JP2008141478A - Broadcast search system and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a broadcast search system and program capable of performing data search to nodes belonging to the respective segments in a network divided into a plurality of segments. <P>SOLUTION: Since a virtual hub H1 for performing unicast communication with the respective nodes N1-N10 for search is provided, data is retrieved to the nodes belonging to any of the plurality of segments S1-S6 by transmitting a search request packet of the data as a unicast packet. Thus, the data stored by being divided into the plurality of nodes is easily searched only by adding the virtual hub H1 without replacing a plurality of routers R1, R2 with the ones corresponding to multicast. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a broadcast search system and a broadcast search program for performing a broadcast search for a plurality of nodes belonging to each segment in a network divided into a plurality of segments.

  Conventionally, when performing a data search in a network in which a plurality of nodes are connected, there has been an invention in which data is distributed and stored in a plurality of storage devices (see, for example, Patent Document 1).

  In the invention described in Patent Literature 1, the load on each storage device can be reduced by storing data in a plurality of storage devices in a distributed manner. Further, when all the data is stored in one storage device, the data cannot be read at all if the storage device fails. On the other hand, if data is distributed and stored in multiple storage devices, even if one of the storage devices fails, some data cannot be read, so damage can be suppressed and other data Can still be searched.

Conventionally, as a data search method in a network, three methods are generally used: peer-to-peer search (unicast search), broadcast search, and multicast search.
Japanese Patent Laid-Open No. 7-141575

  However, in a network divided into a plurality of segments, there are the following problems when searching for data stored in a distributed manner among nodes belonging to each segment. That is, in the network divided into a plurality of segments as described above, the segments are usually connected by a router. Therefore, when performing a broadcast search, there is a problem that the searchable range of data is only within the same segment, and the search cannot be performed for nodes belonging to other segments.

  Further, when performing a multicast search, there is a problem that a search cannot be performed for nodes belonging to other segments unless all the routers connecting the segments support multicast.

  In addition, when performing peer-to-peer search (unicast search), search request commands must be issued in order to all search target nodes, and there is a problem that processing increases as the number of nodes increases. Further, in order to perform peer-to-peer search (unicast search) from any node, each node needs to know the IP address information of all other nodes. However, if the number of nodes is increased or decreased (login / logoff) frequently, there is a problem that it is troublesome to update the IP address information of each node.

  In addition, it is considered that the data information stored in each node is collected and the entire data information list is created to manage the data collectively. However, if data is frequently added or deleted, the entire data information is stored. There was a problem that it was troublesome to update the list.

  Therefore, an object of the present invention is to provide a broadcast search system and a broadcast search program that can perform data search for nodes belonging to each segment in a network divided into a plurality of segments.

  The present invention has the following configuration as means for solving the above problems.

(1) A broadcast search system in a network divided into a plurality of segments,
A plurality of data storage means for storing a plurality of data, an operation means for accepting a data search operation, and a node communication means for transmitting and receiving packets, each of which belongs to one of the plurality of segments and has a unique IP address Nodes
A router that forwards only unicast packets between segments;
A virtual hub provided with a unique IP address, comprising list storage means for storing each IP address of the plurality of nodes, and hub communication means for transmitting and receiving unicast packets to and from the plurality of nodes;
With
Each of the nodes further includes an IP storage unit that stores an IP address of the virtual hub. When a data search operation is received by the operation unit, information for requesting the virtual hub to search for the data; The node communication means transmits a search request packet including its own IP address information which is transmission source information,
When the virtual hub receives the search request packet by the hub communication means, the search request packet is transmitted to each node by the hub communication means,
Each node receives the search request packet by the node communication means, and when the data storage means stores the data requested to be searched, the node stores the data to the transmission source node. The node communication means transmits a reply packet including information indicating that the IP address is present and its own IP address information.

  In this configuration, in the broadcast search system, the virtual hub stores the IP address of each node of the network, and each node transmits a search request packet to the virtual hub when receiving a data search request. The virtual hub transmits a search request packet to each node. When the node that has received the search request packet stores the data requested for search, the node transmits a reply packet to that effect to the node that has requested the search. Therefore, according to the broadcast search system of the present invention, since each node to be searched is provided with a virtual hub that transmits and receives unicast packets, regardless of which of the plurality of segments it belongs to, Data can be searched for nodes. As a result, data can be easily retrieved by simply adding a virtual hub without replacing a plurality of routers. In addition, since the virtual hub stores the IP addresses of all nodes, each node can search data for all nodes without storing the IP addresses of all nodes, and increase / decrease of nodes (login / Even if logoff is frequent, the IP address information of each node can be updated only by the virtual hub, and the updating effort can be simplified.

