JP3290801B2 - Resource location detection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting a resource location,
In particular, the present invention relates to a resource location detection method for detecting the location of resources such as databases managed in a distributed network system.

[0002]

2. Description of the Related Art Conventionally, a method for detecting in which server system resources such as a database which is distributed and managed in a distributed network system exists,
Generally, there are two types.

FIG. 7 is a schematic configuration diagram of one of the methods, which requires a server that collectively manages the locations of resources. In FIG. 7, a communication path 70 includes a client 71 that issues a resource access request and a resource location storage server 72 that collectively manages the locations of resources.
And the servers 73 and 74 having resources are connected, and a distributed network system is constructed.

FIG. 8 is a flowchart showing the operation of the client 71. The operation of the client 71 for detecting the location of a resource will be described.

[0005] When the client 71 receives an access request for a resource from the access request program on the client 71 (step 801), it inquires of which server the resource to be accessed to the resource location storage server 72 exists. (Step 802). When the server having the resource is notified from the resource location storage server 72 (step 803), the client 71
A resource access request is issued to the server (step 804), and the resource is used.

FIG. 9 is a schematic block diagram of another system for detecting the presence of a resource, in which a request for access to the resource is issued to all servers in the distributed network system. In FIG. 9, a client 91 that issues a resource access request and servers 92 and 93 having resources are connected to a communication path 90, and a distributed network system is constructed.

FIG. 10 is a flowchart showing the operation of the client 91. The operation of the client 91 for detecting the location of a resource will be described.

When the client 91 receives an access request for a resource from the access request program on the client 91 (step 1001), it inquires of all servers 92 and 93 in the network system whether or not there is a resource (step 1002). . Only servers with resources will respond to this query, other servers without resources will not. Client 91
Receives the response from the server having the resource, knows the existence of the server (step 1003), and issues a resource access request to the server (step 1010).
04), use resources.

[0009]

However, in the former method, which requires a server that collectively manages the locations of resources, a large load is placed on the resource location storage server 72 as the number of clients or resources increases. I will.

On the other hand, the latter method of issuing a resource access request to all servers in a distributed network system leads to an increase in traffic on a communication path, which may lower the performance of the entire network system.

As described above, in any of the conventional methods, the efficiency of detecting the location of resources is reduced with an increase in the scale of a distributed network system or an increase in resources.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to efficiently locate a resource even if a large number of clients or resources exist in a distributed network system. Provides a detectable resource location scheme.

[0013]

Resource location detection method according to the present invention in order to achieve the object described above SUMMARY OF THE INVENTION comprises a plurality of server system with resources, resources in the server system via the communication means It includes a client system that issues the access request, and in a distributed network system for managing resources in a network system is dispersed, the client system, self Accession
The resource accessed and the location of the resource at the time of access
Resources that are associated with the server system
A resource location information table held as information; a resource location information management means for searching and updating resource location information with respect to the resource location information table; and a resource location information table.
Server system by referring to the file
To and a resource location information control means for issuing a request for access resources, the server system, the self-in current
What resources you own and what you own in the past
The server system to which the resource was transferred
A resource holding information table that holds the resource as resource holding information, a resource holding information managing unit that searches and updates the resource holding information in the resource holding information table, and a control and resource of the resource holding information managing unit. Resource holding information control means for managing the resource location information management means
Server system in response to a resource access request.
Destination server included in the travel notification information sent from the
Registered in the resource location information table
Update the location of the resource, and manage the resource holding information.
The means is that the resources owned by the other server system
When the resource is moved to the destination server system
And register it in the resource holding information table
Things .

Further , a server system to which the resources are transferred
The resource holding information management means in the system is moved
The resource holding information table using the
It is to register in the file .

[0015] The resource holding information management means may include:
For resources registered in the resource holding information table,
The time when the access request was made to correspond to the resource
It is recorded in the resource holding information table .

Further, the resource holding information management means includes
Resource retention for resources previously held on request
Information that has not been accessed for a predetermined period of time
It is to be deleted from the source holding information table .

[0017]

Further , the resource location information control means, if the resource to be accessed is not registered in the resource location information table or if there is no response to the access request from the server system, The resource location is inquired to the system by broadcast, and the resource location information
The location information table in the server system corresponding to the cast
Updates the location of the resource registered in the file
It is .

