JP2006217538A - Information communication system and initial zone management node device or like included in same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an information communication system (content distribution system) which can reduce communication load in a communication path between node devices by constructing an overlay network with the communication load taken into consideration, and to provide an initial zone management node device (default zone root node) or the like included in the information communication system. <P>SOLUTION: In the information communication system in which the overlay network is formed by the participation of the plurality of node devices mutually connected through a communication path and the overlay network is formed so as to have a plurality of zones, when the communication load in the communication path between one node device and the other node device is within a prescribed range, the one node device and the other node device are arranged so as to belong to the same zone in the overlay network. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a peer-to-peer (P2P) type content distribution system including a plurality of node devices connected to each other via a network, and in particular, distributed from one node device to another node device. The present invention relates to a technical field such as an information communication system in which content data to be distributed is stored in a plurality of node devices, and an initial zone management node device included in the information communication system.

  In this type of content distribution system, each node device stores content data by specifying location information regarding content data distributed and stored in a plurality of node devices (for example, auxiliary information such as a title of the content data). Content information desired by the user based on the index information described in the list. Can be downloaded. Such a list is shared information that should be commonly used in a plurality of node devices, and is generally managed by a management server that manages all content data stored on the content distribution system. The list is distributed to each node device.

  As a method not using a management server, in an overlay network logically constructed using a distributed hash table (DHT (Distributed Hash Table)), a request node that desires content distribution manages content information. The node device is accessed by hearing the location of the node device that stores the content information from the node device. In such an overlay network, even when node devices frequently participate and leave (leave), load balancing needs to be performed appropriately. Non-Patent Document 1 describes participation and withdrawal in an overlay network. A technique for appropriately distributing load even when (separation) is frequently performed is disclosed.

  FIG. 29 is a diagram showing an example of a connection mode of each node device in a content distribution system based on an overlay network logically constructed using a conventional distributed hash table.

  As shown in the lower frame 101 of FIG. 29, IX (Internet eXchange) 3, ISP (Internet Service Provider) 4, DSL (Digital Subscriber Line) line operator (device) 5, FTTH (Fiber To The Home) line A network (real-world network) 8 such as the Internet is constructed by an operator (device) 6 and a communication line (for example, a telephone line or an optical cable) 7.

  The content distribution system S is configured to include a plurality of node devices 1a, 1b, 1c,... 1x, 1y, 1z,. Network system. Each node device 1a, 1b, 1c... 1x, 1y, 1z... Is assigned destination information such as an IP address and information (node information) indicating the node device including the device information. The device information and the IP address are not duplicated among the plurality of node devices 1.

  In such a content distribution system S, when a node device 1 accesses information held by another node device 1, it must know the IP address as destination information of the node device 1 having that information. . For this purpose, it is a simple method for each node device 1 participating in the network 8 to know the IP addresses of all the node devices 1 participating in the network 8 and the information index of each device. However, when the number of terminals becomes as large as tens of thousands and hundreds of thousands, it is not realistic to remember the IP addresses of all the node devices 1. Further, when the power of any node device is turned on or off, the IP address of the arbitrary node device stored in each node device 1 is frequently updated, which makes operation difficult.

  Therefore, in one node device 1, only the minimum necessary IP address of the node device 1 among all the node devices 1 participating in the network 8 is remembered (stored), and the IP address is set. For node devices 1 that are not known (not stored), a system has been devised in which information is transferred between the node devices 1 and sent to each other.

Until now, as an example of such a system, a technique for constructing an overlay network 9 as shown in an upper frame 100 of FIG. 29 by an algorithm using a distributed hash table has been used. That is, the overlay network 9 means a network that forms a virtual link formed using the existing network 8.
"Examination of lightweight load balancing method for distributed hash table" The Institute of Electronics, Information and Communication Engineers IEICE technical report

  By the way, the content distribution system using the distributed hash table (DHT) knows itself based on the content ID obtained by hashing the content according to a predetermined rule when the node device 1 requests distribution of the desired content. By transmitting content inquiry information (hereinafter, “content inquiry information” is referred to as “query”) to the node device 1 that has been transferred, the query is transferred between the node devices 1 in the overlay network 9. Finally, the node device 1 that knows in which node device 1 content data of the corresponding content is stored is reached, and the location of the node device 1 that stores the content data is taught from this node device 1 It is structured to be accessed.

  At this time, the network distance between the node device 1 that desires the content and the node device 1 that actually stores the content may be far. That is, the node device 1e and the node device 1h illustrated in FIG. 29 appear to be adjacent to each other in the overlay network 9 (virtual link) illustrated in the upper frame 100, but in the actual network 8, the node device 1e. When the node device 1h exchanges contents, as shown in the lower frame 101 of FIG. 29, the node device 1e first passes to the FFTH line strong person 6 and then passes through the ISP4, IX3, ISP4, and the DSL line operator 5. As a result, the node device 1h is reached, and a large number of relay devices must be routed, which increases the communication load of the network 8.

  The present invention has been made in view of the above problems and the like, and information communication that can reduce the communication load by constructing an overlay network in consideration of the communication load in the communication path between the node devices. It is an object of the present invention to provide an initial zone management node device included in a system and an information communication system.

  In order to solve the above problem, an information communication system is formed by joining a plurality of node devices connected to each other via a communication path, and the overlay network has a plurality of zones. When the communication load on the communication path between one node device and another node device is within a predetermined range, the one node device and the other node device are identical in the overlay network. It is arranged so as to belong to a zone.

  According to this, since it becomes possible to arrange the node devices so that node devices whose communication loads in the actual communication path are within a predetermined range (that is, the communication loads are small) belong to the same zone even on the overlay network. When information communication using the overlay network is performed, it is possible to control to exchange information between node devices having a relatively small communication load, thereby reducing the communication load of the entire system. Overall operational efficiency can be improved.

  In order to solve the above-mentioned problem, the invention according to claim 2 is the information communication system according to claim 1, wherein when a new node device requests participation in the information communication system, the new node A new zone is generated in the overlay network when the communication load on the communication path between the device and the node device belonging to the initial zone to which the device belongs first when participating in the information communication system is within a predetermined range. The new node device and the node device belonging to the initial zone are arranged to belong to the generated new zone.

  According to this, when a new node device participates in the information communication system, the new node device has a communication load on a communication path with the new node device among the node devices belonging to the initial zone. Can generate a new zone with a predetermined range of node devices.

  In order to solve the above-mentioned problem, the invention according to claim 3 is the information communication system according to claim 1 or 2, wherein the node device belonging to one zone in the plurality of zones, and the plurality of the plurality of zones When the communication load on the communication path between a node device belonging to another zone in the zone is within a predetermined range, the one zone and the other zone are merged.

  According to this, when the communication load applied to the communication path between two or more node devices belonging to different zones is within a predetermined range, by merging the zones, it is based on the communication load of the communication path between the node devices. Thus, each node device can be optimally arranged on the overlay network.

  In order to solve the above problems, in the information communication system according to any one of claims 1 to 3, the one node device can share shared information to be shared among the plurality of node devices. The shared information is copied and held so that it can be shared with a node device belonging to a zone different from the zone to which the one node device belongs.

  According to this, when a certain node device holds (releases) shared information in a sharable manner, the node device that holds (opens) the shared information by copying it to the node devices included in each zone ( The node device that desires to distribute the shared information is a node device in the zone to which the node belongs, and the node device holds the shared information in a sharable manner. It becomes possible to receive delivery from.

  In order to solve the above-mentioned problem, according to a fifth aspect of the present invention, in the information communication system according to any one of the first to fourth aspects, the one node device is between the plurality of node devices. When holding shared information to be shared in a sharable manner, if there is a request for distribution of the shared information from the other node device to the one node device, the other node device belongs. When the number of zone requests for a zone exceeds a predetermined range, the shared information is duplicated and held sharable to any one of the node devices belonging to the zone to which the other node device belongs. Features.

  According to this, when a certain node device holds (releases) shared information in a sharable manner, the node device to which the node device to which the shared information is desired belongs belongs to a node device included in a zone that exceeds a predetermined range. Because it becomes possible to control to be a node device (content node) that replicates shared information and holds (opens) so that it can be shared, popular shared information can be autonomously placed in each zone, It is possible to reduce the communication load of the entire system and respond quickly to the shared information distribution request.

  In order to solve the above-described problem, the invention according to claim 6 is the information communication system according to any one of claims 1 to 5, wherein each of the node devices is a zone to which the node device belongs. Each of the plurality of node devices has unique device identification information for uniquely identifying the node device, and each of the node devices is arranged in an overlay network. It is arranged in any one of the zones corresponding to the zone information included in the device identification information included in the device.

  According to this, by including the zone information in the unique device identification information possessed by each node device, it is possible to accurately arrange each node device in the space on the overlay network based on the device identification information. Therefore, it is possible to place the node device in each zone on the overlay network relatively easily without requiring special zone placement control.

  In order to solve the above-mentioned problem, the invention according to claim 7 is the information communication system according to any one of claims 1 to 6, wherein the communication load is a relay device on the communication path. An information communication system, characterized in that the information communication system is determined based on the number of communication statistics or a statistical value of communication response time over a certain period.

  According to this, the communication load is determined based on the number of relay devices on the communication path or the statistical value of the communication response time for a certain period, thereby further increasing the network connection distance between the node devices. Based on this, it becomes possible to determine the communication load, and it is possible to improve the operational efficiency of the system.