(2) A broadcast search system in a network divided into a plurality of segments,
A plurality of data storage means for storing a plurality of data, an operation means for accepting a data search operation, and a node communication means for transmitting and receiving packets, each of which belongs to one of the plurality of segments and has a unique IP address Nodes
A data storage means for storing a plurality of data, an operation means for accepting a data search operation, and a base node communication means for transmitting and receiving packets are installed one by one for each segment, and each is assigned a unique IP address. A base node,
A router that forwards only unicast packets between segments;
A virtual hub provided with a unique IP address, comprising list storage means for storing each IP address of the base node, and hub communication means for transmitting and receiving unicast packets to and from the base node;
With
Further, each of the base nodes includes IP storage means for storing the IP address of the virtual hub,
The node that has received the data search operation by the operation means transmits the search request packet, which is a broadcast packet including information requesting the data search and its own IP address information as the transmission source information, by the node communication means. And
When the base node belonging to the same segment as the source node receives the search request packet by the base node communication means, the base node communication transmits the search request packet converted into a unicast packet to the virtual hub. Send by means,
When the virtual hub receives the search request packet by the hub communication unit, the hub communication unit transmits the search request packet to each base node,
When each base node receives the search request packet transmitted from the virtual hub by the base node communication means, it converts the search request packet into a broadcast packet and transmits it to another node by the base node communication means. And
Each of the nodes and the base node receives the search request packet, and when the data storage means stores the requested data, stores the data to the transmission source node. The node communication means transmits a reply packet including the information indicating that it is present and its own IP address information.

  In this configuration, in the broadcast search system, the virtual hub stores the IP address of each base node of the network, and when each node accepts a search request for data, A broadcast packet requesting a search to the base node is transmitted. When the base node receives the broadcast packet requesting the search, the base node transmits the search request packet converted into the unicast packet to the virtual hub. When receiving the search request packet, the virtual hub transmits the search request packet to each node. When receiving the search request packet, the base node that has received the search request packet converts it into a broadcast packet and transmits the search request packet to each segment. When each node stores the data requested for search by the received search request packet, each node transmits a reply packet to that effect to the node that requested the search. Therefore, according to the broadcast search system of the present invention, since the virtual hub and the base node are provided, regardless of which of the plurality of segments it belongs to, any node can send data to each node and each base node. Can be searched. In addition, the virtual hub only needs to transmit the search request packet to the base node, and each base node transmits the search request packet to other nodes by broadcasting, so the virtual hub and the base node share the load to search for data. it can. In addition, since the virtual hub stores the IP addresses of all base nodes, each node and each base node can search data without storing the IP addresses of all nodes and all base nodes, and increase / decrease the number of nodes (login Even if logoff is frequent, the IP address information of each base node need only be updated by the virtual hub, and the updating effort can be simplified.

(3) In a network divided into a plurality of segments, IP storage means for storing each IP address of a plurality of nodes belonging to any of the segments and storing data in a distributed manner;
And receiving a search request packet including information for requesting data search and IP address information of the transmission source transmitted and received by one of the nodes and transmitting / receiving unicast packets to / from the plurality of nodes. A hub communication means for reading out the IP address of each node and transmitting the search request packet to each node;
It is characterized by functioning a computer.

  In this configuration, the computer can function as the IP storage means and the hub communication means as described above. Therefore, when searching for data stored in a distributed manner in a plurality of nodes, it is related to which segment it belongs to. Instead, it is possible to reliably transmit a search request packet to each node and cause each node to search for data.

  According to the broadcast search system of the present invention, since a virtual hub that performs unicast communication with each node to be searched is provided, a data search request packet is unicast to any node belonging to any of a plurality of segments. Data can be retrieved by sending it as a packet. As a result, data stored in a distributed manner and stored in a plurality of nodes can be easily retrieved by simply adding a virtual hub without replacing a plurality of routers with ones compatible with multicast.

  In addition, according to the broadcast search system of the present invention, a base node is provided for each segment obtained by dividing the network, and a virtual hub that performs unicast communication with each base node is provided to perform data search. The load at the time of the search can be shared between the virtual hub and the base node, and the data search can be performed efficiently.

  FIG. 1 is a block diagram showing a schematic configuration of a broadcast search system. FIG. 2 is a block diagram showing a schematic configuration of nodes and virtual hubs in the broadcast search system. Hereinafter, the broadcast search system SS1 constructed in the network NW1 will be described as an example.

  As shown in FIG. 1, the network NW1 is divided into six segments S1 to S6, and each segment is connected by routers R1 and R2. That is, the router R1 connects the segments S1, S2, S4, S5, and S6. Router R2 connects between segments S2 and S3.

  Nodes N1 and N2 are connected to (belong to) the segment S1. A node N3 is connected to the segment S2. Nodes N4 and N5 are connected to the segment S3. A node N6 and a virtual hub H1 are connected to the segment S4. Nodes N7, N8, and N9 are connected to the segment S5. Node N10 is connected to segment S6.

  A unique IP address is assigned to each of the nodes N1 to N10 and the virtual hub H1. That is, the IP address of the node N1 is [192.160.10.1], the IP address of the node N2 is [192.160.10.2, the IP address of the node N3 is [192.160.20.1], the node The IP address of N4 is [192.160.30.1], the IP address of the node N5 is [192.160.30.2], the IP address of the virtual hub H1 is [192.160.40.1], and the node N6 [192.160.40.2], the IP address of the node N7 is [192.160.50.1], the IP address of the node N8 is [192.160.50.2], and the IP address of the node N9 The address is [192.160.50.3], and the IP address of the node N10 is [192.160.60.1].

