit 12 or the like by the CPU. By participating in the content distributed storage system S, processing as at least one of the user node, relay node, root node, cache node, content holding node, and content pre-holding node described above is performed. .

  In addition, the control unit 11 that performs processing as the storage instruction device includes an acquisition unit, a node information storage unit, a selection unit, a storage instruction unit, a determination unit, an identification information generation unit, a divided node information generation unit, a storage instruction information in the present invention. It functions as a receiving means, an updating means, and a disclosure date / time information obtaining means. The storage instruction processing program and the node processing program may be downloaded from a predetermined server on the network 8, for example, or recorded on a recording medium such as a CD-ROM and stored in the recording medium. You may make it read via a drive.

  When the content input server CS or another node Nn instructs to store a new replica of the content to be input to the content distributed storage system S, the replica is stored in the storage unit 12. The storage destination candidate list received together with the storage instruction is also temporarily stored in the storage unit 12. Then, the list is divided for transmission and storage, one node Nn (an example of the first predetermined number) is selected from the storage destination candidate list for storage, and the replica and transmission are selected for the selected node Nn. The save destination candidate list is sent to instruct to save the replica. The division of the storage destination candidate list will be described in detail later.

[2-2. Configuration and function of authentication server AS]
Next, a schematic configuration of the authentication server AS will be described with reference to FIG. FIG. 3 is a block diagram illustrating a schematic configuration of the authentication server AS according to the embodiment.

  As shown in FIG. 3, the authentication server AS included in the distributed content storage system S according to the embodiment includes a CPU having a calculation function, a working RAM (Random Access Memory), and a ROM (Read Only) for recording various data and programs. Control unit 101 composed of a memory), a storage unit 102 composed of an HD etc. for storing and storing various data and programs, etc., and each node Nn included in the content distributed storage system S through a network A communication unit 103 for controlling communication of information between the content input server CS and the database server DS, and an instruction signal according to the instruction received from an operator who operates the authentication server AS. And an input unit 104 (for example, a keyboard, a mouse, or an operation panel) to be output to 101. Configured Te, the control unit 101, storage unit 102, the communication unit 103 and input unit 104 is connected so can exchange data with each other through a bus 105.

  Then, when the CPU in the control unit 101 executes various programs recorded in the storage unit 102 or the like, the control unit 101 performs overall control of the overall operation as the authentication server AS according to the embodiment.

  As illustrated in FIG. 4, the control unit 101 receives a registration request to the content distributed storage system S from a node (new participation node) that desires to newly participate in the content distributed storage system S (see FIG. 4 [ 1]), by performing authentication processing to determine whether registration (participation in the content distributed storage system S) is permitted or not, if registration is permitted, participation (registration) in the content distributed storage system S is permitted. The described terminal certificate is notified to the newly participating node via the communication unit 103 (see [2] in FIG. 4).

  Then, the date and time when the terminal certificate is notified to the new participating node (FIG. 4 [2]) (or the date and time when the registration request is received from the new participating node (FIG. 4 [1]) may also be used). The registration date / time of the participating node in the system S is transmitted as node information together with the node ID and IP address to the database server DS via the communication unit 103, and a request is made to record the registration date / time of the new participating node (registration date / time). (Recording request) (see FIG. 4 [3]). In addition, the new participation node that has received the terminal certificate from the authentication server AS and is permitted to participate transmits a participation message to the contact node and participates in the distributed content storage system S (FIG. 4 [4]). ]reference). In FIG. 4, only the nodes N5, N8, N10, etc. are shown as nodes Nn participating in the content distributed storage system S (P2P network 9), and the diagram is simplified.

[2-3. Configuration and function of database server DS]
Next, a schematic configuration of the database server DS will be described with reference to FIG. FIG. 5 is a block diagram showing a schematic configuration of the database server DS according to the embodiment.

  As shown in FIG. 5, the database server DS included in the content distributed storage system S according to the embodiment includes a CPU having a calculation function, a working RAM (Random Access Memory), and a ROM (Read Only) for recording various data and programs. A user who stores and stores (stores) node information including a registration date / time, a node ID, and an IP address of each node Nn in response to a registration date / time recording request from the control unit 201 and the authentication server AS. A storage unit 202 including an information database 202a and configured to store and store (store) various data, programs, and the like, and other devices such as each node Nn, content input server CS, and authentication server AS through the network A communication unit 203 for controlling communication of information with the database server DS An input unit (for example, a keyboard, a mouse, an operation panel, or the like) 204 that receives an instruction from an operating operator and outputs an instruction signal corresponding to the instruction to the control unit 201. The storage unit 202, the communication unit 203, and the input unit 204 are connected to each other via a bus 205 so that data can be exchanged.

  Then, when the CPU in the control unit 201 executes various programs recorded in the storage unit 202 and the like, the control unit 201 performs overall control of the entire operation as the database server DS according to the embodiment.

