JP4808173B2 - Distributed system, data management server, and data distribution method - Google Patents

Description

  The present invention relates to a distributed system that provides data.

  A technology that realizes information sharing / distribution to any node in the system by distributing a large number of databases in the system, storing all data in the system in each database, and keeping the data in sync at all times Proposed. For example, Patent Document 1 describes a technique in a distributed database system including a master site that accesses a master database and a replication site that is connected to the master site via a network and accesses a replication database. . In this system, when a replication site receives a replication database update request from a client, the replication site transmits the update request to the master site. The master site updates the master database according to this update request. When the replication site receives the update result of the master database from the master site, the replication database is updated according to the update result.

  Patent Document 2 describes a technique for realizing information sharing / distribution to any node in the system by multicast transmission of data from a data source into the network of the system and selective reception on the data requesting side. Has been. This technology includes multiple PLCs (Programmable Logic Controllers) for monitoring and controlling process equipment and facilities, multiple MMIs (Man Machine Interfaces) installed at multiple monitoring bases, and between these PLCs and MMIs. It is applied to a distributed control system that transmits a control command and process information by arbitrarily connecting to the network. A location number is assigned to each monitoring base, and by setting the location number, one or a plurality of monitoring bases to which control instructions and process information are transmitted between the MMI and the PLC are specified. Further, a control LAN (Local Area Network) protocol for specifying a transmission destination as multicast by omitting a location number, an MMI number, or a PLC number is provided.

JP 2002-116939 A Japanese Patent Laid-Open No. 2003-18215

  In the technique described in Patent Document 1, a large number of databases are distributed in the system, all data in the system is stored in each database, and the stored data is always kept synchronized. This realizes information sharing / distribution to any node in the system. Therefore, the technique described in Patent Document 1 needs to store all data used in the system in each database regardless of the data transmission source, usage frequency, and the like. For this reason, when the number of data increases, it is necessary to expand the storage area in all databases, and the load of data synchronization processing also increases. That is, the load of management / operation and processing of the server that manages the database increases.

  The technology described in Patent Document 2 realizes information sharing / distribution to any node in the system by multicast transmission of data from a data source into the network of the system and selective reception on the data request side. . Therefore, the message reaches a node that does not request data for multicast communication. All the nodes that have received this message perform a process for determining whether or not the received data is necessary for the own node. For this reason, when the number of nodes increases, the network load and the load of received data determination processing at each node increase.

  The present invention has been made in view of the above problems, and in a distributed system including one or more networks and interconnecting them, a server that manages a database even if the number of data and the number of nodes increase It is an object of the present invention to provide a technology that does not increase the load of management / operation and processing, and does not increase the network load and the processing load at each node.

The present invention has been made to achieve the above object, and at least one of a data management server, a data source for providing a data value, and a user terminal is connected to each of a plurality of communication networks connected to each other. A distributed system in which each of the data management servers transmits a data value acquired from the data source to each user terminal, each of the data management servers having previously acquired a data value and data identification information of data values, a storage device for storing management information and data source identification information for the data source that provides the data values are associated, and obtains the data value from each data source, the storage Data acquisition means for storing collected information in which the acquired data value is associated with the data identification information of the data value; Data providing means for transmitting data identification information included in the collected information and a data value corresponding to the data identification information to the user terminal, and data including data identification information of the requested data value transmitted from the user terminal Data request receiving means for receiving the request, inquiry means for sending inquiry information as to whether or not to store the data value of the data identification information included in the data request to another data management server, and another data management server When the inquiry information is received , whether or not the collected information includes the data identification information included in the inquiry information , or the management information includes the data identification information included in the inquiry information. and whether determined that, if the corresponding data is included in at least one of said collecting information and the management information, the determination result And response means for transmitting a response including, on the collection information, whether whether the data identification information included in the data request is included in the management information includes data identifying information included in the data request Determining means for determining whether or not to select a data management server that transmits a data value in response to a data request, and when the data request from the user terminal is received, the selecting means If the determination result included in the response transmitted from the data management server and the determination result by the determination means notify that the data identification information corresponding to the collection information is included, the determination result Information is collected in the determination result included in the response transmitted from the other data management server and the determination result by the determination means. If there is nothing to notify that the data identification information corresponding to the management information is included and there is a notification notifying that the management information includes the data identification information, the data identification corresponding to the management information If one of the data management servers that has obtained the determination result for notifying that the information is included is selected and the selected data management server is itself, the data acquisition means is configured to Data source identification information associated with data identification information included in the data request is extracted, a data value is acquired from a data source of the extracted data source identification information, and the acquired data value is obtained from the data request is stored as the collected information in association with data identifying information contained in the data identification the data providing means, included from the collected information, to the data request Information and extracts the corresponding data value, and transmits to the user terminal transmitting the data request, if the selected data management server is another data management server, the data providing means, the other was the selected Data response execution instruction including data identification information included in the received data request and terminal identification information of the user terminal that transmitted the data request is transmitted to the data management server, and the data response execution instruction is received. The data acquisition unit of the management server extracts data source identification information associated with the data identification information included in the data response execution instruction from the management information of the management server, and data of the extracted data source identification information Acquire the data value from the source, and associate the acquired data value with the data identification information of the data value as own collection information Is憶, the data providing means of the data management server which has received the data response execution instruction, from said collected information thereof, extract the data values associated with the data identification information included in the data response execution instruction And transmitting to the user terminal of the terminal identification information included in the data response execution instruction.

  According to the technology of the present invention, since the data management server that holds the requested data provides the data with priority, it is not necessary for each data management server to hold all the data. Therefore, even if the amount of data increases, the load of management / operation and processing of the data management server does not increase. In addition, since one of the plurality of data management servers transmits only to the terminal that requested the data, even if the number of user terminals requesting the data increases, the network load and the processing load at each data source are increased. There is no increase. That is, it is possible to guarantee responsiveness to a data request from an arbitrary communication path without interfering with real-time processing and communication in a data source and a network to which the data source is connected.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram illustrating a system configuration example of the present embodiment. In FIG. 1, the system according to the present embodiment includes devices in each of a base 101, a base 102, and a factory 103. Devices in each of the base 101, the base 102, and the factory 103 are connected via a communication network 104. The devices in the base 101 and the base 102 constitute, for example, an information network. The devices in the factory 103 constitute a control system network. The communication network 104 is an arbitrary communication network such as a WAN (Wide Area Network), a LAN, a dedicated line, or a public network.

  Hereinafter, when the devices having the same function among the devices in each of the base 101, the base 102, and the factory 103 are distinguished from each other, description will be given by assigning, for example, “-a1” and “-b” to the devices.

  The base 101 includes a data management server 111-a, a user terminal 121-a, an application server 131-a, a gateway server 141-a, and the like. The data management server 111-a, user terminal 121-a, application server 131-a, gateway server 141-a, and the like are connected to each other via a communication network 151-a. The communication network 151-a is connected to the communication network 104 via the gateway server 141-a.

  The base 102 includes a data management server 111-b, a user terminal 121-b1, a user terminal 121-b2, a gateway server 141-b, and the like. The data management server 111-b, user terminal 121-b1, user terminal 121-b2, gateway server 141-b, and the like are connected to each other via a communication network 151-b. The communication network 151-b is connected to the communication network 104 via the gateway server 141-b.

  The factory 103 includes a communication network 151-c, a communication network 151-d, a communication network 151-e, a communication network 151-f, and the like. Each of the communication network 151-d, the communication network 151-e, and the communication network 151-f is connected to the communication network 151-c. Each of the communication network 151-d, the communication network 151-e, and the communication network 151-f is connected to the communication network 104 via the communication network 151-c.

  The data management server 111-c, user terminal 121-c1, user terminal 121-c2, gateway server 141-c, and the like are connected to the communication network 151-c. The communication network 151-c is connected to the communication network 104 via the gateway server 141-c.

  A data management server 111-d, a user terminal 121-d, a device 161-d1, a device 161-d2, a device 161-d3, a gateway server 141-d, and the like are connected to the communication network 151-d. The communication network 151-d is connected to the communication network 151-c via the gateway server 141-d.

  A data management server 111-e, a device 161e, a gateway server 141-e, and the like are connected to the communication network 151-e. The communication network 151-e is connected to the communication network 151-c via the gateway server 141-e.

  A data management server 111-f, equipment 161-f, gateway server 141-f, and the like are connected to the communication network 151-f. The communication network 151-f is connected to the communication network 151-c via the gateway server 141-f.

  Each data management server 111 is, for example, an information processing apparatus, temporarily stores data, and manages the distribution of the data. The user terminal 121 is an arbitrary information terminal such as a PC (Personal Computer) or a mobile phone. The user terminal 121 runs a user program and is used by a user to request data. The application server 131 is installed with an arbitrary program used for business purposes. The device 161 acquires data and provides it to the data management server 111. The device 161 is arbitrary, but includes, for example, a sensor, a control device (controller, PLC) that controls various facilities and devices, and the like. For example, in the example of FIG. 1, data such as measurement values, measurement time, control results, equipment operation status, contact data, I / O output, and the like are acquired in the factory 103, and the acquired data is managed as any data. Output to the server 111. The device 161 is not particularly limited as long as it has a communication function and a data acquisition function. Specific examples of the device 161 include, for example, an arbitrary facility or device, a sensor that transmits data such as a measurement value via a nearby access point (not shown), etc. by short-range wireless communication, an RFID (Radio Frequency Identification) tag, or the like It is. Note that the communication function and the data acquisition function of the device 161 may be realized by the same device, or may be realized by a plurality of devices. Each gateway server 141 is installed in each communication network 151 and relays communication between the networks. The communication network 151 is an arbitrary communication network such as a WAN, a LAN, a dedicated line, or a public network.

  Since the user terminal 121, the application server 131, the gateway server 141, the communication network 151, the device 161, and the like are not particularly different from the conventional technology, detailed description thereof is omitted.

  The system configuration of this embodiment is arbitrary and is not limited to that shown in FIG. The present embodiment is applicable to a system in which one or more communication networks are connected to each other. Further, the number of data management servers 111, user terminals 121, application servers 131, gateway servers 141, and devices 161 connected to each communication network 151 is arbitrary, and is not limited to that shown in FIG.

  Next, a configuration example of the data management server 111 will be described with reference to FIG.

  First, a hardware configuration example of the data management server 111 will be described with reference to FIG.

  2A, the data management server 111 includes an arithmetic device 201, a memory 202, a secondary storage device 203, an input device 204, an output device 205, a communication device 206, and the like. The arithmetic device 201, the memory 202, the secondary storage device 203, the input device 204, the output device 205, the communication device 206, and the like are connected to each other via a bus 207.

  The arithmetic device 201 is, for example, a CPU (Central Processing Unit). The arithmetic device 201 implements functions to be described later by executing a program (not shown) loaded in the memory 202.

  The secondary storage device 203 can write and read data such as a storage medium such as a CD (Compact Disc) or a DVD (Digital Versatile Disk) and a drive device of the storage medium, an HDD (Hard Disk Drive) or a silicon disk. It is a storage medium.

  The input device 204 is, for example, a mouse, a keyboard, a scanner, a microphone, or the like. The output device 205 is, for example, a display device, a speaker, a printer, or the like. The communication device 206 is an arbitrary communication device such as a LAN unit, for example.

  Next, an example of functional blocks of the data management server 111 will be described with reference to FIG.

  2B, the memory 202 of the data management server 111 has a collection data table 231, a user management information table 232, a local network information table 233, a history management information table 234, and the like. The collected data table 231 stores data values currently collected from each device 161 and information related to collection / accumulation of those data. The data stored in the collected data table 231 is not duplicated. The user management information table 232 stores conditions for acquiring data from the device 161, conditions for transmitting data to the user terminal 121, and the like. The own network information table 233 stores information related to data that can be acquired from the device 161 connected to the same communication network 151 as the own network information table 233. The history management information table 234 stores information related to the collection results of data collected and accumulated from the device 161 and the like. The history management information table 234 stores information related to data that has been collected, stored, and transmitted in the past but is not currently collected, stored, or transmitted.

  Details of the collected data table 231, user management information table 232, own network information table 233, history management information table 234, etc. will be described later.

  The arithmetic unit 201 implements the middleware 211 by executing the program loaded in the memory 202 as described above. The middleware 211 includes a data providing unit 221, a receiving unit 222, a data user management unit 223, a data management unit 224, a communication control unit 225, and the like.

