JP2005092784A - Dynamic switching method for search system, switching device for dynamically switching search system, and switching program dynamically switching search system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform efficient search even if a large load is generated in a network or in an index server. <P>SOLUTION: A traffic volume is measured by a measurement part 12 for monitoring whether a measurement value exceeds a threshold value or not. When the measurement value exceeds the threshold value, a switching processing part 13 refers to management contents in an operation condition management part 14 and requires a terminal processing part 15 to switch the operation condition from a pure type to the index server, and the terminal processing part 15 switches the operation condition from the pure type to the index server. Alternatively, the switching processing part 13 requires the terminal processing part 15 to separate a part of a device, which is connected to its own device as a child node, and the terminal processing part 15 separates the part of the device connected as the child node to the own device. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a dynamic search method switching method and a search method in an information search system that uses a peer-to-peer method to search for information held in a distributed manner in a plurality of devices connected to a network. The present invention relates to an apparatus for switching between and a switching program for dynamically switching a search method.

2. Description of the Related Art Conventionally, in a peer-to-peer (P2P) type information search system (hereinafter referred to as a P2P system as appropriate), content information such as electronic files is mainly distributed in a network. In this state, the information can be searched and exchanged without installing an information search server or an information delivery server in the network. Typical examples include Gnutella and JXSTA.
There are two types of P2P systems: a Pure type and a Hybrid type. These are outlined below.

Hereinafter, a configuration example of a pure P2P system will be described with reference to FIGS. 12 and 13. FIG. 12 is a configuration diagram showing the configuration of a pure P2P system. FIG. 13 is a block diagram showing a configuration of each terminal apparatus of FIG.
The pure type P2P system is composed of a plurality of terminal devices, and FIG. 12 shows four terminal devices 100-1, 100-2, 100-3, and 100-4. In the pure type, the terminal devices are configured in an N-to-N manner in which all communication is performed directly.

  As shown in FIG. 13, the terminal device 100 (the devices 100-1 to 100-4 in FIG. 12) includes a communication protocol control unit 101, a user interface 102, a search condition input unit 103, and a search request processing unit 104. A search function processing unit 105, a search result display unit 106, a shared content management unit 107, and an index information database 108, and is connected to the IP network 120.

  The communication protocol control unit 101 is connected to the IP network 120 and controls the communication protocol so that data can be exchanged correctly between devices. The user interface 102 includes an input unit such as a keyboard and a mouse and a display unit such as a display. For example, it is used for inputting search conditions by the user, and the search result is displayed.

  The search condition input unit 103 outputs the search condition from the user interface 102 to the search request processing unit 104. The search request processing unit 104 performs a process of transmitting a search request packet based on the search condition from the search condition input unit 103 and performs a process of receiving a response to the transmitted search request packet, and obtains a search result based on the response. The search result display unit 106 is displayed. The search function processing unit 105 performs a search process by referring to the index information database 108 via the shared content management unit 107. The search result display unit 106 performs processing for displaying the search result received from the search request processing unit 104 on the display unit of the user interface 102. The shared content management unit 107 manages the index information database 108. The index information database 108 stores index information.

  Hereinafter, a configuration example of the hybrid P2P system will be described with reference to FIGS. 14 and 15. FIG. 14 is a configuration diagram showing the configuration of a hybrid P2P system. FIG. 15 is a block diagram showing the configuration of the index server of FIG. However, each terminal device of FIG. 14 has a configuration substantially similar to that of FIG.

  The hybrid P2P system includes an index server and a plurality of terminal devices. In FIG. 14, one index server 110 and four terminal devices 100-1, 100-2, 100-3, 100 are included. -4 is shown. In the hybrid type, the relationship between a server and a terminal device called a conventional client / server type is a one-to-N configuration, and a pure type terminal device is a two-to-N configuration. Has a configuration.

  As shown in FIG. 15, the index server 110 includes a communication protocol control unit 111, a search function processing unit 112, a shared content management unit 113, and an index information database 114, and is connected to the IP network 120. ing. The communication protocol control unit 111 is connected to the IP network 120 and controls the communication protocol so that data can be exchanged correctly between devices. The search function processing unit 112 refers to the index information database 113 via the shared content management unit 112, performs a search based on the search condition included in the search request packet received via the communication protocol control unit 111, and the search result Respond. The shared content management unit 113 manages the index information database 114. The index information database 114 stores index information.

A search system using such a P2P system is disclosed (see, for example, Patent Document 1 and Patent Document 2).
JP 2002-229836 A JP 2000-137641 A

  The pure type described above is suitable for information sharing on a small network group and has a feature that it can be easily introduced because it does not require a management server or the like. However, the pure type has a problem that when the number of terminal devices increases, the search range becomes wider and the search speed deteriorates. In addition, there is a problem that traffic increases due to packets broadcast between the terminal devices. Furthermore, since the same search is performed by a plurality of terminal devices, there is a problem that the search efficiency is lower than when searching on one server.

  Moreover, the hybrid type described above is suitable for information sharing on a large-scale network group, and has a feature that it is superior in search speed and scalability than the pure type. However, the hybrid type has a problem that the load on the server increases due to the concentration of searches and inquiries on the server. Further, there is a problem that if the server fails, the entire P2P system will not function.

  As described above, the pure type and the hybrid type each have a problem. However, in the conventional P2P system including the technology disclosed in the above patent publication, the terminal device 100 (100-1 to 100- 4) operates only as a terminal device, and the index server 110 is configured to operate only as an index server. For this reason, only a pure type or a hybrid type operation could be performed. As a result, there is a problem that efficient search cannot be performed when a large load occurs on the network or when a large load occurs on the index server.

  Therefore, the present invention provides a dynamic search method switching method and an apparatus for dynamically switching a search method that can perform an efficient search when a large load occurs on a network or when a large load occurs on an index server. And a switching program for dynamically switching a search method.

