JP2008293145A - Information processor, information processing method and information processing program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a content delivery system, for reducing overall power consumption and noise. <P>SOLUTION: To index information EXX recorded in a route node RN or cache node CN to be referable from a requester RQ, auxiliary information HP containing report time information 100 showing the time of reporting the route node RN or the like to the requester RQ is added in addition to a content ID and an IP address of a content holder CH. In the route node RN or cache node CN, the content holder CH delivered most recently is preferentially selected and reported to the requester RQ. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention belongs to the technical fields of an information processing apparatus, an information processing method, and an information processing program, and more specifically, stores content (distribution information) such as a movie to be distributed via a network for the distribution. The information processing apparatus belongs to a technical field of an information processing apparatus that performs distribution of the distribution information from the storage apparatus, an information processing method in the information processing apparatus, and a program for the information processing apparatus.

  In recent years, network technologies such as the Internet have been remarkably advanced, and research on a content distribution system as disclosed in, for example, Patent Document 1 below has been conducted.

  Here, in the content distribution system, for example, content such as a movie is any content in the content distribution system by the producer or manager (hereinafter, the producer or manager is simply referred to as a manager or the like). It is first distributed to the node via the network and stored / stored in each content node. Note that the first distribution of content in the content distribution system by the administrator or the like is hereinafter referred to as “content input”.

  When the input content is distributed in the content distribution system, it is operated by a person who desires to view the content from the content node that stores / stores moving image information or the like corresponding to the content. The moving image information and the like are distributed (transmitted) to the request node.

  For the definition of the “content node”, the paragraph number [0071] of the following Patent Document 1 can be referred to. For example, the definition of the “request node” can be referred to, for example, Patent Document 1 below. Reference may be made to paragraph numbers [0064] and [0065] of the specification.

  Further, in the content distribution system, the content once entered is not limited to the content node that is the first destination after the initial introduction, but is based on, for example, a distributed hash table (so-called DHT (Distributed Hash Table)) algorithm. Thus, a copy (replica) of the content is created in another node. Then, by creating the replicas for a while, there are a plurality of content nodes in the content distribution system that store / store the same content in addition to the content node that was initially input. As a result, distribution of the distribution sources is realized, and the distribution to the request node is speeded up and stabilized.

  The node on which the replica is created is hereinafter referred to as “replica node” as appropriate. For the DHT algorithm, reference can be made to, for example, the description of paragraph numbers [0039] to [0072] of FIG.

Here, in the DHT used in the DHT algorithm described in Patent Document 1 below, since the content node or replica node has not been weighted relatively, the content that is desired to be distributed is displayed. Regarding the accumulated content nodes or replica nodes, each node is provided for the distribution of the content with almost equal opportunity.
JP 2006-197400 A

  However, in the content distribution system described in Patent Document 1 described above, each of the content nodes or replica nodes that store the content desired to be distributed as described above is provided for the distribution of the content almost equally. Therefore, the number of content nodes or replica nodes operating when the content distribution system is viewed as a whole increases.

  As a result, when assuming, for example, a distribution company where a large number of content nodes and replica nodes are collected in one place, there is a problem that the power consumption of the entire content distribution system related to the distribution company increases. there were.

  Therefore, the present invention has been made in view of the above-described problems, and an object of the present invention is to provide a node included in a content distribution system capable of reducing overall power consumption, and an information processing method in the node. And providing a program for the node.

  In order to solve the above problems, the invention described in claim 1 includes storage means for storing storage device information indicating a storage device that stores distribution information to be distributed for one or a plurality of the storage devices. In the information processing device, distribution of the distribution information stored in the storage device corresponding to each storage device information is stored as storage device identification information for identifying the storage device corresponding to each storage device information. The transmission time information indicating the time of transmission to the distribution requesting device requesting is included in each of the storage device information, and the distribution requesting information requesting the distribution is transmitted from the distribution requesting device. The storage device that indicates the storage device that stores the distribution information for which the distribution is requested by the received distribution request information, the receiving unit that receives the distribution request information In transmitting the information to the distribution requesting device that has transmitted the distribution request information, the searching unit that searches the storage unit, and the storage device identification information corresponding to the searched storage device information, Transmitting means for transmitting the storage device identification information having a new transmission time to the distribution requesting device.

  Therefore, when transmitting the storage device identification information corresponding to the distribution request to the distribution request device, the storage device identification information indicating the storage device that stores the distribution information for which distribution is requested is the one with the new transmission time. Since it is transmitted, there is a high possibility that a new distribution can be received in parallel from the storage apparatus that is currently distributed, so that the power consumption caused by the start of the distribution process in the new storage apparatus An increase or the like can be suppressed.