  The data providing unit 221 extracts data from the collected data table 231 based on the transmission conditions for each user in the user management information table 232 and transmits the data to the user terminal 121. The reception unit 222 includes a data request reception unit 226, a response processing unit 227, an execution instruction determination unit 228, and the like. When the data request accepting unit 226 accepts a data request from the user terminal 121, the data request accepting unit 226 searches for the corresponding data from the collected data table 231, the own network information table 233, the history management information table 234, and the like. Further, the data request receiving unit 226 transmits an inquiry about the requested data to the other data management server 111, and 1 of the plurality of data management servers 111 is obtained from a response to the inquiry and its own search result. And issues a data response execution instruction to the selected data management server 111. The response processing unit 227 refers to the collected data table 231, the own network information table 233, the history management information table 234, etc., and responds to inquiries from other data management servers 111. When receiving the data response execution instruction, the execution instruction determining unit 228 selects a data management server 111 that conforms to a predetermined policy, and sends a data response execution instruction to the selected data management server 111. Issue. In some cases, the data response execution instruction is issued to itself. The data user management unit 223 updates the user management information table 232 or the like. The data management unit 224 updates the collected data table 231 and the like and refers to information in the collected data table 231 to acquire data from each device 161. The communication control unit 225 controls data transmission / reception by the middleware 211. The function of this communication control unit 225 is the same as that of the prior art.

  Next, details of each table in the memory 202 of the data management server 111 will be described.

  First, an example of the collected data table 231 will be described with reference to FIG.

  In FIG. 3, the collected data table 231 includes fields such as a data name 301, a data value 302, a time stamp 303, a collection period 304, the number of users 305, and data source information 306. The data name 301, the data value 302, the time stamp 303, the collection cycle 304, the number of users 305, the data source information 306, etc. of each row are associated with each other.

  The data name 301 is the data name of the data requested by the user. In the present embodiment, it is assumed that the data name is unique for data distributed in the system. The data value 302 is the data value of the corresponding data name 301. In the present embodiment, it is assumed that a plurality of data values 302 are stored in time series for one data name 301. Note that the number of data values 302 corresponding to one data name 301 is arbitrary. This number may be determined for each system, for example. The time stamp 303 is the date and time when each corresponding data value 302 is acquired. The collection cycle 304 is a cycle in which the data value of the corresponding data name 301 is collected. The number of users 305 stores the number of users who return a response from among users who currently request the data of the corresponding data name 301. The value of the number of users 305 is updated every time the validity period of the data request becomes invalid. The data source information 306 is information related to the data source (device 161) of the corresponding data name 301. In the present embodiment, the data source information 306 includes path information 311 and properties 312. The path information 311 is a network or gateway server (not shown) that passes when data is transmitted and received between the device 161 that is the data source of the corresponding data name 301 and itself (the data management server 111). is there. The property information 312 is a valid period of the data source of the corresponding data name 301, a sampling cycle, and the like.

  Next, an example of the user management information table 232 will be described with reference to FIG.

  In FIG. 4, the user management information table 232 has fields such as a user name 401, request data 402, filtering conditions 403, validity period 404, user terminal information 405, and last transmission date and time 406. The user name 401, request data 402, filtering condition 403, validity period 404, user terminal information 405, last transmission date and time 406, etc. of each row are associated with each other.

  The user name 401 is a user name of a user who himself (the data management server 111) transmits response data. The request data 402 is all the data names requested by the user with the corresponding user name 401. Information regarding the data of the data name of the request data 402 is stored in the collected data table 231 described above. The filtering condition 403 is a condition for transmitting the data value of the corresponding request data 402 to the user terminal 121 of the user with the corresponding user name 401. For example, the filtering condition 403 “cycle = 20” indicates that the data value of the corresponding request data 402 is acquired once every 20 seconds and further transmitted to the user terminal 121 of the user with the corresponding user name 401. Further, for example, the filtering condition 403 “Line = X” indicates that the data value of the “X” -th manufacturing line in the corresponding request data 402 is transmitted to the user terminal 121 of the user with the corresponding user name 401. Show. The filtering condition 403 is arbitrary. In addition to the above, for example, a predetermined time such as 5 hours after receiving a data request or a predetermined time period such as 10:00 to 13:00 every day may be used. The valid period 404 is the remaining time during which the data value of the corresponding request data 402 is transmitted to the user terminal 121 of the user with the corresponding user name 401. The user terminal information 405 is information regarding the user with the corresponding user name 401. The user terminal information 405 includes route information 411, identification information 412 and the like. The route information 411 is a network, a gateway server, or the like that passes when data is transmitted / received between the communication network 151 to which the user terminal 121 of the user is connected and itself (the data management server 111). Identification information 412 is identification information of the user terminal 121. In this embodiment, the identification information of the user terminal is not particularly limited, but is, for example, the address of the user terminal 121, the telephone number of the user terminal 121 that is a mobile phone, the host name, and the like. The last transmission date and time 406 is the date and time when the latest one of the date and time transmitted to the user terminal 121 of the user with the corresponding user name 401 is transmitted.

  Next, an example of the own network information table 233 will be described with reference to FIG.

  In FIG. 5, the own network information table 233 has fields such as a data name 501 and a property 502. The data name 501, property 502, etc. of each row are associated with each other.

  The data name 501 is the data name of data. The property 502 is information regarding the data source (device 161) of the corresponding data name 501. Here, the property 502 includes an address 511, an interface 512, a data type 513, a data size 514, and the like. The address 511 is the address of the device 161 that is the data source of the corresponding data name 501. The interface 512 is an interface of the device 161 that is the data source of the corresponding data name 501. The data type 513 is a data type of a data value transmitted by the device 161 that is the data source of the corresponding data name 501. The data size 514 is the data size of the data value transmitted by the device 161 that is the data source of the corresponding data name 501.

  The own network information table 233 stores only the data name and property acquired by the device 161 connected to the same communication network 151 as the data management server 111 having the own network information table 233. Specifically, for example, in the case of the data management server 111-d shown in FIG. 1 as an example, the own network information table 233 stores the data acquired by each of the devices 161-d1, 161-d2, and 161-d3. The data name and the property of the data are stored. The own network information table 233 shown as an example in FIG. 5 is an example of a table stored in the data management server 111-d shown as an example in FIG.

  Next, an example of the history management information table 234 will be described with reference to FIG.

  In FIG. 6, the history management information table 234 has fields such as a data name 601, data source information 602, and a final collection date / time 603. The data name 601, the data source information 602, the last collection date and time 603 of each row are associated with each other.

  The data name 601 is the data name of data. The data source information 602 is information related to the data source (device 161) of the corresponding data name 601. The data source information 602 includes path information 611, properties 612, and the like. The path information 611 is a network, gateway server, or the like that passes when data is transmitted and received between the device 161 that is the data source of the corresponding data name 601 and itself (the data management server 111). The property information 612 is a valid period of the data source corresponding to the data name 601, a sampling cycle, and the like. The final collection date and time 603 is the date and time when the latest data value transmitted from the data source of the corresponding data name 601 is received.

  Next, an example of the operation of the system of this embodiment will be described.

  First, the outline of the system of the present embodiment will be described with reference to FIG.

  FIG. 7 shows an example of an outline of information distribution between the device 161 as a data source and the user terminal 121 of the user in the system configuration shown in FIG. 1 as an example.

  Here, as a precondition, it is assumed that no one is collecting, storing and transmitting data. In such a case, first, it is assumed that the user c1 requests the data values of the data names “dataA” and “dataB” using the user terminal 121-c1 connected to the communication network 151-c. Furthermore, it is assumed that the user c2 requests the data values of the data names “dataA” and “dataC” using the user terminal 121-c2 connected to the communication network 151-c. In addition, each of the devices 161-d1, 161-d2, and 161-d3 connected to the communication network 151-d transmits data values having data names “dataA”, “dataB”, and “dataC”. Shall.

  When data is requested as described above, the data management server 111 issues a data response execution instruction to any one of the data management servers 111. The data management server 111 to which this data response execution instruction is issued selects one of the data management servers 111 that conforms to a predetermined policy. The selected data management server 111 collects, stores, and transmits the requested data. Here, it is assumed that this policy either gives priority to the responsiveness to the user or gives priority to the reduction of the communication load from the device 161 as the data source to the data management server 111. Here, it is assumed that the data management server 111-d is selected as the data management server 111 that collects, stores, and transmits requested data. The data management server 111-d starts collecting and accumulating data values of the data names “dataA”, “dataB”, and “dataC”. The data management server 111-d transmits the data values of the data names “dataA” and “dataB” to the user terminal 121-c1. Further, the data management server 111-d transmits the data values of the data names “dataA” and “dataC” to the user terminal 121-c2.

  After starting the data transmission as described above, the user b1 uses the user terminal 121-b1 connected to the communication network 151-b to transfer the data with the data names “dataA”, “dataB”, and “dataD”. Shall be requested. Furthermore, it is assumed that the user b2 requests data with the data names “dataC” and “dataD” using the user terminal 121-b2 connected to the communication network 151-b. In addition, the device 161-e connected to the communication network 151-e transmits a data value having the data name “dataD”.

  In this case, as described above, each data management server 111 selects one of the data management servers 111 to which a data response execution instruction is issued, from the data management servers 111 that comply with a predetermined policy. The selected data management server 111 collects, stores, and transmits the requested data. Here, it is assumed that the data management server 111-c is selected as the data management server 111 that collects, stores, and transmits requested data. In addition, since the data name currently collecting, storing and transmitting the data value and the data name requested this time at least partially match, the newly selected data management server 111-c The data collection / storage and transmission performed by the server 111-d is taken over. That is, the data management server 111-d stops collecting, storing, and transmitting data values of the data names “dataA”, “dataB”, and “dataC”. On the other hand, the data management server 111-c starts collecting and accumulating data values of data names “dataA”, “dataB”, “dataC”, and “dataD”. The data management server 111-c transmits the data values of the data names “dataA” and “dataB” to the user terminal 121-c1. The data management server 111-c transmits the data values of the data names “dataA” and “dataC” to the user terminal 121-c2. The data management server 111-c transmits the data values of the data names “dataA”, “dataB”, and “dataD” to the user terminal 121-b1. The data management server 111-c transmits the data values of the data names “dataC” and “dataD” to the user terminal 121-b2.

  Next, an example of a schematic sequence shown in FIG. 7 will be described with reference to FIG. FIG. 8 illustrates an example after a data request is received from the user terminal 121-b1. Although not shown, it goes without saying that the same processing is performed on the other user terminals 121.

  In FIG. 8, the user terminal 121-b1 transmits a data request (S801). Here, the destination of the data request of each user terminal 121 is the data management server 111 connected to the same communication network 151 as itself. Accordingly, the user terminal 121-b1 transmits a data request to the data management server 111-b. This data request includes the user name of the user b1, the identification information of the user terminal 121-b1, the data name of the data desired to be requested, data collection and transmission conditions, and the like. Upon receiving the data request from the user terminal 121-b1, the data management server 111-b transmits an inquiry regarding the received data request to the other data management server 111 by multicast (S802, S803). This inquiry includes the data name included in the data request. Further, the data management server 111-b refers to its own memory 202 and searches for the data with the name included in the received data request (S804).

  Each of the data management server 111-c and data management server 111-d that received the inquiry refers to its own memory 202 and searches for the data requested by the received data request (S805, S806). Although not shown, the data management server 111-b may transmit the same inquiry to each of the data management servers 111-a and 111-e and the data management server 111-f. The operation examples of the data management servers 111-a and 111-e and the data management server 111-f that have received this inquiry are the same as those of the data management server 111-c and the data management server 111-d. As a result of the search in S805 and S806, when the corresponding data is collected / stored / transmitted, etc., each of the data management server 111-c and the data management server 111-d collects / stores / transmits the corresponding data, etc. Is transmitted to the data management server 111-b that transmitted the inquiry. Here, it is assumed that the data management server 111-d transmits to the data management server 111-b that the corresponding data is collected / stored / transmitted (S807). Although not shown, here, the data management server 111-e transmits to the data management server 111-b that the corresponding data can be acquired from the device 161 connected to the same communication network 151 as itself. To do.

  The data management server 111-b selects the data management server 111 that performs a response process to the received data request from the response from the other data management server 111 and its search result (S808). Here, it is assumed that the data management server 111-b selects the data management server 111-d. The data management server 111-b transmits a data response execution instruction for the received data request to the data management server 111-d (S809). In this data response execution instruction, in addition to the user name and identification information of the user b1 included in the data request, the data name to be requested, the data collection and transmission conditions, the data management server 111-b Includes the data name of the data to be transmitted to the user who is requesting the same data requested in the data request received in S801 among the data that has been transmitted, and information regarding the user transmitting the data and the user terminal 121 It is.

  The data management server 111-d that has received the data response execution instruction selects the data management server 111 that is suitable for sending a data response according to one of the load reduction priority and the response priority priority. S810). Here, it is assumed that the data management server 111-d selects the data management server 111-c. The data management server 111-d issues a data response execution instruction to the data management server 111-c (S811). The information included in this data response execution instruction is the same as described above.

  The data management server 111-c that has received the data response execution instruction selects the data management server 111 that is suitable for sending a data response according to one of the load reduction priority and the response priority priority. S812). Here, it is assumed that the data management server 111-c selects itself. The data management server 111-c collects and accumulates data from the device 161 based on the data collection condition included in the data response execution instruction (S813). Further, the data management server 111-c transmits the collected / accumulated data to the user terminal 121-b1 in accordance with the data transmission condition included in the data response execution instruction (S814). Although not shown in FIG. 8, data is similarly transmitted to each of the user terminal 121-c1, the user terminal 121-c2, and the user terminal 121-b2.

