JP4096223B2 - Service search apparatus and method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a service search apparatus and method for providing information indicating which service is provided by which node in a network to a node that is about to receive the service.
[0002]
[Prior art]
In a wide area network in which a plurality of networks are connected to each other, as a method of providing information about which node provides what service to a node that is about to receive the service, for example, “ 10-56451 ”(Reference 1) describes ARP (Address Resoluti).
on Protocol) table, a method for exhaustively searching all nodes is disclosed.
Japanese Patent Laid-Open No. 11-167585 (Document 2) discloses a method for periodically collecting and managing information about services by multicast.
Japanese Patent Laid-Open No. 11-195048 (Document 3) discloses a method for determining a range for searching a node according to cost information.
[0003]
However, if the methods disclosed in the above-mentioned documents 1 to 3 are applied to a plurality of networks, a lot of processing time is required, and traffic in the network is excessively increased.
[0004]
[Problems to be solved by the invention]
The present invention has been made in view of the above-described problems of the prior art, and searches for which service is provided by which node in the network, and for the node that is about to receive the service. It is an object of the present invention to provide a service search apparatus and method that can be provided.
It is another object of the present invention to provide a service search apparatus and method that can search for a service in a short processing time without excessively increasing traffic in the network.
It is another object of the present invention to provide a service search apparatus and method for easily searching for services across a plurality of networks.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, a service search apparatus according to the present invention is a service search apparatus for searching for a service provided by a network, the search range setting means for setting a search range of a service in the network, and the network And a service search means for searching for a service included in the set search range.
[0006]
Preferably, the network includes a plurality of areas, one or more of the service search devices are placed in each of the plurality of areas, and the search range setting means includes one or more of each of the plurality of areas. In each of the other areas included in the set range, the first service information collecting means for setting the search range including a part or all and collecting the first service information of the service provided in the same area Second service information collection means for collecting the collected second service information, and the service search means is configured to set the set from the collected first service information and second service information. Search for services provided in the scope.
[0007]
Preferably, each of the services is provided by service providing means included in the network, the service providing means transmits the service information in response to an inquiry, and the first service information collecting means has the same area. The first service information transmitted from each of the service providing means is collected.
[0008]
Preferably, the second service information collecting unit includes a service information transmitting unit that transmits a part or all of the collected first service information as the second service information in response to an inquiry. Makes an inquiry to another area and collects the second service information collected in the other area.
[0009]
Preferably, each of the first service information includes a use condition of the service, and filtering means for filtering the collected first service information based on the use condition of each of the first service information. And the service information transmitting means transmits the service information obtained as a result of the filtering as the second service information.
[0010]
Preferably, the service search means searches for a service provided in the set range from the collected first service information and second service information in response to a request from a request source, The filtering means performs filtering based on usage conditions of each of the first service information and the request source.
[0011]
Preferably, the first service information and the second service information include geographical information of a location of the service providing unit, and the search range setting unit includes the first service information and the second service information. The search range is set based on geographical information included in the information.
[0012]
Preferably, the network includes service search device registration means for registering service search devices in each of the plurality of areas, and service search device detection means for detecting other service search devices placed in the same area; Registration means for registering the service search apparatus to which the service search apparatus belongs to the service search apparatus registration means according to a result of detection of the other service search apparatus, and the second service information collection means includes the service search The second service information collected by the service search device in another area registered in the device registration means is collected.
[0013]
Preferably, clustering means for generating cluster information indicating clusters obtained as a result of clustering the locations of the service providing means included in the same area based on the geographical information included in the collected first service information. The second service information collecting means further collects cluster information generated in another area, and the search range setting means is based on the cluster information generated in the same area and the other area. The search range is set.
[0014]
Preferably, the network includes service search device registration means for registering service search devices in each of the plurality of areas, and service search device detection means for detecting other service search devices placed in the same area; According to a result of detection of the other service search device, the service search device to which the service search device belongs, and registration means for registering the generated cluster information in the service search device registration means, and the search range setting The means sets the search range based on the cluster information generated in the same area and the registered cluster information.
[0015]
Preferably, communication condition detection means for detecting a communication condition between the same area and another area is provided, and the search range setting means sets the search range based on the detected communication condition. To do.
[0016]
Preferably, in response to a request from a request source, the service search means selects a service provided in the set range from the collected first service information and second service information according to a search condition. The search range setting means searches and sets the search range based on the request source and / or the search condition.
[0017]
The service search method according to the present invention is a service search method for searching for a service provided by a network, wherein a service search range in the network is set, and is included in the set search range in the network. Search for services.
The program according to the present invention is a search program for causing a computer to search for a service provided by a network, and includes a step of setting a search range of a service in the network, and the network includes the set search range. Searching for a service to be executed.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
[Background of the invention]
First, the background of the present invention will be described.
Various services can be received via the network. Even if the services are the same, some services such as quality and attributes such as a communication protocol are different depending on a server to be provided.
[0019]
Service attributes
For example, when connecting to a server via a network and trying to receive a print service, depending on the server, quality such as resolution at the time of printout, performance such as paper discharge speed, additional functions such as the presence or absence of a sorter, various print protocols The communication protocol such as the above, the permission for the presence or absence of the access right, etc., and the cost (hereinafter also referred to as “service attributes”) are different.
[0020]
[Service location (service location)]
The service is identified by the network address, domain name, and URL of the server device that provides the service (hereinafter also referred to as “service location (service location)”). This service location can be used to access a server that provides the service.
Hereinafter, although described as a server (device) and a client (device), the former means a device that provides a wide range of services, and the latter means a device that receives a wide range of services, regardless of actual names. .
[0021]
Here, since the service has the attribute (service attribute) as described above, the user can use any server, what attribute service, what restrictions (protocol, charging method, etc.) and measurement. It is necessary to select a server in consideration of whether it can be obtained by a standard (such as cost).
However, it is difficult for users to obtain such knowledge, especially when the user accesses the network for the first time, when the user accesses the other network temporarily away from the network they normally access, Users usually have no such knowledge.
[0022]
On the other hand, a wide area network such as the Internet is composed of a plurality of networks (IP subnet, corporate intranet, Internet service provider, etc.) that are logically layered and connected to each other. Each of these multiple networks differs in many respects, including the operating entity, network design and operation method, and is not homogeneous.
Interconnection between networks included in a wide area network is performed while preventing mutual interference between networks via relay devices such as routers and firewalls.
[0023]
In order to search for service locations in consideration of service attributes, for example, there is a method of detecting service attributes provided by all nodes reachable in the network and extracting what the user desires from the detected service attributes. is there.
Specifically, such a search is realized by a pre-registration method, a brute force method, a simultaneous broadcast method, a WWW robot search method, or the like.
[0024]
[Pre-registration method]
In the pre-registration method, when a server providing a service is installed, the service location, service attribute, etc. are registered in a database having a search function, information registered in advance is searched, and the result is obtained by the user. To provide.
As an example of this method, a corporate organization directory using Lightweight Directory Access Protocol (LDAP), Version 3 (IETF RFC2251), and Clearing House ("Local Area Network-Ethernet Overview-" Revised 2nd Edition, Xetox XNS) Ed., Published by Maruzen Co., Ltd., March 25, 1988).
This method requires a database that centrally manages service attributes and service locations of all nodes in the network.