  The virtual hub H1 stores an IP address list that summarizes the IP addresses of the nodes N1 to N10 as shown in FIG.

  As shown in FIG. 2A, each of the nodes N1 to N10 has the same configuration, and includes an operation unit 21, a display unit 23, a LAN interface (communication unit) 25, a storage unit 27, and a control unit 29. Yes.

  The operation unit 21 receives a data search operation (input) by a user.

  The display unit 23 displays the name of a file to be searched for received by the operation unit 21. The display unit 23 displays items to be transmitted to the user.

  The LAN interface (communication unit) 25 transmits and receives data (packets).

  The storage unit 27 includes a hard disk drive (HDD) 271, a ROM 273, and a RAM 275. A hard disk drive (HDD) 271 is a database that stores data in units of files. In addition, different files are stored in the hard disk drives 271 of the nodes N1 to N10. In consideration of file backup, it is also possible to set at least two nodes to store the same file.

  The ROM 273 stores a data search program executed by the control unit 29 and the like.

  The RAM 275 stores its own IP address assigned by a DHCP server (not shown) and the IP address of the virtual hub H1.

  The control unit 29 is composed of a CPU or MPU and controls each of the above units. Further, the control unit 29 reads out and executes a data search program from the ROM 273. That is, when the operation unit 21 receives a file search operation, the control unit 29 searches for a file on the hard disk drive 271. When the hard disk drive 271 does not have a file for which the search operation has been accepted, the control unit 29 sends a unicast packet (search request packet) including the file information for which the search operation has been accepted and its own IP address information to the LAN interface 25. To the virtual hub H1.

  As shown in FIG. 2B, the virtual hub H1 has the same configuration as the nodes N1 to N10, and includes an operation unit 31, a display unit 33, a LAN interface (communication unit) 35, a storage unit 37, and a control unit 39. It has.

  The operation unit 31 receives an operator's operation (input) during maintenance or the like.

  The display unit 33 displays content corresponding to the operation received by the operation unit 31.

  The LAN interface (communication unit) 35 transmits and receives data (packets).

  The storage unit 37 includes a hard disk drive (HDD) 371, a ROM 373, and a RAM 375. A hard disk drive (HDD) 371 stores a plurality of data and programs.

  The ROM 373 stores a broadcast search program executed by the control unit 39.

  The RAM 375 stores its own IP address. The RAM 375 stores the IP address list shown in FIG.

  The control unit 39 is composed of a CPU or MPU and controls each of the above units. In addition, when receiving a search request packet via the LAN interface 35, the control unit 39 executes a broadcast search program. That is, the control unit 39 confirms the IP address information included in the search request packet and reads the IP address list stored in the RAM 375. Then, the control unit 39 causes the LAN interface 35 to transmit this search request packet to all the nodes listed in the IP address list other than the node that has transmitted the search request packet.

  Since the routers R1 and R2 have the same configuration as a general router, detailed description thereof is omitted. Routers R1 and R2 are routers that do not support multicast, and transfer only unicast packets between segments. Routers R1 and R2 do not transfer broadcast packets to other segments.

  Next, an overview of the broadcast search system SS1 in the network NW1 and the operation of each device will be described.

  In the broadcast search system SS1, a plurality of files are distributed and stored in each of the nodes N1 to N10. Each of the nodes N1 to N10 can be used as a search terminal (search request node) for searching for a file stored in another node. Furthermore, in the network NW1, a plurality of segments are connected using general routers R1 and R2 that do not support multicast. Therefore, each node N1 to N10 of the network NW1 cannot perform broadcast search or multicast search for all other nodes beyond the segment to which the node belongs.

  Therefore, in the broadcast search system SS1 of the present invention, a file can be searched for all the nodes N1 to N10 so as to search all the nodes N1 to N10 belonging to any of the plurality of segments S1 to S6 divided from the network NW1. A virtual hub H1 that transmits and receives cast packets is provided, and a file can be searched through the virtual hub H1.

  Here, the IP address of the virtual hub H1 is fixed, and each of the nodes N1 to N10 stores the IP address information of the virtual hub H1 in the hard disk drive 271 or the ROM 273 in advance. Each of the nodes N1 to N10 confirms connection to the virtual hub H1 at the time of activation. Then, the virtual hub H1 acquires the IP address information of each operating node, creates the IP address list of each node shown in FIG. 1B, and stores it in the RAM 375. Further, the virtual hub H1 confirms connection to the nodes listed in the IP address list at regular intervals. Then, the virtual hub H1 grasps the operation status of each node and updates the IP address list. In this way, the virtual hub H1 performs a broadcast search using the IP address list indicating the latest connection status of each node.

  The broadcast search system SS1 in the network NW1 shown in FIG. 1 performs the following process when searching for a file. FIG. 3 is a flowchart for explaining the operation of the broadcast search system.