  Note that the collected data table 231 shown as an example in FIG. 3 starts transmission of data to each of the user terminals 121-c1 and 121-c2 in the operation examples shown in FIGS. To the data management server 111-d from when the data request is received from each of the user terminal 121-b1 and the user terminal 121-b2. 4 starts transmission of data to each of the user terminal 121-c1 and the user terminal 121-c2 in the operation example illustrated in FIG. 7 and FIG. 8 described above. And the data management server 111-d from when the data request is received from each of the user terminal 121-b1 and the user terminal 121-b2.

  Next, an operation example of the data management server 111 alone will be described in detail.

  First, with reference to FIG. 9, an operation example when a data request is first received from any of the user terminals 121 will be described.

  The data request accepting unit 226 of the data management server 111 accepts the data request transmitted from the user terminal 121 (S901). This data request includes a user name, identification information of the user terminal of the user, a data name of the requested data, a filtering condition for the requested data, a remaining time for transmitting the data, and the like.

  Specifically, for example, in the case of the operation example shown in FIGS. 7 and 8 described above, the data request transmitted from the user terminal 121-c1 used by the user c1 includes the user name “user c1”, the identification information “ID_c1”, data name “dataA, dataB” for each requested data, filtering condition “cycle = 20”, remaining time “06:00:00” for transmitting data, and the like are included. The data management server 111-c receives a data request including these pieces of information.

  Specifically, for example, in the case of the operation example shown in FIGS. 7 and 8 described above, the data request transmitted from the user terminal 121-b1 used by the user b1 includes the user name “user b1”, The identification information “ID_b1”, the data names “dataA, dataB, dataD” for each requested data, the filtering condition “cycle = 10”, the remaining time “18:00:00” for transmitting data, and the like are included. The data management server 111-b receives a data request including these pieces of information.

  The data request accepting unit 226 multicasts to another data management server 111 an inquiry as to whether or not to hold information related to the data requested by the data request accepted in S901 (S902). At this time, the data request receiving unit 226 includes at least the data name included in the received data request in the inquiry.

  Specifically, for example, in the case of the operation example shown in FIGS. 7 and 8, the data management server 111-c that has received the data request transmitted from the user terminal 121-c1 a, the data management server 111-b, the data management server 111-d, the data management server 111-e, and the data management server 111-f are each transmitted an inquiry including the data names “dataA”, “dataB”, and the like.

  Specifically, for example, in the case of the operation example shown in FIGS. 7 and 8 described above, the data management server 111-b that has received the data request transmitted from the user terminal 121-b1 is the data management server. 111-a, data management server 111-c, data management server 111-d, data management server 111-e, and data management server 111-f are assigned data names “dataA”, “dataB”, “dataD”, etc. Send a containing query.

  Next, the data request receiving unit 226 refers to the memory 202 and searches for data requested by the data request received in S901 (S903). For this purpose, the data request receiving unit 226 refers to the data name 301 of the collected data table 231 and searches for a data name that matches the data name included in the data request received in S901. What is matched by this search is the data that is currently collected / stored / transmitted and that matches the data included in the data request. Further, the data request receiving unit 226 refers to the data name 601 in the history management information table 234 and searches for a data name that matches the data name included in the data request received in S901. What is matched by this search is data that matches the data included in the data request among the data collected, stored and transmitted in the past. Further, the data request receiving unit 226 refers to the data name 501 of the own network information table 233, and searches for a data name that matches the data name included in the data request received in S901. What is matched by this search is data that matches data included in the data request among data that can be acquired from the device 161 connected to the same communication network 151 as that of the search.

  Specifically, for example, in the case of the operation example shown in FIG. 7 and FIG. 8 described above, the data request reception unit 226 of the data management server 111-c that has received the data request transmitted from the user terminal 121-c1 is Then, the data name 301 of the collected data table 231 is referred to search for data that matches each of “dataA” and “dataB”. The data request receiving unit 226 refers to the data name 601 of the history management information table 234 and searches for data that matches each of “dataA” and “dataB”. Further, the data request receiving unit 226 refers to the data name 501 of the own network information table 233 and searches for data that matches each of “dataA” and “dataB”. In the case of the operation example shown in FIGS. 7 and 8, as described above, when receiving a data request from the user terminal 121-c 1, no one is collecting, storing, or transmitting data. Therefore, the data request accepting unit 226 determines that the corresponding information is not included in any of the collected data table 231, the own network information table 233, and the history management information table 234.

  Specifically, for example, in the case of the operation example shown in FIGS. 7 and 8 described above, the data request reception unit of the data management server 111-b that has received the data request transmitted from the user terminal 121-b1. 226 refers to the data name 301 of the collected data table 231 and searches for data that matches each of “dataA”, “dataB”, and “dataD”. The data request reception unit 226 refers to the data name 601 in the history management information table 234 and searches for data that matches each of “dataA”, “dataB”, and “dataD”. Further, the data request receiving unit 226 refers to the data name 501 of the own network information table 233 and searches for data that matches each of “dataA”, “dataB”, and “dataD”. In the operation example shown in FIGS. 7 and 8, as described above, when the data request from the user terminal 121-b1 is received, only the data management server 111-d collects, stores, and transmits data. It is in the state of doing. Therefore, the data request reception unit 226 of the data management server 111-b determines that the corresponding information is not included in any of the collected data table 231, the own network information table 233, and the history management information table 234.

  The data request receiving unit 226 waits for a response to an inquiry to another data management server 111 (S904). The response sent from each data management server 111 includes the data name of the data currently collected / stored / transmitted that matches the data included in the query, collected / stored / transmitted in the past At least one of the data name of the data that matches the data included in the query and the data name acquired from the device 161 connected to the same communication network 151 as the data is included. Details of this will be described later.

  Specifically, for example, in the case of the operation example shown in FIG. 7 and FIG. 8 described above, as described above, when receiving a data request from the user terminal 121-c1, no one collects and stores data. In this state, transmission is not performed. Accordingly, only the data management server 111-d indicates that the data names “dataA” and “dataB” and that these data can be acquired from the device 161-d connected to the same communication network 151-d as itself. A response including information etc. is transmitted. The data management server 111-c receives the response transmitted from the data management server 111-d.

  Specifically, for example, in the case of the operation example shown in FIGS. 7 and 8 described above, as described above, when the data request from the user terminal 121-b1 is received, the data management server 111- Only d is a state in which data of data names “dataA”, “dataB”, and “dataC” are collected, stored, and transmitted. Accordingly, the data management server 111-d transmits a response including data names “dataA” and “dataB” and information indicating that these data are currently being collected, stored, and transmitted. In addition, the data management server 111-e sends a response including the data name “dataD” and information indicating that this data can be acquired from the device 161-e connected to the same communication network 151-e as itself. Send. The data management server 111-c receives the response transmitted from the data management server 111-d and the response transmitted from the data management server 111-e.

  The data request reception unit 226 selects the data management server 111 that responds to the data request received in S901 described above (S905). Details of this selection process will be described later. Next, the data request accepting unit 226 issues a data response execution instruction to the data management server 111 selected in S905 (S906). In this data response execution instruction, the data name of the requested data, the filtering condition of the requested data, the remaining time for transmitting the data, the user name of the user requesting the data, the identification information of the user terminal of the user, etc. Is included. Here, when the data management server 111 selected in S905 is itself, the data request accepting unit 226 activates update processing of a collection data table 231, a user management information table 232, and the like which will be described later.

  Specifically, for example, in the case of the operation example shown in FIGS. 7 and 8 described above, the data request reception unit 226 of the data management server 111-c that has received the data request from the user terminal 121-c1 In this process, the data management server 111-d is selected. In this case, the data request receiving unit 226 sends the user name “user c1”, the identification information “ID_c1”, the data name “dataA, dataB” for each requested data, and the filtering condition “cycle” to the data management server 111-d. = 20 ”, and the data response execution instruction including the remaining time“ 06:00:00 ”for transmitting data is issued.

  Specifically, for example, in the case of the operation example shown in FIGS. 7 and 8 described above, the data request receiving unit 226 of the data management server 111-b that has received the data request from the user terminal 121-b1 is In step S905, the data management server 111-d is selected. In this case, the data request accepting unit 226 sends the user name “user b1”, the identification information “ID_b1”, the data name “dataA, dataB, dataD” for each requested data, the filtering condition to the data management server 111-d. A data response execution instruction including “cycle = 10”, the remaining time “18:00:00” for transmitting data, and the like is issued.

  Here, the details of the selection processing example of the data management server 111 in S905 described above will be described with reference to FIG.

  In FIG. 9, the data request accepting unit 226 first determines whether or not an inquiry response transmitted in the above-described processing of S902 has been received (S911). This determination may be arbitrary. For example, the data request receiving unit 226 determines whether or not a response has been received within a predetermined time after transmitting the inquiry in S902 described above, or has received a predetermined number of responses to the inquiry. It may be determined based on whether or not.

  If no response has been received as a result of the determination in S911, the data request receiving unit 226 selects itself as a response to the data request received in S901 described above (S912).

  If a response is received as a result of the determination in S911, the data request reception unit 226 is requested by the data request received in S901 described above, at least one of the received response and the search result in S903 described above. It is determined whether the collected data is currently collected / stored / transmitted (S913).

  As a result of the determination in S913, when there is data that is currently collected / stored / transmitted in the data request received in S901, the data request receiving unit 226 transmits the response to the data management Of the servers 111 and themselves, the one that collects, stores, and transmits the same data as the requested data is selected as the one that responds to the data request received in S901 (S914). For this purpose, the data request accepting unit 226 counts the number of data names of data currently collected, stored, and transmitted for each response. Further, the data request receiving unit 226 counts the number of data searched in the above-described processing of S903. The data request receiving unit 226 compares these numbers and selects the data management server 111 or the one that has transmitted the response having the largest number.

  On the other hand, as a result of the determination in S913, if there is no data currently collected / stored / transmitted in the data request accepted in S901, the data request accepting unit 226 accepts the data requested in S901. In step S915, it is determined whether there is data collected, stored, and transmitted in the past for the data requested by the data request.

  As a result of the determination in S915, when there is data that has been collected / stored and transmitted in the past for the data requested in the data request received in S901, the data request reception unit 226 transmits the response. Among 111 and itself, the one that collects, accumulates, and transmits the same data as the requested data is selected as the one that responds to the data request received in S901 described above (S916). This specific processing example is the same as S914 described above except that the number of data names of data collected, stored, and transmitted in the past is counted, and thus will not be described.

  As a result of the determination in S915, if there is no data that has been collected, stored and transmitted in the past for the data requested in the data request received in S901, the data request accepting unit 226 transmits the response. Among them, the device 161 that is the data source of the requested data and the device that is connected to the same communication network 151 as the data source are selected as the one that responds to the data request received in S901 (S917). ). This specific processing example is the above-mentioned except that the number of data names of data that matches the data included in the query among the data that can be acquired from the devices 161 connected to the same communication network 151 is counted. Since it is the same as S914 and S916, it abbreviate | omits.

  Specifically, for example, in the case of the operation example shown in FIGS. 7 and 8, the data management server 111-c receives the data request from the user terminal 121-c1 as described above. In step S903, the unit 226 determines that the collection data table 231, the own network information table 233, and the history management information table 234 do not include the corresponding information. In step S904, the data A response including the data names “dataA” and “dataB” from the management server 111-d and information indicating that these data are acquired from the device 161 connected to the same communication network 151-d as itself. Receiving. Therefore, the data request accepting unit 226 of the data management server 111-c has the largest number of data connected to the same communication network 151 as the device 161 that is the data source of the same data as the requested data in the process of S917. The management server 111-d is selected.

  Specifically, for example, in the case of the operation example shown in FIGS. 7 and 8, the data of the data management server 111-b that has received the data request from the user terminal 121-b1 as described above. In step S903, the request reception unit 226 determines that the corresponding data is not included in any of the collection data table 231, the own network information table 233, and the history management information table 234, and in step S904. , A response including data names “dataA” and “dataB” from the data management server 111-d and information indicating that these data are currently being collected, stored, and transmitted, and the data management server 111- a response including the data name “dataD” from e and information indicating that these data are acquired from the device 161 connected to the same communication network 151-e as itself It has been received. Therefore, the data request receiving unit 226 of the data management server 111-c selects the data management server 111-d that is currently collecting, storing, and transmitting the same data as the requested data in the process of S914.

  As a result of the determination in S915, the case where the data requested in the data request accepted in S901 described above has not been collected / stored / transmitted in the past, that is, the data request accepted in S901 mentioned above. This is a case where the requested data has not been collected, stored and transmitted so far.

  Next, an operation example when an inquiry transmitted from another data management server 111 is received will be described with reference to FIG.

