JP2001125830A - Cache managing device, network system and computer readable recording medium recording program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow plural proxy servers to effectively use information stored in cache. SOLUTION: This cache managing device is provided with a cache arrangement information table 13 obtained by relating plural proxy servers 1 and 2 with information stored by cache storing means 11 and 12 of each proxy server 1 and 2. Also, when any information to be accessed is not stored in the cache storing means of the accessed proxy server, an inquiry for whether or not the information to be accessed is held in the cache storing means of the other proxy server is transmitted by a cache transmitting means 3a. Then, at the time of receiving the inquiry from a cache retrieving means 3c, a cache information retrieving means 4c refers to the cache arrangement information 13, and when the information to be accessed is held in the cache storing means of the other proxy server, the proxy server which holds the information to be accessed is communicated to the accessed proxy server so as to be accessed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cache management device for managing the contents of a cache storage device provided in a proxy server, a network system, and a computer-readable recording medium on which a program is recorded.

[0002]

2. Description of the Related Art In general, a WWW (World Wide Web) proxy server accesses a server on an external network on behalf of a user who accesses an external network (Internet) from an internal network (intranet). And returns the accessed information to the users on the internal network.

Further, the WWW proxy server is provided with a cache storage device for temporarily storing information, and frequently accessed information is provided to the user from the cache storage device.

By operating such a WWW proxy server as a proxy for a user's access request to an external network, only the WWW proxy server can be seen from the outside, and there is an advantage that security is enhanced.

[0005] Further, by providing the WWW proxy server with the cache storage device, there is an advantage that unnecessary access to the upstream WWW server (in some cases, on the external network) is not caused.

[0006] With the recent development of information transmission using WWW, access to WWW servers has been increasing.
The load on the WW proxy server is also increasing. Therefore, it is common to employ a system configuration in which a plurality of WWW proxy servers are installed to distribute the load accompanying an increase in user access.

[0007]

However, when a plurality of WWW proxy servers are installed as described above, the information in the cache storage device is distributed for each WWW proxy server.

Therefore, for example, when a certain user accesses a WWW proxy server that does not have necessary information in the cache storage device by distributing the load, even if another WWW proxy server stores the necessary information in the cache storage device. Even if you do, that information will not be used.

In this case, the accessed WWW proxy server accesses an upstream WWW server. That is, by providing a plurality of WWW proxy servers, there is a problem that the hit ratio to the cache storage device is reduced, and the effect of using the cache storage device is reduced by distributing the load.

[0010] When a user terminal accesses an arbitrary WWW proxy server among a plurality of WWW proxy servers for load distribution, WWW information originally having a certain relationship (lump) is converted into a plurality of WWW proxy servers. It will be stored across the cache storage of the server. Examples of WWW information having a certain relationship include WWW information relating to the same company and the same industry,
There is WWW information and the like linked by links.

Therefore, a user terminal that has accessed a WWW proxy server that stores only a part of WWW information having a certain relevance,
Only the WWW information stored in the cache storage device of the W proxy server can be retrieved, but the WW of the other parts
W information must make a request to an upstream WWW server. As a result, there is a problem that the traffic increases and the response time felt by the user becomes longer.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a cache management device, a network system, and a program for efficiently accessing information distributed and held in cache storage devices of a plurality of proxy servers. It is an object of the present invention to provide a recorded computer-readable recording medium.

[0013]

The gist of the present invention is that, when a plurality of proxy servers are provided, what kind of information is stored in the cache storage device of each proxy server. is there. Another feature is that if there is information to be accessed in a cache storage device of any of the proxy servers, the proxy server is designated as an access destination.

The first aspect of the present invention relates to a cache management device for managing information stored in cache storage means of a plurality of proxy servers. In the first invention, the storage means stores cache arrangement information in which the plurality of proxy servers are associated with information stored in the cache storage means of each of the proxy servers, and the cache search means stores the plurality of proxy servers. In the case where the access target information is not stored in the cache storage unit of the accessed proxy server, whether the access target information is stored in the cache storage unit of another proxy server different from the accessed proxy server The cache information search unit refers to the cache arrangement information in response to the inquiry from the cache search unit, and the access target information is stored in the cache storage unit of a proxy server different from the accessed proxy server. If this information is stored, Notify accessed proxy server Rokishisaba to be accessed.