[0025]
[Brute force method]
The brute force method accesses all network addresses included in the network address space and inquires about service attributes.
As an example of this method, there is serial pinging using ICMP (Internet Control Message Protocol; IETF RFC792) echo.
This method requires traffic and processing time according to the size of the address space.
[0026]
[Broadcast system]
In the broadcast method, a response request to the server by broadcast communication (such as IP multicast) and / or advertisement of own service by broadcast broadcast of the server (Advertise) is performed.
Examples of this method include SLP (Service Location Protocol, Version 2; IETF RFC2608) and SSDP (Simple Service Discovery Protocol).
[0027]
According to the broadcast method, it is possible to search service attributes within the reach of the broadcast, and the reach of the broadcast is the router / firewall and packet lifetime (number of router HOPs). Limited by.
The range in which service attributes can be searched and collected by this broadcast method (hereinafter also referred to as “service collection area”) is limited by the location in the network space, and depends on the geographical distance between the server device and the client device. There are no direct restrictions.
The service collection area by the simultaneous broadcast method is expected to be limited to the scope of the network where the management entity is the same, for example, in operation. Therefore, there are many isolated service collection areas in the wide area network. It is expected that
The broadcast method requires processing time and traffic according to the size of the reach of the simultaneous broadcast.
[0028]
[WWW robot search method]
The WWW robot search method uses a program called a search engine or search robot to automatically follow hyperlinks attached to the WWW information providing service, discover other WWW information providing services, and register them in the database. For example, a keyword search by text to this database is provided for the user.
Examples of this method include Lycos and Alta Vista.
[0029]
The operation of the search robot in this method depends on WWW systems such as HTTP (Hyper Text Transfer Protocol, Version 1.o; IETF RFC1945) and W3C HTML (Hyper Text Markup Language), and searches only the services provided by the WWW server. can do.
Further, according to this method, since the search robot follows the hyperlink, a large amount of traffic occurs in the network, and it takes a lot of processing time to reflect and update the search result in the database.
Moreover, it is only a network search function provider as mentioned above that can apply this system to a wide area network as a practical problem.
[0030]
[Search by geographical location]
In general, there is no geographical distance / regional restriction in providing a service via a network, and a service that can be used by a user is not limited by a place where a server device is placed.
Therefore, the user of the service via the network can originally select the server device in consideration of the service attribute, the constraint condition, and the measurement standard, and the location of the server device and the server device are It is not necessary to consider whether it is connected to other networks.
[0031]
However, when the user needs to receive a service result as an article, for example, a print service, there are some that have to consider the geographical location of the server device in order to receive the service.
In such a case, it is necessary to search for a service location that is close to the user and the client device, or a service location that is located in a location that is easy for the user to access even if the geographical location is remote.
In such a case, it is necessary to perform a service search taking into account the geographical distance as well as the distance in the network.
[0032]
Here, since there is generally no direct relationship between the geographical distance and the distance in the network, for example, the client apparatus is connected to a network other than the client apparatus while being in the vicinity of the user. In addition, there may be a server device that cannot be found by searching for a service closed in one network.
Therefore, even when searching for a server device located geographically close, it is necessary to perform a search across a plurality of networks.
[0033]
[Problems caused by licensing]
Furthermore, when trying to search for a service via a plurality of networks, there is a problem due to the use permission.
In general, regardless of whether or not you charge, you can license the service by allowing all users to use it uniformly, or by granting use only to pre-registered users. Is done.
[0034]
In the latter case, that is, when registration is required in advance for use permission, authentication is required for using the service.
Because the authentication method differs for each server device, and because of security problems, the server device cannot be accessed without entering a password, and the service attribute of the server device cannot be obtained.
Therefore, even if an attempt is made to access a server device using the latter method, the server device cannot be accessed unless the password for authentication is acquired in advance, and the service attributes of the server device cannot be known.
[0035]
[Outline of Service Search According to the Present Invention]
In the service search according to the present invention, a plurality of services are included in a wide area network or the like, and the services are detected by closing them, and the services provided for each collected area (service collection area) are detected. Are collected as service information (to be described later with reference to FIG. 7) together with geographic information of the server device that provides the service information.
In addition, the service collection area can be said to have a uniform network with the same management subject and operation method in this area.
Examples of the service collection area include a range where simultaneous broadcasting is possible, a range where the firewall does not block, a range where network resources are registered in one directory, and the like.
[0036]
The collected service information is disclosed inside and outside the service collection area, and a disclosure level including a plurality of stages is set for each of the disclosed service information.
When provision of published service information is requested, a filtering process is performed to determine whether or not to disclose the service information to the request source according to the requesting user and the network. Provided to the requester.
[0037]
When service information is searched in the service search according to the present invention, first, a search target range is set, service information published in the set search range is searched, and obtained as a result of the search. Information such as service location and service attributes is provided for the user.
[0038]
[Search range setting method]
Hereinafter, the search range setting method described above will be described in more detail.
FIG. 1 is a diagram schematically illustrating a configuration of a wide area network 1 including a plurality of networks.
The wide area network 1 includes, for example, three networks (networks A to C) 12A to 12C interconnected via the network relay device 14-1. The network 12A includes a client device 16A and a plurality of server devices 18A indicated by black circles in FIG. 1, the network 12B includes a plurality of server devices 18B indicated by white circles in FIG. 1, and the network 12C is a server device. Includes 18C.
[0039]
[Setting search range from the viewpoint of geographical space]
As can be seen with reference to FIG. 1, the spread of the wide area network 1 can be seen from the perspective of the geographic space 10 and the perspective of the network space.
FIG. 2 is a diagram showing a geographical positional relationship from the viewpoint of the geographical space 10 of the client device 16A and the server devices 18A and 18B in the wide area network 1 shown in FIG.
As shown in FIG. 1, when viewed from the client device 16A, the server device 18B of the network 12B is connected via the network relay device 14-1 from the viewpoint of the network space. It is far from 18A.
[0040]
On the other hand, as shown in FIG. 2, since part or all of the service areas of the network 12A and the network 12B may overlap on the geographical space 10, from the viewpoint of the geographical space 10, the server is more than the server device 18A. The device 18B may be closer to the client device 16A.
[0041]
For example, for a service that requires the user to receive the geographical result of the service, such as a print service, the client is connected to the same network 12A as the client device 16A and is closer to the client than the server device 18A in terms of network space. The server device 18B, which is connected to the network 12B different from the device 16A and is connected via the network relay device 14-1, can be closer from the viewpoint of the geographical space 10 than the viewpoint of the network space 10.
In such a case, it is more advantageous for the user of the client device 16A to use the server device 18B than to use the server device 18A, and the service search range is given priority in view of the geographical location of the server. It is good to decide.
[0042]
Furthermore, when there is a certain degree of distribution in the distribution of the server devices 18A and 18B within the service areas of the networks 12A and 12B, a plurality of geographical ranges in which each of the plurality of server devices 18A and 18B can provide a service are determined. It can be considered that the server devices 18A and 18B are geographically distributed.
Therefore, as shown in FIG. 2, among the plurality of server apparatuses 18A and 18B, those having a close geographical positional relationship are divided into a plurality of groups, and there are server apparatuses 18A and 18B included in each of these groups. When each range is divided into one region (cluster), clustering is performed, and a set of these regions can be considered as the geographical service area of each of the server devices 18A and 18B.