  In order to solve the above-mentioned problem, an invention according to claim 8 is an overlay network formed by participation of a plurality of node devices connected to each other via a communication path, and the overlay network has a plurality of zones. A formed information communication system, which is a node device included in the information communication system, and belongs to the initial zone to which the information communication system belongs first and belongs to the initial zone When the initial zone management node device that manages the device receives unique device identification information for uniquely identifying the node device from the new node device and receives a request to participate in the information communication system, the device identification information A placement control means for placing the new node device in the initial zone based on the initial zone, and a location in the initial zone. Zone information transmitting means for transmitting zone information indicating a new zone to a node device that is the source of the departure information when receiving the departure information indicating the departure of the initial zone from any of the node devices, When a new node device is placed in the initial zone by the placement control means of the initial zone management node device, a communication load related to a communication load in the communication path with another node device belonging to the initial zone A communication load information acquisition unit for acquiring information, a leave information transmission unit for transmitting the leave information to the initial zone management node device when a communication load applied to the acquired communication load information is within a predetermined range, When the zone information is received from the zone management node device, the new node device itself and the others are added to the overlay network. The new zone should belong and a node device, characterized by having a a zone generating means for generating on the basis of the zone information.

  In order to solve the above-mentioned problem, an invention according to claim 9 is the node apparatus constituting the information communication system in the information communication system according to claim 8, and belongs to one zone in the plurality of zones. The zone management node device that manages the node device belonging to the one zone obtains the communication load information acquisition means for acquiring the communication load information related to the communication load in the communication path with the other node device belonging to the zone. And a zone information transmitting means for transmitting zone information indicating the other zone to a node device belonging to the one zone when the communication load applied to the acquired communication load information is within a predetermined range; Among the zones, each zone management node device that manages each zone other than the one zone and the other zones indicates the disappearance of the one zone. A node device belonging to the one zone has unique device identification information for uniquely identifying the node device from the plurality of node devices. When receiving the zone information from the zone management node device, an identification information changing unit is provided that changes the device identification information based on the zone information.

  In order to solve the above problem, the invention according to claim 10 is the information communication system according to claim 9, wherein the invention belongs to one zone in the plurality of zones and is not a zone management node device of the one zone. The node device includes a communication load information acquisition unit that acquires communication load information related to a communication load in the communication path with the node device belonging to the other zone, and a communication load related to the acquired communication load information is predetermined. In the case of a range, zone information transmitting means for transmitting zone information indicating the other zone to the zone management node device, and the device of the one node device itself based on the zone information indicating the other zone And an identification information changing means for changing the identification information.

  In order to solve the above-mentioned problem, an invention according to claim 11 is the information communication system according to any one of claims 8 to 10, wherein the node device in the plurality of node devices is the plurality of nodes. A shared information management node device that manages shared information to be shared among the node devices is at least one zone management node that manages a zone other than the zone to which the information storage node device that stores the shared information belongs A replication start information transmitting means for transmitting replication start information for instructing the apparatus to start replication of the shared information to the other zone; and a replication node to replicate and store the shared information from the zone management node apparatus Upon receiving the replication node information indicating the device, the destination information of the information storage node device that stores the shared information is transmitted to the replication node device and the replication is performed. And when the zone management node device receives the replication start information from the shared information management node device, the zone management node device transmits the replication information from the node device belonging to the zone managed by the zone management node device. A replication node device selection means for selecting a node device, and a replication node information transmission means for transmitting the replication node information indicating the selected replication node device to the shared information management node device, When receiving the destination information of the information storage node device from the shared information management node device and instructing the replication of the shared information, the replication node device requests the information storage node device to copy the shared information. And having shared information acquisition means for acquiring the shared information from the information storage node device, wherein the information storage node device has at least one or more When serial from duplicating node device receives a request for replication of the shared information, characterized by having a common information transmission means for transmitting the common information to the requesting of the duplication node device.

  In order to solve the above-mentioned problem, the invention according to claim 12 is the information communication system according to any one of claims 8 to 11, wherein the communication load is a relay device on the communication path. It is determined based on the number or the statistical value of the communication response time for a certain period.

  In order to solve the above problem, the invention according to claim 13 is an overlay network formed by participation of a plurality of node devices connected to each other via a communication path, and the overlay network has a plurality of zones. An initial zone management node device that is included in the formed information communication system, belongs to an initial zone included in the plurality of zones, and manages a node device belonging to the initial zone, from a new node device to the node Placement control for placing the new node device in the initial zone based on the device identification information upon receiving unique device identification information for uniquely identifying the device and receiving a request to participate in the information communication system Means and from one of the node devices belonging to the initial zone, receiving the leaving information indicating the leaving of the initial zone If that is characterized by having a a zone information transmitting means for transmitting the zone information that indicates a new zone to the source node device of the withdrawal information.

  In order to solve the above problems, the invention according to claim 14 is an overlay network formed by participation of a plurality of node devices connected to each other via a communication path, and the overlay network has a plurality of zones. A new node device that requests participation in the formed information communication system, and is a node device that constitutes the information communication system, and belongs to an initial zone to which the information communication system first belongs, When placed in the initial zone by the initial zone management node device that manages the node devices belonging to the zone, obtains communication load information related to the communication load in the communication path with other node devices belonging to the initial zone. Communication load information acquisition means for performing the communication load on the acquired communication load information within a predetermined range In this case, when receiving the leaving information transmitting means for transmitting the leaving information to the initial zone management node device and the zone information indicating the new zone from the initial zone management node device, the new node device itself is included in the overlay network. And a zone generating means for generating a new zone to which the other node device should belong based on the zone information.

  In order to solve the above-mentioned problem, according to a fifteenth aspect of the present invention, in the node device according to the fourteenth aspect, the communication load is a number of relay devices on the communication path or a communication response time of a certain period. It is determined based on a statistical value.

  In order to solve the above problems, the invention according to claim 16 is an overlay network formed by participation of a plurality of node devices connected to each other via a communication path, and the overlay network has a plurality of zones. A zone management node device that is included in the formed information communication system, belongs to one zone in the plurality of zones, and manages a node device that belongs to the one zone, and belongs to another zone. A communication load information acquisition unit that acquires communication load information related to a communication load on the communication path to and from a device, and if the communication load related to the acquired communication load information is within a predetermined range, belongs to the one zone Zone information transmitting means for transmitting zone information indicating the other zone to the node device; And having a disappearance information transmitting means for transmitting a zone annihilation information indicating the disappearance of the first zone to the zone management node device for managing one zone and the zone other than the other zones, the.

  In order to solve the above-mentioned problem, the invention according to claim 17 is the zone management node apparatus according to claim 16, wherein the shared information management node apparatus manages shared information to be shared among the plurality of node apparatuses. Upon receipt of the replication start information, a replication node device selection means for selecting a replication node device to replicate and store the shared information from the node devices belonging to the zone managed by the zone management node device, and the selected And duplication node information transmitting means for transmitting duplication node information indicating the duplication node device to the shared information management node device.

  In order to solve the above-mentioned problem, the invention according to claim 18 is the zone management node device according to claim 16 or claim 17, wherein the communication load is the number of relay devices on the communication path or a fixed number. It is determined based on a statistical value of the communication response time of the period.

  In order to solve the above-described problem, the invention according to claim 19 is an overlay network formed by participation of a plurality of node devices connected to each other via a communication path, and the overlay network has a plurality of zones. A shared information management node device that is included in the formed information communication system and manages shared information to be shared among the plurality of node devices, except for a zone to which the information storage node device that stores the shared information belongs Replication start information transmitting means for transmitting replication start information for instructing the other zone to start replication of the shared information to at least one zone management node device that manages another zone; and the zone management node device Receiving the replication node information indicating the replication node device to which the shared information should be copied and stored from Characterized by having a a copy instructing means for copy instructing to transmit the address information of the information storage node device that stores the common information to the node device.

  According to the present invention, since it becomes possible to arrange each node device so that node devices having a small communication load on the actual communication path belong to the same zone even on the overlay network, the overlay network is used. When information communication is performed, it becomes possible to control to exchange information between node devices with a relatively small communication load, thereby improving the operation efficiency of the entire system by reducing the communication load of the entire system. be able to.

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

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

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

  As shown in the lower frame 101 of FIG. 1, IX (Internet eXchange) 3 as an relay device, ISP (Internet Service Provider) 4, DSL (Digital Subscriber Line) line operators (devices) 5a and 5b, FTTH ( A network (real-world network) 8 such as the Internet is constructed by a fiber to the home (line device) 6 (device) 6 and a communication line (for example, a telephone line or an optical cable) 7. Since each node device 1 and the relay device are the same members as those of the background art, detailed description of the same configuration as that of the background technology is omitted.

  The content distribution system S uses a plurality of node devices 1 connected to the network 8 via the DSL line operator 5a as node devices existing in the zone 1, and a plurality of node devices 1 connected to the network 8 via the FTTH line operator 6. The node device 1 is a node device existing in the zone 2, and a plurality of node devices 1 connected to the network 8 via the DSL line operator 5b are node devices existing in the zone 3.

  The default zone is an initial zone on the overlay network 9 to which a node device newly participating in the content distribution system S first belongs. The default zone will be described in detail later.

  The node devices 1a, 1b, 1c... 1x, 1y, 1z,... Connected to each other via the network 8 include node information including destination information such as IP (Internet Protocol) addresses. (Node information) indicating a node ID (IDentifier) (device identification information) as a unique value for specifying each node device is further assigned. These IP addresses and node IDs do not overlap among a plurality of node devices. In the following description, when any one of the node devices 1a, 1b, 1c... 1x, 1y, 1z.

  In the content distribution system S, when the node device 1 accesses information held by another node device 1, it is necessary to know destination information such as an IP address of the node device 1 having the information.

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

  The node ID as the device identification information is not particularly limited as long as each node device can be uniquely identified. For example, a serial number or a machine name assigned in advance at the time of factory shipment can be used. More specifically, the zone ID as the zone information indicating the default zone (initial zone) of the overlay network 9 to which the overlay network 9 belongs first when participating in the content distribution system S as the information communication system, the manufacturing number, the machine name, etc. Can be used as a node ID [zone ID-GUID] for each node device 1 by using a hash value obtained by hashing with a common hash function (hash algorithm) as a GUID (Global Unique IDentifier) It is. Each node device 1 will be described in detail later [4. When a new zone is arranged from the default zone based on the new zone generation processing operation], the own node ID is updated using the zone ID corresponding to the zone after the arrangement.