In the cache management device according to the first aspect of the invention, if information to be accessed is stored in the cache storage means of any one of the plurality of proxy servers, no matter which proxy server is accessed. The information to be accessed in any of the proxy servers can be effectively used.

Therefore, it is possible to improve the hit ratio to the cache storage device while realizing load distribution between the proxy servers, thereby suppressing traffic and shortening the response time. it can.

According to a second aspect of the present invention, there is provided a cache management device comprising:
However, the storage unit stores, as proxy category information, a category to which information to be stored in the cache storage unit of each proxy server belongs, in addition to the cache arrangement information. Further, the cache information determination unit refers to the storage content of the cache storage unit of each proxy server and the proxy category information,
It is determined whether or not there is information belonging to a category to be stored in the cache storage unit of another proxy server in the cache storage unit of a certain proxy server. When it is determined that there is information belonging to the category to be stored in the cache storage unit of the above, this information is moved to the cache storage unit of the proxy server to be stored.

In the cache management device according to the second invention, since the information belonging to the category is stored in the cache storage means of the appropriate proxy server, the related information is distributed and held in a plurality of proxy servers. Can be prevented.

Therefore, the hit rate can be further improved, and the traffic increase and the response time to the user can be shortened.

The third invention relates to a network system including a plurality of proxy servers each having cache storage means. The network system according to the third aspect of the present invention includes a storage unit for storing cache arrangement information in which a plurality of proxy servers are associated with information stored in cache storage units of the respective proxy servers; When the access target information is not stored in the cache storage unit of the accessed proxy server, an inquiry is made as to whether the access target information is stored in the cache storage unit of another proxy server different from the accessed proxy server. In response to an inquiry from the cache search means and the cache search means, the cache location information is referred to. If the information to be accessed is stored in the cache storage means of a proxy server different from the accessed proxy server, this access A proxy that stores the target information ; And a cache information retrieval means for accessing notifies the server accessed the proxy server.

That is, the network system according to the third aspect of the present invention incorporates the cache management device according to the first aspect of the present invention, and can provide the same effect as the first aspect of the invention.

A network system according to a fourth aspect of the present invention is the same network system as the third aspect of the invention, except that the storage means includes information to be stored in the cache storage means of each proxy server in addition to the cache arrangement information. The category is stored as proxy category information. Also, the cache information determination unit refers to the storage content of the cache storage unit of each proxy server and the proxy category information, and stores the category to be stored in the cache storage unit of another proxy server in the cache storage unit of one proxy server. It is determined whether there is information belonging to. further,
When the cache information determination means determines that there is information belonging to a category to be stored in the cache storage means of another proxy server by the cache information determination means, the information is transferred to the cache storage means of the proxy server to be stored. .

That is, the network system according to the fourth aspect of the present invention incorporates the cache management device according to the second aspect of the present invention, and can achieve the same effects as the first aspect of the invention.

According to a fifth aspect of the present invention, there is provided a storage function for causing a computer to store cache arrangement information in which a plurality of proxy servers are associated with information stored in cache storage means of each proxy server; If the information to be accessed is not stored in the cache memory of the accessed proxy server,
A cache search function for inquiring whether or not the information to be accessed is stored in cache storage means of a proxy server different from the accessed proxy server; and If the information to be accessed is stored in the cache storage means of a different proxy server from the accessed proxy server, the accessed proxy server is notified of the proxy server storing the information to be accessed, and the access is performed. And a computer-readable storage medium storing a program for realizing a cache information search function to be performed.