[0043]
As the geographical information indicating the geographical position of each of the server apparatuses 18A to 18C (hereinafter, also referred to as “server apparatus 18” when any of these is not specified), for example, latitude / longitude, administrative district If the geographical information is shared among a plurality of service search devices, the content and format must be unified among these devices.
[0044]
[Setting the search range from the viewpoint of network space]
FIG. 3 shows the positional relationship from the viewpoint of the network space of the client device 16A and the server devices 18A and 18B in the wide area network 1 (FIGS. 1 and 2) to which the network 12D is added via the network relay device (R2) 14-2. FIG.
On the other hand, for services in which the distance from the viewpoint of the geographical space 10 is not a primary constraint condition, such as downloading data from a WWW server, whether or not the service is connected to the same network 12A as the client device 16A, Regardless of whether the geographical distance is near or far, it is advantageous for the user to select a server device that can transfer data to the client device 16A at a higher speed and receive a service.
In such a case, from the viewpoint of network space such as transmission speed and transmission capacity of the networks 12A to 12C (hereinafter referred to simply as “network 12” when any one of the networks 12A to 12C is not specified). Priority should be given to determining the service search range.
[0045]
Specifically, as shown in FIG. 3, the transmission speed and transmission capacity inside each network 12, the transmission speed and transmission capacity of relay links (LA to LD) 20A to 20D connecting these networks, and these Overhead, processing load, and the like in the network relay apparatuses 14-1 and 14-2 that perform relay processing between the networks affect the communication between the client apparatus 16A and the server apparatuses 18A to 18C.
In the client device 16A, these elements are detected as the response speed of the server devices 18A to 18C and the throughput during file transfer.
[0046]
Therefore, when giving priority to the viewpoint of the network space, the communication path is evaluated based on the number of relay stages of the network and the transmission bandwidth of the bottleneck, and the client via the communication path that is expected to be able to transfer data at high speed. The search range of the service can be limited to the server devices 18A to 18B that are in a range that can be connected to the device 16A.
That is, when priority is given to the viewpoint of the network space, for example, the service search range can be obtained by evaluating the distance in the network space using the evaluation function represented by the following expression 1.
[0047]
[Expression 1]
f (number of network relay stages, bottleneck transmission band); f is a function (1)
[0048]
In this case, the smaller the number of relay stages in the network, the shorter the distance in the network space, and the transmission speeds of bottlenecks such as the relay links 20A to 20D, the network relay device 14-1, and the network relay device 14-2. It is estimated that the higher the transmission speed is, the larger the transmission capacity is, the shorter the distance in the network space is.
[0049]
The number of relay stages in the evaluation function f can be obtained, for example, as the number of network relay devices 14-1 and 14-2 (for example, the number of router HOPs) between the client device 16A and the server devices 18A to 18C.
Further, the transmission capacity in the evaluation function f can be estimated from the time required for data transfer and the size of the data, and such information is, for example, the MIB (Simple Network Management Protocol; IEFT RFC821) MIB ( It can also be obtained from a remote network as network management information such as (Management Information Base) information.
Further, when data communication is actually performed and the transmission capacity in the evaluation function f is estimated end-to-end, or the transmission capacity in the evaluation function f is acquired by SNMP from a router device or the like. is there.
[0050]
[First embodiment]
Hereinafter, a first embodiment of the present invention will be described.
FIG. 4 shows the service search devices 3A-1 to 3D according to the present invention (hereinafter simply referred to as “service search devices 3A to 3D” or “service search device 3” when any one of them is shown without being specified). It is a figure which illustrates the structure of the 2nd wide area network 5 in which) was used.
[0051]
As shown in FIG. 4, in the wide area network 5, networks 12A and 12B such as IP networks are connected via a router device 22-1, and the networks 12B and 12D are connected via a router device 22-2. 12C and the network 12D are connected via a firewall device 24.
[0052]
The network 12A includes client devices 16A and 18A and one or more service search devices 3A-1 to 3A-l. The network 12B includes a server device 18B and one or more service search devices 3B-1 to 3B-m. The network 12C includes a server device 18C.
The network 12C further includes one or more service search apparatuses 3C-1 to 3C-n (l, m, and n are integers).
The network 12D includes a directory device 50 and a service search device 3D.
In the wide area network 5, communication other than simultaneous broadcast between the nodes is performed by a message described in XML and an HTTP protocol.
[0053]
FIG. 5 is a diagram illustrating a hardware configuration of the service search apparatus 3 illustrated in FIG.
As shown in FIG. 5, the service search device 3 includes a computer main body 30 including a CPU 300 and a memory 302, an input device 32 such as a keyboard / mouse, a display device 34, a network interface (network IF) 36, and a recording device 38. Is done.
That is, the service search device 3 adopts a configuration as a computer having a communication function with other nodes (client device 16A, server devices 18A to 18C, and other service search devices 3).
[0054]
FIG. 6 is a diagram showing a configuration of a service search program 4 that executes a service search in the service search apparatus 3 shown in FIG.
As shown in FIG. 6, the service search program 4 includes a service information collection unit 40, a search range setting unit 42, a service disclosure unit 44, and a service search unit 46. For example, the service search program 4 is recorded on the recording medium 380 shown in FIG. The data is supplied to the search device 3, loaded into the memory 302, and executed.
The service search program 4 realizes the above-described service search according to the present invention by these components.
[0055]
[Service Information Collection Unit 40]
Here, a plurality of service collection areas are included in a wide area network or the like as described above, and each area is closed to indicate an area where service detection and service collection are performed.
Hereinafter, in order to simplify the description, a case where the service collection areas of the service search apparatus 3 are the networks 12 will be described as a specific example.
The service information collection unit 40 collects service information from the server devices 18 included in the service collection area, for example, with each network 12 as one service collection area.
[0056]
That is, in the network 12A, the service information collection unit 40 of the service search device 3A (service search program 4) is a service indicating service attributes such as quality of service and communication protocol provided by each of the plurality of server devices 18A belonging to the network 12A. Collect information.
In the network 12B, the service information collection unit 40 collects service information of each of the plurality of server devices 18B belonging to the network 12B. In the network 12C, the service information collecting unit 40 collects service information of the server device 18C belonging to the network 12C.
The service information collection unit 40 holds the collected service information in a format as shown in FIG. 7 and provides it as a service database for search by the service information disclosure unit 44, and the geography of the server device 18 shown in FIG. Information is output to the search range setting unit 42.
Specific examples of “update date / date and time” shown in FIG. 7 may include dates and times such as “2001.20 11:51”. Refer to FIG. 8 for the contents of “service information”. Will be described later.
[0057]
FIG. 7 is a diagram showing service information held by the service information collection unit 40 (FIG. 6) of the service search device 3 (service search program 4).
As shown in FIG. 7, the service information collection unit 40 stores a service identifier (service ID), an update date / time, and service information in association with each other.
This service database is used for search by the service disclosure unit 44, and the update is notified to the search range setting unit 42 and the service disclosure unit 44.
[0058]
FIG. 8 is a diagram showing service information transmitted from the server device 18 to the primary service search device 3.
As shown in FIG. 8, the service information includes data of service type, network information, geographic information, usage permission information, and service attributes.
Service attributes include general attributes and service-dependent attributes.