  Further, the node ID needs to have a number of bits that can accommodate the maximum number of nodes that can be operated. For example, if the number is 128 bits, 2 ^ 128≈340 * 10 ^ 36 node devices can be operated. In practice, it is assumed that SHA-1 (Secure Hash Algorithm 1) (number of generated digits 160 bits) or MD5 (Message Digest 5) (number of generated digits 120 bits), which are known hash functions, is used. For example, MD5 is used. In such a case, [Zone ID (120 Bit) −GUID (120 Bit)] is used. It is also possible to mask the upper or lower bit and use it as, for example, [Zone ID (20 Bit) −GUID (100 Bit)]. From the viewpoint of ensuring the uniqueness of the node ID, It is better to use a sequence of combined lengths.

  An example of a node ID acquired using MD5 is shown below.

First, when generating the GUID from the machine name:
GUID = md5 (“client00070512.beacon.net”) = 43ecabd445852e6eeaf684d103009d69
If the GUID is generated from the global IP address,
GUID = md5 ("123.210.123.210") = 7bbbefcf537806afa2ae4f423d5d3d90
Is obtained.

And, when generating the zone ID as zone information from the date and time (character string with format) when the zone was born in the zone generation process described in detail later,
Zone ID = md5 ("Saturday, January 1, 2005 22: 15: 30.000") = 0df71b25c05e1b2b4f2142237eee3184
Is obtained and the zone ID is generated from the date and time (UTC (Coordinated Universal Time)) when the zone was born,
Zone ID = md5 ("1105683227") = fde4e1570c0d90549cf813e351a4885c
Is obtained.

  By combining these and obtaining a node ID as device identification information as [zone ID-GUID], it is possible to uniquely identify each node device while identifying the zone to which each node device 1 belongs. become.

  As described above, since the node ID is generated including the zone ID in the present embodiment, the node IDs of the respective node devices 1 are gathered together in the same ID space, and the node devices 1 belonging to the same zone are gathered. In one zone, they are distributed without any bias.

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

  In the present embodiment, an overlay network 9 constructed by an algorithm using DHT is assumed, and a node device 1 arranged on the overlay network 9 participates in the content distribution system S (in other words, the overlay network 9 The node device 1 participating in the network. Participation in the content distribution system S is performed when a node device that has not yet participated sends a participation request to the node device 1z in the default zone. In the following description, this node device 1z is referred to as a default zone root node ZRd as an initial zone management node device.

  In addition, content (for example, movies, music, etc.) data as shared information distributed from one node device 1 to another node device 1 is distributed to a plurality of node devices 1 participating in the content distribution system S. However, a unique (unique) number (hereinafter referred to as a content ID) is assigned to each content data.

  The content ID has the same length as the node ID (for example, 128 bits), the zone ID to which the node device 1 that stores the content belongs, the content name (content title), and the content outline information, for example. A hash value obtained by hashing a keyword such as (summary) with a hash function common to the node ID is obtained (that is, arranged in the same ID space as the hash value of the IP address of the node device 1). It can be used as a content GUID, and can be used for each content as a content ID [zone ID-content GUID] by combining them. The node device 1 having the node ID closest to the content ID (for example, the higher-order digits match more) manages the location information of the node device that stores the content data.

  As a result, the content data can be distributed on the content distribution system S without any bias. Note that even if the content data is different, it is assumed that the same keyword (for example, the name of the content) is used. In this case, the hash value is the same to avoid the same hash value. The keyword may be, for example, a combination of content name and copyright information (for example, performer name, director name, original author name, singer name, composer name, or songwriter name).

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

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

  Here, “management” does not mean that content data is stored / held, but “knows in which node device 1 content data is stored”. . That is, in FIG. 2, the node device 1 having the node IDa knows in which node device 1 the content data having the content IDa is stored, and the node device 1 having the node IDb and the node having the node IDc Similarly, the device 1 knows in which node device 1 the content data having the content IDb and the content data having the content IDc are stored. In this way, a node device that knows in which node device 1 certain content data is stored is called a content root node CR (shared information management node device) of the content data. That is, the node device 1 having the node IDa is the content root node CR of the content data having the content IDa, and the node device 1 having the node IDb is the content root node CR of the content data having the content IDb, The node device 1 having the node IDc is a content root node CR of content data having the content IDc.

  In addition, a pair of content data and a content root node CR is created under the rule that “a node device that manages content data having a certain content ID is a node device 1 having a node ID close to that content ID”. Even in such a case, the content root node CR of some content data suddenly stops functioning, or the content data disappears in a node device in which the content data is stored (hereinafter simply referred to as “content node”). It is possible that Even in such a case, unless the content root node CR confirms the existence of the content data and updates its own index information, the content data information managed by the content root node CR remains indefinitely. . When the content data once disappeared, but again when the same content data is registered, the content root node CR is selected again under the above rules, and a new node device joins the previous one. A node device different from the content root node CR may be selected as a new content root node CR.

  Accordingly, as the content distribution system S builds a huge network of hundreds, thousands, and so on, the node device withdraws from the content distribution system S (node device power failure or failure, or part of the network) And the participation frequency is high, and the frequency of new storage or deletion of the content data in the node device is high, so that the content node from which the content data is stored is known. In reality, there are not a single node device but a large number of node devices.

  Further, the number of node devices (content nodes) that hold certain content data is not necessarily one. There are cases where a large number of node devices hold the same content and participate in the content distribution system S, respectively. Also in such a case, the node device to be the content root node CR is determined separately depending on the timing at which each node device participates in the content distribution system S and the situation at the time of content duplication by the content duplication processing described in detail later. Therefore, as a result, a certain node device may know two or more node devices (content nodes) holding the same content data.

[1-2. Create routing table]
Here, an example of a method for creating a routing table used in DHT will be described with reference to FIG. In the present embodiment, when a plurality of node devices 1 are participating in the content distribution system S, when a certain node device 1 generates a new zone in a zone generation process that will be described in detail later, or a self belongs. When a zone merges with another zone, it is a method used to update the routing table that was previously owned.

  FIG. 3 is a diagram illustrating an example of a configuration of a routing table in DHT.

  First, as shown in FIG. 3A, the ID space is divided into several areas. This area is different from a plurality of zones provided in the ID space, and the ID space is divided to create a routing table. In practice, about 16 divisions are often used. In order to simplify the explanation, it is assumed here that the number is divided into four and the ID is represented by a quaternary number having a bit length of 16 bits. An example in which the node ID of the node device 1N is “10230210” and the routing table of the node device 1N is created will be described.

(Level 1 routing)
First, if the ID space is divided into four, each area is represented by four numbers with different maximum digits when expressed in quaternary numbers: “0XXXXXXX”, “1XXXXXXX”, “2XXXXXXX”, “3XXXXXXX” (where X is a natural number from 0 to 3, The same). Since the node ID of the node device 1N itself is “10230210”, the node device 1N exists in the area “1XXXXXXX” in the lower left in the figure. Then, the node device 1N appropriately selects the node device 1 existing in an area other than the area where the node device exists (that is, the “1XXXXXXX” area), and stores the IP address of the node ID in the level 1 table. . FIG. 4A shows an example of a level 1 table. Since the second column indicates the node device 1N itself, it is not necessary to store the IP address.

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

(Level 3 routing)
Further, as shown in FIG. 3C, among the areas divided into four by the above routing, the area where the user exists is further divided into four, and further four areas “100XXXXX”, “101XXXXX”, “102XXXXX”, “103XXXXX” And divide. Then, similarly to the above, the node device 1 existing in an area other than the area where it exists is appropriately selected, and the IP address of the node ID is stored in the level 1 table. FIG. 4C is an example of a level 3 table. Since the third column shows the node device 1N itself, it is not necessary to store the IP address, and the second column and the fourth column are blank because there is no node device in the area.

  In this way, all the 16-bit IDs can be covered by creating the routing table as shown in FIG. As the level goes up, white space becomes more noticeable in the table.

  To actually create a table so as to have the above-described configuration, first, when joining the content distribution system S, the routing table is copied from the connected node device. In addition, at the time of knowing the existence of another node device 1 at the time of message transfer, etc., it is determined which cell of the table the node ID of that device matches, and the contents of each table are added. To go. At the timing when it is known that another node device has left, the node ID of the device is deleted from the table.

  In accordance with the method described above, the routing table used by the node device 1 is created and updated.

[2. Node device configuration]
Next, the configuration and function of the node device 1 will be described. In addition, each node device 1 performs content processing as a shared information management node device that receives a query from a zone root node ZR as a zone management node device that manages each zone, a request node, or a terminal on a route by processing performed by each node device 1 Although it functions as a content node as an information storage node device that holds content as shared information that is targeted for inquiry by the root node CR and the request node, the configuration is the same.

  FIG. 5 is a diagram illustrating a schematic configuration example of the node device 1.

  As shown in FIG. 5, each node device 1 includes a control unit 11 as a computer including a CPU having a calculation function, a working RAM, a ROM for storing various data and programs, the content data, and the index. The storage unit 12 (the content data may be stored in the node device 1 that is not stored) is received as a storage unit composed of an HDD or the like for storing (storing) information, the DHT, the program, and the like. A buffer memory 13 for temporarily storing content data; a decoder unit 14 for decoding (data expansion, decoding, etc.) encoded video data (video information) and audio data (audio information) included in the content data; Predetermined drawing processing is applied to the decoded video data, etc. A video processing unit 15 that 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 D (Digital ) / A (Analog) converted and then amplified and output by an amplifier, a speaker 18 that outputs an audio signal output from the audio processor 17 as a sound wave, and other nodes through the network 8 A communication unit 20 for controlling communication of information with the apparatus 1 and an input unit (for example, a keyboard, a mouse, or the like) that receives an instruction from the user and gives an instruction signal corresponding to the instruction to the control unit 11 , An operation panel, etc.) 21, a control unit 11, a storage unit 12, a buffer memory 13, a decoder unit 14, Fine communication unit 20 are connected to each other via a bus 22.