  In order to solve the above-described problem, the invention according to claim 2 is the information processing device according to claim 1, wherein the storage device information corresponds to the storage device information corresponding to the storage device information. The distribution information indicating that the distribution information requested to be distributed by request information is currently being distributed is further included, and the transmission means is in the process of transmitting the storage device identification information. Based on the information, among the storage device identification information for identifying the storage device storing the distribution information being distributed, the storage device identification information with the new transmission time is transmitted to the distribution request device. Configured as follows.

  Therefore, since it is possible to receive new distribution from the storage device that is currently distributing distribution information using the distribution information, it is possible to more effectively suppress an increase in power consumption.

  In order to solve the above-mentioned problem, the invention according to claim 3 is the information processing apparatus according to claim 2, wherein the distribution-in-progress information is a predicted distribution end time of the distribution information corresponding to the in-distribution information. The transmission means is configured to transmit only the storage device identification information whose predicted distribution end time is later than the current time to the distribution request device when transmitting the storage device identification information. Is done.

  Therefore, since the information during distribution is the estimated distribution end time, and only the storage device identification information whose estimated distribution end time is later than the current time is transmitted to the distribution request device, it is ensured that the storage device that is executing the distribution further New distribution can be received.

  In order to solve the above-mentioned problem, the invention according to claim 4 is the information processing apparatus according to any one of claims 1 to 3, wherein the transmission means is the storage device having the latest transmission time. Only identification information is configured to be transmitted to the distribution requesting device.

  Accordingly, since only the storage device identification information with the latest transmission time is transmitted to the distribution requesting device, it is possible to receive new distribution from the storage device that is executing distribution while simplifying the processing.

  In order to solve the above-mentioned problem, the invention according to claim 5 is the information processing apparatus according to any one of claims 2 to 4, wherein the transmission means is distributing based on the information during distribution. When the distribution information does not exist, the storage device identification information corresponding to the searched storage device information is transmitted to the distribution request device.

  Therefore, even when there is no storage device that is distributing the requested distribution information, it is possible to receive distribution of necessary distribution information from any storage device.

  In order to solve the above problems, the invention described in claim 6 includes storage means for storing storage device information indicating a storage device for storing distribution information to be distributed for one or a plurality of the storage devices. An information processing method executed in an information processing device, wherein storage device identification information for identifying the storage device to which each storage device information corresponds corresponds to the storage device to which each storage device information corresponds. The transmission time information indicating the time of transmission to the distribution requesting device that requests distribution of the stored distribution information is included in each of the storage device information, and the distribution requesting the distribution from the distribution requesting device When the request information is transmitted, a receiving step for receiving the distribution request information and the distribution information for which the distribution is requested by the received distribution request information are stored. A search step for searching the storage device for the storage device information indicating the storage device, and the distribution that has transmitted the distribution request information for the storage device identification information corresponding to the searched storage device information A transmission step of transmitting the storage device identification information having a new transmission time to the distribution requesting device when transmitting to the requesting device.

  Therefore, when transmitting the storage device identification information corresponding to the distribution request to the distribution request device, the storage device identification information indicating the storage device that stores the distribution information for which distribution is requested is the one with the new transmission time. Since it is transmitted, there is a high possibility that a new distribution can be received in parallel from the storage apparatus that is currently distributed, so that the power consumption caused by the start of the distribution process in the new storage apparatus An increase or the like can be suppressed.

  In order to solve the above-described problem, an invention according to a seventh aspect causes a computer to function as the information processing apparatus according to any one of the first to fifth aspects.

  Therefore, when transmitting the storage device identification information corresponding to the distribution request to the distribution request device, the storage device identification information indicating the storage device that stores the distribution information for which distribution is requested is the one with the new transmission time. Since the computer functions so as to transmit, it is highly possible that a new distribution can be received simultaneously from the storage apparatus currently being distributed, so that the distribution process is started in the new storage apparatus. An increase in power consumption caused by the above can be suppressed.

  As described above, according to the present invention, when transmitting the storage device identification information corresponding to the distribution request to the distribution request device, the storage device indicating the storage device that stores the distribution information requested to be distributed. Since the new transmission time of the identification information is transmitted, there is a high possibility that a new distribution can be received simultaneously from the storage apparatus that is currently distributed. An increase in power consumption caused by the start can be suppressed.

  Therefore, it is possible to reduce the power consumption of the entire content distribution system.