  When the control unit 201 receives the node information of the newly participating node from the authentication server AS and receives a registration date / time recording request (registration date / time recording request) (see FIG. 4 [1]), the user information in the storage unit 202 is received. The database 202a stores the registration date / time, node ID, and IP address of the new participating node in association with each other.

  FIG. 6 shows an example of node information stored and saved in the user information database 202a. In the user information database 202a, every time there is a node newly participating in the content distributed storage system S, the node information of the new participating node received from the authentication server AS according to the procedure described above is registered. Therefore, in this user information database 202a, the registration date and time (Nx_n), node ID (Nx_n), and IP address (Nx_n) of all the nodes Nn participating in the content distributed storage system S are associated with the node information Nx_1. , Node information Nx_2, node information Nx_3, and node information Nx_n are registered (stored).

  Then, in response to a request from the content input server CS, the control unit 201a extracts and stores the requested number of pieces of node information whose registration date is more recent (newly registered) from the user information database 202a. A destination candidate list is generated and transmitted to the content input server CS.

[2-4. Configuration and function of content input server CS]
Next, a schematic configuration of the content input server CS will be described with reference to FIG. FIG. 7 is a block diagram showing a schematic configuration of the content input server CS according to the embodiment.

  As shown in FIG. 7, the content input server CS included in the content distributed storage system S according to the embodiment includes a CPU having a calculation function, a working RAM (Random Access Memory), and a ROM (Read Read) that records various data and programs. For recording and storing (stores) content data to be input, content data that has already been input, a storage destination candidate list acquired from the database server DS, and other necessary programs. A storage unit 302 configured as a node information storage unit composed of an HD or the like, and a communication unit for controlling communication of information with other devices such as each node Nn, authentication server AS, and database server DS through the network 8 303 and accepting an instruction from an operator who operates the content input server CS And an input unit (for example, a keyboard, a mouse, or an operation panel) 304 that outputs an instruction signal corresponding to the instruction to the control unit 301, and includes a control unit 301, a storage unit 302, a communication unit 303, and an input. The units 304 are connected to each other via a bus 305 so as to be able to exchange data with each other.

  Then, the CPU in the control unit 301 reads out and executes the program (including the storage instruction processing program of the present invention) recorded in the storage unit 302 and the like so as to control the overall operation and cooperate with the above-described components. Then, the content input server CS is caused to function as a storage instruction device in the present invention. And the control part 301 which performs a process as a preservation | save instruction | indication apparatus functions as an acquisition means in this invention, a node information storage means, a selection means, a determination means, a preservation | save instruction means, and an identification information generation means. The storage instruction processing program may be downloaded from a predetermined server on the network 8, for example, or recorded on a recording medium such as a CD-ROM and via a drive of the recording medium. It may be read.

  As shown in FIG. 8, when the control unit 301 inputs a new content replica to the content distributed storage system S, that is, when it is distributed and stored in the nodes Nn participating in the content distributed storage system S, the database server For example, the DS requests a storage destination candidate list in which node information of, for example, 10 nodes (an example of the second predetermined number) having a short participation period in the content distributed storage system S is posted (FIG. 8 [1] ], The storage destination candidate list is acquired from the database server DS (acquisition means) (see FIG. 8 [2]).

  And the control part 301 preserve | saves the acquired preservation | save destination candidate list in the memory | storage part 302 (node information memory | storage means), for example, one random (1st predetermined predetermined) among the node information published in the said preservation | save destination candidate list Node information (selection means), and save instruction information is sent to the node Nn corresponding to the node information to instruct to save a replica of the new content (see FIG. 8 [3]). . For example, when the node information Nx_1 is selected from the node information posted on the storage destination candidate list, the node N1 indicated by the node information Nx_1 is instructed to store a replica of the new content (save instruction unit). .

  In the present embodiment, when the control unit 301 of the content input server CS instructs the storage of the content replica, the content replica is transmitted to the storage destination node Nn together with the instruction, so-called “push type”. Is stored. Then, the node Nn instructed to store the content replica records the replica in the cache area of its own storage unit 12 to become a content pre-holding node and to notify the root node that the replica has been stored. (In other words, for publishing to other nodes Nn participating in the system S), a publish message including the content ID of the replica and its own node information is directed to the root node ( Send to the root node). As a result, the publish message arrives at the root node by DHT routing using the content ID as a key, like the content location inquiry (search) message described above.

  The control unit 301 also transmits a storage destination candidate list acquired from the database server DS to the storage destination node Nn.

  In the example shown in FIG. 8, only the nodes N5, N8, N10, etc. are shown as nodes Nn participating in the content distributed storage system S (P2P network 9), and the diagram is simplified. Further, the content input server CS obtains from the database server DS a storage destination candidate list in which 10 pieces of node information from the node information Nx_1 to the node information Nx_10 are posted, but the content input server CS acquires new content. The number to be stored in the system (the number to be stored) is determined according to the popularity of the content, etc., and the number of node information requested to the database server DS (second predetermined number) can be changed as appropriate according to the number to be stored. For example, when a large number of replica distribution requests are predicted after the release, the number of storages is determined to be large, and at least the number of storages determined is requested to be node information. That's fine. Note that the popularity of content refers to, for example, when the content is a movie and has already been released to the theater, or is determined according to the number of spectators, or based on the award history of contests, etc. If the content is music, it may be determined in consideration of the sales of the artist's past works.