  FIG. 6 shows an example of index information stored in the storage unit 12. The index information stores node information (including destination information such as an IP address) of a content node as an information storage node device managed by itself. Then, [6-1-2. When a query requesting content location information is received according to the content data search method], the corresponding content is searched with reference to the index information.

  The storage unit 12 stores destination information such as an IP address of a default zone root node ZRd (initial zone management node device) to be accessed first when participating in the content distribution system S (overlay network 9).

  Further, when participating in the content distribution system S (overlay network 9) as its own node ID, the default zone ID “0000” to which it first belongs and the GUID “XXXX” (X Is a natural number and is a unique value for each node device.) And a node ID [0000-XXXX].

  As the CPU in the control unit 11 executes various programs stored in the storage unit 12 or the like, the initial zone management node device, the zone management node device, the shared information management node device, or the information storage node device in the present application The entire node device 1 is controlled in an integrated manner.

[3. Operation to participate in content distribution system S]
Next, the operation of participating in the content distribution system S will be described.

[3-1. Processing of node device when participating in content distribution system S]
First, processing of the node device 1 when the node device 1 participates in the content distribution system S will be described with reference to FIGS. 7 to 9.

  FIG. 7 is a flowchart illustrating processing performed when the program stored in the control unit 11 of the node device 1 is executed by the control unit 11.

  First, when participation in the content distribution system S is instructed by the user operating the input unit 21, the user's own GUID is transmitted to the default zone root node ZRd and a participation request is transmitted (step S1). Thereafter, when destination information such as the IP address of the neighboring device is received from the default zone root node ZRd (step S2), the routing table is obtained by connecting to the neighboring device based on the destination information (step S3).

  This will be described more specifically using an example of a state in which the node device 1 illustrated in FIG. 9 participates in the content distribution system S. The node device 1 desiring to participate in the content distribution system S first belongs to the default zone, but by accessing the default zone root node ZRd and requesting participation in the content distribution system S, As shown in the figure, it is arranged at a location corresponding to the node ID in the ID space. For example, the node device 1 with the node ID [0000-0001] having the GUID “0001” participates in the content distribution system S first, and the node device with the node ID [0000-0003] having the GUID “0003” later. When 1 is added, the default zone root node ZRd transmits destination information such as the IP address of the node device 1 with the node ID [0000-0001] to the node device 1 with the node ID [0000-0003]. . Then, the node device 1 with the node ID [0000-0003] accesses the node device (node ID [0000-0001]) based on the destination information, and the routing included in the node device 1 with the node ID [0000-0001]. Get a duplicate table. Note that, in the situation shown in the figure, since only the node ID [0000-0000] of the fault zone root node ZRd is described in the routing table owned by the node device 1 with the node ID [0000-0001]. After duplicating the routing table, the node ID of the node device 1 with the node ID [0000-0001] is described and acquired.

  Next, the control unit 11 functions as a communication load information acquisition unit, measures a network distance with a connected neighboring device (step S4), and determines whether or not the network distance is shorter than a predetermined range (step S4). S5).

  More specifically, the number of hops reflecting the number of times the relay device was relayed in communication with a neighboring device (as known from the amount of decrease in the TTL field in the IP packet) and the statistical value of the communication response time for a certain period, Acquired as communication communication load information indicating the communication load. If the acquired communication load information is larger than a predetermined range (for example, the number of hops is “2”, etc.), it is determined that the network distance is far (communication load is large), and if the predetermined range is close (communication) It is determined that the load is small.

  If it is determined that the network distance is far (communication load is large) (step S5: No), the process is terminated. On the other hand, if it is determined that the network distance is short (communication load is small) (step S5). : Yes), the process proceeds to a new zone processing routine (step S6), and the process is terminated after the routine is completed.

[3-2. Processing of default zone root node when node device participates in content distribution system S]
Next, processing of the default zone root node when the node device participates in the content distribution system S will be described with reference to FIGS.

  FIG. 8 is a flowchart showing processing performed when the program stored in the control unit 11 of the default zone root node ZRd is executed by the control unit 11.

  This process is started by receiving a participation request from the node device 1 that desires to participate, and the control unit 11 functions as an arrangement control unit.

  First, when the default zone root node ZRd receives a participation request, the default zone root node ZRd refers to the belonging node table stored in the storage unit 12 and acquires destination information of a neighboring device to which the transmission source node device of the participation request is to be connected (step S7). .

  FIG. 10A shows an example of the belonging node table stored in the storage unit 12 of the default zone root node ZRd when the node device 1 with the node ID [0000-0003] participates in the content distribution system S. As shown in the figure, the default zone root node ZRd has node information (node ID, IP address (destination information) and network participation date and time) of all the node devices 1 belonging to the zone managed by itself. Yes. When the node device 1 with the node ID [0000-0003] participates in the content distribution system S, only the node device 1 with the node ID [0000-0001] belongs to the default zone. The default node root node ZRd acquires the IP address “121.43.154.65” as the destination information of the node device 1 with the node ID [0000-0001].

  Subsequently, the acquired destination information is transmitted to the transmission source node device of the participation request (step S8). According to an example of the state in which the node device 1 illustrated in FIG. 9 participates in the content distribution system S, the node ID [0000.0001] of the node device 1 with the node ID [0000-0001] is the node ID as the transmission source node device. [0000-0003] is transmitted to the node device 1.

  Then, the node information of the transmission source node device is added to the affiliation node table stored in the storage unit 12 (step S9), and the process ends. FIG. 10B shows an example of the belonging node table to which the node information of the node device 1 with the node ID [0000-0003] that is the transmission source node device is added.

[4. New zone generation processing operation]
Next, the new zone generation processing operation will be described.

[4-1. Node device processing when creating a new zone]
First, processing of the node device 1 when the node device 1 leaves the default zone and generates a new zone will be described with reference to FIGS. 11 and 12.

  FIG. 11 is a flowchart illustrating processing performed when the program stored in the control unit 11 of the node device 1 is executed by the control unit 11.

  This process is started when it is determined in step S5 in FIG. 7 that the network distance to the neighboring device is short (communication load is small).

  First, mutual confirmation is performed on neighboring devices and new zone generation (step S10). More specifically, each node ID is transmitted and received to prepare for later processing.

  Subsequently, it is determined whether or not its own node ID is larger than the node ID of the neighboring device (step S11). If the node ID is larger (step S11: Yes), the control unit 11 functions as a leaving information transmitting unit, and the default zone A message to leave the current zone is transmitted to the root node ZRd (step S12). The device with the larger node ID becomes the zone root node ZR of the new zone. In addition, the zone leaving message is transmitted including not only its own node ID but also the node IDs of neighboring devices that generate a new zone.

  This will be described more specifically with reference to FIG. The node device 1 with the GUID “0004” is described in [3-1. When a request is made to participate in the default zone root node ZRd based on the processing of the node device 1 when participating in the content distribution system S], the node having the node ID [0000-0003] as a neighboring device is obtained. The communication distance information indicating the communication load on the communication path with the neighboring device is obtained by measuring the network distance to the device 1. Therefore, since the network distance from the node device 1 with the node ID [0000-0003] is short, the node device 1 with the node ID [0000-0004] is a node device with the node ID [0000-0003] as a neighboring device. Mutual confirmation of 1 and new zone creation. Thereafter, since the node ID [0000-0004] of the own node is larger than the node device 1 of the node ID [0000-0003] as the neighboring device, the zone leave message to leave the current zone is sent to the default zone root node ZRd. (Separation information) is transmitted as indicated by the alternate long and short dash line in the figure.

  Subsequently, when a new zone ID is received from the default zone root node ZRd (step S13), the received new zone ID is transmitted to the neighboring device (step S14). More specifically, referring to FIG. 12, as indicated by a solid line, the node device 1 with the node ID [0000-0004] receives the new zone ID [1000], and the received new zone ID [1000] It transmits to the node device 1 with ID [0000-0003].

  Then, in the node device 1 with the node ID [0000-0004], the control unit 11 functions as a zone generating unit, and changes its own node ID to [new zone ID-new zone ID] (step S15). Zone root node ZR. Referring to FIG. 12, the node device 1 with the node ID [0000-0004] changes its own node ID to [new zone ID-new zone ID], that is, [1000-1000], and While leaving a certain default zone and belonging to the new zone (zone ID 1000), it becomes the zone root node ZR of the new zone (zone ID 1000).

  Then, a new zone generation completion message is transmitted to the other zone root node ZR (step S16), and the process is terminated. As shown in FIG. 12, if the other zone is only the default zone, a new zone creation completion message is transmitted to the default zone. As shown in FIG. 13, there is already another zone (zone ID 0500) in addition to the default zone. In this case, a new zone generation completion message is also transmitted to the zone root node ZR (node ID [0500-0500]) of the other zone. The destination information such as the IP address of the zone root node ZR of another zone may be configured to be acquired together when the new zone ID is acquired from the default zone root node ZRd in the process of step S13 described above.

  Subsequently, in the process of step S11, if the own node ID is not larger than the node ID of the neighboring device, that is, if the own node ID is smaller than the node ID of the neighboring device (step S11: No), the new zone ID Is received from the neighboring device (step S12). According to the example shown in FIG. 12, since the node device 1 with the node ID [0000-0003] has a smaller node ID than the node device 1 with the node ID [0000-0004] described above, the node device with the node ID [0000-0004] The transmission of a new zone ID from the node device 1 is awaited.

  When a new zone ID is received from the neighboring device (step S17), its own node ID is changed to [new zone ID-GUID] (step S15), and the process is terminated. Referring to FIG. 12, the node device 1 with the node ID [0000-0003] changes its own node ID to [new zone ID-GUID], that is, [1000-0003], thereby changing the original zone ID. The user leaves a certain default zone and belongs to the new zone (zone ID “1000”).