  As described above with reference to FIG. 9, when receiving a data request from the user terminal 121, the data management server 111 multicasts an inquiry including the data name of the requested data to the other data management server 111.

  In FIG. 10, when the response processing unit 227 of the data management server 111 receives the inquiry (S1001), the response processing unit 227 refers to the collected data table 231 and selects the data name of the data currently collected / stored / transmitted. It is determined whether or not a matching item is included (S1002). For this purpose, for example, the response processing unit 227 refers to the data name 301 of each row of the collected data table 231 and searches for a data name that matches the data name included in the query.

  Specifically, for example, in the case of the operation example shown in FIG. 7 and FIG. 8 described above, as described above, the data management server 111-c that has received the data request from the user terminal 121-c1 Queries including data names “dataA”, “dataB”, etc. are sent to each of the server 111-a, the data management server 111-b, the data management server 111-d, the data management server 111-e, and the data management server 111-f. Send. As described above, when receiving a data request from the user terminal 121-c1, no one is collecting, storing, or transmitting data. Accordingly, the response processing units 227 of the data management server 111-a, the data management server 111-b, the data management server 111-d, the data management server 111-e, and the data management server 111-f are stored in the collected data table 231. Determines that the corresponding information is not included.

  Specifically, for example, in the case of the operation example shown in FIG. 7 and FIG. 8 described above, as described above, the data management server 111-b that has received the data request from the user terminal 121-b1 Each of the data management server 111-a, the data management server 111-c, the data management server 111-d, the data management server 111-e, and the data management server 111-f has a data name “dataA”, “dataB”, “dataD Send inquiry including " Upon receiving this inquiry, the response processing unit 227 of the data management server 111-d refers to the data name 301 of each row of the collected data table 231 shown in FIG. 3 as an example, and sets “dataA”, “dataB”, “dataD”. Search for a match for each. In the case of the collected data table 231 illustrated in FIG. 3, since the data name 301 “dataA” and the data name 301 “dataB” are included, the response processing unit 227 determines that the corresponding information is included. .

  If a match is found as a result of the determination in S1002, the response processing unit 227 holds the data name of the matching data in a predetermined area or the like of the memory 202 as being currently collected, stored, and transmitted. (S1003). At this time, the response processing unit 227 stores all data names in a predetermined area of the memory 202 when there are two or more corresponding items.

  Specifically, for example, in the case of the operation example illustrated in FIG. 7 and FIG. 8 described above, the response processing unit 227 of the data management server 111-d that has received the inquiry for the data request transmitted from the user terminal 121-b1. In the processing of S1002 described above, it is determined that the data names “dataA” and “dataB” are included in the collected data table 231 shown as an example in FIG. Therefore, the response processing unit 227 stores the data names “dataA” and “dataB” in the predetermined area of the memory 202 as what is currently collected, stored, and transmitted.

  As a result of the determination in S1002, if there is no match, or after the processing in S1003 described above, the response processing unit 227 refers to the history management information table 234 and has collected, accumulated, and transmitted in the past. It is determined whether a data name that matches the data name included in the query is included (S1004). For this purpose, for example, the response processing unit 227 refers to the data name 601 of each row of the history management information table 234 and searches for data that matches the data name of the data included in the query.

  Specifically, for example, in the case of the operation example shown in FIG. 7 and FIG. 8 described above, as described above, the data management server 111-c that has received the data request from the user terminal 121-c1 Queries including data names “dataA”, “dataB”, etc. are sent to each of the server 111-a, the data management server 111-b, the data management server 111-d, the data management server 111-e, and the data management server 111-f. Send. As described above, when receiving a data request from the user terminal 121-c1, no one is collecting, storing, or transmitting data. Accordingly, the response processing unit 227 of each of the data management server 111-a, the data management server 111-b, the data management server 111-d, the data management server 111-e, and the data management server 111-f includes the history management information table 234. Is determined to contain no relevant information.

  If a match is found as a result of the determination in S1004, the response processing unit 227 stores the data name of the matching data in a predetermined area or the like of the memory 202 as having been collected, stored, and transmitted in the past. (S1005). At this time, the response processing unit 227 stores all data names in a predetermined area of the memory 202 when there are two or more corresponding items.

  As a result of the determination in S1004, if a match is not included, or after the processing in S1005 described above, the response processing unit 227 refers to the own network information table 233 and is connected to the same communication network 151 as itself. It is determined whether or not the data names of the data acquired from the devices 161 that are included include data that matches those included in the inquiry (S1006). For this purpose, for example, the response processing unit 227 refers to the data name 501 of each row of the own network information table 233 and searches for data that matches the data name of the data included in the query.

  Specifically, for example, in the case of the operation example shown in FIG. 7 and FIG. 8 described above, as described above, the data management server 111-c that has received the data request from the user terminal 121-c1 Queries including data names “dataA”, “dataB”, etc. are sent to each of the server 111-a, the data management server 111-b, the data management server 111-d, the data management server 111-e, and the data management server 111-f. Send. The response processing unit 227 of the data management server 111-d that has received this inquiry refers to the data name 501 of each row of the own network information table 233 shown in FIG. In the case of the own network information table 233 shown in FIG. 5 as an example, the data name 501 includes “dataA” and “dataB”. Therefore, the response processing unit 227 of the data management server 111-d determines that the collected data table 231 includes the corresponding information.

  If a match is found as a result of the determination in S1006, the response processing unit 227 obtains the data name of the matching data from the device 161 connected to the same communication network 151 as that of the memory. It is held in a predetermined area 202 or the like (S1007). At this time, the response processing unit 227 stores all data names in a predetermined area of the memory 202 when there are two or more corresponding items.

  Specifically, for example, in the case of the operation example shown in FIG. 7 and FIG. 8 described above, the data management server 111 that received the inquiry for the data request transmitted from the user terminal 121-c1 in the processing of S1006 described above. The -d response processing unit 227 determines that the data names “dataA” and “dataB” are included in the own network information table 233. Accordingly, the response processing unit 227 stores the data names “dataA” and “dataB” in a predetermined area of the memory 202 as data acquired from the device 161 connected to the same communication network 151 as that of the response processing unit 227.

  As a result of the determination in S1006, if a match is not included, or after the process of S1007 described above, the response processing unit 227 refers to a predetermined area of the memory 202 and It is determined whether there is a data name stored in at least one process (S1008).

  When the data name is stored as a result of the determination in S1008, the response processing unit 227 transmits a response (S1009). At this time, the response processing unit 227 responds with the data name and whether each data is currently being collected / stored / transmitted, collected / stored / transmitted in the past, or the same communication as itself. And information indicating whether the information is acquired from the device 161 connected to the network 151.

  Specifically, for example, in the case of the operation example shown in FIG. 7 and FIG. 8 described above, the response processing unit 227 of the data management server 111-d that has received the inquiry for the data request transmitted from the user terminal 121-c1. Stores the data names “dataA” and “dataB” to be acquired from the device 161 connected to the same communication network 151 in the predetermined area or the like of the memory 202 in the processing of S1007 described above. . Accordingly, the response processing unit 227 transmits a response including information indicating that the data is acquired from the device 161 connected to the same communication network 151 as the self and the data names “dataA” and “dataB” to the data management. Send to server 111-c.

  Specifically, for example, in the case of the operation example shown in FIG. 7 and FIG. 8 described above, the response processing of the data management server 111-d that has received the inquiry for the data request transmitted from the user terminal 121-b1 The unit 227 stores the data names “dataA” and “dataB” in the predetermined area or the like of the memory 202 in the above-described processing of S1002, assuming that they are currently collected, stored, and transmitted. Accordingly, the response processing unit 227 transmits a response including information indicating that the data is currently collected / stored / transmitted and the data names “dataA” and “dataB” to the data management server 111-b. To do.

  As a result of the determination in S1008, if the data name of the data is not stored, the response processing unit 227 ends the process.

  Next, with reference to FIG. 11, an operation example when a data response execution instruction transmitted from another data management server 111 or a data response execution instruction instructed to be executed by itself is received will be described.

  As described above with reference to FIG. 9, the data management server 111 issues a data response execution instruction to the selected data management server 111. In FIG. 11, the selected data management server 111 accepts a data response execution instruction (S1101). As described above, the data response execution instruction includes the data name of the requested data, the filtering condition of the requested data, the time limit for requesting the data, the user name of the user requesting the data, the user terminal 121 of the user Identification information and the like are included.

  Next, the execution instruction determination unit 228 acquires information regarding the device 161 that is the data source of the requested data (S1102). For this purpose, for example, the execution instruction determination unit 228 determines whether the requested data is currently collected / stored and transmitted. For this purpose, the execution instruction determination unit 228 refers to, for example, the data name 301 of each row of the collected data table 231 and determines whether or not the data name included in the data response execution instruction is included. As a result of the determination, if the data name included in the data response execution instruction is included, the execution instruction determining unit 228 matches the data name included in the data response execution instruction from the collected data table 231. The data name 301 is searched, and the path information 311 and the property 312 corresponding to the corresponding data name 301 are referred to. When the requested data is not currently collected / stored / transmitted, the execution instruction determination unit 228 determines whether the requested data has been collected / stored / transmitted in the past. For this purpose, the execution instruction determination unit 228 refers to, for example, the data name 601 of each row of the history management information table 234 and determines whether or not a data that matches the data name of the data included in the data response execution instruction is included. To do. As a result of this determination, when the data response execution instruction includes data that matches the data name of the data, the execution instruction determination unit 228 determines from the history management information table 234 the data included in the data response execution instruction. A data name 601 that matches the data name is searched, and path information 611 and property 612 corresponding to the corresponding data name 601 are referred to. When the requested data has not been collected / stored / transmitted at present and in the past, the execution instruction determination unit 228 indicates that the device 161 serving as the data source of the requested data is connected to the communication network to which the device 161 is connected. It is determined whether or not it is connected to 151. For this purpose, the execution instruction determination unit 228 refers to, for example, the data name 501 of each row of the own network information table 233, and determines whether or not a data name that matches the data name included in the data response execution instruction is included. To do. As a result of the determination, when the data response execution instruction includes data that matches the data name of the data, the execution instruction determination unit 228 determines from the own network information table 233 the data included in the data response execution instruction. A data name 501 that matches the data name is searched, and a property 502 corresponding to the corresponding data name 501 is referred to. If the data that matches the data name of the requested data is not included in any of the collected data table 231, the own network information table 233, and the history management information table 234, the execution instruction determination unit 228 A data source query including the data name of the requested data may be sent to the server 111. Each data management server 111 that has received this data source query refers to the data name 501 in each row of its own network information table 233 and searches for a data name that matches the data name included in the data source query. When there is a data name 501, the property 502 corresponding to the data name 501 may be read, and the read data of the property 502 may be transmitted as a response. The data management server 111 that has received this response acquires route information to the device 161 that is the data source of the requested data by transmitting a predetermined command including the address 511 of the property 502 included in the response. Also good. Further, for example, each of the devices 161 serving as the data source broadcasts and transmits the data name and data value acquired by the device 161 and the response to the inquiry from the data management server 111 as described above. The data management server 111 may acquire the route information by selectively receiving the data 161, the data value, the response, and the like of the device 161 to be acquired from the data 161 broadcasted by each device 161.

  Specifically, for example, in the case of the operation example illustrated in FIGS. 7 and 8, as described above, the data management server 111-c that has received the data request from the user terminal 121-c 1 is the data management server 111. -d, user name “user c1”, identification information “ID_c1”, data name “dataA, dataB” for each requested data, filtering condition “cycle = 20”, remaining time “06: A data response execution instruction including “00:00” is issued. In this case, the execution instruction determination unit 228 of the data management server 111-d acquires information regarding the device 161 that is the data source of each data of the data names “dataA” and “dataB”. For this purpose, the execution instruction determination unit 228 refers to the data name 301 of each row of the collected data table 231 and determines whether or not the data names “dataA” and “dataB” are included. Further, the execution instruction determination unit 228 refers to, for example, the data name 601 of each row of the history management information table 234 and determines whether or not the data names “dataA” and “dataB” are included. . As described above, when receiving a data request from the user terminal 121-c1, no one is collecting, storing, or transmitting data. Accordingly, neither the collected data table 231 nor the history management information table 234 includes the corresponding data. Furthermore, the execution instruction determination unit 228 refers to the data name 501 of each row of the own network information table 233 shown in FIG. 5 as an example, and whether the data matches the data names “dataA” and “dataB”. Judge whether or not. As a result of the determination, since the corresponding data is included, the execution instruction determination unit 228 changes the property 502 corresponding to the data name 501 “dataA” and the data name 501 “dataB” from the own network information table 233. Refer to the corresponding property 502.