  The control unit 29 of any one of the nodes N1 to N10 (for example, the node N7) of the network NW1 waits until receiving a file search operation from the operation unit 21 (s1: N), and performs a file search operation from the operation unit 21. When it is received (s1: Y), it searches its own hard disk drive 271 and checks whether there is a file for which the search operation has been received (s2). When the file subjected to the search operation is stored in the hard disk drive 271 (s3: Y), the control unit 29 has completed the search and stores the search target file in the hard disk drive 271. Is displayed on the display unit 23 (s8).

  On the other hand, if the file for which the search operation has been performed is not stored in the hard disk drive 271 (s3: N), the control unit 29 of the node N7 has information on the file for which the search operation has been performed from the operation unit 21 (for example, file Information such as name, file size, file creation date / update date), information for requesting retrieval of this file, own IP address information as the transmission source, and IP address information of the virtual hub H1 as the transmission destination The search request packet, which is a unicast packet including, is transmitted (s4).

  The search request packet transmitted from the node N7 is transferred from the segment S5 to the segment S4 by the router R1 and sent to the virtual hub H1.

  The virtual hub H1 waits until receiving the search request packet from the node N7 (s11: N), and when receiving the search request packet from the node N7 (s11: Y), the node that is the transmission source of this packet A search request packet, which is a unicast packet, is transmitted simultaneously or sequentially to all the nodes N1 to N6 and N8 to N10 other than N7 (s12). Then, the process of step s11 is performed.

  Specifically, the control unit 39 of the virtual hub H <b> 1 reads the IP address list from the RAM 375 when the LAN interface 35 receives a search request packet whose source is the node N <b> 7. Then, the control unit 39 generates a search request packet in which the destination IP address information of the search request packet is replaced with any of the nodes N1 to N6 and N8 to N10. As a result, the search request packet includes information on the file for which the search operation has been performed, information for requesting the search for the file, IP address information of the node N7 that is the transmission source, and nodes N1 to N6 and N8 that are the transmission destinations. A unicast packet including any IP address information of N10. The control unit 39 causes the LAN interface 35 to transmit these search request packets (unicast packets) to the nodes N1 to N6 and N8 to N10.

  The control unit 29 of each of the nodes N1 to N6 and N8 to N10 waits until the search request packet is received by the LAN interface 25 (s21: N), and when the search request packet is received by the LAN interface 25 (s21 : Y), the file information included in the packet is read, and it is confirmed whether or not this file is stored in the hard disk drive 271 (s22).

  If the hard disk drive 271 does not store the requested file for search, the control unit 29 of each node does not respond to the search request (s23: N), and then performs the process of step s21. On the other hand, when the hard disk drive 271 stores the file requested to be searched (s23: Y), the control unit 29 of each node stores information indicating that the file is stored and its own IP address information. And a reply packet (unicast packet) is created. Then, the control unit 29 transmits this reply packet to the node N7 that has requested the search (s24).

  For example, when the node N4 stores the file requested to be searched, the control unit 29 of the node N4 reads the IP address information of the transmission source (node N7) included in the search request packet, and the file requested to be searched. A reply packet (unicast packet) including information indicating that the data is stored, the IP address information of the transmission source node (node N4) and the IP address information of the transmission destination node N7 is created. . Then, the control unit 29 of the node N4 causes the LAN interface 25 to transmit this reply packet.

  The reply packet transmitted from the node N4 is transferred from the segment S3 to the segment S2 by the router R2, and further transferred from the segment S2 to the segment S5 by the router R1 and sent to the node N7.

  The node N7 that requested the search waits until a reply packet is received (s5: N). When the reply packet is received (s5: Y), the node N4 that stores the file requests the file transmission. A packet is transmitted (s6). That is, when the control unit 29 of the node N7 receives this reply packet through the LAN interface 25, the control unit 29 confirms the information included in the packet, requests the transmission of the file, and the IP address information of the transmission source (node N7) And a transmission request packet (unicast packet) including the destination (node N4) IP address information. Subsequently, the control unit 29 of the node N7 causes the LAN interface 25 to transmit this transmission request packet.

  The node N4 storing the file stands by until a file transmission request packet is received (s25: N). When a file transmission request packet is received (s25: Y), the file data from the hard disk drive 271 is received. And the search target file is transmitted to the node N7 that requested the search (s26). When the reception of the file is completed (s7), the node N7 displays on the display unit 23 that the search has been completed and that the search target file has been acquired and stored in the hard disk drive 271 (s8).

  Then, when the transmission and reception of the file are completed, the node N7 and the node N4 end the exchange and perform the processing from steps s1 and s21.

  As described above, in the broadcast search system SS1 shown in FIG. 1, when the virtual hub H1 receives a search request packet transmitted from any node, the search request packet is transmitted to each node by unicast communication. Send. As a result, even in a network divided into a plurality of segments, it is possible to search for a file that is distributed and stored in each node like a broadcast search without changing the current network configuration by simply providing a virtual hub. .

  Here, the virtual hub H1 may be provided in any segment of the network NW1, or may be newly provided in the network NW1. Further, for example, by installing a broadcast search program on an existing management computer in the network NW1, this management computer can function as a virtual hub.