  Then, information (publication date / time information) indicating the publication date / time, which is the date / time when the content replica can be shared between other nodes Nn, is included in the storage instruction information or the content replica and transmitted to the selected node Nn. Configure to The node Nn that receives the save instruction information and receives the replica save instruction stores the replica in the cache area of its own storage unit 12 in association with the content ID, and performs registration processing (transmission of a publish message). .

  After that, when the release date and time indicated by the save time information or the release time information acquired in the content replica is reached, the content information (content ID, title, etc.) is posted on the catalog list distributed by the system operator, and the content The other nodes Nn participating in the distributed storage system S generate a content location inquiry message (query) that inquires about the location of a desired replica based on the content ID of the content listed in the catalog list and send it to the root node. (In other words, the location of the replica of the content is inquired to the root node), the node Nn holding the replica is known, and the replica can be downloaded from the node Nn holding the replica.

  In addition, the number of node information requested by the content input server CS to the database server DS (second predetermined number) is larger than the number of nodes Nn selected by the node Nn that has received the storage instruction (first predetermined number). To do.

  Further, the node Nn that receives the replica storage instruction from the content input server CS instructs the other nodes Nn participating in the content distributed storage system S to store the content replica. That is, the node Nn that has received a replica storage instruction from the content input server CS functions as a storage instruction device. Then, the other node Nn that has received this storage instruction similarly instructs other nodes Nn participating in the content distributed storage system S to store the content replica. As described above, the content input server CS functioning as a storage instruction device or the node Nn participating in the system S repeats the replica storage instruction to the node Nn participating in the system S until the release date and time. Content replicas can be distributed and stored in advance in the system S before publication.

[3. Save destination candidate list]
Next, division of a storage destination candidate list that is transmitted and received between each node Nn when a replica storage instruction is issued will be described.

  The node Nn that has received the storage instruction information from the content input server CS (storage instruction information receiving means) determines the storage destination candidate list acquired from the content input server CS as the storage destination candidate list for storage and the storage destination candidate list for transmission. Divide into FIG. 9 shows an example in which the storage destination candidate list received from the content input server CS is divided into two so that the node information is halved.

  For example, a storage destination candidate list (node information Nx_1 to Nx_10) in which, for example, ten (second predetermined number) node information is posted from the content input server CS (node information Nx_1 to Nx_10) is acquired and stored in its own storage unit 12 (node Information storage means). After that, five pieces of node information (an example of the third predetermined number) are extracted from the saved destination candidate list (node information Nx_1 to Nx_10) and divided, and the destination candidate list (node information Nx_6) as divided node information is divided. ˜Nx — 10) (divided node information generating means).

  Then, the storage destination candidate list (node information Nx_1) that is obtained by removing the node information Nx_6 to Nx_10 obtained by dividing (extracting) the storage destination candidate list (node information Nx_1 to Nx_10) stored in the storage unit 12 of itself. To Nx_5) (update means), and from the save destination candidate list (node information Nx_1 to Nx_5) stored in the storage unit 12, the node Nn to be instructed to save is selected (selection means), and the selected node Nn The node information extracted with respect to the transmission destination candidate list for transmission (node information Nx_6 to Nx_10) is transmitted together with the replica, and the storage is instructed (storage instruction means).

  Hereinafter, the storage destination candidate list transmitted from the database server DS to each node Nn through the content input server CS will be described with reference to FIGS.

  FIG. 10 is a diagram illustrating a state of the storage destination candidate list exchanged between the database server DS, the content input server CS, and the nodes N5 and N1, and FIG. 11 is exchanged between the nodes N1, N7, and N8. It is a figure which shows the mode of a preservation | save destination candidate list.

  The database server DS extracts, from the user information database 202a, node information having a more recent registration date and time (newly registered) as many times as requested by the content input server CS, and a storage location where the node information is posted A candidate list (node information Nx_1 to Nx_10) is generated and transmitted to the content input server CS.

  The content input server CS stores the received storage destination candidate list (node information Nx_1 to Nx_10) in its own storage unit 302, and a node that instructs to store a replica from the stored storage destination candidate list (node information Nx_1 to Nx_10) One Nn is selected at random. In the figure, the node N5 is selected, and the selected node N5 is instructed to store the replica together with the storage destination candidate list (node information Nx_1 to Nx_10).