  More specifically, for example, in the case of the operation example shown in FIGS. 7 and 8, as described above, the data management server 111-b that has received the data request from the user terminal 121-b1 User name “user b1”, identification information “ID_b1”, data name “dataA, dataB, dataD” for each requested data, filtering condition “cycle = 10”, remaining data to be transmitted to server 111-d A data response execution instruction including the time “18:00:00” is issued. In this case, the execution instruction determination unit 228 of the data management server 111-d acquires information regarding the device 161 that is the data source of each data name “dataA”, “dataB”, and “dataD”. As described above, when the data request from the user terminal 121-b1 is received, the data names “dataA” and “dataB” are being collected, stored, and transmitted. Therefore, the execution instruction determination unit 228 refers to the data name 301 in each row of the collected data table 231 shown in FIG. 3 as an example, and whether or not a data that matches the data names “dataA” and “dataB” is included. To determine. As a result of this determination, since the corresponding data is included, the execution instruction determination unit 228 corresponds to the data source information 306 corresponding to the data name 301 “dataA” and the data name 301 “dataB” from the collected data table 231. Data source information 306 to be referred to is referred to. In addition, the execution instruction determination unit 228 transmits a data source query including the data name “dataD” to the other data management server 111. The data management server 111-e that has received this data source query reads the property 502 corresponding to the data name 501 “dataD” from its own network information table 233, and transmits it as a response to the data management server 111-d.

  Next, the execution instruction determination unit 228 determines whether “load reduction priority” or “responsiveness priority” is set as a policy of the entire system (S1103). Here, this policy is determined in advance for each of all the data management servers 111, and information indicating any policy is stored in a predetermined area or the like of each secondary storage device 203 or the like. The execution instruction determination unit 228 determines this by referring to this information. Here, “load reduction priority” gives priority to reducing the network load and the like that occurs when the data management server 111 collects and stores data requested by the user. Further, “response priority” gives priority to certainty when the data management server 111 transmits a response including the requested data to the user terminal 121.

  If the result of the determination in S1103 is “load reduction priority”, the execution instruction determination unit 228 selects the data management server 111 that has the least load related to data acquisition from the data source device 161 of the requested data. Select (S1104). Here, the technique for selecting the data management server 111 with a low load is not particularly limited. For example, the execution instruction determination unit 228 refers to the path information between each of the data management servers 111 and each of the data source devices 161 of the requested data, and determines the data management server 111 having the minimum path. You may choose. Further, for example, the execution instruction determination unit 228 acquires the network load of each communication network 151, the server load of each data management server 111, and the like, and the data management server connected to the communication network 151 having the minimum network load. 111, the data management server 111 with the smallest server load may be selected. When the data management server 111 is selected based on whether or not the route is the smallest, the execution instruction determination unit 228 first acquires route information. This route information is included in the information acquired by the processing of S1102 described above. That is, for example, when the data name 301 of the collected data table 231 includes data that matches the data name of the data included in the data response execution instruction, the execution instruction determination unit 228 corresponds to the corresponding data name 301. The route information 311 to be referred to is referred to. For example, when the data name 601 of the history management information table 234 includes a data name that matches the data name of the data included in the data response execution instruction, the execution instruction determination unit 228 sets the corresponding data name 601 to the corresponding data name 601. The corresponding route information 611 is referred to. For example, when the data name 501 of the local network information table 233 includes a data name that matches the data name of the data included in the data response execution instruction, the execution instruction determination unit 228 sets the corresponding data name 501. Refer to the corresponding property 502. In addition, for example, the path information acquired from the property 502 included in the response to the data source query including the data name of the requested data from the other data management server 111 is referred to. The execution instruction determination unit 228 counts the number of gateways, routers, etc. between each of the data management servers 111 and each of the data source devices 161 of the requested data, and selects the one that minimizes this number To do. When selecting the data management server 111 from the network load of each communication network 151, the server load of each data management server 111, etc., the execution instruction determination unit 228 acquires at least one of the network load and the server load, for example. To do. Each of the network load and the server load is, for example, a traffic amount or a resource usage rate. The technology for acquiring these is the same as that of the prior art, and it may be extracted from the response to the inquiry or broadcast information, or may be acquired by another device (not shown). The execution instruction determination unit 228 selects the data management server 111 having the smallest network load and server load from the acquired network load and server load.

  At this time, the execution instruction determination unit 228 determines whether the same data as the requested data is currently being collected / stored / transmitted. Therefore, the execution instruction determination unit 228 refers to the data name 301 of each row of the collected data table 231 and determines whether there is the same data name included in the data response execution instruction received in S1101. As a result of this determination, if there is the same data, the execution instruction determination unit 228 stores the data name of the data in a predetermined area of the memory 202. This data name is the data name of the data to be collected / stored / transmitted instead of the data management server 111 selected in S1104.

  On the other hand, if the result of the determination in S1103 is “responsiveness priority”, the execution instruction determining unit 228 selects the data management server 111 that has the best response to the user terminal 121 that transmitted the data request. (S1105). Here, the technique for selecting the best response is not particularly limited. For example, the response information is obtained from the path information between each of the data management servers 111 and the user terminal 121 that has transmitted the data request. You may select the one that gives the best performance. In addition, for example, for example, the network environment information for each user terminal 121 may be selected in advance so that the responsiveness is the best. In addition, for example, the performance information of each data management server 111 may be selected to have the best responsiveness. When selecting from the route information, the execution instruction determination unit 228 first acquires the route information. The route information includes, for example, a predetermined command (for example, “telnet”) including each address of the data management server 111 and identification information (address, etc.) of the user terminal 121 that has transmitted the data request included in the data response execution instruction. It is obtained by issuing "traceroute" etc.). The execution instruction determination unit 228 counts the number of gateways, routers, and the like on the route included in the route information, and selects the one having the smallest number. For example, when selecting from network environment information, the execution instruction determination unit 228 refers to network environment information and network configuration information (both not shown) stored in advance in the secondary storage device 203 or the like. The network environment information includes information indicating whether the user terminal 121 is wired connection, wireless connection, or always connection in association with each piece of identification information of the user terminal 121. The network configuration information includes location information for each data management server 111, location information for each user terminal 121, location information for each access point such as the user terminal 121, and the like. The execution instruction determination unit 228 refers to the network environment information, and from the identification information of the user terminal 121 included in the data response execution instruction, whether the user terminal 121 used by the user is a wired connection or a wireless connection, or is always connected It is determined whether or not. As a result of this determination, if the user terminal 121 used by the user is wirelessly connected or not always connected, the execution instruction determining unit 228 refers to the network configuration information and searches for position information of the user terminal 121. . The execution instruction determination unit 228 refers to the location information of each access point in the network configuration information and searches for the access point closest to the searched user terminal 121. Next, the execution instruction determination unit 228 refers to the location information of each data management server 111 in the network configuration information, and selects the one closest to the searched access point. For example, when selecting from the performance information of each data management server 111, the execution instruction determination unit 228 stores the performance information in advance in the secondary storage device 203 or the like. This performance information includes, for each data management server 111, the number of data currently collected / stored and transmitted, the capacity of a storage area for storing data collected / stored at present and the past, and data currently collected / stored. Including the number of users who are sending. The execution instruction determination unit 228 refers to the performance information, the number of data currently collected / accumulated and transmitted, the capacity of the storage area for storing data collected / accumulated in the past and the past, and the current collection / accumulation The data management server 111 having the highest data response performance is selected from one or a combination of the number of users transmitting data.

  At this time, the execution instruction determination unit 228 determines whether data is currently being transmitted to the same user terminal 121 as the user terminal 121 that transmits the requested data. Therefore, the execution instruction determination unit 228 refers to the identification information 412 of each row of the user management information table 232 and determines whether there is the same identification information included in the data response execution instruction received in S1101. . If there is the same result as a result of the determination, the execution instruction determination unit 228 stores the identification information or the like in a predetermined area or the like of the memory 202. The user terminal 121 having this identification information is a destination that causes the data management server 111 selected in S1104 to transmit data or the like instead of itself.

  Specifically, for example, in the operation example shown in FIGS. 7 and 8, as described above, the execution instruction of the data management server 111-d that has received the data response execution instruction from the data management server 111-b1. It is assumed that the determination unit 228 has selected the data management server 111-c in the process of S1105 described above. In this case, the data names 301 of each row of the collected data table 231 illustrated in FIG. 3 include the same data names “dataA” and “dataB” as the data names included in the received data response execution instruction. Therefore, the execution instruction determination unit 228 stores “dataA”, “dataB”, and the like in a predetermined area of the memory 202. In addition, the execution instruction determination unit 228 refers to the request data 402 in each row of the user management information table 232 illustrated in FIG. 4 as an example, and identifies corresponding to those including “dataA” and “dataB”. Information 412 “ID_c1” and “ID_c2” are read and stored in a predetermined area of the memory 202.

  Next, the execution instruction determination unit 228 determines whether or not the data management server 111 selected in the process of S1104 or S1105 described above is itself (S1106).

  As a result of the determination in S1106, when the selected data management server 111 is itself, the execution instruction determination unit 228 updates the collection data table 231, the user management information table 232, and the like (S1107). Therefore, for example, the execution instruction determination unit 228 first determines whether or not the requested data has already been collected, stored, and transmitted, and the device 161 that is the data source of the requested data is the same communication network as itself. 151 is determined whether it is connected. Therefore, for example, the execution instruction determination unit 228 refers to the data name 301 of each row of the collected data table 231 and determines whether there is a data name that matches the data name included in the data response execution instruction. For example, the execution instruction determination unit 228 refers to the data name 601 of each row of the history management information table 234 and determines whether there is a data name included in the data response execution instruction. For example, the execution instruction determination unit 228 refers to the data name 501 in each row of the own network information table 233 and determines whether there is a data name that matches the data name included in the data response execution instruction.

  As a result of these determinations, if the collected data table 231 includes corresponding data, the execution instruction determining unit 228 causes each data that matches each of the data names included in the data response execution instruction in the collected data table 231. The collection period 304 and the number of users 305 corresponding to the name 301 are updated. Here, the execution instruction determination unit 228 sets the value of the filtering condition “cycle” included in the data response execution instruction and the collection period 304 corresponding to the data name 301 that matches each of the data names included in the data response execution instruction. If the values are different, the greatest common divisor of those periods is set as a new collection period 304. Further, the execution instruction determination unit 228 updates the value of the number of users 305 corresponding to the data name 301 that matches each of the data names included in the data response execution instruction in the collected data table 231. In addition, the data user management unit 223 adds a new line to the user management information table 232, and adds the user name 401, request data 402, filtering condition 403, validity period 404, path information 411, identification information of the added line. As 412 and the like, the user name of the user included in the data response execution instruction, the filtering condition, the remaining time for transmitting data, the route information from itself to the user terminal 121, the identification information of the user terminal 121, and the like are stored. Here, the route information from itself to the user terminal 121 is acquired by issuing a predetermined command including its own address and identification information of the user terminal 121 that is a data transmission destination, for example, as described above. May be.

  Further, for example, when the above-described determination result indicates that the data corresponding to the collection data table 231 is not included and the data corresponding to the history management information table 234 is included, the execution instruction determination unit 228 From the management information table 234, the data name 601 that matches the data name included in the data response execution instruction, the data source information 602 corresponding to the data name 601 and the like are read, and the new row added to the collected data table 231 is read. Data name 301, data source information 306, etc. are stored. Further, the execution instruction determination unit 228 stores the value of the filtering condition “cycle” and the number of users “1” included in the data response execution instruction in the collection cycle 304 and the number of users 305 corresponding to the data name 301. To do. Further, the data user management unit 223 adds a new line to the user management information table 232, and the user name 401, the request data 402, the filtering condition 403, the validity period 404, the path information 411, and the identification information of the added line. As 412 and the like, the user name included in the data response execution instruction, the filtering condition, the remaining time for transmitting data, the route information from itself to the user terminal 121, the identification information of the user terminal 121, and the like are stored. Here, the route information from itself to the user terminal 121 is acquired by issuing a predetermined command including its own address and identification information of the user terminal 121 that is a data transmission destination, for example, as described above. May be.

  In addition, for example, as a result of the above-described determination, when data corresponding to both the collection data table 231 and the history management information table 234 is not included, and data corresponding to the own network information table 233 is included, The execution instruction determination unit 228 includes, as the data name 301, the collection cycle 304, and the number of users 305 of the new row added to the collection data table 231, the data name included in the data response execution instruction, the value of the filtering condition “cycle”, The number of users “1” and the like are stored. As described above, the data source information 306 of the collected data table 231 includes path information 311 and properties 312. In order to acquire the path information 311, the execution instruction determination unit 228 may acquire the path information 311 by issuing a predetermined command including its own address and the address of the device 161 serving as a data source, as described above. In addition, in order to obtain the property 311, the execution instruction determination unit 228 displays a property 502 corresponding to the data name 501 of each row of the own network information table 233 that matches the data name included in the data response execution instruction. read out. The execution instruction determination unit 228 stores the path information and properties acquired in this way as data source information 306 corresponding to the data name 301 added in the above processing. Further, the data user management unit 223 adds a new line to the user management information table 232, and the user name 401, the request data 402, the filtering condition 403, the validity period 404, the path information 411, and the identification information of the added line. As 412 and the like, user identification information, filtering conditions, remaining time for transmitting data, route information from itself to the user terminal 121, identification information of the user terminal 121, and the like are stored. Here, the route information from itself to the user terminal 121 is acquired by issuing a predetermined command including its own address and identification information of the user terminal 121 that is a data transmission destination, for example, as described above. May be.