[0019]

In the resource location detection method according to the present invention having the above-described configuration, when a client system receives an access request to a resource, the client system searches the resource location information table and registers the resource location information table. Issues an access request to the existing server system. By receiving the request acceptance from the server system, the client system can detect the server system that is the resource location.

Further, in response to an access request from a client system, the server system notifies the client system of movement notification information including the destination server system when the resource requested by the access request is moved to another server system. I do.

Upon receiving the movement notification information, the client system updates the resource location information table in the destination server system. Further, by issuing an access request to the server system at the destination again and receiving the request acceptance from the server system, it is possible to detect the server system at the resource location.

On the other hand, when the server system moves the resource to another server system, the server system registers the destination server system in the resource holding information table, and thereafter, responds to an access request from the client system. Can be notified to the client system, and the location of the resource can be easily detected by the client system.

Further, the destination server system registers the moved resource in the resource holding information table, so that the client system can easily detect the location of the resource thereafter.

Further, since the time when there is an access request to the own server system is recorded, resource holding information that has not been accessed for a predetermined period can be deleted from the resource holding information table.

By issuing a broadcast only when the server system is not registered in the resource location information table or when there is no response from the server system, the location of the resource can be prevented while preventing an increase in traffic on the communication path. Can be detected.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram showing an embodiment of a resource location detection system according to the present invention. In FIG. 1, a server system 21 having resources such as a database and a client system 11 for issuing a request to access resources to the server system 21 are connected to a communication path of the distributed network system.

The client system 11 stores a resource location information table 12 which stores resource location information indicating which server system 21 the resource to be accessed exists, and searches and updates the resource location information in the resource location information table 12. Search unit 1 for searching as resource location information management means to be performed
3 and an updating unit 14 for updating. In the resource location information table 12, resources and server systems having the resources are registered in association with each other.

Further, the client system 11 is provided with a communication unit 16 as communication means for communicating with the server system 21.
A resource location information control unit 15 as resource location information control means for controlling the search unit 13, the update unit 14, and the communication unit 16.
And an access request program execution unit 17 for executing a program for requesting access to resources.
The resource location information control unit 15 receives a resource access request from the access request program execution unit 17, issues a search instruction to the search unit 13, an update instruction to the update unit 14, and a communication unit 16. It issues a resource access request, accepts a response from the server system 21 to the resource access request via the communication unit 16, determines the content of the response, and issues a broadcast transmission instruction.

On the other hand, the server system 21 includes a resource holding information table 22 for holding resource holding information indicating whether the resource requested to be accessed by the client system 11 exists in the server system itself or has been moved to another server system. A search unit 23 that searches for resources as a resource holding information management unit that searches for and updates resource holding information with respect to the holding information table 22, and an updating unit 24 that performs updating
And In the resource holding information table 22, the resources of the own server system 21 and the time when there is an access request to the resources are registered. However, if the resource moves to another server system 21,
The server system 21 as the destination is registered.

Further, the server system 21 includes a communication unit 26 as a communication unit for communicating with another system,
3. It has a resource holding information control unit 25 as resource holding information control means for controlling the updating unit 24 and the communication unit 26. The resource holding information control unit 25 receives a resource access request from the client system 11 via the communication unit 26, issues a search instruction to the search unit 23,
It issues an update instruction to the update unit 24, a response of an access result to the resource access request via the communication unit 26, and accepts a resource move instruction. Further, it has a resource storage unit 28 for storing resources managed by its own server system 21.

Although the distributed network system in this embodiment includes a plurality of server systems, only one server system 21 is shown in FIG.

The feature of the present embodiment is that the server system 21 having the resource which is the object of the access request is detected by using the resource location information and the resource holding information. This makes it possible to detect the server system 21 without requiring a server system for collectively managing the locations of resources and without issuing access requests to all server systems every time an access request is issued. .

FIG. 2 is a flowchart showing a process for detecting a resource location in the client system 11. The operation from issuing an access request in the client system 11 to detecting the resource location in the client system 11 will be described with reference to FIG. Will be described.

When an access request to a certain resource is received from the access request program (step 201), the resource location information table 12 is searched to check whether there is a server system 21 having the resource (step 202).