  Here, in the above description, the node that has received the file search operation first searches its own hard disk drive, and if there is no file to be searched, the search request packet is transmitted to the virtual hub. However, the present invention is not limited to this, and may be configured as follows. That is, when the file search operation is received by, for example, the node N7, first, a search request packet is generated and transmitted to the virtual hub H1. When the virtual hub H1 receives the search request packet, the virtual hub H1 transmits the search request packet, which is a unicast packet, to all the nodes N1 to N10 all at once or in sequence, and each of the nodes N1 to N10 transmits the search request packet. It can also be configured to search for its own hard disk upon receipt. With this configuration, when a search operation is accepted, files are searched in all the nodes immediately. Therefore, particularly when there are many nodes, the probability that a file exists in the node that accepted the search operation is low. The file search time can be shortened compared to searching for another node after searching the hard disk.

  Next, the configuration of another broadcast search system will be described. FIG. 4 is a block diagram showing a schematic configuration of a broadcast search system different from FIG. Hereinafter, the broadcast search system SS2 constructed in the network NW2 will be described as an example.

  As shown in FIG. 4, the network NW2 is divided into six segments S11 to S16, and each segment is connected by routers R11 and R12. That is, the router R11 connects the segments S11, S12, S14, S15, and S16, respectively. The router R2 connects the segments S12 and S13.

  The base node K11 and the node N11 are connected (belongs) to the segment S11. A base node K12 is connected to the segment S12. A base node K13 and a node N12 are connected to the segment S13. A base node K14 and a virtual hub H11 are connected to the segment S14. A base node K15 and nodes N13 and N14 are connected to the segment S15. A base node K16 is connected to the segment S16.

  A unique IP address is assigned to each of the base nodes K11 to K16, each of the nodes N11 to N14, and the virtual hub H11. That is, the IP address of the node N11 is [192.168.10.1], the IP address of the base node K11 is [192.168.10.2], and the IP address of the base node K12 is [192.168.20.1]. ], The IP address of the base node K13 is [192.168.30.1], the IP address of the node N12 is [192.168.30.2], and the IP address of the virtual hub H1 is [192.168.5.40.1]. ], The IP address of the base node K14 is [192.168.5.40.2], the IP address of the node N13 is [192.168.50.1], and the IP address of the base node K15 is [192.168.5.50.2]. ], The IP address of the node N14 is [192.168.5.50.3], and the IP address of the base node K16 is [192.168.165. It is a.

  The virtual hub H11 stores the base nodes K11 to K16 and its own IP address list as shown in FIG.

  Nodes N11 to N14 and base nodes K11 to K16 illustrated in FIG. 4 have the same configurations as the nodes N1 to N10 illustrated in FIG. Also, the virtual hub H11 shown in FIG. 4 has the same configuration as the virtual hub H1 shown in FIG. Therefore, illustration and description are omitted.

  Since the routers R11 and R12 have the same configuration as a general router, detailed description thereof is omitted. Routers R11 and R12 are routers that do not support multicast, and transfer only unicast packets between segments. Also, the routers R11 and R12 do not transfer the broadcast packet to other segments.

  Next, an overview of the broadcast search system SS2 in the network NW2 and the operation of each device will be described.

  In the broadcast search system SS2, a plurality of files are divided and stored in the nodes N11 to N14 and the base point nodes K11 to K16. Also, the nodes N11 to N14 and the base point nodes K11 to K16 are all search terminals (search request nodes) for other nodes and base points. Furthermore, in the network NW2, a plurality of segments are connected using general routers R11 and R12 that do not support multicast. Therefore, each of the nodes N11 to N14 and the base nodes K11 to K16 of the network NW2 cannot perform broadcast search or multicast search for all other nodes beyond the segment to which the node belongs.

  Therefore, in the broadcast search system SS2 of the present invention, files can be searched for all the nodes N11 to N14 and all the base nodes K11 to K16 belonging to any of the plurality of segments S11 to S16 obtained by dividing the network NW2. The base nodes K11 to K16 that transmit and receive broadcast packets to and from the nodes N11 to N14 and the virtual hubs H11 that transmit and receive unicast packets to and from the base nodes K11 to K16 are provided, and the base nodes K11 to K16 and the virtual hub H11 It is configured to be able to search for files via

  Here, the IP address of the virtual hub H11 is fixed, and each of the base nodes K11 to K16 stores the IP address information of the virtual hub H11 in advance. Each of the base nodes K11 to K16 performs connection confirmation with the virtual hub H11 at the time of activation. Then, the virtual hub H11 acquires the IP address information of each active base node, creates an IP address list of each base node as shown in FIG. 4B, and stores it in the RAM 375. In addition, the virtual hub H11 confirms connection to the base node listed in the IP address list at regular intervals. The virtual hub H11 then grasps the operating status of each base node and updates the IP address list. The virtual hub H11 performs a broadcast search using an IP address list indicating the latest connection status of each node.

  A data search program different from the nodes N1 to N10 shown in FIG. 1 is installed in the nodes N11 to N14. That is, the control unit 29 of the nodes N11 to N14 searches for a file on the hard disk drive 271 when the operation unit 21 receives a file search operation. If the hard disk drive 271 does not have a file for which the search operation has been accepted, the control unit 29 sends a broadcast packet (search request packet) including the file information for which the search operation has been accepted and its own IP address information from the LAN interface 25. Send to the entire segment to which the node belongs. Further, when receiving the search request packet (broadcast packet), the control unit 29 of the nodes N11 to N14 searches for a file in the hard disk drive 271 and, if the file is stored, transmits the file to the search request source node. .