  Next, the best mode for carrying out the present invention will be described with reference to the drawings. The embodiment described below is a distribution system that distributes the content using a network such as the Internet, and the content is directly exchanged between terminal devices belonging to the network (in other words, In this embodiment, the present invention is applied to a distribution system in which content is shared among a plurality of terminal devices, that is, a so-called P2P (Pear to Pear) distribution system. In the following description, the terminal device is generally referred to as a “node”.

Initially the principle of (I) the present invention, before the specifically described embodiments of the present invention, per the principles of the present invention, P2P type distribution system according to the embodiment (hereinafter, simply referred to as a delivery system) with Overview explain.

(A) Overview of Distribution System First, an overview of a distribution system according to an embodiment will be described with reference to FIGS. 1 and 2. 1 and 2 are schematic diagrams showing an outline of the distribution system.

  The distribution system using DHT described in Patent Document 1 is partially described in Patent Document 1, but the content itself distributed by the distribution system is unique from other contents. A unique content ID is assigned. The bit length of the content ID is also the same as the bit length of the node ID. In general, the content ID includes title data indicating the title of the content, attribute data indicating the attributes of the data constituting the content, data for several bytes from the top of the data configuring the content, and the like. A value obtained by applying a hash function is used.

  Here, in relation to the fact that corresponding node IDs and content IDs are expressed with the same bit length, the nodes and content are assumed to be scattered in the same ring-shaped virtual ID space. Can think. That is, as shown in FIG. 1A in which one node is displayed with ● and one content is displayed with ○, the ring Rc to which the content belongs and the ring Rn to which the node belongs are virtually concentrically assumed. Further, if it is defined that the value of each ID increases counterclockwise in each ring Rc and Rn, it can be assumed that each node or each content exists without overlapping on each ring Rc and Rn. If each ID is expressed in 128-bit length as in the above example, the number of digits is too large. In FIG. 1A, for the sake of simplicity of explanation, the bit length of each ID is set to 32 bits. Expressed (the same applies hereinafter). Then, as described above, due to the use of the hash function in determining the value of each ID, each node and each content are present in a substantially distributed manner on each of the above rings Rc and Rn. Become.

  On the other hand, in the distribution system using the DHT, “a node that manages content to which a certain content ID is assigned is a node to which a node ID having a value closest to the value of the content ID is assigned”. ing.

  Here, “near” may be any definition as long as it is consistent in various provisions related to the distribution system. Specifically, for example, “a value that does not exceed the value of the content ID”. And having the smallest difference between values as IDs ”.

  More specifically, for example, as illustrated in FIG. 1A, a node having a node ID value “A0334055” and a node having a node ID value “A03340FF” are adjacent to each other on the ring Rn. If it exists, the content ID value “A0334080” is managed by the node whose node ID value is “A0334055”. In FIG. 1A, the terminal information for managing the content of “◯” is indicated by an arrow extending from each “◯”. In this way, various contents can be managed by being distributed among a large number of nodes.

  At this time, “management” does not mean that the content assigned with the content ID is recorded therein, but recognizes the location of the node where the content is recorded (for example, an IP address). It means that The node where the content is actually recorded may be different from the managed node, or the content to be managed may be recorded in the managed node.

  The above-described content management node is referred to as a “root node”. The root node records index information consisting of a pair of a content ID indicating the content that is to be managed and the IP address of the node in which the content indicated by the content ID is recorded. Record so that it can be referred to by other nodes in the distribution system. In some cases, the index information includes the title of the content, the attribute (genre), and the like.

  In addition, when the content IDs indicating different contents are close to coincidence, and there is no other node having a node ID close to that value, a plurality of indexes corresponding to a plurality of contents by one root node Information will be recorded. Furthermore, when the same content is recorded in a plurality of different nodes and the node recording the same content is close to one root node by chance, The index information of a plurality of nodes each recording content is recorded. An example of the index information EX in the root node described above is shown in FIG.

  Further, a node that actually records each content itself is referred to as a “content holder”. At this time, since the content holder itself is a node, the node ID exists on the ring Rn in FIG.

  Next, in the distribution system using the DHT, the DHT (routing table) itself, which is one of the devices for eliminating the necessity for each node to record the IP addresses of all the nodes as described above, will be described. To do.

  In the DHT according to the embodiment, the ID space illustrated in FIG. 1 is subdivided while increasing the number of levels for each stepped level (for example, in the case of level 1, the ID space is divided into four). Routing information that describes a pair of a node ID of an arbitrary node and its IP address is described for each area (for each area subdivided in stages). For example, when the distribution source inquiry information for requesting the content distribution source information is transferred to the root node in which the index information is recorded, the inquiry information is transferred to the target root node while referring to the routing information. To do. That is, each time the level in DHT increases, the node ID of the routing destination matches the node ID of the root node to be reached one digit at a time, and the request information finally reaches the root node to be reached. Will do.