In step 203, if the server system 21 is detected, an access request is issued to the server system 21 (step 204). If the response from the server system 21 to which the resource is issued is accepted (step 207), the resource location information table 12 is updated and the detection of the location of the resource is completed (step 21).
0). Note that in this case, the updating process only involves overwriting with the same server system name having the resource, so that there is no need to actually update.

In this manner, the location of a resource can be detected only by issuing an access request to only the server system 21 having the resource for which the access is requested.

If it is determined in step 207 that the response from the server system 21 that is the destination of the request is not accepted, it is checked whether or not the response from the server system 21 is movement notification information (step 208). Here, when the server system 21 cannot hold the resources held by the server system 21 due to the limitation of the system resources such as the storage capacity and the system load, the resources are moved to another server system. (Step 205). In this case, the server system 21 having received the access request responds to the client system 11 by adding the server system to which the resource has been moved to the movement notification information.
Therefore, when the response from the server system 21 is the movement notification information, the client system 11 issues an access request again in the destination server system included in the movement notification information (Step 204). As a result, by repeating the same processing as described above, the request acceptance is received from the server system 21 (step 207), the resource location information table 12 is updated, and the detection of the resource location is completed (step 210).

As described above, even if the resource to be accessed is moved, the server system 21 having the resource can be detected by sequentially searching for the server system. Therefore, since an access request can be issued to the server system as an alternative, the location of the resource can be detected without imposing a load on the communication path.

On the other hand, if the server system 21 having the resource which is the object of the access request is not detected from the resource location information table 12 in step 203, a broadcast for asking the location of the resource is issued. Alternatively, if there is no response from the server system 21 in step 208, a broadcast is issued (step 20).
6). Upon receiving the broadcast, the server system 21 having the resources included in the broadcast responds to the client system 11 to that effect. As a result, the client system 11 proceeds to step 209
When the server system 21 that is the resource holding destination is detected by the response from the server system 21, the resource location information on the resource and the server system 21 that is the holding destination is registered in the resource location table 12 (step 21).
0), the detection of the location of the resource ends.

If there is no response from any of the server systems 21 in step 209, it is determined that this resource does not exist in the distributed network system, and an access failure is notified to the access request program execution unit 17 (step 211). ), And terminate the process.

As described above, when the server system 21 is registered in the resource location information table 12, an access request is issued only to the server system 21, and when the server system is not registered in the resource location information table 12, By issuing the broadcast only when there is no response from the server system 21, it is possible to prevent unnecessary increase in traffic on the communication path.

FIG. 3 is a flowchart showing processing for detecting a resource location in the server system 21. Next, referring to FIG.
The operation until responding to 1 will be described.

When a request to access a resource is received (step 301), the resource holding information table 22 is searched,
The presence or absence of resource holding information of the resource is checked (step 30).
2). The present embodiment is characterized in that, when the resource is found as a result of the search (step 303), the time when there is an access request is recorded in the resource holding information table 22 in association with the resource. If it has already been recorded, it will be updated (step 304).

In step 305, another server system name is stored in the resource holding information table 2 in association with the resource.
If the resource has been registered in the client system 11, it is determined that the resource has been moved to the server system, and the destination server system is added to the movement notification information.
Is notified of the movement notification information as a response to the access request (step 306). If another server system name is not registered in association with the resource, the server system 21 notifies the client system 11 that the resource exists in the server system 21 as a response to the access request (step 307). ).

As described above, the server system 21
The response to the access request from the client system 11 is notified.

FIG. 4 is a flowchart showing a resource transfer process when another server system receives a resource transfer request from the server system that is the transfer source. The resource transfer process in the server system to which the resources are transferred will be described with reference to FIG.

When the resource transfer destination server system receives the resource transfer request from the resource transfer source server system (step 401), it performs the resource transfer (step 402). This transfer of resources is transferred to another server system that is capable of acting as a resource preservation agent because of the limitation of system resources such as storage capacity and system load in the source server system, more efficient operation, and equalization of access frequency. When the system administrator or the like determines that it is better to move, it is performed according to the instruction of the system administrator. In step 403, if the resource is the resource holding information table 2
Check if it already exists in 2. If the resource is detected in step 404, the resource holding information table 2
The destination server system registered corresponding to the resource is deleted from Step 2 (Step 405). This indicates that the resource has been held in the server system. On the other hand, if the resource is not detected, the resource is registered in the resource holding information table 22 (step 40).
6). In this way, resources can be moved between server systems.