General attributes include accounting data, security information, transfer protocol information, and operational organization information.
[0059]
The service type indicates a type of service provided by the server device 18, for example, a print service or a scan service.
[0060]
The network information indicates information necessary for uniquely identifying the server device 18 in the wide area network 5, for example, an IP address, an FQDN (Fully Qualified Domain Name), or a URI (Universal Resource Identifier).
[0061]
The geographical information includes information indicating the geographical information of the server device 18.
The geographical information includes the latitude / longitude information of the place where the server device 18 is placed as essential information, and the address of the building where the server device 18 is placed, the name of the building, and the floor number as other optional information. Information such as floor section and room names.
[0062]
The use permission information indicates a range in which the server device 18 provides a service. For example, the service license information provides unlimited service to the client device 12 of any network 12, or in the network 12 to which the server device 18 belongs. It shows that it restricts to.
[0063]
The charge information of the general attribute indicates a usage fee and a payment method for the service provided by the server device 18.
[0064]
The security information indicates a security protocol corresponding to a service provided by the server device 18.
[0065]
The transfer protocol information indicates a communication protocol and API (Application Program Interface) for receiving a service provided by the server device 18.
[0066]
The management organization information indicates the name, name, and contact method of the company, department, organization, or individual that operates the service of the server device 18.
[0067]
The service-dependent attribute is set for each service type of the service provided by the server device 18 and indicates the quality of service, performance, additional function, supported document format, supported language, supported character set, driver acquisition location, and the like.
[0068]
[Search range setting unit 42]
FIG. 9 is a diagram showing a configuration of the search range setting unit 42 shown in FIG.
As shown in FIG. 9, the search range setting unit 42 includes a clustering unit 420, a mutual discovery unit 422, a search range generation unit 424, and a network analysis unit 426.
[0069]
With these components, the search range setting unit 42 uses the number of stages and data transmission capacity of the router device 22 shown in FIG. 4 to the search range setting unit 42 of the other primary service search device 3 (service search program 4). Etc. (network information), and the service search range required from the viewpoint of geographical space and the search range required from the viewpoint of network space are set.
[0070]
[Clustering unit 420]
In the search range setting unit 42, the clustering unit 420 further processes the geographic information of the service information (FIG. 8) input from the service information collecting unit 40, and the geographical distribution of the server device 18 in the network 12 to which the cluster belongs. Are clustered as shown in FIG. 2 to create a cluster.
Furthermore, the service search device 3 uses the average value (center of gravity) of the latitude / longitude coordinates of the cluster created as described above as a representative point of the cluster, and further, within the distance from the representative point to each server device 18, Let the longest distance be the size of each cluster (cluster size).
[0071]
FIG. 10 is a diagram showing cluster information registered in the directory device 50 by the search range setting unit 420 (FIG. 9) of the service search device 3 (service search program 4; FIG. 6).
FIG. 11 is a diagram showing server distribution information output from the clustering unit 420 shown in FIG. 9 to the service disclosure unit 44 (FIG. 6).
Among these pieces of generated information, the clustering unit 420 outputs cluster information including the representative points of the clusters and the cluster size to the mutual discovery unit 422 as shown in FIG.
Further, as shown in FIG. 11, the search range setting unit 420 provides server distribution information including a cluster ID, a representative point, and a list of services (service IDs) provided by each server device 18 included in each cluster. Output to the public unit 44.
An example of the contents of the network address of the service search apparatus shown in FIG. 10 is an IP address such as “139.168.0.1”, and an example of the contents of the “cluster representative point list” is “E139 ° 44′35. 66 ", N35 ° 39'58.76""," E139 ° 44'25.27 ", N35 ° 40'08.30" Numerical values can be mentioned.
As examples of the “representative points” shown in FIG. 11, the representative point “E139 ° 44′35.66”, N35 ° 39′58.76 ”of the cluster ID · C1, and the representative point“ E139 ”of the cluster ID · C1. As an example of latitude / longitude such as “° 44′25.27 ″, N35 ° 40′08.30 ″” and “services belonging to cluster (service ID list)”, “S3, S4” for C1, and “ IDs such as “S1, S2” can be cited.
[0072]
[Mutual discovery unit 422]
FIG. 12 is a flowchart showing the mutual discovery process and registration in the directory device by the mutual discovery unit 422 shown in FIG.
When there are a plurality of service search devices 3 in one network 12A to D (hereinafter also referred to simply as “network 12” when any one of them is not specified), One of the service search devices 3 (service search program 4) operates as the primary service search device 3, and the other service search device 3 (service search program 4) operates as the backup service search device 3.
[0073]
In step 100 (S100), the mutual discovery unit 422 (FIG. 9) of the search range setting unit 42 of the service search device 3 (service search program 4) activated in any of the networks 12 is the same by simultaneous broadcast communication. It requests a response from another service search device 3 in the network 12, waits for a response for a certain period, and advertises its existence to the other service search device 3.
[0074]
In step 102 (S102), the mutual discovery unit 4223 that performed the simultaneous broadcast communication (S100) determines whether or not there is a response from the primary service search device 3, and if there is a response, the process of S104 is performed. In other cases, the process proceeds to S106.
[0075]
In step 104 (S104), the mutual discovery unit 4223 that has performed the simultaneous broadcast communication recognizes itself as the backup service search device 3.
The primary service search apparatus 3 that has returned this response registers the service search apparatus 3 that has performed the simultaneous broadcast communication as a backup service search apparatus.
[0076]
In step 106 (S106), the mutual discovery unit 422 that has performed the simultaneous broadcast communication recognizes the server device 18 to which the mutual discovery unit 422 belongs as the primary service search device 3, and uses the preset network address of the directory device 50 as a directory. Communicate with device 50.
[0077]
[Registration of Primary Service Search Device 3 to Directory Device 50]
Further, the mutual discovery unit 422 of the service search device 3 (service search program 4) that has performed the simultaneous broadcast communication has an entry of the service search device 3 to which the directory search device 50 belongs by communication with the directory device 50. If the address and cluster information (FIG. 10) has already been registered as information of the primary service search device 3, the registration is left as it is.
[0078]
Further, when the address of the other service search device 3 is registered as the primary service search device 3, the mutual discovery unit 422 deletes the entry of the other service search device 3, and the service search device 3 to which it belongs And the network address and cluster information (FIG. 10) of the service search apparatus 3 to which it belongs are registered as information of the primary service search apparatus 3.
[0079]
If the network address of any service search device 3 is not registered in the directory device 50, the mutual discovery unit 422 creates an entry for the service search device 3 to which the directory search device 50 belongs, and creates the created entry. In addition, the address and cluster information (FIG. 10) of the service search device 3 to which it belongs are registered as information of the primary service search device 3.
[0080]
The service search device 3 of each network 12 can communicate by obtaining the network address of the primary service search device 3 of any network 12 by accessing the directory device 50 of the network 12D.
[0081]
Further, the mutual discovery unit 422 receives the address and cluster information (FIG. 10) of the primary service search device 3 of the other network 12 from the directory device 50 and notifies the search range generation unit 424 of these information.
In addition, the mutual discovery unit 422 notifies the network analysis unit 426 of the address of the primary service search device 3 of the other network 12.