  In the distribution system using DHT, the inquiry information (query) as described above, distribution request information for requesting distribution of the content itself, a registration message described later, and the like are referred to as “message”. When the DHT having the above-described mechanism is used, the message can be efficiently transferred to the target node in the ID space as illustrated in FIG. In the following description, when a new content is recorded in the content holder, a message generated in the content holder is referred to as a registration message so that it can be discovered (published) from other nodes. A message transmitted from a requester described later to a root node or a cache node described later is referred to as a distribution source inquiry message.

  Here, as described above, since the value of the node ID of the root node is closest to the value of the node ID of the content holder that manages the content by the root node, the distribution source inquiry message is the distribution request. Immediately before the content holder requested by the message is reached, the root node that manages the content to be distributed is reached. Then, the root node that has received the distribution source inquiry message returns the IP address of the content holder storing the content requested by the distribution source inquiry message to the transmission source of the distribution source inquiry message. That is, from the index information (see FIG. 1B) recorded in the root node, the title indicating the content requested by the distribution source inquiry message, the attribute information, and the IP of the node as its content holder The address or the like is returned to the node that is the source of the distribution source inquiry message. By utilizing such DHT, the location of the desired content can be efficiently recognized at the distribution request source, for example. The node that is the content distribution request source described above is hereinafter referred to as a “requester”.

  Next, a description will be given of content registration processing when new content is accumulated in a certain node.

  When new content is stored in a node, that is, the content holder for that content, the content holder will publish that the content has been stored to other nodes in the distribution system.

  That is, when new content is stored in a certain node, the node that is a content holder for the stored content calculates a content ID corresponding to the content based on the title of the stored content.

  Next, the content holder transmits a registration message with a node having a node ID having the same value as the calculated content ID as a destination (regardless of whether or not the node having the node ID actually exists). This registration message includes the title indicating the content, the attribute information, the IP address of the node as the content holder, and the like, and is sent to the node as the destination of each level via each routing destination according to the description of the DHT. Sequentially transferred.

  When the node having the closest node ID is reached, the node recognizes that the node to which the registration message is to be transferred thereafter does not exist in the ID space. Recognizing that the node to be transferred is itself), the node to which the registration message arrives at this point becomes the root node for managing new content. Then, the node that becomes the root node records the content ID included in the registration message, the IP address indicating the content holder, the attribute information, and the like as index information EX illustrated in FIG. 1B.

  Next, the concept of “cache node” in the distribution system according to the embodiment will be described with reference to FIG. In FIG. 2 and FIG. 3 to be described later, the root node is indicated by a double circle, the content holder is indicated by a circle marked with “X”, and the requester is indicated by a circle marked with “|” inside, which will be described later. A cache node is indicated by a circle with + in the inside, and other general nodes are indicated by a circle.

  When the distribution source inquiry message Qr from the requesters RQ1 to RQ3 is transferred to the root node RN (or content holder CH) by the routing using the DHT described above, the transfer route (in FIGS. 2A and 2B) 2 (a) is similar to the path followed by the registration message Qp (shown by the solid line in FIGS. 2 (a) and 2 (b)) as shown in FIG. If the index information EX exemplified in FIG. 1B is also recorded in each node on the path (indicated by reference numeral CN in FIG. 2A), it corresponds to the distribution source inquiry message Qr passing through the path. Before the delivery source inquiry message Qr reaches the destination route node RN or the content holder CH. The response corresponding to the message Qr can be returned to the requesters RQ1 to RQ3.

  That is, the requesters RQ1 to RQ3 that request distribution of the content published in the distribution system transmit the distribution source inquiry message Qr that requests the IP address of the node (that is, the content holder CH) in which the content is recorded. Then, the distribution source inquiry message Qr is transferred to the routing destination described in the DHT in each node and approaches the root node RN. Finally, the route merges with the route of the registration message Qp from the content holder CH and reaches the root node RN.

  Here, when the path on the ring Rc shown in FIG. 2A is replaced with a tree structure, the result is as shown in FIG. 2B, which is referred to as “spanning tree” in the embodiment.