  Each node device 1 that has performed the zone generation processing may create a routing table in which the node's own routing table is discarded and each node information is newly recorded, or the node's own routing table is stored. Only the mutual node information may be updated without being discarded. Furthermore, when a certain zone exists in the ID space, the above-described [1-2. The routing table may be reconstructed according to the procedure described in “Creating a Routing Table”.

[4-2. Processing of default zone root node ZRd when creating a new zone]
Next, processing of the default zone root node ZRd when the node device 1 leaves the default zone and generates a new zone will be described with reference to FIG.

  FIG. 14 is a flowchart showing processing performed when the control unit 11 executes a program stored in the control unit 11 of the default zone root node ZRd.

  This process starts when a zone leave message is received in the process of step S12 of FIG.

  In the default zone root node ZRd, when the control unit 11 functions as zone information transmission means and receives a zone leave message from any node device 1 belonging to the default zone, a new zone ID is generated and a zone leave message is transmitted. It transmits to the original node device 1 (step S30).

  Thereafter, when a new zone completion message is received from the node device 1 that is the transmission source of the zone leaving message, that is, from the zone root node ZR of the new zone (step S31), the belonging node table and the zone root node stored in its own storage unit 12 The table is updated (step S32), and the process ends.

  More specifically, the zone leaving message received in step S30 includes not only its own node ID but also the node IDs of neighboring devices that generate a new zone, so that it has left based on the zone leaving message. The node device 1 is deleted from the belonging node table stored in the storage unit 12. Then, since the zone ID of the new zone and the IP address information of the zone root node are stored in the new zone completion message, they are added to the zone root node table stored in the storage unit 12.

  As another example in generating a new zone, the default zone root node ZRd can instruct the generation of a new zone. All the node devices 1 always access the default root node ZRd when participating in the content distribution system S. At this time, the default zone root node ZRd grasps the network connection location of all the node devices 1 based on the IP address etc. transmitted from the node device, so that the new node device 1 (GUID) as shown in FIG. Can be realized by teaching neighboring devices when “0004” participates, and further indicating which one should become the zone root node ZR of the new zone.

  A new zone may be generated by two or more neighboring devices. For example, as shown in the figure, it is possible to instruct to create a new zone when three or more neighboring devices are gathered.

  FIG. 16 shows an example of an ID space created by repeatedly participating in the content distribution system S and generating a new zone as described above.

  FIG. 16 shows an ID space of the content distribution system S in which four zones including the default zone (zone ID “0000”, zone ID “0500”, zone ID “1000”, and zone ID “2000”) are formed. It is desirable that the size of each zone is configured so that node devices connected to each line company gather. The size of this zone depends on a predetermined range of network distance (communication load) determined in advance in the processing of steps S4 and S5 described with reference to the flowchart of FIG. If it is “within 2”, a zone is formed for each DSL line provider 5a, FTTH line provider 6 and DSL line provider 5b as shown in FIG.

  In FIG. 16, the zone with the zone ID “0000”, that is, the default zone includes the default zone root node ZRd with the node ID [0000-0000], the node device 1 with the node ID [0000-0002], and the node ID [0000]. -0055] and the node device 1 with the node ID [0000-0158] belong.

  Then, the zone root node ZR with the node ID [0500-0500] and the node device 1 with the node ID [0500-0014] belong to the zone with the zone ID “0500”.

  The zone with the zone ID “1000” includes the zone root node ZR with the node ID [1000-1000], the node device 1 with the node ID [1000-0003], and the node device 1 with the node ID [1000-0003]. Belongs to.

  Further, the zone with the zone ID “2000” includes the zone root node ZR with the node ID [2000-2000], the node device 1 with the node ID [2000-0032], and the node device 1 with the node ID [2000-0250]. Belongs to.

  The zone root node ZR (including the default zone root node ZRd) of each zone stores the zone root node information of each zone existing on the ID space as a zone root node table as shown in FIG.

  17A is a zone root node table stored in the storage unit 12 of the default zone root node ZRd, and FIG. 17B is stored in the storage unit 12 of the zone root node ZR with the zone ID “0500”. FIG. 17C is a zone root node table stored in the storage unit 12 of the zone root node ZR with the zone ID “1000”, and FIG. It is a zone root node table stored in the storage unit 12 of the zone root node ZR of “2000”.

  Furthermore, as shown in FIG. 18, the zone root node ZR (including the default zone root node ZRd) of each zone stores the node information of the node device 1 belonging to the zone managed by each zone as the belonging node table.

  FIG. 18A is an affiliation node table stored in the storage unit 12 of the default zone root node ZRd, and FIG. 18B is stored in the storage unit 12 of the zone root node ZR with the zone ID “0500”. FIG. 18C is an affiliation node table stored in the storage unit 12 of the zone root node ZR with the zone ID “1000”, and FIG. 18D is the zoning node table “2000”. It is an affiliation node table memorize | stored in the memory | storage part 12 of the zone root node ZR. A node ID and an IP address are recorded as node information of the node device 1 belonging to each zone. In addition, as described in the description of FIG. 10 above, the date and time when each node device 1 participates in the network may be stored in the affiliation node table, but the description will be omitted for the sake of simplification.

[5. Merge zones
Next, the merging of zones will be described with reference to FIGS.

[5-1. Zone merge processing]
Zone merging means that a node device 1 belonging to a certain zone and a node device 1 belonging to another zone communicate with each other and are close to each other in network, in other words, nodes belonging to each zone. This is caused by starting the zone merging process when it is determined that the number of relay devices on the communication path between devices or the statistical value of the communication response time for a certain period is small and the communication load is small. At this time, the control unit 11 of the node device 1 functions as a communication load information acquisition unit.

  FIG. 19 is a flowchart showing processing performed when the program stored in the control unit 11 of the node device 1 is executed by the control unit 11. In this embodiment, the zone with the smaller zone ID takes in the zone with the larger zone ID, and the zone with the larger zone ID disappears.

  First, mutual confirmation is performed for neighboring devices and zone merging (step S40). More specifically, it functions as zone information transmission means, and transmits / receives node IDs generated including each other's zone IDs to prepare for later processing.

  Subsequently, it is determined whether or not its own zone ID is larger than the zone ID of the neighboring device (step S41). If the zone ID is smaller (step S41: No), the process ends. If the zone ID is larger (step S41: Yes), It is determined whether or not the current node is the zone root node ZR as the zone management node device (step S42).

  Specifically, using FIG. 20, the node device 1 with the node ID [0500-0014] belonging to the zone ID “0500” and the node device with the node ID [1000-0003] belonging to the zone ID “1000”. 1 communicate with each other and the network distance between them is close (the communication load is small), the node device 1 with the node ID [0500-0014] and the node device 1 with the node ID [1000-0003] Both control units 11 each start zone merging processing. Then, as shown by the alternate long and short dash line in the figure, the zone merge is mutually confirmed, and when the process of step S41 is executed, in the control of the node device 1 with the node ID [0500-0014], its own zone ID is It is determined that it is smaller than the zone ID, and in the control of the node device 1 with the node ID [1000-0003], it is determined that its own zone ID is larger than the zone ID of the neighboring device. Therefore, the zone merging process by the node device 1 with the node ID [0500-0014] ends at this stage. On the other hand, the node device 1 with the node ID [1000-0003] shifts to the process of step S42 and determines whether it is the zone root node ZR.

  If it is not the zone root node ZR in the process of step S42 (step S42: No), the zone ID of the merged zone is transmitted to the zone root node ZR of its own zone (step S43). In the zone root node ZR that has received this, although the flow is not shown, the same processing as S46 and S47 is performed, and after changing the zone IDs of all the node devices in the zone, the zone is extinguished. More specifically, as indicated by a broken line in FIG. 20, the node device 1 with the node ID [1000-0003] merges with the node device 1 with the node ID [1000-1000] that is the zone root node ZR of its own zone. The zone ID “0500” of the previous zone is transmitted.

  In step S44, the control unit 11 functions as identification information changing means, changes its own node ID to [merging destination zone ID-GUID], and transmits a zone participation request message to the zone root node ZR of the merging destination zone. (Step S44). Note that the zone root node ZR of each zone has a zone root node table in the storage unit 11 as shown in FIG. 17, and knows the IP address as destination information of the zone root node ZR of all zones. The destination information of the zone root node ZR of the merged zone is obtained by asking the zone root node ZR of its own zone.

  Then, the zone participation acceptance message is received from the zone root node ZR of the merged zone (step S45), and the process is terminated.

  If it is determined in step S42 that the node is the zone root node ZR (step S45: Yes), a node ID change instruction message including the zone ID of the merge destination is transmitted to all nodes belonging to the zone. (Step S46). In the node that has received this, although the illustration of the flow is omitted, processing similar to S44 and S45 is performed.

  Specifically, using FIG. 21, the node device 1 with the node ID [0500-0014] belonging to the zone ID “0500” and the node device with the node ID [1000-1000] belonging to the zone ID “1000”. 1 (zone root node ZR) communicate with each other to find that the network distance between them is close (the communication load is small) and the node device 1 with the node ID [0500-0014] and the node ID [1000-1000] ], Both control units 11 of the node device 1 start zone merging processing.

  As in the procedure described above with reference to FIG. 20, the zone merging is mutually confirmed as shown by the one-dot chain line in FIG. 21, and in the process of step S41, the control of the node device 1 with the node ID [0500-0014] is performed. Determines that its own zone ID is smaller than the zone ID of the neighboring device, and determines that its own zone ID is larger than the zone ID of the neighboring device in the control of the node device 1 with the node ID [1000-1000]. . At this stage, the zone merging process by the node device 1 with the node ID [0500-0014] is performed by the zone ID “0500” of the other party's zone ID (the node ID [1000-1000] according to the example shown in FIG. 21). Therefore, the determination in step S41 is “No” and the process ends. On the other hand, the node device 1 with the node ID [1000-1000] shifts to the process of step S42, determines that it is the zone root node ZR, shifts to the process of step S46, and assigns the node ID [1000 belonging to the zone. The node ID change instruction message including the zone ID “0500” of the merge destination is transmitted to the node device 1 of -0003] and the node device 1 of the node ID [1000-0003] as indicated by the broken line in FIG.