  When the node N5 receives the storage destination candidate list (node information Nx_1 to Nx_10) from the content input server CS and receives an instruction to save the replica, the node N5 receives a third predetermined number from the storage destination candidate list (node information Nx_1 to Nx_10). The node information is extracted (divided), and the storage destination candidate list (node information Nx_1 to Nx_5) for storage excluding the extracted node information is stored in its own storage unit 12. One node for instructing to store the replica is randomly selected from the storage destination candidate list (node information Nx_1 to Nx_5) stored in the storage unit 12 of the device itself. In the figure, the node N1 is selected, and the selected node N1 is instructed to store the replica together with the transmission destination candidate list (node information Nx_6 to Nx_10) including the extracted node information.

  Next, when the node N1 receives the storage destination candidate list on which five (second predetermined number) node information (Nx_6 to Nx_10) is received from the node N5 and receives an instruction to store the replica, the storage destination candidate list A third predetermined number of node information is extracted (divided) from (node information Nx_6 to Nx_10), and a storage destination candidate list (node information Nx_6 to Nx_7) for storage excluding the extracted node information is stored in its own storage unit 12. To remember. From the storage destination candidate list (node information Nx_6 to Nx_7) stored in the storage unit 12 of the self, one node (first predetermined number) instructing the storage of the replica is randomly selected. In the figure, the node N7 is selected, and the selected node N7 is instructed to store the replica together with the transmission destination candidate list (node information Nx_8 to Nx_10) including the extracted node information.

  Further, after instructing the node N1 to store the replica, the node N5 deletes the information of the node N1 instructed to store from the storage destination candidate list stored in its own storage unit 12, as shown in FIG. The third predetermined number of node information is further extracted (divided) from the updated storage destination candidate list (node information Nx_2 to Nx_5), and the storage destination candidate list for storage excluding the extracted node information ( Node information Nx_2 to Nx_3) is stored in its own storage unit 12. Then, one node instructing to save the replica is randomly selected from the save destination candidate list (node information Nx_2 to Nx_3) stored in the storage unit 12 of the self. In the figure, the node N3 is selected, and the selected node N3 is instructed to store the replica together with the transmission destination candidate list (node information Nx_4 to Nx_5) for transmission composed of the extracted node information.

  Similarly, the node N3 also divides the storage destination candidate list (node information Nx_4 to Nx_5) received from the node N1 for storage and transmission, and replicas the node N4 selected from the storage destination candidate list for storage. Instruct to save.

  In the example shown in FIG. 12, the node N4 has received the storage destination candidate list in which only the node information of the node N5 is posted, and the node N4 instructs the node N5 to store. However, as described above, since the node N5 has already stored the replica according to the storage instruction from the content input server CS, the storage instruction is duplicated for the node N5 as it is. In preparation for such a case, when the content input server CS sends the storage destination candidate list to the node N5, the node information of the node N5 may be deleted from the storage destination candidate list and transmitted. Good.

  As described above, the node Nn that has received the storage instruction from the content input server CS functions as a storage instruction device, and the node Nn that has a relatively short participation period in the content distributed storage system S posted in the storage destination candidate list. The node Nn that received the save instruction saves the replica, and the node Nn that received the save instruction further instructs other nodes Nn to save the replica based on the save destination candidate list I will do it. The content replica storage instruction and the storage based on the instruction are indicated by the storage instruction information received from the content input server CS or other node Nn that is the storage instruction source or the disclosure date / time information received in the content replica. It will be repeated until the content release date.

  By the way, since the storage destination candidate list is divided and updated every time a storage instruction is given at each node Nn, it is assumed that the node information posted in the storage destination candidate list before the release date is lost. Also, when the content input server CS cannot acquire the storage destination candidate list from the database server DS, or when the node Nn that receives the storage instruction from the content input server CS cannot receive the storage destination candidate list from the content input server CS Is also envisaged. In such a case, for example, when the content input server CS cannot acquire the storage destination candidate list from the database server DS, the control unit 301 of the content input server CS functions as identification information generating means, and the content input server CS The CS is configured to generate a first predetermined number of node IDs and send a save instruction message toward the generated node ID. Further, even when the node Nn that has received the storage instruction from the content input server CS cannot receive the storage destination candidate list from the content input server CS, the control unit 11 sets the first predetermined number of node IDs in each node Nn. Generate and send a save instruction message toward the generated node ID.

  Then, the sent save instruction message reaches the node Nn having the same node ID as the generated node ID or the node Nn having a node ID close to the generated node ID, and the final destination of the save instruction message That is, the node Nn stores the replica. In this case, in addition to the configuration in which the storage instruction message and the replica are transmitted together and the replica is transmitted by the “push type”, only the storage instruction message is transmitted, and the node Nn that is the final destination of the storage instruction message is the message The storage instruction source (content input server or node Nn) is requested based on the node information (node ID, IP address, etc.) of the storage instruction source included in the request to obtain a replica to be acquired. May be.

[4. Processing of each device]
In the above operation, processing in the authentication server AS, database server DS, content input server CS, and each node Nn will be described in detail with reference to the drawings.