  In the above-described processing, when the data response execution instruction includes the last transmission date and time for each user, the execution instruction determination unit 228 sets each final transmission date and time for the final transmission corresponding to the user name 401 of each user. Stored in each date and time 406. When the data transmission execution instruction does not include the final transmission date and time, the execution instruction determination unit 228 may set the value of the final transmission date and time 406 corresponding to the user name 401 to “NULL”.

  Specifically, for example, in the case of the operation example shown in FIGS. 7 and 8, as described above, the data management server 111-c sends the user name “user c1” and the identification to the data management server 111-d. Data response execution instruction including information “ID_c1”, data name “dataA, dataB” for each requested data, filtering condition “cycle = 20”, remaining time “06:00:00” for transmitting data, etc. Sending. As described above, at this time, no data management server 111 collects, stores, or transmits data. Therefore, the execution instruction determination unit 228 of the data management server 111-d stores “dataA”, “20”, and “1” as the data name 301, the collection cycle 304, the number of users 305, and the like of the collection data table 231. . Further, the execution instruction determination unit 228 acquires the route information “AAAAA” from itself to the device 161-d1 by the above-described operation example, and as the route information 311 corresponding to the data name 301 “dataA” of the collected data table 231. Store. Further, the execution instruction determination unit 228 reads the property 502 corresponding to the data name 501 “dataA” from the own network information table 233 illustrated in FIG. 5 as an example, and corresponds to the data name 301 “dataA” of the collected data table 231. Store as property 312. Furthermore, the data user management unit 223 adds a new line to the user management information table 232, and includes the user name 401, request data 402, filtering condition 403, validity period 404, identification information 412 and the like of the added line. “User c1”, “cycle = 20”, “06:00:00”, “ID_c1”, and the like are stored. Further, the execution instruction determination unit 228 acquires the route information “ccc1” from the user terminal 121-c1 to the user name 401 “user c1” in the user management information table 232 by the above-described operation example. Stored as route information 411. The execution instruction determination unit 228 performs the same process on “dataB”.

  Here, in the case of the operation example shown in FIGS. 7 and 8, as described above, the data management server 111-c receives its own data request from the user terminal 121-c1, and the collected data table 231 thereof. After the necessary information is stored in the user management information table 232 and the like, the user name “user c2”, the identification information “ID_c2”, and the data name “dataA, dataC” for each requested data are received from the user terminal 121-c2. ”, The filtering condition“ cycle = 30, Line = X ”, the data request including the remaining time“ 03:30:00 ”to transmit the data, etc., and the data management server 111-d performs the process of S1107 An example in the case of selecting will be described. In this case, as described above, the collection data table 231 stores the data name 301 “dataA”, the collection cycle 304 “20”, the number of users 305 “1”, the data source information 306, and the like. In this case, the execution instruction determination unit 228 includes the value of the collection period 304 “20” corresponding to the data name 301 “dataA” in the collection data table 231 and the filtering condition of “dataA” requested from the user terminal 121-c2. Get the greatest common divisor "10" with "cycle = 30". The execution instruction determination unit 228 replaces the value of the collection period 304 corresponding to the data name 301 “dataA” in the collection data table 231 with the acquired greatest common divisor “10”, and further corresponds to the data name 301 “dataA”. The value of the number of users 305 to be replaced is replaced with a value “2” obtained by adding the number of users to be newly transmitted.

  On the other hand, as a result of the determination in S1106, if the selected data management server 111 is not itself, the execution instruction determination unit 228 issues a data response execution instruction to the selected data management server 111 (S1108). This data response execution instruction includes at least the same information as the data response execution instruction received in S1101. Furthermore, when a data name is stored in a predetermined area of the memory 202 in the above-described processing of S1104, information for collecting, storing, and transmitting data of this data name is further included. For this information, the execution instruction determination unit 228 searches the request data 402 in each row of the user management information table 232 for data that matches the data name included in the predetermined area of the memory 202. It is obtained by reading out the corresponding request data 402, the user name 401, the filtering condition 403, the valid period 404, the user terminal information 405, the last transmission date and time 406, etc. corresponding to the request data 402. Further, when the identification information of the user terminal 121 is stored in a predetermined area of the memory 202 in the processing of S1105 described above, information for transmitting the collected / accumulated data to the user terminal 121 of the user of this identification information is included. Further included. For this information, the execution instruction determination unit 228 searches the identification information 412 of each row of the user management information table 232 for information that includes the identification information included in the predetermined area of the memory 202, The user name 401, request data 402, filtering condition 403, validity period 404, user terminal information 405, last transmission date and time 406, etc. corresponding to the identification information 412 are obtained by reading. When these pieces of information are further added to the data response execution instruction and transmitted, the data user management unit 223 and the execution instruction determination unit 228 update the collected data table 231 and the user management information table 232, respectively. For this purpose, for example, the data user management unit 223 includes the user name 401, request data 402, filtering condition 403, and valid period 404 included in the data response execution instruction in the above-described processing among the rows of the user management information table 232. , User terminal information 405 (route information 411, identification information 412), last transmission date 406, and the like are deleted. Furthermore, the execution instruction determination unit 228 refers to the data name 301 of each row of the collected data table 231 and searches for the data name included in the request data 402 deleted from the user management information table 232 in the above-described processing. The execution instruction determination unit 228 subtracts the value of the number of users 305 corresponding to the corresponding data name 301 by the number transmitted to the deleted user, and overwrites it as a new value. When the number of users 305 becomes “zero” as a result of this update, the execution instruction determination unit 228 displays the latest date and time among the data name 301, data source information 306, and time stamp 303 corresponding to the number of users 305. Are stored as the data name 601, the data source 602, and the last collection date and time 603 of the newly added row in the history management information table 234. Further, the execution instruction determination unit 228 deletes the data name 301, the data value 302, the time stamp 303, the collection cycle 304, the number of users 305, the data source information 306, and the like corresponding to the number of users 305.

  Specifically, for example, in the case of the operation example illustrated in FIGS. 7 and 8, as described above, the data management server 111-b that has received the data request from the user terminal 121-b 1 -d includes user name “user b1”, identification information “ID_b1”, data name “dataA, dataB, dataC” for each requested data, filtering condition “cycle = 10”, remaining time “ A data response execution instruction including “18:00:00” is issued. In this case, the execution instruction determination unit 228 of the data management server 111-d selects the data management server 111-c in the process of S1105 as described above. As described above, the execution instruction determination unit 228 of the data management server 111-d stores the identification information “ID_c1”, “ID_c2”, and the like of the user terminal 121 in a predetermined area or the like of the memory 202 in the process of S1105. Yes. Accordingly, the execution instruction determination unit 228 determines that the user name 401 “user c1”, request data 402 “dataA, dataB”, filtering condition 403 “cycle = 20”, and valid from the user management information table 232 shown in FIG. Period 404 “05:00:30”, route information 411 “ccc1”, identification information 412 “ID_c1”, last transmission date and time 406 “2006.12.11 13:00:20”, and user name 401 “user c2”, request Data 402 “dataA, dataC”, filtering condition 403 “cycle = 30, Line = X”, validity period 404 “02:30:00”, route information 411 “ccc2”, identification information 412 “ID_c2”, last transmission date 406 “2006.12.11 13:00:00” or the like is read, and further included in the data response execution instruction and transmitted to the data management server 111-c. Furthermore, the data user management unit 223 obtains information associated with the user name 401 “user c1” and information associated with the user name 401 “user c2” from the user management information table 232. delete. The execution instruction determination unit 228 subtracts the number “2” of deleted users from the number of users 305 “2” corresponding to the data name 301 “dataA” in the collected data table 231 illustrated in FIG. This subtracted value is “zero”. Therefore, the execution instruction determination unit 228 newly adds the newest data name “dataA”, data source information 306 corresponding to the data name 301 “dataA”, and time stamp 303 to the history management information table 234. The data is stored as the data name 601 of the added row, the data source information 602, the last collection date and time 603, and the information associated with the data name 301 “dataA” in the collection data table 231 is deleted. Similarly, the execution instruction determination unit 228 uses the latest data source information 306 and time stamp 303 corresponding to each of the data names 301 “dataB” and “dataC” in the collected data table 231 as the history. Stored as data name 601, data source information 602, last collection date and time 603 of each newly added row in the management information table 234, and associated with each of the data names 301 “dataB” and “dataC” in the collection data table 231 Delete the stored information.

  The data management server 111 that has received the data response execution instruction transmitted in the process of S1108 performs the above-described operation described with reference to FIG.

  Next, an operation example in which the data management server 111 collects and accumulates data from each device 161 will be described with reference to FIG. The operation example shown in FIG. 12 is activated every predetermined time, for example.

  In FIG. 12, the data management unit 224 refers to the collected data table 231 (S1201). Next, the data management unit 224 selects one piece of data from the collected data table 231 in descending order or the like (S1202). Next, the data management unit 224 determines whether or not the selected data collection condition is satisfied (S1203). For this purpose, the data management unit 224 refers to the collected data table 231 and selects the latest one of the time stamps 303 corresponding to the data name 301 of the data selected in S1202 and the data name of the data selected in S1202. Reference is made to the collection period 304 corresponding to 301. Next, the data management unit 224 determines whether the collection period has elapsed since the previous data collection / accumulation based on the date and time of the read time stamp 303 and the read collection period 304. Therefore, the data management unit 224 determines whether or not the current collection date / time has passed the read collection cycle 304 from the date / time of the read time stamp 303. As a result of this determination, when the time has elapsed, the data management unit 224 determines that the selected data collection condition is satisfied.

  As a result of the determination in S1203, if the collection condition of the selected data is satisfied, the data management unit 224 acquires the selected data (S1204) and stores the acquired data (S1205). For this purpose, for example, the data management unit 224 identifies the device 161 with reference to the data source information 306 corresponding to the data name 301 of the data selected in S1202 described above, and acquires data from the identified device 161. Although this acquisition technique is not particularly limited, for example, the data management unit 224 acquires the address of the device 161 from the path information 311 included in the referenced data source information 306, and sends the data to the acquired address or the like. A command or the like for requesting transmission of the above may be transmitted. Further, for example, each of the devices 161 serving as the data source broadcasts and transmits the data name, data value, and the like acquired by itself within the network. The data management server 111 may acquire data by selectively receiving the acquisition target of the data names and data values broadcasted by the devices 161. The data management unit 224 adds the acquired data to the data value 302 corresponding to the data name 301 of the data selected in S1202 described above, and further adds the current date and time to the time stamp 303 corresponding to the same data name 301 To do.

  As a result of the determination in S1203, if the collection condition of the selected data is not satisfied, or after the processing in S1205 described above, the data management unit 224 has selected all the data in the collection data table 231. Determination is made (S1206).

  If all the data has not been selected as a result of the determination in S1206, the data management unit 224 performs the above-described processing after S1202 again, and selects unselected data.

  If all the data has been selected as a result of the determination in S1206, the data management unit 224 ends the process.

  Next, an operation example in which the data management server 111 transmits data collected / stored from each device 161 to each user terminal 121 will be described with reference to FIG. The operation example shown in FIG. 13 is activated every predetermined time, for example.

  In FIG. 13, the data providing unit 221 refers to the user management information table 232 (S1301). Next, the data providing unit 221 selects one user from the user management information table 232 in descending order or the like (S1302). Next, the data providing unit 221 determines whether the data transmission condition of the selected user is satisfied (S1303). Therefore, for example, the data providing unit 221 refers to the filtering condition 403 and the last transmission date and time 406 corresponding to the user name 401 of the user selected in the above-described processing of S1302 in the user management information table 232. The data providing unit 221 determines whether the referenced filtering condition 403 includes a transmission date and time condition and at least one of the last transmission date and time 406 and the current date and time satisfies the filtering condition 403. .

  If the data transmission condition of the selected user is satisfied as a result of the determination in S1303, the data providing unit 221 reads data to be transmitted to the user (S1304), and the read data is transmitted to the user terminal of the user. It transmits to 121 (S1305). For this purpose, the data providing unit 221 reads, for example, the request data 402 and user terminal information 405 corresponding to the user name 401 of the user selected in the above-described processing of S1302. Next, the data providing unit 221 reads from the collected data table 231 the data value 302 corresponding to the data name 301 that matches each data name of the read request data 402. At this time, when the filtering condition 403 of the user includes a data condition (for example, “Line = X” or the like), the data providing unit 221 reads only the data value 302 that matches the condition. The data providing unit 221 transmits the read data value 302 to the identification information included in the route information 411 of the read user terminal information 405. Further, the data providing unit 221 updates the last transmission date and time 406 corresponding to the user name 401 of the user selected in the above-described processing of S1302 in the user management information table 232 to the current date and time.