  As shown in FIG. 2A, the route of the distribution source inquiry message Qr transmitted from each requester RQ and the route of the registration message Qp transmitted from the content holder CH are in any node on these routes. Eventually cross. Accordingly, the index information EX included in the registration message Qp is recorded in a temporarily recordable temporary recording area at each node on the route for reaching the root registration message Qp to the root node RN ( That is, the registration message Qp is transferred (temporarily cached). Then, a reply to the distribution source inquiry message Qr from the requester RQ is made before the distribution source inquiry message Qr reaches the root node RN from the node where the distribution source inquiry message Qr on the route to the root node RN has arrived. It can be done. A node that is a node other than the root node RN and temporarily stores the index information EX in this manner is hereinafter referred to as a “cache node” CN.

(B) Principle of the present invention Next, the principle of the present invention based on the above-described distribution system will be described with reference to FIG.

  The index information EX in the above-described distribution system is as illustrated in FIG. 1B, which includes information indicating the content itself corresponding to each index information EX (for example, FIG. 1B). In addition to the title, genre, or director name, etc., the corresponding content ID and the IP address of the content holder CH as the storage device in which the content is recorded, etc. The information indicating the notification time, which is the time when the corresponding requester RQ is notified as the return information RT of the IP address or the like to be displayed, is not included.

  Therefore, as shown in FIG. 3, in the present invention, for each of the index information EX, the IP address indicating the content holder CH in which the content corresponding to the index information EX is recorded is updated in the requester RQ. Notification time information 100 indicating a notification time that is a notification time, and predicted end time information indicating an end prediction time that is an expected time at which delivery from the content holder CH corresponding to the IP address notified at the notification time ends. 101, and auxiliary information HP each including 101 is added. In FIG. 3, the newly added auxiliary information HP is characteristically shown, and information indicating the content itself originally included as the index information EX is omitted.

  Then, when another requester RQ refers to the index information EX together with the auxiliary information HP, based on the auxiliary information HP, priority is given to the content holder CH that started the latest distribution (with respect to the other requester RQ). Connect and receive the distribution from the connected content holder CH in parallel with the other requester RQ.

  Accordingly, as illustrated in FIG. 4, for example, when there are two content holders CH that deliver the same content CT when viewed at a certain timing T, the first content holder CH (“ The second content holder CH (denoted as “No. 2” in FIG. 4) started to deliver the same content CT later than the first content holder CH. To receive the distribution from the second content holder CH.

  In this way, with respect to the distribution of the same content CT, other content holders CH other than the second content holder CH that currently distributes the content CT without newly starting the operation for distribution. By receiving the distribution of the content CT in parallel from the second content holder CH, as a result, the number of content holders CH that are operating as a whole distribution system is reduced (in other words, not increased), and the consumption as the whole Reduce power and noise.

  Of the information included in the auxiliary information HP, the predicted end time information 101 is a notification target based on the notification time indicated by the notification time information 100 in the root node RN that stores the information. The distribution start time from the content holder CH is predicted, the distribution required time is calculated from the data amount of the content to be distributed, and the calculated distribution required time is added to the predicted distribution start time. The estimated delivery end time is calculated and stored in a pair with the corresponding notification time information 100.

  In the following embodiments, index information according to the present invention to which auxiliary information HP is added will be referred to as index information EXX. Further, in FIG. 3, index information EXX corresponding to a plurality of contents is recorded in one root node RN, and for each content, index information EXX indicating a plurality of content holders CH that record the same contents is stored. The state currently recorded is illustrated.

  Furthermore, the same index information EXX is recorded not only in the root node RN shown in FIG. 3 but also in the above-mentioned cache node CN, and by referring to this, the distribution source inquiry from the requester RQ is recorded. Even if the message Qr does not reach the root node RN, the corresponding return information RT can be returned to the requester RQ by referring to the auxiliary information HP to the distribution source inquiry message Qr.

  As described above, the index information EXX including the auxiliary information HP according to the present invention is recorded by the root node RN and the cache node CN, respectively, so that the content that has started to be distributed most recently (to other requesters RQ). The distribution of desired content is received in parallel from the holder CH, and this makes it possible to reduce power consumption and noise as a whole distribution system.

(II) Embodiment Next, an embodiment according to the present invention based on the above-described principle will be specifically described with reference to FIGS.

  First, a schematic configuration of a node according to the embodiment will be described with reference to FIG. FIG. 4 is a block diagram illustrating a schematic configuration of the node according to the embodiment. In the present embodiment, the content holder CH, the requester RQ, the root node RN, the cache node CN and the other nodes N basically have the same hardware configuration, and thus represent them. The outline of the configuration of the general node N will be described with reference to FIG.