[4-1. Processing of authentication server AS]
FIG. 13 is a flowchart showing the processing of the control unit 101 in the authentication server AS. For example, when a system administrator or the like is instructed to operate the authentication server AS via the input unit 104 (or communication) (When information indicating that the process is instructed is received via the unit 103).

  First, the control unit 101 determines whether or not the power of the authentication server AS is turned off (step S10). If not turned off (step S10: No), it newly participates in the content distribution storage system S. It is determined whether or not a registration request has been made from a node (a new participating node) that desires (step S11).

  As a result of the determination, if a registration request is made (step S11: Yes), the participation determination (authentication process) is performed based on the node ID, IP address, etc. received from the new participation node Nn, and participation (registration) is performed. Is approved (step S12), the terminal certificate is notified to the new participating node Nn via the communication unit 103. (Step S13).

  Then, the control unit 101 transmits the node information of the newly participating node Nn to the database server DS to request recording of the registration date and time (Step S14), and proceeds to Step S10.

  On the other hand, when the registration request is not made (step S11: No), the process proceeds to step S10.

  Then, when the power is turned off (step S10: Yes), the process is terminated.

[4-2. Processing of new entry node Nn]
FIG. 14 is a flowchart showing processing of the control unit 11 when the node Nn participates in the content distributed storage system S. For example, a user who wants to participate in the content distributed storage system S can input via the input unit 204. It starts when the execution of the process is instructed.

  First, the control unit 11 determines whether or not the power of the node device Nn is turned off (step S20). If not turned off (step S20: No), the content is newly stored in the authentication server AS. A registration request is made to participate in the system S (step S21).

  Next, a terminal notice is obtained from the authentication server AS (step S22), and it is determined whether or not a terminal certificate has been obtained (step S23). If the terminal certificate can be acquired as a result of the determination (step S22: Yes), the content distribution storage system S is joined (joins the P2P network 9) and the process is terminated (step S24).

  On the other hand, when the terminal notice cannot be acquired from the authentication server AS (step S22: No), the process proceeds to step S20. This is to make a registration request to the authentication server AS again.

  Then, when the power is turned off (step S20: Yes), the process is terminated.

[4-3. Database server DS processing]
FIG. 15 is a flowchart showing the processing of the control unit 201 in the database server DS. For example, when a system administrator or the like operates through the input unit 204 to instruct execution of the processing (or through the communication unit 203). And the system administrator receives information to instruct execution of processing from another device operated by the system administrator).

  First, the control unit 201 determines whether or not the power of the database server DS is turned off (step S30). If the power is not turned off (step S30: No), the registration of the new participating node Nn from the authentication server AS. It is determined whether date / time recording is requested (step S31).

  As a result of the determination, if recording of the registration date / time is requested (step S31: Yes), the node information (node ID, IP address, registration date / time) of the new participating node acquired from the authentication server AS is stored in the user information database 202a. Register (step S32). On the other hand, if recording of the registration date / time is not requested from the authentication server AS (step S31: No), the process proceeds to step S33.

  Next, it is determined whether or not transmission of the storage destination candidate list is requested from the content input server CS (step S33).

  As a result of the determination, when transmission of the storage destination candidate list is not requested (step S33: No), the process proceeds to step S30, and when transmission of the storage destination candidate list is requested (step S33: Yes). Then, among the node information registered in the user information database 202a, node information having a newer registration date is listed as the requested number to generate a storage destination candidate list (step S34). That is, when ten requests are made, a storage destination candidate list is generated that includes ten pieces of node information from node information having the latest registration date and time to node information having the tenth newest registration date and time. Then, the generated storage destination candidate list is transmitted to the content input server CS (step S35), the process proceeds to step S30, and the processes from step S30 to step S35 are repeated until the power is turned off.

  Then, when the power is turned off (step S30: Yes), the process is terminated.

[4-4. Processing of content input server CS]
FIG. 16 is a flowchart showing processing of the control unit 301 in the content input server CS. For example, when a system administrator or the like operates the input unit 304 to instruct execution of the processing (or the communication unit 303 The storage instruction processing program of the present invention is read out and the processing is started (when information indicating that the processing is instructed is received from another device operated by the system administrator).

  First, the control unit 301 determines whether or not the power of the content input server CS has been turned off (step S40). If the power has not been turned off (step S40: No), a new content distribution storage system S is input. It is determined whether there is content to be processed (step S41).

  As a result of the determination, if there is no content to be input (step S41: No), the process proceeds to step S40. If there is content to be input (step S41: Yes), a node is determined based on the degree of popularity of the content. A storage destination candidate list is requested from the database server DS by designating the number of information (second predetermined number) (step S42).

  Subsequently, it is determined whether or not the storage destination candidate list has been acquired from the database server DS (step S43). If it can be acquired (step S43: Yes), the first predetermined number (from the acquired storage destination candidate list ( For example, one node Nn is selected (step S44), a storage destination candidate list is transmitted to the selected node Nn, and an instruction to store a replica of the content is transmitted (storage instruction information is transmitted) (step S45).