  Then, in the process of step S47, the control unit 11 functions as a disappearance information transmission unit, refers to the zone root node table, and sends the current zone zone ZR (including the default zone root node ZRd) to the current zone. A zone disappearance message indicating that the zone disappears is transmitted (step S47).

  More specifically, the node device 1 with the node ID [1000-1000] refers to the zone root node table shown in FIG. 18C, and the default zone root node with the zone ID “0000”. A zone disappearance message is indicated by a solid line in FIG. 20 for the node device 1 with the node ID [0000-0000] that is ZRd and the node device 1 with the node ID [2000-2000] that is the zone root node ZR with the zone ID “2000”. Send as shown.

  Thereafter, the processes of step S44 and step S45 described above are performed.

  The node device 1 that has received the node ID change instruction message including the merged zone ID from the zone root node ZR in step S46 described above performs the processes in steps S44 and S45 described above. The process of step S44 is configured to be performed based on the received merged zone ID.

FIG. 22 shows an example of an ID space when the zone merging process is completed with the zone ID “0500” and the zone ID “1000”.
As shown in the figure, when merging is performed, the node ID is changed as described above, so that the order in the ID space is also changed.

  When the zones are merged, each node device 1 belonging to the zone to be merged (according to the example shown in FIG. 22, the zone ID “0500” and the zone ID “1000”) is [1-2. Reconstruct the routing table according to the procedure described in [Create Routing Table].

[6. Publish content]
[6-1-1. How to register content data]
Next, in the content distribution system S having such a configuration, when a certain node device 1 publishes content as shared information owned by itself to other node devices on the content distribution system S so as to be shared. The method is described.

  This node device 1 becomes a content node as an information storage node device that holds (stores) content.

  The content node obtains a content ID from the content title and the like, and transmits a public message to a node device having the same node ID as the content ID (whether or not this node device actually exists at this point). To do. The public messages are successively transferred according to the routing table, and when the node message 1 is transferred to the node device 1 having the node ID closest to the content ID included in the public message, the node device 1 is no longer the destination. If it is determined that there is no other node device, it is determined that the node device 1 itself should be a content root node CR that manages the content, and the content ID, auxiliary information (attribute information such as title and genre, and supervision) Node information including destination information such as copyright information (such as name) and IP address of the content node is stored as index information (see FIG. 6).

  As shown in FIG. 23, when the node device 1 with the node ID [1000-0003] intends to publish content, the content ID is first generated.

  In order to generate a content ID, first, keywords such as a content name (content title) and content summary information (summary) are hashed by a hash function common to the above-described node ID. A hash value is acquired as a content GUID.

  When the content is first published, the content ID is arranged in the default zone. That is, the zone ID of the default zone and the acquired content GUID are combined and released as a content ID [default zone ID (0000) −content GUID].

  An example of a content GUID acquired using MD5 from the content title is shown below.

Content GUID = md5 (“Seven Lawrence”) = 634f43265ecd4edd64843c0b8cfff23c
Content GUID = md5 (“Arabic Samurai”) = 385c1853340575d5b79ce03233179215
Content GUID = md5 (“Mozart Symphony No.41 Jupiter”) = d046ffd4a032b1cc3a46b86ee2b2642c
In the following description, the content GUID is represented by a 4-digit natural number for the sake of simplicity.

  According to the example shown in FIG. 23, when the node device 1 (hereinafter referred to as a content node) with the node ID [1000-0003] publishes the content, the content ID [0000-0056] is generated and the content ID [ 0000-0056] together with an IP address “255.62.14.102” (see FIG. 18C) for identifying its own device is transmitted.

  Then, when the public message is repeatedly transmitted according to the routing table and received by the node device 1 with the node ID [0000-0055], the node device 1 with the node ID [0000-0055] has no destination to transmit the public message. Public message transfer ends. At this time, the node device 1 with the node ID [0000-0055] becomes the content root node CR with the content ID [0000-0056] (indicated by a black diamond in FIG. 23).

  The content root node CR includes the content ID [0000-0056], auxiliary information (attribute information such as title and genre, copyright information such as director name), and node information (IP address “255.62.14.102”). Is stored in the storage unit 12 as index information. Thus, the registration of the content data with the content ID [0000-0056] is completed.

[6-1-2. Content data search method]
When registration is completed based on the above-described method, content data copy registration processing described later is started. Before that, an example of a content node search method will be described.

  Referring to FIG. 23, when node device 1 with node ID [0500-0500] (hereinafter referred to as “request node”) searches for a content node holding content data having content ID “0000-0056”. The procedure will be described. A route to the content route node CR is represented by a solid line arrow.

  First, the request node hashes the title or the like of the desired content with a common hash function, and acquires the content ID “0000-0056”. Then, referring to its own routing table, content inquiry information (hereinafter, “content inquiry information” is referred to as “query”) is transmitted to the node device 1 having a node ID in the same area as the content ID.

  In the figure, a query is transmitted from the request node to the node device 1 with the node ID [0000-0000].

  Subsequently, the node device 1 with the node ID [0000-0000] searches for the content ID included in the query with reference to the index information stored in its own storage unit 12, and does not have the corresponding content ID (that is, the content) And the received query is transferred to the node device 1 with the node ID [0000-0055].

  In this way, a query is transferred to an upstream node device, that is, a node device interposed between itself and the content root node CR, and the content ID digit is adapted in order from the top to the content root node CR. Approaching.

  Then, the node device 1 having the node ID [0000-0055] that has received the query finds the corresponding content ID by referring to the index information stored in the storage unit 12 of the content ID included in the query, and The destination information such as the IP address “255.62.14.102” of the content node indicating the location is transmitted to the request node. Then, the request node that has received this accesses the content node based on the acquired IP address, makes a content data distribution request as indicated by the alternate long and short dash line in the figure, and the content node that has received the distribution request makes a request to the request node. The content is distributed as shown by the broken line in the figure.

[6-2. Content data replication registration]
Next, processing when content data is replicated in each zone will be described with reference to FIGS.

  24 (A) and 24 (C) are flowcharts showing processing performed when the program stored in the control unit 11 of the content root node CR is executed by the control unit 11, and FIG. FIG. 24D is a flowchart showing processing performed when a program stored in the control unit 11 of the default zone root node ZRd is executed by the control unit 11, and FIG. 24D shows a zone to which no content ID belongs. 7 is a flowchart showing processing performed when a program stored in the control unit 11 of the zone root node ZR (including the default zone root node ZRd) is executed by the control unit 11.

  When a new content is registered, the processing of FIG. 24A is started by the content root node CR as the shared information management node device. More specifically, the process starts when new content information (content ID or the like) is registered in the index information of the content root node CR.

  First, in the content root node CR, the control unit 11 functions as a copy start information transmitting unit, and transmits a copy start message of content to the default zone to the default zone root node ZRd (step S60). According to the example shown in FIG. 25, from the content root node CR (node device 1 with node ID [0000-0055]) to the default zone root node ZRd (node device 1 with node ID [0000-0000]) as shown by the chain line in the figure. A replication start message is sent to.

  Then, the process proceeds to the process of FIG. 24D, and the default zone root node ZRd that has received the replication start message refers to the content data registration history and randomly selects from node devices other than the most recently registered node device. A node device 1 for duplication is selected (step S75). Here, the content data registration history refers to any node device among the node devices 1 in which the default zone root node ZRd belongs to its own zone in the replication processing of content data performed in the past. Is stored in the storage unit 12 as a registration history. Here, a node device other than the most recently registered node device is selected so that the same node device is not always selected as a node device for duplication.

  Next, a new content ID is generated and returned to the content root node CR together with the node information (node information for duplication) of the node device 1 selected as the node device for duplication (step S76). The new content ID is generated based on its own zone ID. That is, according to the example shown in FIG. 26, the zone ID “0000” of the default zone and the content GUID “0056” are combined to generate the content ID “0000-0056” and transmitted to the content root node CR as shown by the solid line in the figure. To do.

  Then, the content root node CR receives the replication node information and the new content ID from the default zone root node ZRd (step S61). At this time, the content root node CR adds the replication node information and the new content ID to its own index information.

  Then, the control unit 11 functions as a duplication instruction unit, and transmits a content duplication instruction message to the node device for content duplication using the IP address included in the duplication node information as destination information (step S62). Then, a copy request message for requesting the copy of the content to another zone is transmitted to the default zone root node ZRd (step S63).

  Then, the process proceeds to the process of FIG. 24 (B), and the default zone root node ZRd that has received the duplication request message indicates whether or not there is another zone in its own zone root node table (FIG. 17 (A)). If there is no other zone (step S70: No), the process is terminated, and if there is another zone (step S70: Yes), the zone route node table (FIG. 17 (FIG. 17 Referring to A)), a content duplication start message is transmitted to the other zone root node ZR (step S71). According to the example shown in FIG. 25, a replication start message is transmitted from the default zone root node ZRd to the zone root node ZR of each zone as indicated by a one-dot chain line.

  Since the content node already has content in the zone in which the content node exists, the default zone root node ZRd inquires of the content root node CR about the node ID of the content node, and other zones excluding the zone A content duplication start message is transmitted to the zone root node ZR as shown by a one-dot chain line in FIG.

  Then, the process proceeds to the processing of FIG. 24D, and the zone root node ZR that has received the duplication start message functions as a duplication node device selection means by the control unit 11, refers to the content data registration history, and is registered most recently. A node device 1 for replication is selected at random from node devices other than the node device that has been selected (step S75). Next, a new content ID is generated as described above, and the control unit 11 functions as a duplication node information transmission unit, and returns it to the content root node CR together with the node information of the node device 1 selected as the duplication node device. (Step S76).