[0082]
[Primary service search device and backup service search device]
As described above, only the primary service search device 3 registered in the directory device 50 provides a service search function to client devices in the same network, and the backup service search device 3 normally provides a service search function. Do not do.
However, the backup service search device 3 is registered in the primary service search device 3 and periodically performs a health check on the primary service search device 3 to check whether it is operating normally.
If the primary service search device 3 is not operating normally, the backup service search devices 3 negotiate with each other, and any one of the backup service search devices 3 replaces the previous primary service search device 3 with a service search. Provide functionality.
[0083]
[Network analysis unit 426]
The network analysis unit 426 transmits measurement packets to all addresses of the primary service search device 3 of the other network 12 input from the mutual discovery unit 422, and analyzes the interconnection relations of the networks 12A to 12D.
Specifically, for example, the network analysis unit 426 increases the TTL (Time To Live) one by one and transmits an ICMP echo packet, and the primary service search device 3 and the primary service search device 3 of the other network 12 communicate with each other. The number of router devices 22 (hereinafter simply referred to as “router device 22” when any of the router devices 22-1 and 22-2 is indicated without being specified) is detected.
[0084]
Further, for example, the network analysis unit 426 estimates a data transmission capacity with another primary service search device 3 by a method called an ICMP echo packet that continuously transmits an ICMP pair packet.
Based on the number of router devices 22 and the data transmission capacity obtained by the above method, the network analysis unit 426 uses, for example, high-speed information as information indicating the distance in the network space between each of the other service search devices 3. They are arranged in the order in which data transmission is estimated to be possible, and are output to the search range generation unit 424.
[0085]
[Search range generation unit 424]
Based on the search condition input from the service search unit 46, the search range generation unit 424 includes the address of the primary service search device 3 of the other network 12 to be set as the search range and the cluster information of the clusters to be set as the search range. Search range information including (FIG. 10) is generated and returned to the service search unit 46.
The input search condition indicates, for example, a service type, a search target area that specifies the geographical location of the server device 18, and a search target network that specifies the network 12 to be searched from the viewpoint of the network space. Information is included, the service type is essential, and the others are treated as optional information as appropriate.
[0086]
When the search target area is designated, the search range generation unit 424 represents the representative points of the clusters included in the cluster information (FIG. 10) of the primary service search device 3 of the other network 12 input from the mutual discovery unit 422. A search range is generated based on the cluster size.
In this case, for example, the search range generation unit 424 does not specify whether the client device 16 (hereinafter, the client device belongs to any of the networks 12A to 12D) regardless of which of the networks 12A to 12D belongs. Clusters that are geographically close to “client device 16”) are included in the search range.
[0087]
In addition, when a search network is specified, the search range generation unit 424 searches for the primary service of the specified network 12 from the address of the primary service search device 3 of the other network 12 input from the mutual discovery unit 422. The address of the device 3 is searched.
[0088]
In addition, the search range generation unit 424 determines the specified service type when both the search target area and the search network are omitted, and when the specified service should take the search target area into consideration, Performs processing when a search target area is specified.
Further, in this case, the search range generation unit 424 determines that the cluster that is closer to the client device 16 from the viewpoint of the network space when the service to be searched does not need to consider the search target area. Alternatively, a cluster estimated to be able to transmit data at high speed is included in the search range.
[0089]
[Service disclosure unit 44]
FIG. 13 is a diagram illustrating a configuration of the service disclosure unit 44 of the service search apparatus 3 (service search program 4; FIG. 6).
As shown in FIG. 13, the service disclosure unit 44 includes a search processing unit 440 and a disclosure control unit 442.
With these components, the service disclosure unit 44 searches the service database (FIG. 7) of the service information collection unit 40 according to the search conditions from the service search unit 46, and based on the use permission information included in the service information. The filtering process is performed, and the service information of the server device 18 that satisfies the search condition and the filtering condition is returned to the service search unit 46 as a search result.
[0090]
[Service disclosure unit 440]
The service disclosure unit 440 searches the service database (FIG. 7) of the service information collection unit 40 based on the search condition input from the service search unit 46, and searches the service information of the server device 18 that matches the search condition. As a result, the information is output to the public control unit 442.
The search condition includes the cluster IDs (FIG. 11) of all the clusters included in the search range input from the search range setting unit 42 and the network address of the client device 16 that has requested the service search.
[0091]
Of these pieces of information, the cluster ID can be omitted, and when the cluster ID is omitted, the service disclosure unit 440 can search all the searchable databases in the service information collection unit 40 (FIG. 7). The server device 18 included in the cluster is searched.
When the cluster ID is designated, the service disclosure unit 440 refers to the server distribution information (FIG. 11) input from the search range setting unit 42, and obtains service information of the server device 18 included in the designated cluster. Search for.
[0092]
[Public control unit 442]
The public control unit 442 determines the network 12 (request source network 12) to which the client device 16 belongs from the network address of the client device 16 included in the search condition.
[0093]
[Filtering processing]
The publication control unit 442 refers to the use permission information of the service information (FIG. 8) input from the service publication unit 440 and performs filtering to output service information that can be published to the request source network to the service search unit 46. Process.
In other words, the disclosure control unit 442 indicates that the use permission information in the service information input from the service disclosure unit 440 indicates that the use is permitted only within the network 12 to which the server device 18 belongs. The service information is output to the service search unit 46 only when the request source network 12 is a network to which the server device 18 belongs, and in other cases, the service information is not output to the service search unit 46.
[0094]
Alternatively, when the usage permission information indicates that the use is permitted only in the specific network 12, the service information is sent to the service search unit 46 only when the request source network 12 is included in the specific network. In other cases, the data is not output to the service search unit 46.
[0095]
[Service search unit 46]
The service search unit 46 (FIG. 6) receives a search request from the client device 16 included in the same network 12 and the service search unit 46 of the service search device 3 (service search program 4) of another network 12, and is included in this request. Service information search for the service disclosure unit 44 or the service search device 3 (service search program 4) of the other network 12 based on the search condition and the search range input from the search range setting unit 42. Request.
Further, the service search unit 46 makes a search request for the search results returned in response to the inquiry to the service disclosure unit 44 of the same service search program 4 and the service search device 3 (service search program 4) of another network 12. Returned to the client device 16 and the service search unit 46 of the other service search program 4.
[0096]
Hereinafter, the processing of the service search unit 46 will be further described with reference to FIGS. 14 and 15.
[0097]
[Search request from the same network 12]
FIG. 14 shows the search processing (S12) of the service search unit 46 (FIG. 6) of the service search device 3 (service search program 4) that has received a service search request from the client device 16 belonging to the same network 12 (FIG. 4). It is a flowchart to show.
In step 120 (S120), the service search unit 46 receives a service search request (query) from the client device 16 belonging to the same network 12.
[0098]
In step 122 (S122), the service search unit 46 analyzes the received service search request.
[0099]
In step 124 (S124), the service search unit 46 outputs the search condition to the search range setting unit 42.
[0100]
In step 126 (S126), the service search unit 46 receives from the search range setting unit 42 the address of the primary service search device 3 of the other network 12 that should be the search range, and the cluster information ( Search range information including FIG. 10) is received.
[0101]
The service search unit 46 repeats the processes of S142 to S150 included in S140 for all clusters in the search range.
In step 142 (S142), the service search unit 46 determines whether one of the clusters within the search range is included in the network 12 to which the service search unit 46 belongs.