  According to the first aspect of the present invention, in the dynamic switching method of a search method in a plurality of devices that search for information using a peer-to-peer method, each device operating as a pure type is a network traffic And performing a pure operation measurement procedure for determining whether the measurement value during the pure operation exceeds a predetermined threshold value during the pure operation. In the measurement procedure during the pure operation, the measurement value during the pure operation is The device that has determined that the threshold value during the pure operation has been exceeded performs a switching procedure for switching the operation state of the device from the pure type to the index server, and an information collecting procedure for collecting information held by another device. Features.

  According to the second aspect of the present invention, each device operating as an index server measures network traffic, and determines whether the measured value during server operation exceeds a predetermined threshold during server operation. A server operating measurement procedure, and in the server operating measurement procedure, a device that has been determined that a measured value during server operation has exceeded a threshold value during server operation is a selection procedure for selecting a device to be disconnected from its own device; And a procedure for transmitting information to a device to be disconnected from the own device selected in the selection procedure.

  According to a third aspect of the present invention, in the selection procedure, the number of times of summing the number of times of reference of each piece of information in each device from which information has been collected is the number of times that the number of times of reference of each piece of collected information is summed in advance. A determination procedure for determining whether or not there is a device that is equal to or higher than a predetermined ratio, and when it is determined that there is a device that is equal to or higher than the predetermined ratio in the determination procedure, a first device that is selected as a device that separates the device The device selection procedure, the first switching notification procedure for notifying the device selected in the first device selection procedure to switch the operation state to the pure type, and the ratio determined in the determination procedure is equal to or greater than the predetermined ratio. If it is determined that there is no device, a second device selection procedure for selecting an arbitrary device as a device to be disconnected, and an operation state is input to the device selected in the second device selection procedure. And a second switching notification procedure for notifying the server to switch to the network server, the device receiving the notification in the first switching notification procedure performs a first switching procedure for switching the operation state of the device to a pure type, The apparatus that has received the notification in the 2 switching notification procedure performs the second switching procedure for switching the operation state of the own apparatus to the index server.

  The invention according to claim 4 is a device that searches for information using a peer-to-peer method and dynamically switches the search method to measure network traffic when operating as a pure type device. Pure operation time measuring means for determining whether a measured value during pure operation exceeds a predetermined threshold value during pure operation, and the measured value during pure operation by the pure operation time measuring means is a threshold value during pure operation. A switching processing means for switching the operation state of the apparatus from a pure type to an index server when it is determined that the operating state of the apparatus has been exceeded, and a management means for collecting and managing information held by another apparatus. .

  The invention according to claim 5 is a server operation for measuring network traffic when operating as an index server and determining whether a measured value at the time of server operation exceeds a predetermined threshold value at the time of server operation. A time measuring means, a selecting means for selecting a device to be disconnected from its own device when the server operating time measuring means determines that a measured value during the server operation exceeds a threshold during the server operation, and the selecting means Transmitting means for transmitting information to a device that is separated from the device selected by the method.

  The invention according to claim 6 is a switching program that executes a dynamic switching method of a search method in a plurality of devices that search for information using a peer-to-peer method, each operating as a pure type. The device measures a network traffic and performs a pure operation time measurement procedure for determining whether a measurement value during the pure operation exceeds a predetermined pure operation threshold value. In the pure operation measurement procedure, A device that has determined that a measured value during pure operation has exceeded the threshold during pure operation is a switching procedure for switching the operation state of the device from a pure type to an index server, and information collection for collecting information held by other devices And performing a procedure.

  According to the seventh aspect of the present invention, each device operating as an index server measures network traffic and determines whether or not the measured value during server operation exceeds a predetermined threshold value during server operation. A server operating measurement procedure, and in the server operating measurement procedure, a device that has been determined that a measured value during server operation has exceeded a threshold value during server operation is a selection procedure for selecting a device to be disconnected from its own device; And a procedure for transmitting information to a device to be disconnected from the own device selected in the selection procedure.

  According to the present invention, since the search method is dynamically switched according to the traffic volume, an efficient search can be performed.

Embodiments of the present invention will be described below with reference to the drawings. However, a known technique such as Gnutella or JXSTA is used as the search process.
First, an outline of an information search system according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2 are diagrams illustrating a network configuration of an information search system according to an embodiment. However, in FIG.1 and FIG.2, the connection path | route between each apparatus is represented by the continuous line in a figure.

  The devices 1-1 to 1-28 in FIG. 1 form a network with a pure P2P system. Assume that network traffic increases at locations 2a to 2d in FIG. 1 and a load on the entire P2P system occurs. At this time, one of the devices connected to the places 2a to 2d where the load is generated switches the operation to the index server. Then, the device whose operation is switched to the index server collects index information from the peripheral devices, and thereafter performs a search process of the peripheral devices on the index server. Details of the operation content including this switching operation will be described later.

  The network configuration after one 1-3, 1-11, 1-15, and 1-25 connected to the places 2a, 2b, 2c, and 2d where the load is generated is switched to the index server is shown in FIG. It becomes the composition shown. In FIG. 2, the devices are switched to the hybrid configuration at locations 2 </ b> A to 2 </ b> D corresponding to the locations 2 a to 2 d where the load of FIG. 1 is generated.

  Assume that the load is concentrated on some of the devices 1-3, 1-11, 1-15, and 1-25 operating as the index server in FIG. 2, and the load on the entire P2P system is generated. At this time, a part of the device connected to the device operating as the index server where the load is concentrated is disconnected, and the operation of the disconnected device is switched to the pure communication method. Alternatively, disconnect one of the devices connected to the device operating as an index server where the load is concentrated, and switch the operation to a new index server, and select a part of the device connected to the device operating as the index server. Disconnect and connect to a device that newly operates as an index server. Then, an apparatus operating as an index server with a concentrated load moves index information to a pure type or an apparatus whose operation is switched to the index server. Details of the operation content including this switching operation will be described later.

  However, the apparatus operating as an index server in FIGS. 1 and 2 is an apparatus in which the operation of an arbitrary apparatus constituting the network is switched, and the operation of a predetermined apparatus is not switched. In addition, the hybrid type configured by the index server and the terminal is formed in a self-defined manner at an arbitrary location according to the connection path of the device, and is a fixed mode in which only one is configured in the entire network. is not. Furthermore, the network dynamically changes to the form shown in FIG. 1 or the form shown in FIG. 2 depending on the operation mode of the apparatus, that is, the presence or absence of the index server.