Next, a description will be given of the resource transfer processing in the server system from which the resources are transferred, corresponding to the resource transfer processing in the server system to which the resources are transferred shown in FIG. FIG. 5 is a flowchart showing this processing, and the processing will be described with reference to FIG.

As described above, the transfer of resources is performed according to the instruction of the system administrator. Therefore, upon receiving the resource transfer request (step 501), the source server system 21 issues a resource transfer request to another server system (step 502), and then transfers the resource (step 503). Thereafter, the server system name of the transfer destination is registered in the resource holding information table 22 in association with the resource (step 504).

As a result, since it is known that the resources have been moved from the own server system 21 to another server system, the detection of the location of the resources by the client system 11 can be achieved.

By the above processing, the resource holding information table 22 in each server system 21 stores the resource holding information relating to the resources owned by the own server system and the resources previously held by the own server system and moved to another server system. Is registered. However, if the resource holding information on the resources that have not been accessed for a predetermined period is held, an increase in the amount of information leads to an increase in search time. Therefore, it is necessary to arrange the resource holding information registered in the resource holding information table 22 in order to achieve high performance.

FIG. 6 is a flowchart showing a process for organizing the resource holding information in the resource holding information table 22 in the server system 21. The process will be described below with reference to FIG.

The server system 21 receives a request for organizing the resource holding information table 22 from the system administrator or the management system of the server system (step 60).
1) The resource holding information relating to the moved resource that has not been accessed after the period or the date indicated by the organizing request is deleted from the resource holding information table 22 (step 602). The time when the server system 21 was accessed is recorded for each resource as shown in the processing in FIG.

As described above, the resource holding information table 2
2 can be arranged, so that a decrease in performance due to an increase in the amount of information can be prevented.

As described above, according to the present embodiment, by providing the resource location information and the resource holding information to the client system 11 and the server system 21, respectively,
Even if it is not necessary to provide a server system for centrally managing the locations of resources, and even if it does not issue access requests to all server systems every time an access request is issued, a server system having resources to be accessed can be created. Can be detected.

In order to make the above embodiment easier to understand, the client system 11 that issues an access request and the server system 21 that has resources are separated so that each has resource location information and resource holding information.
Each node constituting the network system may have both functions.

[0058]

Effects of the Invention] According to the present onset Akira, client system
Information about the resources accessed by the server system
In the current or past possession of
Only have information about resources
So between client and server, and each server system
The amount of information exchanged as resources are transferred between resources
be able to. This allows many clients or
Means information management and resource location, even if resources exist
Position can be detected efficiently .

[0059] Further, even if the location of the resource to be accessed is moved, the server appropriate in response to the access request
Registered in the resource location information table at the destination server system included in the movement notification information sent from the system
Since so as to update the location of the resources are, the client system can be readily detected location of the resource by issuing a direct access request future destination server system.

[0060] In addition, by registering the server system to move the resources to the resource holding information table of the moving source of the server system, is easily detected even when moving the resources a location of resources on a client system Can be. In addition, information on the transfer of resources
Since it is not distributed to an external server system, resources
May cause an increase in traffic on the communication path due to the movement of
No.

[0061] Also, since so as to register the resource in the resource holding information table of resources moving destination becomes the server system, be detected easily even when moving the resources a location of resources on a client system I can .

[0062] In addition, since the to record the time when for which the access request, it is possible to remove the resource holding information that is not predetermined period access from the resource holding information table. Therefore, it is possible to prevent a decrease in performance due to an increase in the amount of information.

[0063] Also, if the server system is registered in the resource location information table, and issues only the access request the server system, the response from the case or the server system resource location information table server system not registered By issuing a broadcast only when there is no resource, it is possible to detect the location of the resource while preventing an increase in traffic on the communication path.

As described above, according to the present invention, it is possible to cause the client system to easily and selectively detect the location of the resource without requiring a server system for collectively managing the location of the resource. .