  A relay / search program is installed in the base node K11-16. That is, when receiving the search request packet (broadcast packet), the control unit 29 of the base node K11 to 16 converts the search request packet (broadcast packet) into a unicast packet having the virtual hub H11 as a transmission destination, and transmits the search request packet to the virtual hub H11. To do. When receiving the search request packet (unicast packet), the control unit 29 of the base node K11-16 converts the entire segment to which the base node belongs to a broadcast packet, and transmits this search request packet. .

  When the operation unit 21 receives a file search operation, the control unit 29 of the base node K11 to 16 searches for a file on the hard disk drive 271. If the file is stored, the file is transmitted to the search request source node.

  In addition, a broadcast search program different from the virtual hub H1 shown in FIG. 1 is installed in the virtual hub H11. That is, when receiving the search request packet, the control unit 39 checks the IP address information included in the search request packet and reads the IP address list stored in the RAM 375. Then, the control unit 39 causes the LAN interface 35 to transmit the search request packet to all the base nodes listed in the IP address list other than the base node that has transmitted the search request packet.

  Next, the operation of the broadcast search system SS2 will be described. FIG. 5 is a flowchart for explaining the operation of the broadcast search system shown in FIG.

  The broadcast search system SS2 in the network NW2 shown in FIG. 4 performs the following processing when searching for a file.

  The control unit 29 of any one of the nodes N11 to N14 (for example, the node N13) of the network NW2 waits until receiving a file search operation from the operation unit 21 (s41: N). Is received (s41: Y), the hard disk drive 271 is searched for, and the presence or absence of a file for which the search operation has been received is confirmed (s42). When the file subjected to the search operation is stored in the hard disk drive 271 (s43: Y), the control unit 29 indicates that the search is completed and the search target file is stored in the hard disk drive 271. Is displayed on the display unit 23 (s48).

  On the other hand, when the file for which the search operation has been performed is not stored in the hard disk drive 271 (s43: N), the control unit 29 of the node N13 information on the file for which the search operation has been performed from the operation unit 21 (for example, file Information such as name, file size, file creation date / update date), information for requesting retrieval of this file, own IP address information as a transmission source, and broadcast IP address designating the entire segment S15 as a transmission destination A search request packet that is a broadcast packet including information is transmitted (s44).

  The search request packet transmitted from the node N13 is sent to other nodes N14 and the base node K15 in the same segment S15.

  The base node K15 waits until a search request packet is received from a node in the same segment (s51: N) or until a file search operation is received from the operation unit 21 (s53: N). When receiving the search request packet from the node N13 (s51: Y), the base node K15 converts the search request packet into a unicast packet and transmits it to the virtual hub H11 (s52).

  Specifically, the control unit 29 of the base node K15 reads the IP address of the virtual hub H11 from the RAM 275 when the LAN interface 25 receives a search request packet whose source is the node N13. Then, the control unit 29 generates a search request packet in which the transmission destination IP address information of the search request packet is replaced with the virtual hub H11. As a result, the search request packet includes information on the file for which the search operation has been performed, information for requesting search for this file, IP address information of the node N13 that is the transmission source, and IP address of the virtual hub H11 that is the transmission destination. And a unicast packet including information. The control unit 29 causes the LAN interface 25 to transmit this search request packet (unicast packet) to the virtual hub H11. Then, the process of step s54 is performed.

  In addition, when the control unit 29 of the base node K11-16 has not received the search request packet (s51: N) and receives a file search operation from the operation unit 21 (s53: Y), its own hard disk drive. 271 is searched to check whether there is a file for which the search operation has been accepted (s54).

  If the hard disk drive 271 does not store the requested file for search (s55: N), the control unit 29 does not respond to the search request and then performs the process of step s51.

  On the other hand, if the base node has stored the file, the base node and the file search request source node (node N13) perform file transmission / reception processing. That is, when the hard disk drive 271 stores the requested file (s55: Y), the control unit 29 of the base node K15 returns a reply including information to that effect and its own IP address information. This reply packet is transmitted to the node that has created the packet and requested the search (s56).

  The control unit 29 of the node N13 waits until a reply packet is received by the LAN interface 25 (s45: N), and when a reply packet is received by the LAN interface 25 (s45: Y), a file transmission request packet is transmitted. (S46). The control unit 29 of the base node K15 waits until the file transmission request packet is received (s57: N), and when the file transmission request packet is received (s57: Y), the file requested for search is transmitted. (S58).

  When the reception of the requested file is completed (s47), the control unit 29 of the node N13 displays on the display unit 23 that the search has been completed and that the search target file has been acquired and stored in the hard disk drive 271. It is displayed (s48).

  Then, when the transmission / reception of the file is completed, the node N13 and the base node K15 end the exchange and perform the processing from steps s41 and s51.