  The configuration of the apparatus according to the embodiment of the present invention will be described below with reference to FIG. FIG. 3 is a diagram showing a configuration of the apparatus according to the embodiment of the present invention. The devices 1-1 to 1-28 constituting the network shown in FIGS. 1 and 2 are the same as the devices shown in FIG.

The apparatus 10 includes a communication protocol control unit 11, a measurement unit 12, a switching processing unit 13, an operation state management unit 14, a terminal processing unit 15, and a user interface 16, and is connected to the IP network 3. Yes.
The communication protocol control unit 11 is connected to the IP network 3 and controls the communication protocol so that data can be exchanged correctly between devices.

The measurement unit 12 constantly measures, for example, the amount of network traffic during pure type operation or index server operation. Here, the number of search request packets or the number of relay packets is measured, and the measurement result is handled as an approximate value of the traffic amount of the network. When operating as a pure type, each device performs processing to forward search request packets to neighboring devices one after another, so the number of packets transferred at this time is read as the traffic volume of the network to which the device is connected. Can do. Further, when operating as an index server, search request packets are collected in the index server, so that the number of packets collected at this time can be read as the traffic amount of the network configured by the hybrid. However, the measurement unit 12 refers to the management content of the operation state management unit 14 and decides whether to measure the number of packet transfers or the number of packets collected in its own device. In addition to the number of search request packets and the number of relay packets, the measurement unit 12 measures, for example, the number of accesses to the device (number of sessions) and the packet transfer rate (throughput).
When the traffic volume of the measured value exceeds a predetermined threshold value, the measuring unit 12 notifies the switching processing unit 13 of a message to that effect. Note that this threshold value may be set differently between the pure type operation and the index server operation.

When receiving a notification from the measurement unit 12, the switching processing unit 13 refers to the operation state managed by the operation state management unit 14 and switches the operation state of the own device. Specifically, if the operation state managed by the operation state management unit 14 is a pure type, the switching processing unit 13 notifies the terminal processing unit 15 to switch the operation state from a pure type to a hybrid type. At the same time, the switching processing unit 13 changes the management content of the operation state management unit 14 from a pure type to an index server. If the operation state managed by the operation state management unit 14 is an index server, the switching processing unit 13 operates with respect to the terminal processing unit 15 as a device connected to the own device (acts as a child node of the own device). A part of the device) is disconnected from its own device.
The operation state management unit 14 stores and manages the current operation state of the device itself. The operation state to be managed includes a pure type, an index server, and a hybrid type (child node of the index server).

  The terminal processing unit 15 performs a process for setting the operation state to a pure type, an index server, or a hybrid type, or performs a P2P search process. The terminal processing unit 15 includes a common processing unit 20 that performs P2P common processing, a pure type processing unit 30 that performs detection processing during pure type operation, a child of an index server and the index server. And a hybrid processing unit 40 that performs search processing during operation at the node.

  The sharing processing unit 20 includes a message processing unit 21, a search request processing unit 22, and a search result processing unit 23. The message processing unit 21 performs processing for transmitting and receiving messages related to various processing requests and the like. The search request processing unit 22 transmits a search request packet including a search condition designated by using the user interface 16, receives a search request packet from another device, or receives a search request packet from another device. Process to transfer. The search result processing unit 23 receives a response message for the search request packet transmitted by the own device, and displays the content of the response message on a display included in the device 10.

  The pure processing unit 30 includes a transfer destination node management unit 31 and a search function processing unit 32. The transfer destination node management unit 31 manages and stores information such as IP (Internet Protocol) addresses of neighboring peripheral devices in order to transfer various packets. The search function processing unit 32 performs processing related to search, and includes an index database (index DB) 32a and a search processing unit 32b. The index DB 32a stores index information. The search function processing unit 32b performs a search process with reference to the index DB 32a based on the search condition included in the search request packet.

  The hybrid processing unit 40 includes a transfer destination node management unit 41 and a search function processing unit 42. When operating as an index server, the transfer destination node management unit 41 manages and stores information such as an IP address of a device hanging as a child node on its own device. In addition, when operating as a hybrid type, the transfer destination node management unit 41 manages and stores information such as an IP address of a device operating as a connection destination index server. The search function processing unit 42 performs processing related to search, and includes an index database (index DB) 42a and a search processing unit 42b. The index DB 42a stores index information. This index information includes index information of its own device and index information collected from other devices, and the index information is associated with information such as the IP address of the device that originally held the index information. The search processing unit 42b performs a search process with reference to the index DB 42a based on the search condition included in the search request packet. This search processing unit 42b uses information such as the IP address of the first holding device with which the index information is associated to hold information as to which device's index information hits the search as history information. . By using this history information, it is possible to determine which device has high reference frequency with respect to the index information.

  The user interface 16 includes an input unit such as a keyboard and a mouse and a display unit such as a display. For example, it is used for inputting search conditions by the user, and the search result is displayed.

Further, the operation of the apparatus shown in FIG. 3 will be described with reference to FIG. FIG. 4 is a diagram illustrating a network configuration of the information search system according to the embodiment, and corresponds to a part of FIG.
Each of the devices 10-1 to 10-7 in FIG. 4 (the devices 10-1 to 10-7 are the same devices as the device 10 described with reference to FIG. 3) is a pure P2P system and is a network. Is configured. A search request packet is transmitted from the device 10-1 to the devices 10-2, 10-3, 10-4 (solid line in FIG. 4). The devices 10-2, 10-3, and 10-4 that have received the search request packet each receive the search request packet received based on the management content of the transfer destination node management unit 31 of the pure type processing unit 30 of its own device. Transfer (dotted line in FIG. 4). In this way, search request packets are successively transferred between devices, and search processing is performed by the sharing processing unit 20 and the pure processing unit 30 of each device. As a result, the search request packet transmitted by the device 10-1 is distributed to the entire network, and it becomes possible to search for information on the distributed devices.