A sixth aspect of the present invention is a computer-readable recording medium on which a program similar to that of the fifth aspect of the invention is recorded. The storage function stores the program in the cache storage means of each proxy server in addition to the cache arrangement information. The category to which the information to be belongs belongs is stored as proxy category information. Also, the computer refers to the storage contents of the cache storage means of each proxy server and the proxy category information, and stores information belonging to a category to be stored in the cache storage means of another proxy server in the cache storage means of one proxy server. A cache information determination function for determining whether or not there is, and when it is determined by the cache information determination function that there is information belonging to a category to be stored in the cache storage unit of another proxy server,
A cache transfer processing function for transferring this information to the cache storage means of the proxy server to be stored is added.

According to the fifth and sixth aspects of the present invention,
And a computer-readable storage medium storing a program for realizing the function of the cache management device described in the second invention by a computer.

By using a storage medium storing such a program, the above-mentioned functions can be easily added to a computer, a computer, or a network system such as a server which does not have the above-mentioned functions. .

[0028]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a network system provided with a cache management device according to the present embodiment.

The cache management apparatus according to the present embodiment includes a cache information management server 4, an information communication unit 3a as a new element 3 provided in each of the WWW proxy servers 1 and 2, a cache information table creation unit 3b, a cache search. And a cache transfer processing unit 3d.

In FIG. 1, an internal network 5 and an external network 6 are connected by a gateway 7.

The internal network 5 includes a cache information management server 4 and a plurality of WWW proxy servers 1 and 2 for load distribution. Each of the WWW proxy servers 1 and 2 is a local network including a user terminal 8. 9 and 10 are connected.

Each user terminal 8 is set so that all requests for WWW information first access the closest WWW proxy server. That is, the user terminal 8 connected to the local network 9 first accesses the WWW proxy server 1, and the user terminal 8 connected to the local network 10 first
Access the proxy server 2.

W requested to be accessed by the user terminal 8
If the WWW information does not exist in the cache storage devices 11 and 12 of all the WWW proxy servers 1 and 2, the accessed WWW proxy server owns the WWW information requested to be accessed by the user terminal 8 via the external network 6. Connect to the WWW server to be performed by proxy.

Although the case where two WWW proxy servers 1 and 2 are provided is illustrated here, the number may be three or more. Further, the cache information management server 4 may exist in any of the WWW proxy servers.

Hereinafter, the configuration of the cache management device according to the present embodiment will be described. First, the configuration of the cache information management server 4 which is the first element will be described.

The cache information management server 4 includes a cache information storage unit 4a, an information communication unit 4b, a cache information search unit 4c, and a cache information determination unit 4d.

In the cache information storage unit 4a, a cache information table (cache arrangement information) 13 and a Web
The proxy category table 14 is stored.

The cache information table 13 indicates which WW
This is a table for managing what WWW information is stored in the W proxy servers 1 and 2. For example, each W
URL of WWW information stored in each cache storage device 11, 12 for each of the WWW proxy servers 1, 2.
Is stored. Here, the URL “WWW.Acompany.c” indicating the homepage of “Company A” is stored in the WWW proxy server 1.
o.jp "and the URL" WWW.
Bcompany.co.jp "and a URL" WWW.Acompany.Dgroup.co.jp "indicating the homepage of" Company B D group "are stored. Also, the WWW proxy server 2 has a UR indicating the homepage of "C University E Class".
L "WWW.Cuniversity.Eclass.com" is stored.

The Web proxy category table 14 is
This is a table for managing which category of information should be stored in each WWW proxy server 1, 2. Here, since the department related to the local area 9 has a transaction with “Company A” and “Company B”, the information including the designation “Acompany” and the information including the designation “Bcompany” in the URL are transmitted to the proxy server 1. Category that should be stored. In addition, since the department related to the local area 10 has a technical tie-up with “University C”, the information that includes the designation “Cuniversity” in the URL is a category to be stored in the proxy server 2.

The information communication section 4b communicates with each of the WWW proxy servers 1 and 2.