  On the other hand, the virtual hub H11 waits until receiving a search request packet (unicast packet) from any base node (s61: N), for example, a search request packet (unicast packet) from the base node K15. Is received (s61: Y), this search request packet is transmitted to all the base point nodes K11 to K14, K16 other than the base point node K15 all at once or in sequence (s62). .

  Specifically, when receiving the search request packet transmitted from the base node K15 by the LAN interface 35, the control unit 39 of the virtual hub H11 reads the IP address list from the RAM 375. Then, the control unit 39 generates a search request packet in which the transmission destination IP address information of the search request packet is replaced with any of the base nodes K11 to K14 and K16. As a result, the search request packet includes information on the file for which the search operation has been performed in the node N13, information for requesting the search for the file, IP address information of the node N13 that is the transmission source, and a base node K11 that is the transmission destination. To unicast packets including any of the IP address information of K14 and K16. The control unit 39 causes the LAN interface 35 to transmit these search request packets (unicast packets) to the base nodes K11 to K14 and K16.

  The control unit 29 of each of the base nodes K11 to K14 and K16 waits until the search request packet from the virtual hub H11 is received by the LAN interface 25 (s71: N), and the search request packet is received by the LAN interface 25. Then, the search request packet is converted into a broadcast packet (s71: Y), and a search request packet that is a broadcast packet is transmitted to other nodes in the segment to which each base node belongs (s72).

  Specifically, when the control unit 29 of each of the base nodes K11 to K14 and K16 receives the search request packet transmitted from the virtual hub H11 by the LAN interface 35, the destination IP address information of the search request packet is set to each base point. A search request packet, which is a broadcast packet, is transmitted in place of broadcast IP address information that designates the entire segment to which the node belongs.

  Subsequently, the control unit 29 of each of the base nodes K11 to K14, K16 reads out the file information included in the search request packet and checks whether or not this file is stored in the hard disk drive 271 (s73).

  When the hard disk drive 271 does not store the file requested to be searched (s74: N), the control unit 29 of each of the base nodes K11 to K14 and K16 does not respond to the search request. On the other hand, when the hard disk drive 271 stores the file requested to be searched (s74: Y), the control unit 29 determines that the base node and the file search request source node (node N13) are the base node K15. As described in the exchange process (s56 to s58, s45 to s48) of the search request node N13, the file transmission / reception process is performed (s74 to s77, s45 to s48).

  The control units 29 of all the nodes (nodes N11, N12, and N14) excluding the search request source node stand by until the LAN interface 25 receives a search request packet from the base node or the node of the same segment (s81: N) When the search request packet is received by the LAN interface 25 (s81: Y), the file information included in the search request packet is read, and it is confirmed whether or not this file is stored in the hard disk drive 271 (s82). .

  The control unit 29 of each of the nodes N11, N12, and N14 does not respond to the search request when the hard disk drive 271 does not store the requested file (s83: N). On the other hand, when the hard disk drive 271 stores the file requested to be searched (s83: Y), the control unit 29 determines that the base node and the file search request source node (node N13) are the base node K15. As described in the processing of the search request node N13 (s56 to s58, s45 to s48), the file transmission / reception processing is performed (s84 to s86, s45 to s48).

  As described above, in the broadcast search system SS2 shown in FIG. 4, the load at the time of search can be shared by the virtual hub H11 and the base nodes K11 to K16 of each segment, and files can be searched efficiently. In the broadcast search system SS2, the base node that has received the search request packet first transmits the search request packet to other nodes and virtual hubs, and confirms the existence of the file. File search information in a short time.

  In the broadcast search system SS2, when the base node receives the search request packet, the existence of the file is confirmed first, and if the file is not stored, the search request packet is sent to another node or virtual hub. It can also be configured to transmit.

  In the above description, the case where the search request source node also stores a file (data) has been described. However, the search request source node is not limited to this, and the search request source node is a dedicated search node. Is of course good.

  In the above description, a node that has received a file search operation first searches its own hard disk drive. If there is no file to be searched, a search request packet (broadcast packet) is sent to the base node or node of the same segment. When the base node receives the search request packet, the search request packet (unicast packet) is transmitted to the virtual hub. However, the present invention is not limited to this, and may be configured as described below. In other words, when the node N13 accepts a file search operation, for example, a search request packet (broadcast packet) is first generated and transmitted to the base node K15 and the node N14 in the same segment. Subsequently, when receiving the search request packet, the base node K15 transmits a search request packet (unicast packet) to the virtual hub H1. When the virtual hub H1 receives this search request packet, the virtual hub H1 transmits search request packets (unicast packets) all at once to all the base nodes K11 to K16. Each base node K11 to K16 that has received this search request packet transmits the search request packet as a broadcast packet to the segment node to which each base node belongs, and searches its own hard disk after transmission. Each node can also be configured to search its own hard disk upon receiving a search request packet. With this configuration, when a search operation is accepted, files are searched for at all base nodes and all nodes. Therefore, particularly when the number of nodes is large, the probability that a file exists at the node that has accepted the search operation is low. As a result, the search time for the file can be shortened compared to searching for another base node or node after the node receiving the search operation searches its own hard disk.