If the cluster is included in the network 12 to which the cluster belongs, the process proceeds to S144. Otherwise, the process proceeds to S148.
[0102]
In step 144 (S144), the service search unit 46 generates a search condition and requests the service disclosure unit 44 to perform a search.
[0103]
In step 146 (S146), the service search unit 46 receives the search result from the service disclosure unit 44.
[0104]
In step 148 (S148), the service search unit 46 requests the primary service search device 3 of the other network 12 to which the cluster in the search range belongs to search for the service.
[0105]
In step 150 (S150), the service search unit 46 receives the service search result from the primary service search device 3 of the other network 12 to which the cluster in the search range belongs.
[0106]
In step 160 (S160), the service search unit 46 returns the search result to the client device 16 that has requested the service search.
[0107]
[Search request from other network 12]
FIG. 15 shows the search process (S18) of the service search unit 46 (FIG. 6) of the primary service search apparatus 3 (service search program 4) that has received a service search request from the client apparatus 16 belonging to another network 12 (FIG. 4). Is a flowchart showing.
In step 180 (S180), the service search unit 46 receives a service search request from the primary service search device 3 of another network 12 to which the service search unit 46 does not belong.
[0108]
In step 182 (S182), the service search unit 46 analyzes the service search request.
[0109]
In step 184 (S184), the service search unit 46 generates a search condition and requests the service disclosure unit 44 to perform a search.
[0110]
In step 186 (S186), the service search unit 46 receives the search result from the service disclosure unit 44.
[0111]
In step 188 (S188), the service search unit 46 transmits the request to the primary service search device 3 that is the source of the service search.
[0112]
[Operation of wide area network 5]
Hereinafter, the overall operation of the wide area network 5 (FIG. 4) will be described.
[0113]
[Collecting service information in the initial stage of the service search device 3]
First, as described with reference to FIG. 12, the collection of service information performed immediately after the primary service search device 3 registered in the directory device 50 is registered in the directory device 50 (initial stage) will be described.
FIG. 16 is a flowchart showing a service information collection process (S20) performed immediately after the service search device 3 (service search program 4; FIG. 6) is registered in the directory device 50 (initial stage).
FIG. 17 is a diagram showing service information collection processing in the initial stage of the service search device 3 (service search program 4; FIG. 6) shown in FIG.
[0114]
In each network 12, the service information collection unit 40 of the primary service search device 3 (service search program 4) that has registered (FIG. 12) with respect to the directory device 50 follows this registration, step 200 in FIG. 16 (S 200). In FIG. 17B, service information is requested to the server devices 18 belonging to the same network 12 by simultaneous broadcast communication, and the existence thereof is announced (FIG. 17 (1)).
[0115]
The server device 18 is waiting for a service information request from the primary service search device 3, and upon receiving the service information request, returns the service information to the service search device 3 (FIG. 17 (2)).
[0116]
In step 202 (S 202), the service information collection unit 40 receives service information from the server device 18.
[0117]
In step 204 (S204), the service information collection unit 40 registers the service information received within a certain period from the process of S200 in the service database (FIG. 7).
[0118]
In step 206 (S206), the service information collection unit 40 notifies the service disclosure unit 44 and the search range setting unit 42 of the update of the service database.
[0119]
[Collection of Service Information of Newly Connected Server Device 18]
Hereinafter, collection of service information performed when the server device 18 is added to the network 12 will be described.
FIG. 18 is a diagram showing service information collection processing of the service search device 3 (service search program 4; FIG. 6).
FIG. 19 is a flowchart showing service information collection processing (S22) of the service search device 3 (service search program 4; FIG. 6).
As shown in FIG. 18, when the server device 18 is connected and activated in each network 12, the server device 18 provides information on its own presence and a service to be provided to the connected network 12. Public announcement is made by simultaneous broadcast communication (FIG. 18 (1)).
[0120]
As shown in step 220 (S220) of FIG. 19, the service information collection unit 40 (FIG. 6) of the primary service search device 3 (service search program 4) waits for an announcement from the server device 18, and the server device 18 Receive announcements from.
[0121]
In step 222 (S222), the primary service search device 3 requests service information from the server device 18 that has performed the broadcast communication (FIG. 18 (2)).
The server device 18 requested for the service information returns the service information to the primary service search device 3 ((3) in FIG. 18).
[0122]
In step 224 (S224), the service information collection unit 40 of the service search device 3 (service search program 4) receives the service information returned from the server device 18.
[0123]
In step 226 (S226), the service information collection unit 40 determines whether or not the received service information from the server device 18 has already been registered as an entry in the service database (FIG. 7).
If it is registered, the process proceeds to S228. Otherwise, the process proceeds to S230.
[0124]
In step 228 (S228), the service information collection unit 40 updates the service database and notifies the search range setting unit 42 and the service disclosure unit 44 to that effect.
[0125]
In step 230 (S230), the service information collection unit 40 newly registers the received service information of the server device 18 in the service database.
[0126]
In step 232 (S232), the service information collection unit 40 notifies the search range setting unit 42 and the service disclosure unit 44 of the database update.
[0127]
[Retention / deletion of service information]
As described above, the primary service search device 3 that has received the service information from each server device 18 holds the service information from each server device 18 until a certain period of time elapses without receiving new service information.
FIG. 20 is a flowchart showing a process (S24) in which the service information collection unit 40 of the service search apparatus 3 (service search program 4) deletes the service information.
The service information collection unit 40 of the primary service search device 3 (service search program 4) has passed a certain time after the last update of each entry in the step 240 (S240) service database (FIG. 7) shown in FIG. Judge whether or not.
If the certain period has not elapsed, the service information collection unit 40 ends the process.
[0128]
In step 222 (S222), the service information collection unit 40 deletes entries for which a certain period has elapsed from the entries in the service database.
In step 224 (S224), the service information collection unit 40 notifies the search range setting unit 42 and the service disclosure unit 44 of the update of the service database.
[0129]
When the service disclosure unit 44 receives new service information from the server device 18, the service disclosure unit 44 stores and stores the newly received service information instead of the service information that has been stored so far, and the search range setting unit 42 and the service disclosure unit 44 are notified of this.
The predetermined period for holding the service database entry is normally set to, for example, about two days by the administrator of the primary service search apparatus 3.
If this period is set to about 2 days, even if the primary service search apparatus 3 is frequently terminated and started, the service information is not erased each time.
[0130]
FIG. 21 is a diagram illustrating processing in which the service search device 3 registers cluster information in the directory device 50.
As shown in FIG. 21, the search range setting unit 42 of the service search device 3 (service search program 4) displays each cluster created as described above, their representative points, and cluster size as cluster information (FIG. 10). ) Is registered in the directory device 50 (FIG. 21 (1)).
[0131]
[Operation of wide area network 5]
FIG. 22 is a first diagram showing the overall operation of the primary service search device 3A (service search program 4) of the network 12A.
FIG. 23 is a second diagram showing the overall operation of the primary service search device 3 (service search program 4) of the network 12A.
Hereinafter, with reference to FIGS. 22 and 23, the operation of the wide area network 5 described so far will be described with the primary service search device 3A of the network 12A as an example.
[0132]
The client device 16A (FIG. 4) performs simultaneous broadcast communication within the network 12A and requests a response from the primary service search device 3A within the network 12A (FIG. 22 (1)).