  As shown in FIG. 4, the node N included in the distribution system according to the embodiment includes a CPU having a calculation function, a working RAM (Random Access Memory), and a ROM (Read Only Memory) for recording various data and programs. And a recording unit 12 including an HDD or the like for recording and storing (storing) content data as the content itself, the index information EXX, the DHT, and other necessary programs. (The content data is recorded only in the recording unit 12 in the node N as the content holder CH before the distribution), the buffer memory 13 for temporarily storing the received content data, and the content data Encoded video data (video information) and audio data (audio information) From the decoder unit 14 that decodes (decompresses data, decodes, etc.), the video processing unit 15 that performs a predetermined drawing process on the decoded video data and outputs the video signal, and the video processing unit 15 A display unit 16 such as a CRT (Cathode Ray Tube) or a liquid crystal display for displaying an image based on the output video signal, and the decoded audio data after D / A (Digital / Analog) conversion into an analog audio signal Communication between the other node apparatus 1 through the network 8, the audio processing unit 17 that amplifies the signal by an amplifier, the speaker 18 that outputs the audio signal output from the audio processing unit 17 as a sound wave, and the network 8 A communication unit 20 for performing control, and an instruction signal according to the instruction received from each user and an instruction signal according to the instruction. 1, an input unit (for example, a keyboard, a mouse, or an operation panel) 21 to be output to 1, and a control unit 11, a recording unit 12, a buffer memory 13, a decoder unit 14, and a communication unit 20 are connected to a bus 22. Are connected so that data can be exchanged between them.

  Then, when the CPU in the control unit 11 executes various programs recorded in the recording unit 12 or the like, the control unit 11 can execute a requester RQ, a cache node CN, a root node RN, a content holder CH, or other general items. Overall control of the entire operation as the node N is performed.

  When the node N is the root node RN or the cache node CN as the information processing apparatus according to the present invention, the control unit 11 functions as a search unit according to the present invention, and the recording unit 12 stores the memory according to the present invention. The communication unit 20 functions as a receiving unit and a transmitting unit.

  Next, the operation of each node N according to the embodiment will be described separately for the root node RN, the cache node CN, and the requester RQ.

(A) Operations at Root Node and Cache Node First, operations at the root node RN and the cache node CN according to the embodiment will be described with reference to FIG. 6A is a flowchart showing an operation at the time of message reception in the root node RN and the cache node CN according to the embodiment, and FIG. 6B is a flowchart showing a detailed operation as the root node RN. FIG. 6C is a flowchart showing a detailed operation as the cache node CH.

  As shown in FIG. 6, in the root node RN and the cache node CN in which any of the index information EXX according to the present invention has already been accumulated, first, the distribution source inquiry message Qr from any of the nodes N in the distribution system. Is received, it is confirmed whether it is the root node RN or the cache node CN (step S1). If it is the root node RN (step S1; root node), FIG. The process shown in (b) is executed (step S10).

  On the other hand, if it is determined in step S1 that it is a cache node CH (step S1; cache node), the process shown in FIG. 6C as the cache node CH is executed (step S20).

  Next, details of a reply process to the distribution source inquiry message Qr in the route node RN according to step S10 will be described with reference to FIG.

  When the distribution source inquiry message Qr is received at the root node RN (see FIG. 3) that records the index information EXX, as shown in FIG. 6B, first, the distribution source inquiry message Qr is transmitted. In the requester RQ, information indicating index information EXX indicating the desired content is extracted, and one or more index information EXX indicated by the extracted information is searched and extracted in the storage unit 12 (step S11).

  Next, the notification time information 100 and the predicted end time information 101 are extracted from the extracted index information EXX (step S12), and the current time is the predicted end time indicated by the extracted predicted end time information 101. It is confirmed whether it is before any one (step S13).

  Then, when all predicted end times indicated by the predicted end time information 101 already extracted compared with the current time have passed (step S13; NO), as long as this embodiment is concerned, any index information EXX is supported. Since the content holder CH to be returned may be returned to the requester RQ, one of the index information EXX is selected, for example, randomly from the index information EXX extracted in the process of step S11, and the selection is performed. The index information EXX is returned to the requester RQ that has transmitted the distribution source inquiry message Qr (step S14).

  Thereafter, the notification time information 100 in the index information EXX is updated with the time when the index information EXX is returned in the processing of the step S14 as the notification time (step S15).

  Next, based on the updated notification time, the distribution start time to the requester RQ from the content holder CH that is the notification target is predicted, and further, the distribution required time is calculated from the data amount of the content that is the distribution target. The estimated delivery end time is calculated by adding the calculated delivery required time to the predicted delivery start time, and the corresponding expected end time information 101 is updated (step S16). The process as the root node RN ends and the process proceeds to step S2.