  In FIG. 4, it is assumed that the number of search request packets transmitted or transferred from the apparatus 10-1 has increased. Along with this increase, the number of search request packets transferred by the devices 10-2 and 10-3 increases. When this state continues, in the device 10-3, the measurement value by the measurement unit 12 exceeds a predetermined threshold value. Then, a notification that the measured value exceeds the threshold value is transmitted from the measuring unit 12 to the switching processing unit 13. Upon receiving this notification, the switching processing unit 13 refers to the management content of the operation state management unit 14, and since the content is a pure type, notifies the terminal processing unit 15 to switch to the processing of the index server. Upon receiving this notification, the terminal processing unit 15 switches the operation state from the pure type to the index server. At the same time, the switching processing unit 13 changes the management content of the operation state management unit 14 from a pure type to an index server. As a result, the network configuration becomes a hybrid configuration (see FIG. 7).

Further, the operation of the apparatus shown in FIG. 3 will be described with reference to FIG. FIG. 5 is an explanatory diagram for explaining an operation when the device according to the embodiment is switched to the index server.
As described with reference to FIG. 4, when the measurement value by the measurement unit 12 exceeds a predetermined threshold in the device 10-3, the operation state of the device 10-3 is switched from the pure type to the index server. Subsequently, from the device 10-3 whose operation state has been switched to the index server, the device 10-2 using information such as an IP address managed by the transfer destination node management unit 31 of the pure type processing unit 30 of the own device. , 10-4, 10-5, 10-6, and 10-7 (all devices whose information such as IP address is managed by the transfer destination node management unit 31) A notification message M1 including information such as the IP address of the own device for notifying that the switch has been made is transmitted.

  When each of the devices 10-2, 10-4, 10-5, 10-6, and 10-7 receives the notification message M1 from the device 10-3, the terminal processing unit 15 of the device changes the operation state from the pure type. Switch to the hybrid type. At this time, the terminal processing unit 15 of each device, based on the notification message M1, transfers information such as the IP address of the device 10-3 that is the index server to which the device itself is connected, to the forwarding node management unit of the hybrid processing unit 40. 41. Further, the terminal processing unit 15 changes the management content of the operation state management unit 14 from a pure type to a hybrid type.

  In the devices 10-2, 10-4, 10-5, 10-6, and 10-7 whose operations are switched to the hybrid type, the terminal processing unit 15 of the devices 10- 10 is the device 10- that is the transmission source of the notification message M1, respectively. 3, the index information Index2, Index4, Index5, Index6, and Index7 stored in the index DB 32a of the pure type processing unit 30 of the own apparatus is transmitted (dotted line in FIG. 5). Thereafter, when the index information of the devices 10-2, 10-4, 10-5, 10-6, and 10-7 is updated, the updated index information is transmitted to the device 10-3.

  When the device 10-3 receives the index information Index2, Index4, Index5, Index6, and Index7, the terminal processing unit 15 of the device 10-3 transmits the received index information to the IP of the device of the transmission source (first holding source). The information is stored in the index DB 42a of the hybrid processing unit 40 in association with information such as an address. As a result, the indexes of the peripheral devices are stored in the index DB 42a of the device 10-3, and the search process is performed on the device 10-3.

  Further, the search method switching processing described with reference to FIGS. 4 and 5 will be described with reference to FIG. FIG. 6 is a sequence diagram showing the operation of search method switching processing.

  A search request packet is sent from the other device to the device 10-3 (step S101). The measurement unit 12 measures the number of search request packets per unit time, and monitors whether the traffic volume exceeds a predetermined threshold based on the measured value (step S102). When it is detected that the traffic volume exceeds the threshold value, the measurement unit 12 notifies the switching processing unit 13 that the traffic volume exceeds the threshold value (step S103).

  When the switching processing unit 13 receives a notification that the traffic volume has exceeded the threshold value from the measuring unit 12, the switching processing unit 13 refers to the management content of the operation state management unit 14, and since the content is pure type, the switching processing unit 13 The operation state is notified to be switched from the pure type to the index server (step S104). Along with the notification, the switching processing unit 13 changes the management content of the operation state management unit 14 from the pure type to the index server.

  Upon receiving the notification in step S104 from the switching processing unit 13, the terminal processing unit 15 switches the operation state from the pure type to the index server (step S105).

  The terminal processing unit 15 is a device in which information such as an IP address is stored in the transfer destination node management unit 31 of the pure type processing unit 30 (in this sequence, the devices 10-2, 10-4, 10-5, 10- 6, 10-7) using the information such as the IP address, notifies that the operation state of the own device has been switched to the index server and requests the operation state to be switched to the hybrid type. (Step S106).

  The terminal processing units 15 of the devices 10-2, 10-4, 10-5, 10-6, and 10-7 that have received the notification and request in step S106 switch the operating state from the pure type to the hybrid type. At this time, each terminal processing unit 15 stores information such as the IP address of the apparatus 10-3 that made the notification and request in step S106 in the transfer destination node management unit 41 of the hybrid processing unit 40 (step S107). .

  In each of the devices 10-2, 10-4, 10-5, 10-6, and 10-7, the terminal processing unit 15 notifies the index information stored in the index DB 32a of the pure type processing unit 30 in step S106. And it transmits with respect to the terminal device 10-3 which performed the request | requirement (step S108).

  The terminal processing unit 15 of the device 10-3 has the IP address stored in the transfer destination node management unit 31 of the pure type processing unit 30 of the own device in the transfer destination node management unit 41 of the hybrid processing unit 40 of the own device. Is stored (step S109). Further, the terminal processing unit 15 stores the received index information in the index DB 42a of the hybrid processing unit 40 in association with information such as the IP address of the transmission source (first holding source) device (step S110).