As shown in FIG. 23, the service search unit 46 (FIG. 6) of the primary service search device 3A (service search program 4) of the network 12A waits for the simultaneous broadcast communication from the client device 16A, and the client device 16A Upon receiving the simultaneous broadcast communication (FIG. 22 (1)), a response is returned (FIG. 22 (2)).
[0133]
The client device 16A issues a search request (query) with the geographical information (latitude, longitude, etc.) of the client device 16A and search conditions to the primary service search device 3A that has returned the response ((3) in FIG. 22). ).
The search condition attached to the query includes, for example, a search target area, a search target network, and a service condition to be used for search (search service condition).
When the service search unit 46 of the service search device 3A (service search program 4) receives a query from the client device 16A, the primary service search device 3A starts searching.
[0134]
As shown in FIG. 23, the service search unit 46 of the service search device 3A (service search program 4) notifies the search condition to the search range setting unit 42 (FIG. 6).
For example, when the search target area and the search target network are not specified in the query, the search range setting unit 42 of the primary service search device 3A (service search program 4) sets the entire range of the network 12A as the search range, and the service. The search unit 46 is notified.
[0135]
The service search unit 46 of the service search device 3A (service search program 4) notifies the service disclosure unit 44 (FIG. 6) of the search conditions and requests a search for service information of the server device 18A included in the network 12A. .
The service disclosure unit 44 executes a search in response to this request and returns the search result to the service search unit 46.
[0136]
For example, when the vicinity of the client device 16A is specified as a search target area in the query of the client device 16A, the search range setting unit 42 of the service search device 3A (service search program 4) includes the location of the client device 16A. All the clusters of the networks 12A to 12D are set as search ranges.
The service search unit 46 of the service search device 3A (service search program 4) searches the service disclosure unit 44 for service information of the server device 18A included in all clusters within the search range set in the network 12A. Upon request, the service disclosure unit 44 searches for service information in response to the request and returns the search result to the service search unit 46.
[0137]
Further, the search range setting unit 42 of the service search device 3A (service search program 4) requests the directory device 50 for the addresses of the primary service search devices 3B to 3D of the other networks 12B to 12D (FIG. 22 ( 4)) In response to this request, the directory device 50 searches the addresses of the service search devices 3B to 3D, and returns the search result to the search range setting unit 42 of the service search device 3A (FIG. 4 (5)).
The addresses of the service search devices 3B to 3D from the directory device 50 are notified to the service search unit 46.
[0138]
The search range setting unit 42 of the service search device 3A (service search program 4) has the geographic information of the client device 16A compared to the search range setting unit 42 of the networks 12B to 12D service search devices 3B to 3D (service search program 4). And requests for a search for the server device 18 in the cluster including the location of the client device 16A in the networks 12B to 12D.
In response to a request from the service search device 3A, the service search devices 3B to 3D of the networks 12B to 12D search for service information of the server device 18 in the cluster including the location of the client device 16A, and search results are displayed on the network 12A. It returns to the service search unit 46 of the service search device 3A (service search program 4) (FIG. 22 (7)).
The service search unit 46 of the service search device 3A (service search program 4) is obtained from the service disclosure unit 44 of the service search device 3A (service search program 4) and the service search devices 3B to 3D of the other networks 12B to 12D. The retrieved result is returned to the client device 16A (FIG. 22 (8)).
[0139]
[Clustering processing]
The search range setting unit 42 processes the geographic information included in the service information (FIG. 8) collected by the service information collection unit 40 to cluster the server devices 18A in the network 12A as shown in FIG. Then, the center of gravity and cluster size of each cluster obtained as a result of clustering are obtained, and cluster information (FIG. 10) is created.
The search range setting unit 42 creates cluster distribution information (FIG. 11) and outputs it to the service disclosure unit 44.
[0140]
[Search processing]
The service search unit 46 of the service search device 3A (service search program 4; FIG. 6) that has received a service search request from the client device 16 belonging to the same network 12A (FIG. 4), as shown in FIG. The search range is set from the setting unit 42 and output to the service disclosure unit 44 of the same service search device 3A (service search program 4) and the primary service search devices 3B to 3D of the other networks 12B to 12D. Request a search.
[0141]
The service publishing unit 44 performs a filtering process based on the use permission condition and returns the filtered search result to the service search unit 46.
The service search unit 46 returns the search results returned from the service disclosure unit 44 of the same service search device 3A (service search program 4) and the search results returned from the service search devices 3B to 3D of the other networks 12B to 12D. Is transmitted to the client device 16A.
[0142]
Primary service search device 3A (service search program 4) that receives a service search request from a client device 16B (not shown in FIG. 4) belonging to one of other networks 12B to 12D (FIG. 4) (for example, network 12B) As shown in FIG. 15, the service search unit 46 (FIG. 6) requests the service disclosure unit 44 to receive a search result.
The service search unit 46 transmits the search result received from the service disclosure unit 44 to the service search device 3B of the request source network 12B.
The request source service search device 3B sends the request source client device 16B belonging to the same network 12B to the service information received from the other networks 12A, 12C, and 12D and the service in the same service search device 3B (service search program 4). The service information received from the disclosure unit 44 is merged and returned.
[0143]
[Modification]
In the above, the case where the service search device 3 collects service information from each server device 18 by the unique communication sequence shown in FIG. 18 and the like has been described as an example. It is also possible to modify to collect service information by using an existing network management protocol.
In addition, the service search device 3 may provide service information to the client device 16 using a Web page.
[0144]
In addition, it is possible to speed up the search by nearby service search devices communicating in advance and duplicating the service information held by each.
In addition, the service search apparatus 3 may hold service information obtained from other service search apparatuses 3 in a cache.
In addition, service information of all other service search devices 3 is stored in each service search device 3, and when a geographically close search range is set, the service search device 3 stores the service information. Search processing may be performed from service information.
Further, the service search device 3 may add up the server devices 18 actually used by the client device 16 from the service information sent to the client device 16 and reflect them in the search process as popular services.
[0145]
[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described.
FIG. 24 is a diagram showing the configuration of the second service search program 7 according to the present invention.
As shown in FIG. 24, the service search program 7 is used in place of the service search program 4 in the service search apparatus 3 (FIGS. 6 and 9), and a geographic information conversion unit 48 is added to the service search program 4. Take the configuration.
With the above configuration, the service search program 7 uses the administrative area name or the postal code instead of the latitude / longitude of the server device 18 (FIG.) As the geographic information of the service information (FIG. 8), and is similar to the service search device 3 Realize the functions.
[0146]
[Geographic information converter 48]
In the service search program 7, the geographic information conversion unit 48 converts the administrative district or the zip code of the location of each server device 18 included in the service information collected by the service information collection unit 40 into latitude / longitude information, and provides service information. Output to the collection unit 40.
[0147]
In the service search program 7, the service information collection unit 40 performs the same processing as in the service search program 4 using the latitude / longitude information of each server device 18 input from the geographic information conversion unit 48.
[0148]
[Modification]
Note that the geographic information conversion unit 48 may be provided in the directory device 50 and the wide area network 5 may be configured so that the geographic information conversion unit 48 can be shared by many networks 12.
Further, the geographic information conversion unit 48 may be connected to the wide area network 5 as an independent device instead of being provided in the service search device 3 (service search program 7).