  On the other hand, when the storage destination candidate list cannot be acquired from the database server DS (step S43: No), the control unit 303 generates a first predetermined number of node IDs (step S46), and the node of the generated node ID A storage instruction message (storage instruction information) for instructing storage of a content replica is sent to Nn (step S47).

  Thereafter, after instructing storage in step S45 or step S47, the process proceeds to step S40, and the processes from step S40 to step S47 are repeated until the power is turned off.

  Then, when the power is turned off (step S40: Yes), the process is terminated.

[4-5. Processing of Node Nn after Participating in Content Distributed Storage System S]
FIG. 17 is a flowchart showing the process of the control unit 11 in an arbitrary node Nn participating in the content distributed storage system S, and obtains a terminal certificate from the authentication server AS and sends a participation message to the contact node. After the transmission, the storage instruction processing program and the node processing program of the present invention are read and the processing starts.

  First, the control unit 11 determines whether or not the power of the node Nn itself is turned off (step S60). If the power is not turned off (step S60: No), from the content input server CS or another node Nn. It is determined whether or not an instruction to store a content replica has been issued (step S61).

  As a result of the determination, if saving of the replica is instructed, it is determined whether or not the replica of the instructed content can be saved in its own storage unit 12 (step S62). Specifically, based on the free recording capacity of the HD in the storage unit 12 and the data capacity of the replica instructed to store, it can be determined whether or not the instructed replica can be stored. Compare the importance of the replica that has already been stored with the importance of the replica that has been instructed to save (for example, the higher popularity is given priority for storage). The existing replica may be deleted from the storage unit 12 to secure a free recording capacity.

  As a result of the determination, if it is possible to save the replica of the content instructed to be stored in its own storage unit 12 (step S62: Yes), the content replica and the storage from the storage instruction source (content input server CS or another node Nn) are stored. The destination candidate list is received (step S63), and a replica of the content is stored in its own storage unit 12 (step S64). The storage destination candidate list is stored in the storage unit 12.

  On the other hand, when it is not instructed to store the replica (step S61: No), and when it is not possible to store the instructed replica (step S62: No), the process proceeds to step S60.

  Then, after storing the replica (step S64), it functions as a storage instructing device (steps S65 to S72), and instructs other nodes Nn to store the replica based on the node information of the storage destination candidate list.

  First, it is determined whether or not there is a storage destination candidate list in the storage unit 12 (step S66). If there is a storage destination candidate list (step S66: Yes), the storage destination candidate list is transmitted to the storage destination candidate for transmission. The list is divided into a list and a storage destination candidate list for storage (step S67). Specifically, a third predetermined number of node information is extracted from the storage destination candidate list stored in the storage unit 12 to generate a storage destination candidate list for transmission, and the storage destination candidate list stored in the storage unit 12 is Update to the save destination candidate list excluding the extracted node information.

  Next, a first predetermined number of nodes Nn are randomly selected from the storage destination candidate list (for storage) stored in the storage unit 12 (step S68), and the generated storage destination candidate list and contents are selected in the selected node Nn. The replica is transmitted, the replica is instructed (storing instruction information is transmitted), and the node Nn is deleted from the storage destination candidate list in the storage unit 12 (step S69).

  On the other hand, when there is no storage destination candidate list in the storage unit 12 (step S66: No), the control unit 11 generates a first predetermined number of node IDs (step S70), toward the node Nn of the generated node ID. Then, a storage instruction message (sending storage instruction information) for instructing storage of the content replica is transmitted (step S71).

  Then, the loop processing from step S66 to S69 is performed until the publication date and time of the content replica, and the loop processing is terminated when the publication date and time indicated by the received publication date and time information included in the content replica or storage instruction information is reached (step S72). ).

  Thereafter, the process proceeds to step S60, and when the power is turned off (step S60: Yes), the process is terminated.

  As described above, when a new content replica is input to the content distributed storage system S, the content input server CS (or the node Nn) has a node Nn with a short participation period in the content distributed storage system posted. Since the first predetermined number of nodes Nn are selected from the save destination candidate list and the selected node Nn is instructed to save, for the node Nn that is estimated to have a relatively large free recording capacity for recording a replica Thus, it is possible to instruct the storage, and it is possible to realize the distributed content storage system S that can effectively use the recording capacity of the recording unit 12 of each node Nn in a balanced manner.

  In addition, since the first predetermined number of nodes Nn are randomly selected in step S68, it is possible to prevent the storage instructions from being concentrated on the node Nn having the shortest participation period (most recently joined). it can.