  In each of the devices 10-2, 10-4, 10-5, 10-6, and 10-7, when the index information of the own device is updated, the updated index information is converted into the hybrid processing unit 40 of the own device. The information is transmitted to the apparatus 10-3 using information such as the IP address stored in the transfer destination node management unit 41 (step S111). Then, when the updated index information is received in the device 10-3, the terminal processing unit 15 stores the updated index information in the index DB 42a of the hybrid processing unit 40 (step S112).

  As described above, when the network traffic increases and the traffic volume exceeds a predetermined threshold, the operating state of the device that detects the traffic dynamically switches from the pure type to the index server. Thereby, it becomes possible to reduce the traffic in the network and perform an efficient search.

  Next, the operation of the apparatus shown in FIG. 3 will be described with reference to FIG. FIG. 7 is a diagram showing a network configuration of the information search system in the embodiment, and corresponds to a part of the network configured in the hybrid type of FIG.

  In FIG. 7, the device 10-3 is configured to operate as an index server by the search method switching process described above. Further, the devices 10-2, 10-4, 10-5, 10-6, and 10-7 operate as a hybrid type by the above-described search method switching processing. The devices 10-2, 10-4, 10-5, 10-6, and 10-7 are connected around the device 10-3 operating as an index server. When there is an update of the index information, the devices 10-2, 10-4, 10-5, 10-6, and 10-7 transmit an updated packet of the updated index information to the device 10-3 (see FIG. 7 middle dotted line). In addition, the device 10-1 transmits and receives a search request packet to and from the device 10-3 (solid line in FIG. 7).

  A search request packet is transmitted from device 10-1 to device 10-3 (solid line in FIG. 7). When the search request packet is received in the device 10-3, search processing for the search request packet is performed by the sharing processing unit 20 and the hybrid processing unit 40 of the device 10-3. Then, the result of the search process is returned from the device 10-3 to the device 10-1 that is the transmission source of the search request packet. This is repeated, and it becomes possible to search for information on devices distributed on the network.

  In FIG. 7, it is assumed that the number of search request packets transmitted from the device 10-1 to the device 10-3 increases. With this increase, the access load to the device 10-3 increases. When this state continues, in the device 10-3, the measurement value by the measurement unit 12 exceeds a predetermined threshold value. Then, a notification that the measured value exceeds the threshold value is transmitted from the measuring unit 12 to the switching processing unit 13. Upon receiving this notification, the switching processing unit 13 refers to the management content of the operation state management unit 14, and since the content is an index server, the terminal processing unit 15 is supposed to detach a part of its own child node. To request.

  When the terminal processing unit 15 is requested by the switching processing unit 13 to disconnect a part of its own child nodes, the terminal processing unit 15 stores the history information stored in the search processing unit 42b of the hybrid processing unit 40. It is used to determine whether the reference of index information is concentrated on a specific device. In other words, the total number of times of reference of each index information collected from the device 10-2 (if the index information collected from the device 10-2 is Index A and Index B, and the respective reference times are A times and B times. , A + B) is the total number of times of reference of each index information collected from the devices 10-2, 10-4, 10-5, 10-6, 10-7 (devices 10-2, 10-4, 10-). The index information collected from 5, 10-6 and 10-7 is Index A, Index B, Index C, Index D, Index E, Index F, and Index G, and the respective reference counts are A times, B times, C times, D times, and E times. , F times, G times, A + B + C + D + E + F + G) is checked whether it is equal to or higher than a predetermined ratio. Reference index information is judged to be concentrated in the apparatus 10-2. The same is done for the devices 10-4, 10-5, 10-6 and 10-7. When it is determined that the device is concentrated, a process for separating the device determined to be concentrated from the child node is performed. This disconnected device switches the operating state to the pure type. This distributes the load.

  On the other hand, if it is determined that it is not concentrated, the operation state of one child node (device operating as a hybrid type) of the own device is switched to the index server and disconnected from the own device, and A part of the child node is made a child node of the device that newly becomes the index server, and is separated from the own device. Thereby, the load is distributed.

  Further, the operation when the child node described in FIG. 7 is disconnected and the operation state of the disconnected device is switched to the pure type will be described with reference to FIG. FIG. 8 is an explanatory diagram for explaining an operation when the separated device in the embodiment is switched to a pure type. In FIG. 8, description will be made assuming that the reference is concentrated on the index information of the devices 10-2 and 10-5.

  In FIG. 7, as described above, when the measurement value by the measurement unit 12 of the apparatus 10-3 exceeds a predetermined threshold value, the measurement unit 12 notifies the switching processing unit 13 that the threshold value has been exceeded. The notified switching processing unit 13 refers to the management content of the operation state management unit 13 and requests the terminal processing unit 15 to disconnect a part of the child node because the management content is an index server. . Receiving this request, the terminal processing unit 15 refers to the history information stored in the search processing unit 42b of the hybrid processing unit 40, and determines whether or not the reference of the index information is concentrated on a specific device. Here, it is determined that references are concentrated on the index information of the devices 10-2 and 10-5, and the devices 10-2 and 10-5 are selected as devices to be disconnected. The information such as the IP addresses of the devices 10-2 and 10-5 is deleted from the transfer destination node management unit 41 of the hybrid processing unit 40 after it becomes unnecessary.

  The device 10-3 transmits a notification message M2 for notifying the selected devices 10-2 and 10-5 to switch the operation state to the pure type. Receiving this notification message M2, each of the terminal processing units 15 of the devices 10-2 and 10-5 switches the operation state of the own device from the pure type and changes the management content of the operation state management unit 14 from the hybrid type to the pure type. Change to. Further, the device 10-3 receives the index information INDEX1 and INDEX2 received from the devices 10-2 and 10-5 and stored in the index DB 42a of the hybrid processing unit 40 to the original devices 10-2 and 10-5. Transmit (return) and delete the returned index information from the index DB 42a.

  Each of the terminal processing units 15 of the devices 10-2 and 10-5 stores the returned index information in the index DB 32a of the pure type processing unit 30 of the own device. Thereafter, the device 10-1 transmits / receives a search request packet to / from the devices 10-2, 10-3, 10-5 (solid line in FIG. 8). In addition, about apparatus 10-4, 10-6, 10-7, it operates by the hybrid type centering on apparatus 10-3 as it is. Further, as described above, each of the devices 10-4, 10-6, and 10-7 transmits the updated index information to the device 10-3 (solid line in FIG. 8).