[0149]
[Third Embodiment]
Hereinafter, a third embodiment of the present invention will be described.
FIG. 25 is a diagram showing the configuration of the second search range setting unit 52 that is replaced with the search range setting unit 42 in the service search program 4 (FIGS. 6 and 8).
As illustrated in FIG. 25, the search range setting unit 52 has a configuration in which the mutual discovery unit 422 of the search range setting unit 42 is changed to a mutual discovery unit 520.
By replacing the search range setting unit 42 with the search range setting unit 50 in the service search program 4, the wide area network 5 can be configured without using the directory device 50.
[0150]
[Mutual discovery unit 520]
In the wide area network 5 in which the search range setting unit 52 is used, the service search apparatus 3 constitutes a hierarchical network having a tree structure.
Each service search device 3 is set by the administrator with the network address of the upper service search device 3 at the time of installation, and the mutual discovery unit 520 has the upper service search device 3 (service search program 4). It communicates with the mutual discovery unit 520, registers its own network address in the upper-level service search device 3 (service search program 4), and receives a notification of the network address of the lower-level service search device 3.
[0151]
Further, the mutual discovery unit 520 sequentially communicates with the upper and lower service search apparatuses 3 (service search program 4), and obtains cluster information (FIG. 10) of the upper and lower service search apparatuses 3. Receive sequentially.
Through the above processing, the mutual discovery unit 520 of the service search device 3 (service search program 4) of each network 12 can receive the service search device 3 and cluster information of the entire wide area network 5.
The mutual discovery unit 520 outputs the received network address and cluster information of the service search device 3 of each network 12 to the search range generation unit 424 and the network analysis unit 426.
[0152]
【The invention's effect】
As described above, according to the service search apparatus and method according to the present invention, it is possible to search for which node is providing what service in the network and to receive the service. Can be provided.
Further, according to the service search apparatus and method according to the present invention, it is possible to search for a service in a short processing time without excessively increasing the traffic in the network.
Further, according to the service search apparatus and method according to the present invention, a service can be easily searched across a plurality of networks.
[Brief description of the drawings]
FIG. 1 is a diagram schematically illustrating a configuration of a wide area network including a plurality of networks.
2 is a diagram showing a positional relationship from the viewpoint of geographical space between a client device and a server device in the wide area network shown in FIG. 1;
FIG. 3 is a diagram showing a geographical positional relationship from the viewpoint of the network space of a client device and a server device in a wide area network (FIGS. 1 and 2) to which a network is added via a network relay device (R2).
FIG. 4 is a diagram illustrating a configuration of a second wide area network in which the service search apparatus according to the present invention is used.
FIG. 5 is a diagram showing a hardware configuration of the service search apparatus shown in FIG. 4;
6 is a diagram showing a configuration of a service search program for executing a service search in the service search apparatus shown in FIG.
FIG. 7 is a diagram showing service information held by a service information collection unit (FIG. 6) of a service search device (service search program).
FIG. 8 is a diagram showing service information transmitted from a server device to a primary service search device.
9 is a diagram showing a configuration of a search range setting unit shown in FIG.
FIG. 10 is a diagram showing cluster information registered in a directory device by a search range setting unit (FIG. 9) of a service search device (service search program; FIG. 6).
11 is a diagram showing server distribution information output from the clustering unit shown in FIG. 9 to the service disclosure unit (FIG. 6).
12 is a flowchart showing mutual discovery processing and registration in a directory device by the mutual discovery unit shown in FIG. 9;
13 is a diagram showing a configuration of a service disclosure unit of a service search device (service search program; FIG. 6).
FIG. 14 is a flowchart showing a search process (S12) of the service search unit 46 (FIG. 6) of the service search apparatus (service search program) that receives a service search request from a client apparatus belonging to the same network (FIG. 4). .
FIG. 15 is a flowchart showing a search process (S18) of the service search unit (FIG. 6) of the primary service search apparatus (service search program) that has received a service search request from a client apparatus belonging to another network (FIG. 4). is there.
FIG. 16 is a flowchart showing service information collection processing (S20) performed immediately after the service search device (service search program; FIG. 6) is registered in the directory device (initial stage).
17 is a diagram showing service information collection processing in the initial stage of the service search device (service search program; FIG. 6) shown in FIG. 16;
FIG. 18 is a diagram showing service information collection processing of a service search apparatus (service search program; FIG. 6).
FIG. 19 is a flowchart showing service information collection processing (S22) of the service search device (service search program; FIG. 6).
FIG. 20 is a flowchart showing a process (S24) in which the service information collection unit 40 of the service search device (service search program) deletes the service information.
FIG. 21 is a diagram illustrating processing in which a service search device registers cluster information in a directory device.
FIG. 22 is a first diagram showing the overall operation of the primary service search device (service search program) of the network 12A.
FIG. 23 is a second diagram showing the overall operation of the primary service search device (service search program) of the network.
FIG. 24 is a diagram showing a configuration of a second service search program according to the present invention.
FIG. 25 is a diagram showing a configuration of a second search range setting unit according to the present invention.
[Explanation of symbols]
1,5 ... Wide area network
10. Geographic space
12 ... Network
16: Client device
18 ... Server device
22 ... Router device
24 ... Firewall device
3. Service search device
4,7 ... Service search program
40 ... Service information collection department
42, 52 ... Search range setting section
420 ... Clustering unit
422, 520 ... Mutual discovery part
424 ... Search range generator
426 ... Network analysis unit
44 ・ ・ ・ Service disclosure department
440 ... Search processing unit
442 ... Public control part
46 ... Service Search Department
48 ... Geographic information converter
52 ... Search range setting section
50 ... Directory device

Claims (2)

A service search device that receives a search condition to which geographical information of a client device is attached from a client device included in the network and searches for a service provided by the service providing device included in the network, wherein the network includes a plurality of networks. The service search device is placed in each of the plurality of areas, one or more,
Service information collection processing for collecting service information including information on the service provided in the area where the service search device is located and including geographical information of the service providing device that provides the service;
Based on geographical information of the service providing device in the network, the search range of the service in the network, the search range including part or all of one or more of the plurality of areas is set. Search range setting means for
Based on the geographical information of the service providing device included in the collected service information , the cluster representative points obtained as a result of clustering the locations of the service providing means included in the area where the service search device is located, and Clustering processing to generate cluster information indicating the size;
Cluster information collection processing for collecting cluster information generated in other areas;
Based on the geographical information of the client device attached to the search condition and the cluster information generated in the same region and other regions, a search range including clusters with a short network distance from the client device is set. Search range setting means for performing search range setting processing,
A service search apparatus comprising: service information search processing means for searching for a service provided in the set range from the collected service information. The network is
A registration device for registering a service search device included in the network;
The service search device includes:
A simultaneous broadcast process for requesting a response to the other service search devices in the same network by the simultaneous broadcast process;
When there is no response from the other service search devices in response to the simultaneous broadcast processing, this service search processing device is registered in the registration device as a primary service search processing device that performs service search processing in the network. When there is a response from another service search device, the service search processing device is used as a backup service search processing device for backing up the primary service search processing device, and registration processing for registering in the registration device I have a,
The service search device according to claim 1, wherein only the service search device registered in the registration device searches for a service in a network including the service search device.

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