  In the above-described embodiment, the first predetermined number is “1” and one node Nn is selected from the storage destination candidate list. However, the present invention is not limited to this, and a plurality of nodes Nn are selected. May be. When a plurality of nodes Nn are selected (the first predetermined number is 2 or more), the storage destination candidate list is stored by itself (the first predetermined number) for transmission to each node Nn selected as the storage instruction destination. What is necessary is just to divide | segment into "the 1st predetermined number +1" which is the part (1) to do. For example, a storage destination candidate list in which 10,000 (second predetermined number) node information is posted is acquired, and 100 nodes Nn are selected as the first predetermined number from this storage destination candidate list to store replicas. It may be configured to indicate. The first predetermined number depends on the second predetermined number or the period until the release date and time (for example, if there is no time until the release date and time, the first predetermined number is increased and the number of replicas is transferred to a large number of nodes Nn as soon as possible. It may be changed as appropriate in consideration of, for example, completing pre-distribution.

  Further, when the content input server CS cannot select the first predetermined number of nodes Nn to be instructed to store, the first predetermined number of node IDs are generated as in steps S46 and S47, and the generated nodes Since the storage instruction message for instructing the storage of the replica is sent to the ID node Nn, even if the storage destination candidate list cannot be obtained from the database server DS, the node Nn in the content distributed storage system S On the other hand, it is possible to reliably instruct the storage of the replica.

  Further, even when the node Nn cannot select the first predetermined number of nodes Nn to be instructed to store, the first predetermined number of node IDs are generated as in steps S70 and S71. Since the storage instruction message for instructing the storage of the replica is transmitted to the node Nn, the storage destination candidate list is displayed before the publication date and time by repeatedly dividing the storage destination candidate list in the storage instruction and the storage instruction. Even when the node information is lost and the first predetermined number of nodes Nn cannot be selected, it is possible to smoothly execute the replica storage instruction for other nodes Nn until the release date. Further, as another modification example in which each node Nn (and the content input server CS) cannot select the first predetermined number of nodes Nn to be instructed to save, the database server DS is accessed to request a save destination candidate list. You may comprise so that it may do. In this case, the database server DS may be requested and acquired for a storage destination candidate list on which at least the first predetermined number of node information is posted. According to this, each node Nn can acquire a storage destination candidate list composed of the latest node information.

  Further, when the node Nn that has received the save instruction issues a save instruction to another node Nn, the save destination candidate list generated by dividing its own save destination candidate list is stored as the save instruction destination node. Since it is configured to transmit to Nn, the node Nn that has received the storage instruction can also transmit a replica storage instruction based on the storage destination candidate list on which the node Nn having a shorter participation period is posted.

  In addition, the node Nn that has instructed the storage updates its own storage destination candidate list except for the node information of the generated transmission destination candidate list for transmission, and selects the node Nn based on the updated storage destination candidate list In addition, since the replica storage instruction is issued to the selected node Nn, the replica storage instruction process can be shared among the nodes Nn.

  Furthermore, since the node information of the node Nn instructed to store the replica is deleted from the storage destination candidate list stored in the storage unit 12, it is possible to prevent the replica instruction to store the replica to the same node Nn. Can do.

  Note that the node Nn may be configured to delete the node information of the node Nn from the storage destination candidate list after confirming that the replica can be reliably stored in the node Nn instructed to store the replica. In this case, the node Nn (storage instruction destination) that has received the storage instruction may be configured to notify the node Nn that is the storage instruction source of a storage completion report or the like after storing the replica. If the storage instruction source node Nn is not notified of the storage completion report from the storage instruction destination node Nn, the storage instruction source node Nn deletes the storage instruction destination node Nn from the storage destination candidate list and also saves the storage instruction destination node Nn. What is necessary is just to comprise so that the preservation | save instruction | indication message which instruct | indicates preservation | save of a replica may be sent toward node ID published in the node information of the node Nn. This message reaches a node Nn having a node ID close to the node ID, and the reached node Nn receives a replica storage instruction and stores the replica.

  Furthermore, when it is determined in step S62 that the replica of the content instructed to be stored cannot be stored, a storage instruction disabled report may be notified to the storage instruction source node Nn. Then, the storage instruction source node Nn that has received this may be configured to instruct the storage of the replica toward the node ID of the storage instruction source node Nn that has sent the notification, as described above.

  In addition, although the content distributed storage system S in the said embodiment was demonstrated on the assumption that it was formed by the algorithm using DHT, this invention is not limited to this.

It is a figure which shows an example of the connection mode of each node Nn in the content distribution storage system which concerns on this embodiment. It is a block diagram which shows the example of a schematic structure of the node Nn. It is a block diagram which shows the example of a schematic structure of authentication server AS. It is a conceptual diagram which shows a mode that the registration date of a new participating node is registered into the database server DS. It is a block diagram which shows the example of a schematic structure of database server DS. It is an example of the node information memorize | stored and stored in the user information database 202a. It is a block diagram which shows the example of an outline structure of the content input server CS. It is a conceptual diagram which shows a mode that the content input server CS instruct | indicates the preservation | save of a replica to the node Nn. It is explanatory drawing which concerns on the division | segmentation of a preservation | save destination candidate list. It is a figure which shows the mode of the storage destination candidate list exchanged between database server DS, content input server CS, and nodes N5 and N1. It is a figure which shows the mode of the preservation | save destination candidate list exchanged between node N1, N7, and N8. It is a figure which shows the mode of the preservation | save destination candidate list exchanged between node N5, N3, and N4. It is a flowchart which shows the process of the control part 101 in authentication server AS. It is a flowchart which shows the process of the control part 11 in the new participating node Nn. It is a flowchart which shows the process of the control part 201 in the database server DS. It is a flowchart which shows the process of the control part 301 in the content input server CS. It is a flowchart which shows the process of the control part 11 in the node Nn which has participated in the content distributed storage system S. FIG.