  In this way, the load concentrated on the device 10-3 (the load caused by the search request packet for the index information of the devices 10-2, 10-4, 10-5, 10-6, and 10-7) is changed to the device 10-. It can be lowered by separating 2,10-5.

  Further, the search method switching processing described with reference to FIGS. 7 and 8 will be described with reference to FIG. FIG. 9 is a sequence diagram showing the operation of search method switching processing.

  A search request packet is sent from the other device to the device 10-3 (step S201). The measurement unit 12 measures the number of search request packets per unit time, and monitors whether the traffic volume exceeds a predetermined threshold based on the measurement value (step S202). When it is detected that the traffic volume exceeds the threshold, the measurement unit 12 notifies the switching processing unit 13 that the traffic volume has exceeded the threshold (step S203).

  When the switching processing unit 13 receives a notification that the traffic volume has exceeded the threshold value from the measuring unit 12, the switching processing unit 13 refers to the management content of the operation state management unit 14, and the content is an index server. A notification is made to disconnect a part of the child node of the own device (step S204).

  When the terminal processing unit 15 receives the notification of step S204 from the switching processing unit 13, the terminal processing unit 15 refers to the history information stored in the search processing unit 42b of the hybrid processing unit 40, and the reference concentrates on a specific device. Judgment is made. In this sequence, it is determined that references are concentrated on the devices 10-2 and 10-5, and the devices 10-2 and 10-5 are selected as devices to be disconnected (step S205). After the information such as the IP addresses of the devices 10-2 and 10-5 is no longer necessary, the terminal processing unit 15 transfers the devices 10-2 and 10-5 from the transfer destination node management unit 41 of the hybrid processing unit 40. Delete the IP address and other information.

  The terminal processing unit 15 requests the devices 10-2 and 10-5 selected in step S205 to switch the operation state to the pure type (step S206). Receiving this request, each of the terminal processing units 15 of the devices 10-2 and 10-5 switches the operation state of the own device from the hybrid type to the pure type. At this time, the terminal processing unit 15 changes the management content of the operation state management unit 14 from the hybrid type to the pure type (step S207).

  Further, the terminal processing unit 15 of the device 10-3 transmits the index information received from the device 10-2 stored in the index DB 42a of the hybrid processing unit 40 to the device 10-2. In addition, the terminal processing unit 15 transmits the index information received from the device 10-5 stored in the index DB 42a of the hybrid processing unit 40 to the device 10-5 (step S208). The terminal processing unit 15 deletes the index information transmitted to the devices 10-2 and 10-5 from the index DB 42a of the hybrid processing unit 40.

  Upon receiving the index information transmitted from the device 10-3, the terminal processing units 15 of the devices 10-2 and 10-5 store the received index information in the index DB 32a of the pure processing unit 30 (Step S209). ). Thereafter, the terminals 10-2 and 10-5 process the search request packet on the own device and return the search result to the requesting device.

  As described above, when the traffic volume of the device 10-3 operating as the index server exceeds a predetermined threshold, the devices 10-2 and 10-5 on which the reference is concentrated are disconnected and the disconnected device 10 is disconnected. The operating state of −2, 10-5 is switched from the hybrid type to the pure type. As a result, the load on the device 10-3 operating as an index server is reduced, and an efficient search becomes possible.

  Further, the operation when the child node described in FIG. 7 is disconnected and the operation state of a part of the disconnected device is switched to the index server will be described with reference to FIG. FIG. 10 is an explanatory diagram for explaining an operation when the disconnected device is switched to the index server in the embodiment. It is assumed that the reference of index information is not concentrated on any of the devices 10-2, 10-4, 10-5, 10-6, and 10-7.

  In FIG. 7, as described above, when the measurement value by the measurement unit 12 of the apparatus 10-3 exceeds a predetermined threshold value, the measurement unit 12 notifies the switching processing unit 13 that the threshold value has been exceeded. The notified switching processing unit 13 refers to the management content of the operation state management unit 13 and requests the terminal processing unit 15 to disconnect a part of the child node because the management content is an index server. . Receiving this request, the terminal processing unit 15 refers to the history information stored in the search processing unit 42b of the hybrid processing unit 40, and determines whether or not the reference of the index information is concentrated on a specific device. Here, it is determined that the reference of the index information is not concentrated on any of the devices 10-2, 10-4, 10-5, 10-6, and 10-7. Then, the terminal processing unit 15 randomly selects a device that switches the operation state to the index server from the transfer destinations stored in the transfer destination node management unit 41 of the hybrid processing unit 40. Here, the device 10-2 Is selected. Further, the terminal processing unit 15 is stored in the transfer destination node management unit 41 of the hybrid processing unit 40 as a child node of the device 10-2 that is to be disconnected from its own device and newly operates as an index server. In this case, the devices 10-5 and 10-6 are selected. The information such as the IP addresses of the devices 10-2, 10-5, and 10-6 is deleted from the transfer destination node management unit 41 of the hybrid processing unit 40 after it becomes unnecessary.

  The apparatus 10-3 transmits a notification message M3 for notifying the apparatus 10-2 to switch the operation state to the index server. The terminal processing unit 15 of the device 10-2 that has received the notification message M3 switches the operation state of the own device from the hybrid type to the index server, and changes the management content of the operation state management unit 14 from the hybrid type to the index server.

  The terminal processing unit 15 of the device 10-3 refers to the management content of the transfer destination node management unit 41 of the hybrid processing unit 40 with respect to the device 10-2, and the device 10 that is a child node of the device 10-2. Information such as IP addresses of -5 and 10-6 is transmitted. Then, the terminal processing unit 15 of the device 10-2 manages the received information such as the IP addresses of the devices 10-5 and 10-6 in the transfer destination node management unit 41 of the hybrid processing unit 40.