Further, it is not necessary to issue an access request to all server systems every time an access request is issued, and the client system can selectively detect the location of the resource, thereby increasing traffic on the communication path. It is possible to prevent the performance of the entire network system from deteriorating.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a resource location detection method according to the present invention.

FIG. 2 is a flowchart illustrating a process of detecting a resource location in a client system in the present embodiment.

FIG. 3 is a flowchart illustrating a process of detecting a resource location in a server system in the present embodiment.

FIG. 4 is a flowchart illustrating a resource transfer process in a server system to which a resource is transferred in the embodiment.

FIG. 5 is a flowchart illustrating a resource transfer process in the server system that is the transfer source of the resource in the embodiment.

FIG. 6 is a flowchart illustrating a process of organizing resource holding information in a resource holding information table in a server system in the present embodiment.

FIG. 7 is a schematic configuration diagram of a conventional location detection method that requires a server that collectively manages the locations of resources.

FIG. 8 is a flowchart showing the operation of the method shown in FIG.

FIG. 9 is a schematic configuration diagram of a location detection method for issuing a resource access request to all servers in a conventional distributed network system.

10 is a flowchart showing the operation of the method shown in FIG.

[Explanation of symbols]

Reference Signs List 11 client system, 12 resource location information table, 13, 23 search unit, 14, 24 update unit, 15
Resource location information control unit, 16, 26 communication unit, 17 access request program execution unit, 21 server system,
22 resource holding information table, 25 resource holding information control unit.

Continuation of front page (56) References JP-A-4-17056 (JP, A) JP-A-5-225031 (JP, A) JP-A-5-81115 (JP, A) JP-A-4-320550 (JP) , A) JP-A-61-283943 (JP, A) JP-A-5-53896 (JP, A) Maekawa et al., "Distributed operating system-what comes next after UNIX", Kyoritsu Shuppan (1991-11), p. 303 "ACM TRANSACTIONS ON COMPUTER SYSTEM TEMS" VOL. 6, NO. 1 (1 (58) Field surveyed (Int. Cl. ⁷ , DB name) G06F 12/00 G06F 15/16 G06F 17/30

Claims (5)

(57) [Claims] A plurality of server systems having resources;
It includes a client system that issues the access request resources to the server system via the communication means, and in a distributed network system for managing resources in a network system is dispersed, the client system, self access Resources at the time of access
Is associated with the server system where the source was located.
A resource location information table that is stored as resource location information, a resource location information management unit that searches for and updates resource location information with respect to the resource location information table, and a resource location information table that corresponds to the resource location information table.
Issue a resource access request to the server system
Has a resource location information control unit that, the said server system resource itself owns in the current, and odor past
Server system to which resources owned by the
Resource holding information table for holding the resource associated with the system as resource holding information, resource holding information management means for searching and updating resource holding information for the resource holding information table, and resource holding information management Resource holding information control means for controlling means and resource management, wherein the resource location information management means responds to a resource access request.
Move notification sent from the corresponding server system
In the destination server system included in the information,
Updates the location of the resource registered in the report table
And the resource holding information management means stores the resources held by itself.
Is moved to another server system,
The resource holding information is associated with the destination server system.
A resource location detection method characterized by registration in a report table . Wherein prior Symbol the resource holding information management means in the target to become the server system resources, according to claim 1, characterized in that to register the resource holding information table resources which have been moved as a resource holding information The resource location position detection method described . 3. The resource holding information managing means includes:
The time when a access <br/> scan request to the resource registered in the held information table in correspondence with the resource
Claims characterized by recording in a resource holding information table
Item 2. The resource location detection method according to Item 1 . 4. The resource holding information management means according to claim 1, further comprising :
Resource holding information on resources held in the past according to
Information that has not been accessed for a predetermined period of time
4. The method according to claim 3, wherein the information is deleted from the personal information table.
The resource location position detection method described . 5. The resource location information control means according to claim 2, wherein said resource location information control means is configured not to register said resource to be accessed in said resource location information table or to respond to said access request from said server system. query the location of resources in a broadcast to the system, the resource location information management means, depending on the broadcast
Registered in the location information table on the server system
Contract to update the location of the resource
The resource location detection method according to claim 1.