  As a result of the determination in S1303, when the data transmission condition of the selected user is not satisfied, or after the processing in S1305 described above, the data providing unit 221 has selected all of the data in the user management information table 232 It is determined whether or not (S1306).

  As a result of the determination in S1306, if all the data has not been selected, the data providing unit 221 performs the above-described processing after S1302 again, and selects unselected data.

  If all the data has been selected as a result of the determination in S1306, the data providing unit 221 ends the process.

  Next, an operation example in which each data management server 111 updates the user management information table 232 will be described with reference to FIG. This operation example is activated at predetermined time intervals, for example.

  In FIG. 14, the data user management unit 223 of the data management server 111 updates the expiration date of data transmission for each user in the user management information table 232 (S1401). Specifically, for example, when the operation example illustrated in FIG. 14 is activated every time “t”, the data user management unit 223 determines the value of the valid period 404 in each row of the user management information table 232. The value obtained by subtracting “t” is set as the value of the new effective period 404. Next, the data user management unit 223 determines whether there is a data transmission expiration date in the user management information table 232 (S1402). Therefore, for example, the data user management unit 223 determines whether or not the valid period 404 of each row of the user management information table 232 includes a value equal to or less than a predetermined value such as “zero”.

  If the result of determination in S1402 is that there is no expired expiration date, the data user management unit 223 ends the process.

  As a result of the determination in S1402, when there is an expired one, the data user management unit 223 deletes the information from the user management information table 232 (S1403). Further, the data user management unit 223 updates the collected data table 231 (S1404). For this purpose, for example, first, the data user management unit 223 reads the data name included in the request data 402 associated with the valid period 404 equal to or less than a predetermined value. Next, the data user management unit 223 selects the data name 301 in each row of the collected data table 231 that matches the data name included in the read request data 402, and corresponds to the selected data name 301. The number of users 305 is replaced with a value obtained by subtracting “1”. Further, the data user management unit 223 deletes information associated with the valid period 404 equal to or less than a predetermined value in the user management information table 232. The data management unit 224 performs this process for each valid period 404 equal to or less than a predetermined value.

  The data user management unit 223 determines whether or not the collection data table 231 updated in the processing of S1404 has a data transmission user count of “zero” (S1405). For this purpose, the data user management unit 223 refers to the number of users 305 in each row of the collected data table 231 and determines whether there is a value of “zero”.

  As a result of the determination in S1405, if there is a user whose number of data transmissions is “zero”, the data management unit 224 deletes the data in the collected data table 231 (S1408). For this purpose, the data management unit 224 displays the data name 301 and data source information 306 corresponding to the number of users 305 “zero” in the collected data table 231, the data name 601 and data source information 602 in the history management information table 234, and the like. Store as. Further, the data management unit 224 stores the latest time stamp 303 corresponding to the data name 301 or the like as the last collection date and time 603 of the history management information table 234. The data management unit 224 deletes information corresponding to the number of users 305 “zero” in the collected data table 231.

  As described above, the collected data table 231 is updated, and information regarding the data to be collected is deleted. Therefore, the data management unit 224 stops collecting / accumulating data thereafter because there is no information in the collected data table 231.

  Next, a specific example to which the system of the above-described embodiment is applied will be described.

  First, an example in the case of applying the system of this embodiment to an information control system in the manufacturing industry will be described with reference to FIG.

  In FIG. 15, the information control system includes a base 1501, a factory 1502, and the like interconnected via a wide area network 1503. The factory 1502 produces products through a plurality of production processes. Here, it is assumed that the factory 1502 produces products from “Process A” for processing materials, parts, and intermediate products, and “Process B” for inspecting products.

  In the base 1501, each of the data management server 111g, the user terminal 121g, and the gateway server 141g is connected via a communication network 151g. The communication network 151g is connected to the wide area network 1503 via the gateway server 141g.

  In the factory 1502, a communication network 151h, a communication network 151i, and a communication network 151j are installed. The communication network 151h is connected to the wide area network 1503. Each of the communication network 151i and the communication network 151j is connected to the wide area network 1503 via the communication network 151h.

  A data management server 111h, a user terminal 121h, and a gateway server 141h are connected to the communication network 151h. The communication network 151h is connected to the wide area network 1503 via the gateway server 141h. A data management server 111i, a gateway server 141i, and a control device 161i are connected to the communication network 151i. The control device 161 i acquires information related to the process “process A”. A facility / equipment 1501i is connected to the control device 161i. The equipment / equipment 1501i is used for processing in “Process A”. Here, the control device 161i controls the facility / equipment 1501i. Furthermore, the control apparatus 161i shall transmit the operation results, control results, etc. of the installation / equipment 1501i. The communication network 151i is connected to the communication network 151h via the gateway server 141i. A data management server 111j, a gateway server 141j, and a control device 161j are connected to the communication network 151j. The control device 161j acquires information related to the process “process B”. A facility / equipment 1501j is connected to the control device 161j. The facility / equipment 1501j is used for inspection in “Process B”. Here, it is assumed that the control device 161j transmits the operation results, quality inspection results, measurement values, and the like of the facility / device 1501j. The communication network 151j is connected to the communication network 151h via the gateway server 141j.

  In the system illustrated in FIG. 15, for example, the user g uses the user terminal 121 g at the base 1501 as the asset management job, and uses the data name “which is the operation result of the facility / equipment 1501 i used in“ process A ”. It is assumed that each data value of the data name “dataF” which is the operation result of the facility / equipment 1501j used in “dataE” and “process B” is acquired. This task is a routine task of user g. In addition, the user h uses the data name “dataE” and the equipment / equipment 1501j used in the “B process”, which are the operation results of the equipment / equipment 1501i used in the “A process”, as a product tracking operation for maintaining quality. Each data value of the data name “dataG” which is the quality inspection result is acquired. This task is not a routine task of user h, but is performed only when necessary.

  The user terminal 121g includes a data name “dataE” indicating the operation result of the facility / equipment 1501i used in “process A” and a data name “dataF” indicating the operation result of the facility / equipment 1501j used in “process B”. A data request is transmitted to the data management server 111g. The data management server 111g performs the above-described operation. As a result, one of the data management server 111g, the data management server 111h, the data management server 111i, and the data management server 111j has the facility / equipment 1501i used in the “process A” from each of the control device 161i and the control device 161j. The data value of the operation record and the data value of the operation record of the facility / equipment 1501j used in “Process B” are acquired and transmitted to the user terminal 121g.

  The user terminal 121h receives the data name “dataE” indicating the operation result of the facility / equipment 1501i used in “process A” and the data name “dataG” indicating the quality inspection result of the facility / equipment 1501j used in “process B”. The data request containing is transmitted to the data management server 111h. The data management server 111h performs the above-described operation. As a result, one of the data management server 111h, the data management server 111h, the data management server 111i, and the data management server 111j has the facilities / equipment 1501i used in the “process A” from each of the control device 161i and the control device 161j. The data value of the operation result and the data value of the quality inspection result of the facility / equipment 1501j used in “Process B” are acquired and transmitted to the user terminal 121h.

  As described above, in the system according to the present embodiment, it is possible to simultaneously realize data acquisition for routine work and data acquisition for non-standard work in the same environment.

  Next, an example in which the system of this embodiment is applied to an on-vehicle communication system that performs wireless communication between a traveling train and a wireless station installed along a track will be described with reference to FIG. To do. This system collects and stores data requested by train passengers and provides that information as a service.

  In FIG. 16, the system includes a base 1601, a base 1602, a relay station 1603, a relay station 1604, a plurality of radio base stations 1611, a train 1605, a communication network 1606, and the like.

  Each of the radio base station 1611-1, the radio base station 1611-2, the radio base station 1611-3, and the radio base station 1611-4 is installed at regular intervals along the track on which the train 1605 runs. Radio base station 1611-1, radio base station 1611-2, radio base station 1611-3, and radio base station 1611-4 are connected to relay station 1603 and relay station 1604, respectively.

  The train 1605 is equipped with a device 161-o, a wireless communication device 1621, and the like. In addition, the user 1 having the user terminal 121-o gets on the train 1605. For example, the device 161-o acquires the speed of the train 1605 and the like. The user terminal 121-o and the device 161-o are connected to the wireless communication device 1621. The wireless communication device 1621 is connected to a wireless base station 1611 in a communicable area.

  The base 1601 includes a data management server 111-k1, a user terminal 121-k, an application server 131-k, a gateway server 141-k, a communication network 151-k, and the like. The data management server 111-k1, user terminal 121-k, application server 131-k, gateway server 141-k, etc. are connected to the communication network 151-k. The gateway server 141-k is connected to the communication network 1606. The base 1602 includes a data management server 111-l, a user terminal 121-l, a gateway server 141-l, a communication network 151-l, and the like. The data management server 111-l, user terminal 121-l, gateway server 141-l, etc. are connected to the communication network 151-l. The gateway server 141-1 is connected to the communication network 1606.

  Each of the data management server 111-k1, the data management server 111-k2, and the data management server 111-l accumulates data acquired from the equipment 161-o of the train 1605.

  The relay station 1603 includes a data management server 111m, a gateway server 141m, a communication network 151m, and the like. The data management server 111m, the gateway server 141m, and the like are connected to each other. The gateway server 141m is connected to the communication network 1606. The relay station 1604 includes a data management server 111n, a gateway server 141n, a communication network 151n, and the like. The data management server 111n, the gateway server 141n, etc. are connected to each other. The gateway server 141n is connected to the communication network 1606.

  Each of the data management server 111m and the data management server 111n accumulates data acquired from the equipment 161-o of the train 1605.

  Note that each of the relay station 1603 and the relay station 1604 is installed along a track on which the train 1605 travels.

  The user instructs the user terminal 121 to transmit a data request. For example, each of the user k and the user l requests data acquired by the device 161-o from the user terminal 121-k and the user terminal 121-l. Each of the user terminal 121-k and the user terminal 121-l transmits a data request including the data name of the requested data to each of the data management server 111-k and the data management server 111-l. For example, the user o instructs the user terminal 121-o to transmit a data request. The user terminal 121-o transmits a data request including the data name of the requested data to the wireless communication device 1621. The wireless communication device 1621 communicates with the wireless base station 1611-1, the wireless base station 1611-2, the wireless base station 1611-3, the wireless base station 1611-4, etc. that are within the communication range, and this data request Is transmitted to one of the data management server 111-m and the data management server 111-n. That is, when the wireless communication device 1621 communicates with the wireless base station 1611-1 or the wireless base station 1611-2, it transmits a data request to the data management server 111-m. Further, when the wireless communication device 1621 communicates with the wireless base station 1611-3 or the wireless base station 1611-4, the wireless communication device 1621 transmits a data request to the data management server 111-n.

  Each of the data management servers 111 performs the above-described processing for the received data request. Since this process is the same as described above, a description thereof will be omitted.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and design changes and the like within a scope not departing from the gist of the present invention are included. .

  For example, in the above-described embodiment, one data management server is connected to each communication network. However, the present invention is not limited to this. The number of data management servers connected to each communication network is arbitrary.

For example, in the above-described embodiment, the data request is received by the data management server connected to the same communication network. However, the present invention is not limited to this. The data management server that receives the data request is arbitrary.
In this data request, a plurality of data may be requested by one data request. Different collection conditions, filtering conditions, etc. may be set for each data. In that case, the data request includes filtering conditions, the remaining time for transmitting data, and the like. The data management server may perform the above processing for each different filtering condition.

  Further, for example, the data response execution instruction may further include transfer count information. Each time the data management server 111 transfers a data response execution instruction in the process of S1108, it adds “1” to this transfer count information and transmits it. The transfer count information of the received data response execution instruction is predetermined. If the number is greater than or equal to the number, the processing of S1107 and the like may be performed on the assumption that the processing itself of data collection / accumulation and transmission is performed without performing the processing of S1103 to S1106.

1 is a diagram illustrating a system configuration example according to an embodiment of the present invention. In the same embodiment, it is a figure which shows the structural example of a data management server. In the same embodiment, it is a figure which shows an example of a collection data table. In the embodiment, it is a figure which shows an example of a user management information table. In the same embodiment, it is a figure which shows an example of an own network information table. 5 is a diagram illustrating an example of a history information management table in the embodiment. FIG. In the same embodiment, it is a figure explaining an outline. In the embodiment, it is a figure explaining an example of a sequence. 5 is a diagram illustrating an operation example of a data management server in the embodiment. FIG. 5 is a diagram illustrating an operation example of a data management server in the embodiment. FIG. 5 is a diagram illustrating an operation example of a data management server in the embodiment. FIG. 5 is a diagram illustrating an operation example of a data management server in the embodiment. FIG. 5 is a diagram illustrating an operation example of a data management server in the embodiment. FIG. 5 is a diagram illustrating an operation example of a data management server in the embodiment. FIG. It is a figure explaining the specific example to which the system of the embodiment is applied. It is a figure explaining the specific example to which the system of the embodiment is applied.