  Further, the terminal processing unit 15 of the device 10-3 receives the index received from the devices 10-2, 10-5, and 10-6 stored in the index DB 42a of the hybrid processing unit 40 with respect to the device 10-2. The information INDEX3 is transmitted in association with the information such as the IP address of the original holding device. Then, the terminal processing unit 15 of the device 10-2 stores the index information transmitted by the device 10-3 in the index DB 42a of the hybrid processing unit 40 in association with information such as the IP address of the first device that owns the index information. .

  Information such as the IP address of the own device for notifying the terminal processing unit 15 of the device 10-2 and the devices 10-5 and 10-6 that are child nodes of the own device that the own device has become an index server A notification message M4 including is transmitted. The terminal processing units 15 of the devices 10-5 and 10-6 that have received the notification message M4 change the management contents of the transfer destination node management unit 41 of the hybrid processing unit 40 to information such as the IP address of the device 10-3. To information such as the IP address of the apparatus 10-2. Thereafter, the devices 10-5 and 10-6 update the device 10-2 by using information such as the IP address stored in the transfer destination node management unit 41 of the hybrid processing unit 40, respectively. The index information thus transmitted is transmitted (dotted line in FIG. 10). However, for the devices 10-4 and 10-7, the device 10-3 is updated as it is by using information such as the IP address stored in the transfer destination node management unit 41 of the hybrid processing unit 40. The index information thus transmitted is transmitted (dotted line in FIG. 10). The device 10-1 transmits / receives a search request packet to / from the devices 10-2 and 10-3 (solid line in the figure).

  In this way, the load concentrated on the device 10-3 (the load caused by the search request packet for the index information of the devices 10-2, 10-4, 10-5, 10-6, and 10-7) is changed to the device 10-. 2 can be separated from the apparatus 10-3 as a second index server, and the apparatuses 10-5 and 10-6 can be separated from the apparatus 10-3 as child nodes of the apparatus 10-2.

  Further, the search method switching processing described with reference to FIGS. 7 and 10 will be described with reference to FIG. FIG. 11 is a sequence diagram showing the operation of search method switching processing.

  A search request packet is sent from the other device to the device 10-3 (step S301). The measurement unit 12 measures the number of search request packets per unit time, and monitors whether the traffic volume exceeds a predetermined threshold based on the measurement value (step S302). When it is detected that the traffic volume exceeds the threshold value, the measurement unit 12 notifies the switching processing unit 13 that the traffic volume has exceeded the threshold value (step S303).

  When the switching processing unit 13 receives a notification that the traffic volume has exceeded the threshold value from the measuring unit 12, the switching processing unit 13 refers to the management content of the operation state management unit 14, and the content is an index server. A notification is made to disconnect a part of the child node of the own device (step S304).

  When the terminal processing unit 15 receives the notification of step S304 from the switching processing unit 13, the terminal processing unit 15 refers to the history information stored in the search processing unit 42b of the hybrid processing unit 40, and the reference concentrates on a specific device. Judgment is made. In this sequence, it is determined that the reference is not concentrated on any of the devices 10-2, 10-4, 10-5, 10-6, and 10-7, and the terminal processing unit 15 transfers the hybrid processing unit 40. A device that randomly switches the operation state to the index server is selected from the devices stored in the destination node management unit 41, and the device 10-2 is selected in this sequence. Further, the terminal processing unit 15 randomly selects a device as a child node of the device 10-2 from the devices stored in the transfer destination node management unit 41 of the hybrid processing unit 40, and in this sequence, the device 10-5 is selected. , 10-6 are selected (step S305).

  The terminal processing unit 15 requests the device 10-2 selected as the index server to switch the operation state from the pure type to the index server (step S306). Receiving this request, the terminal processing unit 15 of the device 10-2 switches the operation state from the hybrid type to the index server. At this time, the terminal processing unit 15 changes the management content of the operation state management unit 14 from the hybrid type to the index server (step S307).

  The terminal processing unit 15 of the device 10-3 refers to the management content of the transfer destination node management unit 41 of the hybrid processing unit 40, and the IPs of the devices 10-5 and 10-6 that are child nodes of the device 10-2. Information such as an address is transmitted to the apparatus 10-2. The terminal processing unit 15 also associates the index information stored in the index DB 42a of the hybrid processing unit 40 with the information such as the IP addresses of the devices 10-2, 10-5, and 10-6. Send to. At this time, the index information is transmitted in association with information such as the IP address of the device of the first holding source so that the first holding source of the index information can be known (step S308).

  When the terminal processing unit 15 of the device 10-2 receives information such as the IP addresses of the devices 10-5 and 10-6 that are child nodes of the own device, the terminal processing unit 15 receives the IP addresses of the received devices 10-5 and 10-6, and the like. Is stored in the transfer destination node management unit 41 of the hybrid processing unit 40. Further, when receiving the index information, the terminal processing unit 15 stores the received index information in the index DB 42a of the hybrid processing unit 40 in association with information such as the IP address of the first holding device (step S309).

  The terminal processing unit 15 of the terminal processing unit 15 sends information such as the IP address stored in the transfer destination node processing unit 41 of the hybrid processing unit 40 to the devices 10-5 and 10-6 that are child nodes of the own device. Is used to notify that its own device has become an index server (step S310).

  Receiving the notification in step S310, each of the terminal processing units 15 of the devices 10-5 and 10-6 changes the management contents of the transfer destination node management unit 41 of the hybrid processing unit 40 to information such as the IP address of the device 10-3. To information such as the IP address of the apparatus 10-2. That is, the connection destination is switched to the notification source apparatus 10-2 (step S311). Thereafter, the devices 10-5 and 10-6 transmit the updated index information to the device 10-2 using the management contents of the transfer destination node management unit 41 of the hybrid processing unit 40 (step S312). ). And the terminal process part 15 of the apparatus 10-2 will memorize | store the updated index information in index DB42a of the hybrid type process part 40, if the updated index information is received (step S313).