  Then, the process proceeds to the process of FIG. 24C, and the content root node CR receives the node information for duplication and the new content ID from the zone root node ZR (step S80). At this time, the content root node CR adds the node information for duplication and the new content ID to its index information. Similar to the processing in step S62, a content duplication instruction message is transmitted to the node information for content duplication with the IP address included in the node information for content duplication as destination information (step S81), and the processing is terminated.

  Thereafter, in each duplication node device 1 that has received the content duplication instruction message, the control unit 11 functions as a shared information obtaining unit, and obtains content data from the content node. More specifically, when the content node is accessed based on the IP address of the content node included in the content duplication instruction message and the transmission of content data is requested as shown by a dashed line in FIG. The control unit 11 functions as a shared information transmitting unit, and transmits content data to each duplication node device 1 as indicated by a solid line in the figure.

  As described above, the content node is configured to exist in each zone. In this case, unlike the case where the request node wishes to distribute the content (streaming distribution), the purpose is to copy the content data, so the content data may be downloaded.

  In this way, by arranging content nodes that hold content in each zone, when a query is transmitted from the request node, the content root node CR refers to the zone ID included in the node ID of the request node and is the same. Destination information such as the IP address of the content node belonging to the zone is transmitted to the request node. As a result, the request node can always receive content from the same zone. That is, since communication can be received from a nearby content node having a short network distance such as a small number of relays in communication, the communication load of the entire system can be reduced.

  Note that the content root node CR may be configured to transmit the content information of all the content nodes corresponding to the content ID included in the query to the request node. By configuring in this way, the request node first accessed a content node in the same zone as the zone to which the request node itself belongs, but failed to access such as when there is no response, such as when the content node is down In some cases, it becomes possible to access content nodes in other zones.

[6-3. Autonomous optimization of content data]
Next, processing when content data is autonomously and optimally replicated according to the usage frequency of each zone will be described with reference to FIG.

  28 (A) and 28 (C) are flowcharts showing processing performed when the program stored in the control unit 11 of the content root node CR is executed by the control unit 11, and FIG. 28 (B) and FIG. (D) is a flowchart showing processing performed when the control unit 11 executes a program stored in the control unit 11 of the zone root node ZR (including the default zone root node ZRd).

  The processing in FIG. 28A is started when the content root node CR receives the query.

  First, the content root node CR acquires the zone ID of the requesting node that has received the query (step S90). Then, it is determined whether or not the number of requests from the same zone ID (number of zone requests) exceeds a predetermined range (step S91). If the number is within the predetermined range (step S91: No), the process is terminated. If the range is exceeded (step S91: Yes), a content duplication start message is transmitted to the zone root node ZR of the zone (default zone root node ZRd if the zone is the default zone root node ZRd) (step S92). . That is, if queries are frequently sent from the zone with the zone ID “0500”, a content data replication start message is sent to the zone with the zone ID “0500” to create a content node. It is transmitted to the zone root node ZR with ID “0500”. The destination information of the zone root node ZR can be acquired by inquiring the zone root node ZR of the zone to which the content root node CR belongs. The predetermined range of the number of zone requests is, for example, “100 times in the past week”.

  Subsequently, the process proceeds to the process of FIG. 28D, and the zone root node ZR that has received the replication start message refers to the content data registration history and randomly selects from node apparatuses other than the most recently registered node apparatus. The node device 1 for duplication is selected (step S110), and the node information and the new content ID of the selected node device for duplication are transmitted to the content root node CR (step S111). In addition, since the specific process of step S110 and step S111 is the same as that of step S75 and step S76 mentioned above, detailed description is abbreviate | omitted.

  Then, the content root node CR receives the node information for duplication and the new content ID from the zone root node ZR (step S93), and uses the IP address information included in the node information for content duplication as destination information for content duplication. A content duplication instruction message is transmitted with respect to the node information (step S94). Then, a copy request message for requesting the copy of the content to another zone is transmitted to the default zone root node ZRd (step S95). In addition, since the specific process of step S93 thru | or step S95 is the same as that of step S61 thru | or step S63 mentioned above, detailed description is abbreviate | omitted.

  Then, the process proceeds to the processing of FIG. 28B, and the default zone root node ZRd that has received the duplication request message searches the own zone root node table to determine whether or not there is another zone (step S100). If there is no other zone (step S100: No), the process ends. If there is another zone (step S100: Yes), the zone root node ZR is referred to by referring to the zone root node table. A content duplication start message is transmitted (step S101). In addition, since the specific process of step S100 and step S101 is the same as that of step S70 and step S71 mentioned above, detailed description is abbreviate | omitted.

  In other words, since the number of requests from a certain zone has exceeded the predetermined range, based on the expectation that requests from other zones will increase in the future, a copy of the content data is also created in other zones in advance. It becomes possible to prepare for the increase.

  Then, the process proceeds to the processing of FIG. 28D, and the zone root node ZR that has received the copy start message refers to the content data registration history and randomly selects and copies from a node device other than the most recently registered node device. Node device 1 is selected (step S110). Next, a new content ID is generated as described above, and is returned to the content root node CR together with the node information of the node device 1 selected as the node device for duplication (step S111).

  Then, the process proceeds to the process of FIG. 28C, and the content root node CR receives the node information for duplication and the new content ID from the zone root node ZR (step S120). At this time, the content root node CR adds the node information for duplication and the new content ID to its index information. Similar to the processing in step S62, the content duplication instruction message is transmitted to the node information for content duplication using the IP address information included in the node information for content duplication as destination information (step S121), and the processing is terminated.

  Thereafter, each duplication node device 1 that has received the content duplication instruction message sends the above-mentioned [6-2. The content node is accessed based on the method described in [Replication registration of content data], and the content data is acquired to become the content node.

  As explained above, content data is autonomously replicated optimally according to the usage frequency of each zone, so that popular content can be placed in each zone in a large amount, reducing the communication load on the entire system, In addition, it is possible to respond quickly to the request of the request node.

  In addition, the zone root node ZR of each zone can monitor a zone by performing survival confirmation between the zone root nodes ZR. Furthermore, the zone root node ZR of each zone is configured so that the zone root node table owned by each zone can be backed up at regular intervals. As a result, it is possible to cope with a situation where the zone root node ZR is temporarily down when a zone is created or when zones are merged.

  Further, when there are a large number of node devices 1 in one zone (for example, 1000), the zone may be divided.

It is a figure which shows an example of the connection aspect of each node apparatus in the content delivery system which concerns on this embodiment. It is explanatory drawing of ID space. It is a figure which shows an example of a mode that a routing table is produced by DHT. (A) An example of a level 1 table. (B) An example of a level 2 table. (C) An example of a level 3 table. (D) An example of a completed routing table. 2 is a diagram illustrating a schematic configuration example of a node device 1. FIG. An example of the index information memorize | stored in the memory | storage part 12 is shown. 10 is a flowchart showing processing in the control unit 11 of the node device 1 when the node device 1 participates in the content distribution system S. 10 is a flowchart showing processing in the control unit 11 of the default zone root node ZRd when the node device 1 participates in the content distribution system S. It is a figure which shows a mode that the node apparatus 1 participates in the content delivery system S. FIG. It is explanatory drawing of the affiliation node table memorize | stored in the memory | storage part 12 of default zone root node ZRd. It is a flowchart which shows the process in the control part 11 of the node apparatus 1 when the node apparatus 1 produces | generates a new zone. It is a figure which shows a mode that the node apparatus 1 produces | generates a new zone. It is a figure which shows a mode that the node apparatus 1 produces | generates a new zone. It is a flowchart which shows the process in the control part 11 of default zone root node ZRd when the node apparatus 1 produces | generates a new zone. It is a figure which shows a mode that the node apparatus 1 produces | generates a new zone by another Example. It is explanatory drawing of ID space in the content delivery system S. FIG. (A) It is explanatory drawing of the zone root node table memorize | stored in the memory | storage part 12 of default zone root node ZRd. (B) It is explanatory drawing of the zone root node table memorize | stored in the memory | storage part 12 of zone root node ZR of zone ID "0500". (C) It is explanatory drawing of the zone root node table memorize | stored in the memory | storage part 12 of zone root node ZR of zone ID "1000". (D) It is explanatory drawing of the zone root node table memorize | stored in the memory | storage part 12 of zone root node ZR of zone ID "2000". (A) It is explanatory drawing of the affiliation node table memorize | stored in the memory | storage part 12 of default zone root node ZRd. (B) It is explanatory drawing of the affiliation node table memorize | stored in the memory | storage part 12 of zone root node ZR of zone ID "0500". (C) It is explanatory drawing of a storage affiliation node table in the memory | storage part 12 of zone root node ZR of zone ID "1000". (D) It is explanatory drawing of the affiliation node table memorize | stored in the memory | storage part 12 of zone root node ZR of zone ID "2000". It is a flowchart which shows the process in the control part 11 of the node apparatus 1 at the time of performing a zone merge process. It is a figure which shows a mode that zone merge is performed. It is a figure which shows a mode that zone merge is performed. It is a figure when zone merge processing is completed with zone ID “0500” and zone ID “1000”. It is a figure which shows an example of a mode that the node apparatus 1 which is a storage source of content data is searched by DHT. (A) And (C) It is a flowchart which shows the process in the control part 11 of content root node CR when content data is replicated in each zone. (B) It is a flowchart which shows the process in the control part 11 of default zone root node ZRd when content data is replicated in each zone. (D) It is a flowchart which shows the process in the control part 11 of zone root node ZR (including default zone root node ZRd) when content data is replicated in each zone. It is a figure which shows a mode that content data is replicated in each zone. It is a figure which shows a mode that content data is replicated in each zone. It is a figure which shows a mode that content data is replicated in each zone. (A) And (C) It is a flowchart which shows the process in the control part 11 of content root node CR when content data is replicated optimally in each zone autonomously. (B) and (D) are flowcharts showing processing in the control unit 11 of the zone root node ZR (including the default zone root node ZRd) when content data is autonomously and optimally replicated in each zone. It is a figure which shows an example of the connection aspect of each node apparatus in the conventional content delivery system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Node apparatus 8 Network 11 Control part 12 Memory | storage part 13 Buffer memory 14 Decoder part 15 Video processing part 16 Display part 17 Audio | voice processing part 18 Scar 20 Communication part 21 Input part 22 Bus S Content distribution system CR Content root node ZR Zone root node ZRd default zone root node