When the cache information search unit 4c receives an information search request (inquiry) from the WWW proxy servers 1 and 2 through the information communication unit 4b, the cache information search unit 4c refers to the cache information table 13 of the cache information storage unit 4a and receives the request. A search is made for which WWW proxy server stores the WWW information in the cache storage device. As a result of the search, if a WWW proxy server holding the requested WWW information is found, the address of the WWW proxy server is returned to the inquiry source via the information communication unit 4b. On the other hand, if no WWW proxy server that stores the requested WWW information is found, the fact is returned through the information communication unit 4b.

The cache information determination unit 4c receives a list of URLs related to WWW information stored in the respective cache storage devices 11 and 12 from the respective WWW proxy servers 1 and 2 through the information communication unit 4b. Further, the received list is read from the top in order, and the cache information storage unit 4
a, referring to the Web proxy category table 14 in
Cache storage device 1 of each WWW proxy server 1, 2
It is determined whether the WWW information in 1 and 12 should be stored as it is, or if the WWW information is to be moved in order to combine information of the same category, which WWW proxy server should be the destination. Based on the determination result, the address of the WWW proxy server to which certain WWW information is moved is returned to the list transmission source WWW proxy server through the information communication unit 4b.

As a specific method of judging whether or not to move, for example, the Web proxy category table 14
A method for determining whether or not the category name in the URL is included in the URL can be used, and various other methods can also be used.

Next, a new element 3 (the information communication unit 3a, the table creation unit 3b, the cache search unit 3c, the cache transfer unit) of the WWW proxy servers 1 and 2, which are the second elements of the cache management device according to the present embodiment. The processing unit 3d) will be described.

In addition to the new element 3, the WWW proxy servers 1 and 2 having the new element 3 include, for example, the cache storage devices 11 and 12, the user terminal 8, and the HTTP terminal.
It has a configuration and functions as a general proxy server, such as a function of exchanging by protocol. In the following, the new element 3 provided in the WWW proxy server 1 will be described, and the case where the new element 3 is provided in the WWW proxy server 2 will not be described because it is the same.

The information communication unit 3a is an information communication unit 3a of the cache information management server 4 or another WWW proxy server 2.
Communication with the

The table creator 3b checks the URL of the WWW information stored in the cache storage device 11 provided together with the WWW proxy server 1 as appropriate, and based on the contents, via the information communication units 3a and 4b. The contents of the cache information table 13 are updated.

When the WWW information requested from the user terminal 8 does not exist in the cache storage unit 11, the cache search unit 3c sends an information search request asking which WWW proxy server holds this information, in the information communication unit. 3a
To the cache information management server 4 through The WWW proxy server 1 determines the requested W based on the content of the response to the information search request.
The WW information will be accessed.

The cache transfer processing unit 3d updates the WWW information relating to the WWW information in the cache storage device 11 provided together with the WWW proxy server 1 at every set time.
The RL list is sent to the cache information management server 4 through the information communication unit 3a.

Further, the cache transfer processing unit 3d
Based on the transmitted URL list response (including the WWW information to be moved and the destination address designation), the WWW information to be moved in the cache storage device 11 is moved using a data transfer means such as FTP. Move to the WWW proxy server specified as the destination.

The operation of the network system provided with the cache management device according to the present embodiment having the above configuration will be described below.

FIG. 2 is a flowchart showing the operation when the user terminal 8 accesses the WWW proxy server 1.

First, the WWW proxy server 1 receives a request for WWW information from the user terminal 8 (s11).

As a result, the cache search unit 3c of the WWW proxy server 1 sends its own cache storage device 11
A search is made to determine whether the requested WWW information is stored in the storage device (s12).

If the cache storage device 11 stores the requested WWW information, it means that the cache has been hit, and this WWW information is returned to the user terminal 8 (s13).

On the other hand, own cache storage device 1
1 does not hold the requested WWW information, the cache search unit 3c sends the WWW information to the cache information search unit 4c of the cache information management server 4 via the information communication units 3a and 4b. (Step s14). This inquiry includes designation of WWW information requested from the user terminal 8.