  Next, the broadcast search systems SS1 and SS2 are applicable not only to a general file search system but also to a karaoke system that reproduces karaoke songs, for example. Recently, in karaoke stores, there is a karaoke system in which karaoke songs are distributed and stored in karaoke devices installed in each room. Such a karaoke system is often provided in a karaoke store where rooms are provided in a plurality of floors or buildings, and the network is divided into segments for each floor or building. Therefore, the present invention is suitable for searching a file (data) of a karaoke song as a search target in such a karaoke system.

  The broadcast search systems SS1 and SS2 can be applied to an order system that orders food, drinks and the like from each room to an outside delivery store in a karaoke store or the like. As described above, a karaoke store often divides a network into a plurality of segments. In addition, outside branch stores are often connected to a network via a router. In such an order system, when a customer places an order for a specific food, it is necessary to search an inventory (menu) as to which delivery store is available. Therefore, by applying the present invention to this order system and using food and drink as search targets, the menu can be easily searched and food and drink can be ordered smoothly.

  The broadcast search systems SS1 and SS2 are not limited to routers that transfer only unicast packets. Of course, the present invention can be implemented using a multicast-compatible router that transfers unicast packets and multicast packets. .

It is a block diagram which shows schematic structure of a broadcast search system. It is a block diagram which shows schematic structure of the node and virtual hub of a broadcast search system It is a flowchart for demonstrating operation | movement of the broadcast search system. It is a block diagram which shows schematic structure of the broadcast search system different from FIG. 5 is a flowchart for explaining the operation of the broadcast search system shown in FIG.

Explanation of symbols

  NW1, NW2-network SS1, SS2-broadcast search system S1-S6, S11-S16-segment N1-N10, N11-N14-node H1, H11-virtual hub K11-K16-base node R1, R2, R11, R12 -Router 21, 31-Operation unit 23, 33-Display unit 25, 35-LAN interface 27, 37-Storage unit 29, 39-Control unit 271, 371-Hard disk drive 273, 373-ROM 275, 375-RAM

Claims (3)

A broadcast search system in a network divided into a plurality of segments,
A plurality of data storage means for storing a plurality of data, an operation means for accepting a data search operation, and a node communication means for transmitting and receiving packets, each of which belongs to one of the plurality of segments and has a unique IP address Nodes
A router that forwards only unicast packets between segments;
A virtual hub provided with a unique IP address, comprising list storage means for storing each IP address of the plurality of nodes, and hub communication means for transmitting and receiving unicast packets to and from the plurality of nodes;
With
Each of the nodes further includes an IP storage unit that stores an IP address of the virtual hub. When a data search operation is received by the operation unit, information for requesting the virtual hub to search for the data; The node communication means transmits a search request packet including its own IP address information which is transmission source information,
When the virtual hub receives the search request packet by the hub communication means, the search request packet is transmitted to each node by the hub communication means,
Each node receives the search request packet by the node communication means, and when the data storage means stores the data requested to be searched, the node stores the data to the transmission source node. A broadcast search system characterized in that the node communication means transmits a reply packet including information indicating that the message is received and its own IP address information. A broadcast search system in a network divided into a plurality of segments,
A plurality of data storage means for storing a plurality of data, an operation means for accepting a data search operation, and a node communication means for transmitting and receiving packets, each of which belongs to one of the plurality of segments and has a unique IP address Nodes
A data storage means for storing a plurality of data, an operation means for accepting a data search operation, and a base node communication means for transmitting and receiving packets are installed one by one for each segment, and each is assigned a unique IP address. A base node,
A router that forwards only unicast packets between segments;
A virtual hub provided with a unique IP address, comprising list storage means for storing each IP address of the base node, and hub communication means for transmitting and receiving unicast packets to and from the base node;
With
Further, each of the base nodes includes IP storage means for storing the IP address of the virtual hub,
The node that has received the data search operation by the operation means transmits the search request packet, which is a broadcast packet including information requesting the data search and its own IP address information as the transmission source information, by the node communication means. And
When the base node belonging to the same segment as the source node receives the search request packet by the base node communication means, the base node communication transmits the search request packet converted into a unicast packet to the virtual hub. Send by means,
When the virtual hub receives the search request packet by the hub communication unit, the hub communication unit transmits the search request packet to each base node,
When each base node receives the search request packet transmitted from the virtual hub by the base node communication means, it converts the search request packet into a broadcast packet and transmits it to another node by the base node communication means. And
Each of the nodes and the base node receives the search request packet, and when the data storage means stores the requested data, stores the data to the transmission source node. A broadcast search system characterized in that the node communication means transmits a reply packet including information indicating that there is information and its own IP address information. IP storage means for storing each IP address of a plurality of nodes belonging to any of the segments and distributing and storing data in a network divided into a plurality of segments;
And receiving a search request packet including information for requesting data search and IP address information of the transmission source transmitted and received by one of the nodes and transmitting / receiving unicast packets to / from the plurality of nodes. A hub communication means for reading out the IP address of each node and transmitting the search request packet to each node;
Broadcast search program to make a computer function as a computer.

Images