Explanation of symbols

  111: Data management server 121: User terminal 131: Application server 141: Gateway server 151: Communication network 201: Computing device 202: Memory 203: Secondary storage device 204: Input device 205: Output Device: 206: Communication device 211: Middleware 221: Data providing unit 222: Accepting unit 223: Data user managing unit 224: Data managing unit 225: Communication control unit 226: Data request receiving unit 227 : Response processing unit, 228: Execution instruction determination unit, 231: Collection data table, 232: User management information table, 233: Local network information table, 234: History management information table, 161: Device

Claims (9)

At least one of a data management server, a data source providing data values, and a user terminal is connected to each of a plurality of communication networks connected to each other, and each of the data management servers obtains from the data source A distributed system for transmitting the obtained data value to each of the user terminals,
Each of the data management servers
A storage device that stores management information in which data identification information of a data value that has been obtained in the past and data source identification information of a data source that provides the data value are associated;
Retrieve data values from each data source, in the storage device, the data value the acquired data acquisition means for storing the collected information associating the data identification information of said data values,
Data providing means for transmitting data identification information included in the collected information and a data value corresponding to the data identification information to a user terminal;
Data request receiving means for receiving a data request including data identification information of a requested data value transmitted from a user terminal;
Inquiry means for sending inquiry information for inquiring whether or not to store the data value of the data identification information included in the data request to another data management server,
When the inquiry information from another data management server is received , whether or not the data identification information included in the inquiry information is included in the collected information , or the data included in the inquiry information in the management information A response means for determining whether or not identification information is included, and when the corresponding data is included in at least one of the collected information and the management information, a response means for transmitting a response including the determination result;
Determining means for determining whether the collected information includes data identification information included in the data request; and determining whether the management information includes data identification information included in the data request ;
Selecting means for selecting a data management server to transmit a data value in response to a data request;
When receiving a data request from the user terminal, the selection means,
If the determination result included in the response transmitted from another data management server and the determination result by the determination means notify that the data identification information corresponding to the collection information is included, the determination Select one of the data management servers that got the results,
There is no notification that the determination result included in the response transmitted from another data management server and the determination result by the determination means include the data identification information corresponding to the collected information, and the management One of the data management servers that has obtained the determination result for notifying that the data identification information corresponding to the management information is included when there is something that notifies that the data identification information corresponding to the information is included select,
When the selected data management server is itself, the data acquisition means extracts data source identification information associated with the data identification information included in the data request from the management information, and the extracted data A data value is acquired from the data source of the source identification information, the acquired data value is stored as collection information in association with the data identification information included in the data request, and the data providing means is , Extracting the data value corresponding to the data identification information included in the data request, and transmitting to the user terminal that transmitted the data request,
When the selected data management server is another data management server, the data providing means transmits the data identification information included in the received data request and the data request to the selected other data management server. A data response execution instruction including the terminal identification information of the user terminal
The data acquisition means of the data management server that has received the data response execution instruction extracts data source identification information associated with the data identification information included in the data response execution instruction from the management information of itself. A data value is acquired from the data source of the extracted data source identification information, the acquired data value is stored in association with the data identification information of the data value as own collection information, and the data response execution instruction is received The data providing means of the data management server extracts the data value associated with the data identification information included in the data response execution instruction from the collected information of itself, and the terminal included in the data response execution instruction A distributed system characterized by transmitting identification information to user terminals. The distributed system of claim 1 ,
Each of the data management servers
The storage device further includes network information in which data identification information of a data value acquired from a data source connected to the same communication network as the storage device is associated with data source identification information of the data source. ,
When the response means receives inquiry information from another data management server, whether or not the collected information includes the data identification information included in the inquiry information, the management information includes the inquiry information. It is determined whether or not included data identification information is included, whether or not the network information includes data identification information included in the inquiry information, and the collected information, the management information, and the network information When the data corresponding to at least one of the above is included, a response including the determination result is transmitted,
Whether the collected information includes the data identification information included in the data request; whether the management information includes the data identification information included in the data request; Determining whether the information includes the data identification information included in the data request;
In the determination result included in the response transmitted from the other data management server and the determination result by the determination unit, the selection unit does not include data corresponding to the collection information and the management information. And, if there is data that includes the data corresponding to the network information, select one of the data management servers that obtained the determination result that includes the data corresponding to the network information,
When the selected data management server is itself, the data acquisition means extracts data source identification information associated with the data identification information included in the data request from the network information, and extracts the data A data value is obtained from the data source of the data source identification information, the obtained data value is stored as collection information in association with the data identification information of the data value, and the data providing means Extracting a data value associated with the data identification information included in the data request and transmitting the data value to the user terminal that transmitted the data request;
If the selected data management server is another data management server, the data identification information included in the received data request and the terminal identification information of the user terminal that transmitted the data request to the other data management server Send data response execution instruction including
The data acquisition means of the data management server that has received the data response execution instruction extracts data source identification information associated with the data identification information included in the data response execution instruction from its network information. And acquiring the data value from the data source of the extracted data source identification information, storing the acquired data value in association with the data identification information of the data value as its own collection information, and executing the data response The data providing means of the data management server that has received the instruction extracts the data value associated with the data identification information included in the data response execution instruction from the collected information of itself, and executes the data response A distributed system, wherein terminal identification information included in an instruction is transmitted to a user terminal. The distributed system according to claim 1 or 2 ,
Each of the data management servers
The selected data management server acquires communication load information between each data management server and a data source that provides a data value of data identification information included in the data request, and the acquired communication load information From the data management servers, the one with the lightest communication load is selected, and when the selected data management server is another data management server, the received data response execution is sent to the selected data management server. A distributed system, further comprising execution determination means for transmitting a data response execution instruction including data identification information and terminal identification information included in the instruction. The distributed system according to claim 1 or 2 ,
Each of the data management servers
The selected data management server acquires responsiveness information indicating responsiveness between each of the data management servers and the user terminal that has transmitted the data request, and the data management is obtained from the acquired responsiveness information. When the server having the best responsiveness with the user terminal that has transmitted the data request is selected from each of the servers, and the selected data management server is another data management server, the selected data management server In addition, the distributed system further includes execution determination means for transmitting a data response execution instruction including data identification information and terminal identification information included in the received data response execution instruction. The distributed system according to claim 3 ,
Each of the data management servers
The storage device has user management in which terminal identification information of a user terminal that is transmitting a data value by the data providing unit thereof is associated with data identification information of a data value that is transmitted to the user terminal. Have more information,
The execution determination means of the selected data management server determines whether or not the user management information of itself includes the data identification information included in the data response execution instruction, and the corresponding data is included. A data response execution instruction further including terminal identification information associated with the data identification information is transmitted to the selected data management server, and data transmission to the user terminal is stopped. A featured distributed system. The distributed system according to claim 4 ,
Each of the data management servers
The storage device has user management in which terminal identification information of a user terminal that is transmitting a data value by the data providing unit thereof is associated with data identification information of a data value that is transmitted to the user terminal. Have more information,
When the execution determination unit of the selected data management server includes the terminal identification information included in the data response execution instruction in its user management information, the terminal identification is included in the selected data management server. A distributed system characterized by transmitting a data response execution instruction further including data identification information associated with the information and stopping its own data transmission to the user terminal. A distributed system according to any one of claims 1 to 6 ,
The data request further includes condition information that is a condition for transmitting a data value,
The distributed system characterized in that the data providing means of each of the data management servers transmits a data value to the user terminal according to the condition information included in the data request. At least one of a data management server, a data source providing a data value, and a user terminal is connected to each of a plurality of communication networks connected to each other, and the data value acquired from the data source is transmitted to each user terminal. The data management server for transmitting to
A storage device that stores management information in which data identification information of a data value that has been obtained in the past and data source identification information of a data source that provides the data value are associated;
Retrieve data values from each data source, in the storage device, the data value the acquired data acquisition means for storing the collected information in association with data identifying information of said data values,
Data providing means for transmitting data identification information included in the collected information and a data value corresponding to the data identification information to a user terminal;
Data request receiving means for receiving a data request including data identification information of a requested data value transmitted from a user terminal;
Inquiry means for sending inquiry information for inquiring whether or not to store the data value of the data identification information included in the data request to another data management server,
When the inquiry information from another data management server is received , whether or not the data identification information included in the inquiry information is included in the collected information , or the data included in the inquiry information in the management information A response means for determining whether or not identification information is included, and when the corresponding data is included in at least one of the collected information and the management information, a response means for transmitting a response including the determination result;
Determining means for determining whether the collected information includes data identification information included in the data request; and determining whether the management information includes data identification information included in the data request ;
Selecting means for selecting a data management server to transmit a data value in response to a data request;
When receiving a data request from the user terminal, the selection means,
If the determination result included in the response transmitted from another data management server and the determination result by the determination means notify that the data identification information corresponding to the collection information is included, the determination Select one of the data management servers that got the results,
There is no notification that the determination result included in the response transmitted from another data management server and the determination result by the determination means include the data identification information corresponding to the collected information, and the management One of the data management servers that has obtained the determination result for notifying that the data identification information corresponding to the management information is included when there is something that notifies that the data identification information corresponding to the information is included select,
When the selected data management server is itself, the data acquisition means extracts data source identification information associated with the data identification information included in the data request from the management information, and the extracted data A data value is acquired from the data source of the source identification information, the acquired data value is stored as collection information in association with the data identification information included in the data request, and the data providing means is , Extracting the data value corresponding to the data identification information included in the data request, and transmitting to the user terminal that transmitted the data request,
When the selected data management server is another data management server, the data providing means transmits the data identification information included in the received data request and the data request to the selected other data management server. A data response execution instruction including the terminal identification information of the user terminal
When the data response execution instruction is received, the data acquisition unit extracts data source identification information associated with the data identification information included in the data response execution instruction from the management information of the data acquisition unit, and the extraction A data value is acquired from the data source of the data source identification information, the acquired data value is stored as its collected information in association with the data identification information of the data value, and the data providing means A data value associated with the data identification information included in the data response execution instruction is extracted from the collected information and transmitted to the user terminal of the terminal identification information included in the data response execution instruction. Management server. At least one of a data management server, a data source providing data values, and a user terminal is connected to each of a plurality of communication networks connected to each other, and each of the data management servers obtains from the data source A data distribution method in a distributed system for transmitting the data value to each user terminal,
Each of the data management servers
A storage device that stores management information in which data identification information of a data value that has been obtained in the past and data source identification information of a data source that provides the data value are associated;
Data acquisition means for acquiring a data value from each of the data sources, and storing in the storage device collection information in which the acquired data value is associated with data identification information of the data value;
Data providing means for transmitting data identification information included in the collected information and a data value corresponding to the data identification information to a user terminal;
Data request receiving means for receiving a data request including data identification information of a requested data value transmitted from a user terminal;
Inquiry means for sending inquiry information for inquiring whether or not to store the data value of the data identification information included in the data request to another data management server,
When the inquiry information from another data management server is received, whether or not the data identification information included in the inquiry information is included in the collected information, or the data included in the inquiry information in the management information A response means for determining whether or not identification information is included, and when the corresponding data is included in at least one of the collected information and the management information, a response means for transmitting a response including the determination result;
Determining means for determining whether the collected information includes data identification information included in the data request; and determining whether the management information includes data identification information included in the data request;
Selecting means for selecting a data management server to transmit a data value in response to a data request;
The selection means of the data management server (hereinafter, first data management server) that has received the data request includes:
If the determination result included in the response transmitted from another data management server and the determination result by the determination means notify that the data identification information corresponding to the collection information is included, the determination The data identification information corresponding to the collection information is selected in the determination result included in the response transmitted from the other data management server, and the determination result by the determination means. If there is nothing to notify that it is included, and there is something to notify that the data identification information corresponding to the management information is included, the data identification information corresponding to the management information is included Selecting one of the data management servers that have obtained the determination result to notify
If the selected data management server is itself,
The data acquisition means of the first data management server extracts data source identification information associated with the data identification information included in the data request from the management information, and the data source identification information of the extracted data source identification information Acquiring a data value from a data source and storing the acquired data value in association with data identification information included in the data request as collection information;
A step in which the data providing means of the first data management server extracts a data value corresponding to the data identification information included in the data request from the collected information and transmits the data value to the user terminal that has transmitted the data request; And run
When the selected data management server is another data management server (hereinafter referred to as a second data management server),
The data providing means of the first data management server sends, to the second data management server, data identification information included in the received data request and terminal identification information of the user terminal that has transmitted the data request. Transmitting a data response execution instruction including:
The data acquisition unit of the second data management server extracts data source identification information associated with data identification information included in the data response execution instruction from the management information of the second data management server, and the extracted data Acquiring a data value from the data source of the source identification information, storing the acquired data value in association with the data identification information of the data value as own collection information;
The data providing unit of the second data management server extracts a data value associated with the data identification information included in the data response execution instruction from the collected information of the second data management server, and the data response execution instruction data distribution and wherein that you run the steps, a to be transmitted to the user terminal of the terminal identification information included.

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