Explanation of symbols

8 Network 9 P2P network (overlay network)
11, 101, 201, 301 Control unit 12, 102, 202, 302 Storage unit 13 Buffer memory 14 Decoder unit 15 Video processing unit 16 Display unit 17 Audio processing unit 18 Speaker 20, 103, 203, 303 Communication unit 21, 104, 204, 304 Input unit 22, 105, 205, 305 Bus S Content distributed storage system Nn node AS authentication server DS database server CS content input server

Claims (12)

A storage instruction device in a distributed content storage system comprising a storage instruction device for storing content data in a node device so that the plurality of content data can be used between a plurality of node devices that can communicate with each other via a network. ,
Obtaining means for obtaining node device identification information for identifying the node device, and a participation period of participation in the content distribution storage system in the node device of the node device identification information;
Node information storage means for storing node information in which the node device identification information acquired by the acquisition means is associated with a participation period;
Selection means for selecting a first predetermined number of the node devices having a shorter participation period based on node information stored in the node information storage means;
Save instruction means for sending save instruction information to instruct the selected node device to save the content data;
A storage instructing device comprising: The storage instruction device according to claim 1,
The acquisition means acquires, from another device, the node information for a second predetermined number that is greater than the first predetermined number with a shorter participation period,
The node information storage means stores the acquired second predetermined number of the node information,
The selection means selects the first predetermined number of node devices from the second predetermined number of node information stored in the node information storage means,
The save instruction device sends the node information and the save instruction information to a selected node device. The storage instruction device according to claim 2,
Determining means for determining whether or not the first predetermined number of node devices can be selected based on the node information;
If it is determined by the determination means that the selection is possible, the selection means selects the first predetermined number of node devices,
When it is determined by the determination means that selection is impossible, the node apparatus identification information generating means for generating the first predetermined number of the node apparatus identification information is included, and the storage instruction means is the generated node apparatus identification A storage instruction device, characterized in that the storage instruction information is transmitted to a node device specified by the information. The node device functioning as the storage instruction device according to claim 2,
Split node information generating means for extracting a third predetermined number of node devices out of the second predetermined number of node devices specified by the node information stored in the node information storage means and generating split node information; ,
Updating means for updating the node information stored in the node information storage means to the node information storage means, the node information excluding the split node information from the second predetermined number of node devices;
The node device is characterized in that the selection unit selects the first predetermined number of node devices from the node information of the node information storage unit updated by the updating unit. The node device according to claim 4, wherein
The node device, wherein the storage instruction unit sends the divided node information and the storage instruction information to the node device selected by the selection unit. The node device according to claim 4 or 5, wherein
The selection means and the save instruction means select the first predetermined number of node devices and save the selected node device until the date and time when the content data can be used among the plurality of node devices. A node device characterized by repeatedly sending instruction information. The node device according to claim 4, wherein:
The node update device is configured to update the node device by removing the node information of the node device already selected by the selection device from the node information storage device. The node device according to claim 6 or 7, wherein
Having storage instruction information receiving means for receiving the storage instruction information from another device;
When the storage instruction information receiving means receives the storage instruction information,
The acquisition means acquires the node device identification information and a participation period from the other device,
The node information storage means stores node information in which the acquired node device identification information is associated with a participation period,
The selection means selects a first predetermined number of the node devices having a shorter participation period based on the node information stored in the node information storage means,
The node device, wherein the save instruction means sends the save instruction information to the selected node device. The node device according to claim 8, wherein
A node device, comprising: disclosure date / time information acquisition means for acquiring disclosure date / time information indicating the disclosure date / time of the content data from the other device that has transmitted the storage instruction information.   A storage instruction processing program for causing a computer to function as the storage instruction device according to any one of claims 1 to 3.   A node processing program that causes a computer to function as the node device according to any one of claims 4 to 9. A storage instruction method in a distributed content storage system including a storage instruction device for storing content data in a node device so that the plurality of content data can be used between a plurality of node devices that can communicate with each other via a network,
The storage instruction device acquires node device identification information for identifying the node device and a participation period in which the node device identification information participates in the content distributed storage system in the node device, and stores the node information as node information. Storing in association with means;
Based on the node information stored in the node information storage means, the save instruction device selects a first predetermined number of the node devices having a shorter participation period, and content data is selected for the selected node devices. Sending storage instruction information for instructing storage,
A storage instruction method comprising:

Images