  On the other hand, when there is any index information EXX in which the current time is before the predicted end time indicated by the predicted end time information 101 in the determination in step S13 (step S13; YES), the index information EXX is notified. The index information EXX with the latest notification time indicated by the time information 100 (in other words, the delivery start of the corresponding content is the latest) is searched (step S17), and the searched index information EXX is used as the distribution source inquiry message Qr. Is sent back to the requester RQ that has transmitted (step S18), and the process proceeds to step S15 and subsequent steps.

  Next, details of a reply process to the distribution source inquiry message Qr in the cache node CN according to step S20 will be described with reference to FIG.

  When the distribution node inquiry message Qr is received in the cache node CN (see FIG. 3) that records the index information EXX, as shown in FIG. 6C, first, the distribution is performed in the same manner as in the process of step S11. Based on the original inquiry message Qr, one or more index information EXX is retrieved and extracted in the storage unit 12 (step S21).

  Next, the notification time information 100 and the predicted end time information 101 are extracted from the extracted index information EXX (step S22), and the current time is the predicted end time indicated by the extracted predicted end time information 101. It is confirmed whether it is before any one (step S23).

  If there is any index information EXX whose current time is before the predicted end time indicated by the predicted end time information 101 (step S23; YES), the notification indicated by the notification time information 100 of the index information EXX. The latest index information EXX is retrieved (step S24), and the retrieved index information EXX is returned to the requester RQ that has transmitted the distribution source inquiry message Qr (step S25).

  Thereafter, the notification time information 100 in the index information EXX is updated with the time when the index information EXX is returned in the process of step S25 as the notification time (step S26).

  Next, similarly to the process in step S16, the corresponding predicted end time information 101 is updated (step S27), the process as the cache node CN according to the embodiment is terminated, and the process proceeds to step S3.

  On the other hand, in the determination of step S23, when all predicted end times indicated by the predicted end time information 101 already extracted compared with the current time have passed (step S23; NO), as far as this embodiment is concerned, Since any index information EXX stored in the cache node CN is returned, it is useless, so the received distribution source inquiry message Qr is transferred based on DHT (step S28), and the process proceeds to step S3. To do.

(B) Operation in Requester Finally, the operation in the requester RQ according to the embodiment will be described with reference to FIG. FIG. 7 is a flowchart showing the operation of the requester RQ according to the embodiment.

  As shown in FIG. 7, in the requester RQ according to the embodiment, first, when an operation for requesting delivery of desired content by a user is executed in the input unit 21 in the requester RQ (step S31). Then, the control unit 11 in the requester RQ calculates a content ID indicating the content requested to be distributed (step S32). Then, a distribution source inquiry message Qr including the calculated content ID is generated, transmitted to the root node RN on the spanning tree in the network in the distribution system according to the embodiment (step S33), and the transmission result Waits for a return of the desired index information EXX (step S34).

  When the index information EXX corresponding to the transmitted source inquiry message Qr is received (step S33), the index information EXX is connected to the content holder CH indicated by the received index information EXX (step S35). Upon receiving the distribution (step S36), the processing as the requester RQ according to the embodiment is completed.

  As described above, according to the operations of the root node RN, the cache node CN, and the requester RQ as the node N according to the embodiment, the index information EXX corresponding to the distribution source inquiry message Qr is transmitted to the requester RQ. In this case, since the index information EXX indicating the content holder CH that stores the content requested to be distributed is transmitted with a new notification time indicated by the notification time information 100, the content holder CH that is currently distributed simultaneously In particular, since the possibility of receiving a new distribution is increased, it is possible to suppress an increase in power consumption caused by the distribution process being started in the new content holder CH.

  Accordingly, it is possible to reduce the power consumption and noise of the entire content distribution system.

  Further, the auxiliary information HP includes the predicted end time information 101, and only the index information EXX with the predicted end time after the current time is transmitted to the requester RQ. Furthermore, new distribution can be received.

  Furthermore, since only the index information EXX with the latest notification time is transmitted to the requester RQ, it is possible to receive new distribution from the content holder CH that is executing distribution while simplifying the processing.

  Furthermore, even when there is no content holder CH that is delivering the requested content, it is possible to receive the necessary content from any of the content holders CH.

  The programs corresponding to the flowcharts shown in FIGS. 6 and 7 are recorded on an information recording medium such as a flexible disk or a hard disk, or acquired and recorded via the Internet or the like. It is also possible to cause the computer to function as the control unit 11 according to the embodiment by being read and executed by the computer.