  As described above, when the traffic volume of the device 10-3 operating as the index server exceeds a predetermined threshold value, a device randomly selected from the devices that are child nodes of the device 10-3 is selected. Disconnect from the apparatus 10-3 as an index server. At the same time, the randomly selected device is separated from the device 10-3 as a child node of the device 10-2 operating as a new index server. As a result, the load on the device 10-3 operating as an index server is reduced, and an efficient search becomes possible.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various design changes can be made as long as they are described in the claims.

  Further, by recording a program for realizing the functions of the processing units of the above-described embodiments on a computer-readable recording medium, and causing the computer system to read and execute the program recorded on the recording medium You may perform each process mentioned above. The “computer system” here includes an OS and hardware such as peripheral devices. The “computer system” includes a WWW system having a homepage providing environment (or display environment). The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Further, the “computer-readable recording medium” refers to a volatile memory (RAM) in a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included.

  The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

The network block diagram of the pure type information search system in embodiment. 1 is a network configuration diagram of an information search system that partially includes a hybrid type in an embodiment. FIG. The block diagram which shows the structure of the apparatus in embodiment. Explanatory drawing explaining the switching process of a search system. Explanatory drawing explaining the switching process of a search system. The sequence diagram which shows the switching process of a search system. Explanatory drawing explaining the switching process of a search system. Explanatory drawing explaining the switching process of a search system. The sequence diagram which shows the switching process of a search system. Explanatory drawing explaining the switching process of a search system. The sequence diagram which shows the switching process of a search system. The network block diagram of the conventional pure type P2P system. The block diagram which shows the structure of the terminal device of FIG. The network block diagram of the conventional hybrid type P2P system. The block diagram which shows the structure of the index server of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 apparatus, 11 communication protocol control part, 12 measuring part, 13 switching process part, 14 operation state management part, 15 terminal processing part, 20 share processing part, 21 message processing part, 22 search request processing part, 23 search result processing part 30 Pure type processing unit, 31 Destination node management unit, 32 Search function processing unit, 32a Index database, 32b Search processing unit, 40 Hybrid type processing unit, 41 Destination node management unit, 42 Search function processing unit, 42a Index Database, 42b search processor

Claims (7)

In a dynamic switching method of a search method in a plurality of devices that search for information using a peer-to-peer method,
Each device operating as a pure type measures the network traffic and performs a pure operation measurement procedure to determine whether the measurement value during the pure operation exceeds a predetermined pure operation threshold,
In the measurement procedure during the pure operation, the apparatus that has determined that the measurement value during the pure operation has exceeded the threshold during the pure operation is,
A switching procedure for switching the operation state of the own device from the pure type to the index server;
An information collection procedure for collecting information held by other devices;
A dynamic switching method of a search method, characterized by: Each device operating as an index server measures network traffic and performs a server operating time measurement procedure for determining whether the measured value during server operation exceeds a predetermined threshold value during server operation,
The apparatus that has determined that the measurement value during the server operation exceeds the threshold during the server operation in the server operation measurement procedure,
A selection procedure for selecting a device to be disconnected from its own device;
A procedure for transmitting information to a device to be disconnected from the device selected in the selection procedure;
2. The search method dynamic switching method according to claim 1, wherein: In the selection procedure,
In each device from which information is collected, it is determined whether there is a device in which the total number of times of reference of each piece of information of the device is equal to or greater than a predetermined ratio of the total number of times of reference of each piece of collected information. Judgment procedure and
When it is determined in the determination procedure that there is a device that is equal to or greater than the predetermined ratio, a first device selection procedure for selecting a device to detach the device;
A first switching notification procedure for notifying the device selected in the first device selection procedure to switch the operation state to a pure type;
A second device selection procedure for selecting an arbitrary device as a device to be disconnected when it is determined in the determination procedure that there is no device that is equal to or greater than the predetermined ratio;
A second switching notification procedure for notifying the device selected in the second device selection procedure to switch the operation state to the index server;
And
The device that has received the notification in the first switching notification procedure performs the first switching procedure for switching the operation state of the device to the pure type,
3. The dynamic switching method according to claim 2, wherein the device that has received the notification in the second switching notification procedure performs a second switching procedure for switching the operation state of the device to the index server. In a device that searches for information using a peer-to-peer method and dynamically switches the search method,
When operating as a pure type, it measures the network traffic, and determines whether the measured value at the time of pure operation exceeds a predetermined threshold value at the time of pure operation;
A switching processing means for switching the operation state of the apparatus from a pure type to an index server when the pure operation time measurement means determines that the measurement value during the pure operation exceeds a threshold value during the pure operation;
Management means for collecting and managing information held by other devices;
An apparatus for dynamically switching a search method characterized by comprising: Server operating time measurement means for measuring network traffic when operating as an index server and determining whether the measured value during server operation exceeds a predetermined threshold value during server operation;
A selection means for selecting a device to be disconnected from its own device when it is determined by the server operation time measurement means that a measurement value during the server operation exceeds a threshold value during the server operation;
Transmitting means for transmitting information to a device separated from the own device selected by the selecting means;
An apparatus for dynamically switching a search method according to claim 4. A switching program that executes a dynamic switching method of a search method in a plurality of devices that search for information using a peer-to-peer method,
Each device operating as a pure type measures the network traffic and performs a pure operation measurement procedure to determine whether the measurement value during the pure operation exceeds a predetermined pure operation threshold,
In the measurement procedure during the pure operation, the apparatus that has determined that the measurement value during the pure operation has exceeded the threshold during the pure operation is,
A switching procedure for switching the operation state of the own device from the pure type to the index server;
An information collection procedure for collecting information held by other devices;
A switching program for dynamically switching search methods characterized by Each device operating as an index server measures network traffic and performs a server operating time measurement procedure for determining whether the measured value during server operation exceeds a predetermined threshold value during server operation,
The apparatus that has determined that the measurement value during the server operation exceeds the threshold during the server operation in the server operation measurement procedure,
A selection procedure for selecting a device to be disconnected from its own device;
A procedure for transmitting information to a device to be disconnected from the device selected in the selection procedure;
The switching program for dynamically switching the search method according to claim 6.

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