Claims (19)

An information communication system formed by participation of a plurality of node devices connected to each other via a communication path, wherein the overlay network has a plurality of zones,
When the communication load on the communication path between one node device and another node device is within a predetermined range, the one node device and the other node device are placed in the same zone in the overlay network. An information communication system characterized by being arranged to belong to The information communication system according to claim 1,
When a participation request to the information communication system is made from a new node device, the new node device and the node device belonging to the initial zone to which the information node belongs first when participating in the information communication system When the communication load on the communication path is within a predetermined range, a new zone is generated in the overlay network, and the new node device and the node device belonging to the initial zone are included in the generated new zone. An information communication system characterized by being arranged. In the information communication system according to claim 1 or 2,
When the communication load on the communication path between the node device belonging to one zone in the plurality of zones and the node device belonging to another zone in the plurality of zones is within a predetermined range, An information communication system, wherein a zone and the other zone are merged. The information communication system according to any one of claims 1 to 3,
When the one node device holds the shared information to be shared among the plurality of node devices in a sharable manner, the sharing is performed for the node device belonging to a zone different from the zone to which the one node device belongs. An information communication system characterized in that information is duplicated and held sharable. In the information communication system according to any one of claims 1 to 4,
When the one node device holds the shared information to be shared among the plurality of node devices in a sharable manner, there is a distribution information distribution request from the other node device to the first node device. If the number of zone requests for the zone to which the other node device belongs exceeds a predetermined range, the node device belonging to the zone to which the other node device belongs An information communication system characterized in that shared information is duplicated and held sharable. The information communication system according to any one of claims 1 to 5,
Each of the node devices includes zone information indicating a zone to which the node device belongs, and has unique device identification information for uniquely identifying the node device from the plurality of node devices. Is placed in any one of the zones corresponding to the zone information included in the device identification information of each node device. In the information communication system according to any one of claims 1 to 6,
The information communication system, wherein the communication load is determined based on the number of relay devices on the communication path or a statistical value of a communication response time for a certain period. An information communication system formed by participation of a plurality of node devices connected to each other via a communication path, wherein the overlay network has a plurality of zones,
The node device included in configuring the information communication system, belonging to the initial zone to which the information communication system participates first, the initial zone management node device for managing the node device belonging to the initial zone,
When receiving a unique device identification information for uniquely identifying the node device from a new node device and receiving a request to participate in the information communication system, the new zone is added to the initial zone based on the device identification information. Arrangement control means for arranging node devices;
A zone information transmission unit that transmits zone information indicating a new zone to a node device that is a transmission source of the departure information when receiving the separation information indicating the departure of the initial zone from any of the node devices belonging to the initial zone;
Have
The new node device is:
A communication load for acquiring communication load information related to a communication load in the communication path with another node device belonging to the initial zone when the initial zone management node device is arranged in the initial zone by the arrangement control unit. Information acquisition means;
When the communication load applied to the acquired communication load information is within a predetermined range, leave information transmission means for sending the leave information to the initial zone management node device;
Upon receiving the zone information from the initial zone management node device, zone generation means for generating a new zone to which the new node device itself and the other node device belong to the overlay network based on the zone information When,
An information communication system comprising: The information communication system according to claim 8, wherein
A node device that constitutes the information communication system, belongs to one zone in the plurality of zones, and a zone management node device that manages the node device belonging to the one zone,
Communication load information acquisition means for acquiring communication load information related to a communication load in the communication path between the node devices belonging to the other zones;
If the communication load applied to the acquired communication load information is within a predetermined range, zone information transmitting means for transmitting zone information indicating the other zone to a node device belonging to the one zone;
Annihilation information transmitting means for transmitting zone erasure information indicating the disappearance of the one zone to each zone management node device that manages each zone other than the one zone and the other zones among the plurality of zones;
Have
Node devices belonging to the one zone are:
Having unique device identification information for uniquely identifying the node device from the plurality of node devices, and receiving the zone information from the zone management node device, changes the device identification information based on the zone information Identification information changing means to
An information communication system comprising: The information communication system according to claim 9, wherein
One node device belonging to one zone in the plurality of zones and not the zone management node device of the one zone is:
Communication load information acquisition means for acquiring communication load information related to a communication load in the communication path between the node devices belonging to the other zone;
If the communication load applied to the acquired communication load information is within a predetermined range, zone information transmitting means for transmitting zone information indicating the other zone to the zone management node device;
Identification information changing means for changing the device identification information of the one node device itself based on zone information indicating the other zone;
An information communication system comprising: The information communication system according to any one of claims 8 to 10,
A node device in the plurality of node devices, the shared information management node device for managing shared information to be shared between the plurality of node devices,
Replication start information for instructing at least one zone management node device that manages a zone other than the zone to which the information storage node device that stores the shared information belongs to start the replication of the shared information to the other zone A replication start information transmitting means for transmitting
When receiving the replication node information indicating the replication node device to which the shared information is to be copied and stored from the zone management node device, the destination information of the information storage node device that stores the shared information in the replication node device is obtained. A copy instruction means for transmitting and instructing copy;
Have
The zone management node device is:
When receiving the replication start information from the shared information management node device, a replication node device selection means for selecting the replication node device from the node devices belonging to the zone managed by the zone management node device;
Replication node information transmitting means for transmitting the replication node information indicating the selected replication node device to the shared information management node device, and
The replication node device receives the destination information of the information storage node device from the shared information management node device, and when the replication of the shared information is instructed, requests the information storage node device to copy the shared information And having shared information acquisition means for acquiring the shared information from the information storage node device,
When the information storage node device receives a request for duplication of the shared information from at least one of the duplication node devices, the information storage node device has shared information transmission means for transmitting the shared information to the duplication node device that is a request source. An information communication system. The information communication system according to any one of claims 8 to 11,
The information communication system, wherein the communication load is determined based on the number of relay devices on the communication path or a statistical value of a communication response time for a certain period. An overlay network formed by the participation of a plurality of node devices connected to each other via a communication path, the overlay network included in the information communication system formed to have a plurality of zones, and included in the plurality of zones An initial zone management node device that manages a node device that belongs to the initial zone and that belongs to the initial zone,
When receiving a unique device identification information for uniquely identifying the node device from a new node device and receiving a request to participate in the information communication system, the new zone is added to the initial zone based on the device identification information. Arrangement control means for arranging node devices;
A zone information transmission unit that transmits zone information indicating a new zone to a node device that is a transmission source of the departure information when receiving the separation information indicating the departure of the initial zone from any of the node devices belonging to the initial zone;
An initial zone management node device comprising: A new node device that is formed by participation of a plurality of node devices connected to each other via a communication path and requests participation in an information communication system formed so that the overlay network has a plurality of zones. There,
A node device constituting the information communication system, which belongs to the initial zone to which the information communication system belongs first and belongs to the initial zone by an initial zone management node device that manages the node device belonging to the initial zone When arranged, communication load information acquisition means for acquiring communication load information related to the communication load in the communication path with other node devices belonging to the initial zone;
When the communication load applied to the acquired communication load information is within a predetermined range, leave information transmission means for sending the leave information to the initial zone management node device;
When zone information indicating a new zone is received from the initial zone management node device, a new zone to which the new node device itself and the other node device belong to the overlay network is generated based on the zone information. Zone generating means;
A node device comprising: The node device according to claim 14, wherein
The node load is characterized in that the communication load is determined based on the number of relay devices on the communication path or a statistical value of communication response time for a certain period. An overlay network formed by the participation of a plurality of node devices connected to each other via a communication path, and the overlay network is included in an information communication system formed to have a plurality of zones. A zone management node device that manages a node device that belongs to the zone 1 and that belongs to the one zone,
Communication load information acquisition means for acquiring communication load information related to a communication load in the communication path between the node devices belonging to the other zones;
If the communication load applied to the acquired communication load information is within a predetermined range, zone information transmitting means for transmitting zone information indicating the other zone to a node device belonging to the one zone;
Annihilation information transmitting means for transmitting zone erasure information indicating the disappearance of the one zone to each zone management node device that manages each zone other than the one zone and the other zones among the plurality of zones;
A zone management node device comprising: The zone management node device according to claim 16,
Upon receiving replication start information from a shared information management node device that manages shared information that should be shared among the plurality of node devices, the shared information is replicated from the node device that belongs to the zone managed by the zone management node device. A duplication node device selection means for selecting a duplication node device to be stored,
A zone management node device comprising: replication node information transmitting means for transmitting replication node information indicating the selected replication node device to the shared information management node device. In the zone management node device according to claim 16 or 17,
The zone management node device, wherein the communication load is determined based on the number of relay devices on the communication path or a statistical value of communication response time for a certain period. An overlay network formed by the participation of a plurality of node devices connected to each other via a communication path, and the overlay network is included in an information communication system formed to have a plurality of zones, and between the plurality of node devices. A shared information management node device for managing shared information to be shared by
Replication start information for instructing at least one zone management node device that manages a zone other than the zone to which the information storage node device that stores the shared information belongs to start the replication of the shared information to the other zone A replication start information transmitting means for transmitting
When receiving the replication node information indicating the replication node device to which the shared information is to be copied and stored from the zone management node device, the destination information of the information storage node device that stores the shared information in the replication node device is obtained. A shared information management node device comprising: copy instruction means for transmitting and instructing duplication.

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