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

It is a schematic diagram (I) which shows the outline | summary of the delivery system which concerns on embodiment, (a) is a schematic diagram which shows ID space in the said delivery system, (b) is a figure which illustrates index information. It is a schematic diagram (II) which shows the outline | summary of the delivery system which concerns on embodiment, (a) is a schematic diagram which shows the transmission state of the message in the said delivery system, (b) is transmission of the said message represented as a spanning tree. It is a figure which shows a state. It is a figure (I) which shows the principle of this invention. It is a figure (II) which shows the principle of this invention. It is a block diagram which shows the outline structure of the node which concerns on embodiment common about a content holder etc. 4 is a flowchart illustrating operations in the root node and the cache node according to the embodiment, wherein (a) is a flowchart illustrating an operation when a distribution source inquiry message is received, and (b) is a flowchart illustrating details of an operation as a root node. (C) is a flowchart showing details of the operation as a cache node. It is a flowchart which shows the operation | movement in the requester which concerns on embodiment.

Explanation of symbols

11 Control Unit 12 Recording Unit 13 Buffer Memory 14 Decoder Unit 15 Video Processing Unit 16 Display Unit 17 Audio Processing Unit 18 Speaker 20 Communication Unit 21 Input Unit 22 Bus 100 Notification Time Information 101 End Prediction Time Information Rc, Rn Ring EX, EXX Index Information CH Content holder RQ, RQ1, RQ2, RQ3 Requester CT Content RN Root node CN Cache node Qp Registration message Qr Distributor inquiry message N Node HP Auxiliary information RT Reply information

Claims (7)

In an information processing apparatus comprising storage means for storing storage device information indicating a storage device that stores distribution information to be distributed for one or a plurality of the storage devices,
A distribution request for requesting distribution of the distribution information stored in the storage device to which each storage device information corresponds, as storage device identification information for identifying the storage device to which each storage device information corresponds. Transmission time information indicating the time of transmission to the device is included in each of the storage device information,
Receiving means for receiving the distribution request information when the distribution request information requesting the distribution is transmitted from the distribution request device;
Search means for searching the storage device for the storage device information indicating the storage device storing the distribution information requested to be distributed by the received distribution request information;
In transmitting the storage device identification information corresponding to the searched storage device information to the distribution request device that has transmitted the distribution request information, the distribution request device transmits the storage device identification information with a new transmission time. A transmission means for transmitting to
An information processing apparatus comprising: The information processing apparatus according to claim 1,
The storage device information further includes in-distribution information indicating that the distribution information requested to be distributed by the distribution request information is currently being distributed in the storage device to which the storage device information corresponds. And
The transmission means, in transmitting the storage device identification information, based on the in-distribution information, among the storage device identification information for identifying the storage device that stores the distribution information being distributed, An information processing apparatus, wherein the storage apparatus identification information having a new transmission time is transmitted to the distribution request apparatus. The information processing apparatus according to claim 2,
The in-distribution information is prediction time information indicating an estimated distribution end time of the distribution information corresponding to the in-distribution information,
In transmitting the storage device identification information, the transmission means transmits only the storage device identification information whose predicted distribution end time is later than the current time to the distribution request device. The information processing apparatus according to any one of claims 1 to 3,
The information processing apparatus, wherein the transmission means transmits only the storage device identification information having the latest transmission time to the distribution request device. The information processing apparatus according to any one of claims 2 to 4,
The transmission means transmits the storage device identification information corresponding to the searched storage device information to the distribution request device when there is no distribution information being distributed based on the distribution information. Information processing device. An information processing method executed in an information processing apparatus including a storage unit that stores storage device information indicating a storage device that stores distribution information to be distributed for one or a plurality of the storage devices,
A distribution request for requesting distribution of the distribution information stored in the storage device to which each storage device information corresponds, as storage device identification information for identifying the storage device to which each storage device information corresponds. Transmission time information indicating the time of transmission to the device is included in each of the storage device information,
A reception step of receiving the distribution request information when the distribution request information requesting the distribution is transmitted from the distribution request device;
A search step of searching the storage unit for the storage device information indicating the storage device that stores the distribution information requested to be distributed by the received distribution request information;
In transmitting the storage device identification information corresponding to the searched storage device information to the distribution request device that has transmitted the distribution request information, the distribution request device transmits the storage device identification information with a new transmission time. Sending process to send to,
An information processing method comprising:   An information processing apparatus program for causing a computer to function as the information processing apparatus according to any one of claims 1 to 5.

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