The cache information search unit 4c searches the cache information table 13 and checks whether the requested WWW information exists in the cache storage device of another WWW proxy server (s15).

If the requested WWW information does not exist in the cache storage device of another WWW proxy server, the fact is notified to the WWW proxy server 1 which made the inquiry from the cache information management server 4 (s1).
6) Based on the notification, the WWW proxy server 1 accesses the WWW information using the normal HTTP protocol to the upstream WWW server (s17).

On the other hand, the requested WWW information is stored in another WWW.
If it exists in the cache storage device of the proxy server, the address of the WWW proxy server holding the WWW information is notified to the inquiring WWW proxy server 1 (s18).

When the WWW proxy server 1 receives the notification, the WWW proxy server 1 indicates to the WWW proxy server
Access is made by normal processing using the TP protocol (s19).

Then, the accessed WWW information is transmitted from the WWW proxy server 1 to the user terminal 8 (s20).

FIG. 3 is a flow chart showing the operation when the WWW information in the cache storage device 11 of the WWW proxy server 1 is moved.

First, when a certain set time comes, the cache information judgment unit 4d of the cache information management server 4
It requests the W proxy server 1 for a list of URLs related to WWW information currently stored in the cache storage device 11 (s21).

Based on this request, the cache transfer processing unit 3d of the WWW proxy server 1 returns a list of URLs related to WWW information in the cache storage device 11 to the cache information management server 4, and the cache information of the cache information management server 4 The determination unit 4d receives this response (s22).

The cache information determination unit 4d sequentially reads the URLs contained in the received list, and determines to which category of the Web proxy category table 14 the WWW information indicated by the read URL belongs. Then, it is determined whether there is consistency between the WWW information indicated by the read URL and the contents specified in the Web proxy category table 14 (s23).

If there is no consistency, WWW to be moved
The designation of the information and the IP address of the WWW proxy server that should store the category to which the WWW information belongs are notified to the cache transfer processing unit 3d of the WWW proxy server 1 (s24).

In the cache move processing unit 3d of the WWW proxy server 1, the WW to be moved in the notification
The W information is extracted from the cache storage device 11 and moved to the WWW proxy server designated as the destination (s25).

As described above, the cache management device according to the present embodiment is provided in the internal network 5 including the plurality of WWW proxy servers 1 and 2.

By applying this cache management device, an access request to WWW information from the user terminal
If the request is received by the WW proxy server but does not store the requested WWW information in its own cache storage device, and it is necessary to access the upstream (possibly external) WWW server originally, the request is issued. Done W
An inquiry (information search request) is made from the accessed WWW proxy server to the cache information management server 4 as to whether the WWW information is not in the cache storage device of another WWW proxy server.

In the cache information management server 4, WWW
In response to an inquiry from the proxy server, the cache information search unit 4c searches the cache information table 13 to determine which WWW proxy server has the requested WWW information, and the search result is the WWW of the inquiry source. Return to proxy server.

Thus, if the search result from the WWW proxy server indicates another WWW proxy server in the same internal network 5, the WW that has received this result
The W proxy server requests WWW information from the WWW proxy server indicated by the result.

Therefore, the cache storage device 1 of the WWW proxy servers 1 and 2 in the internal network 5
The WWW information stored in 1 and 12 can be effectively used.

Also, while realizing load distribution between the WWW proxy servers 1 and 2, the cache storage devices 11 and 12
The hit rate to the server can be improved, whereby the traffic can be suppressed and the response time can be shortened.

Further, by applying the cache management device according to the present embodiment, what information is to be stored in advance for each of a plurality of WWW proxy servers, information relating to the category is stored in the Web proxy category table 14,
A list of WWW information stored in each cache storage device is periodically acquired from a plurality of WWW proxy servers, and this list and the Web proxy category table 14 are acquired.
Of each WW by the cache information determination unit 4d based on the content of
W proxy servers 1 and 2 are WW for each determined category
Movement is required to retain W information.

In response to this request, the WWW proxy servers 1 and 2 receive another request by the cache transfer processing unit 3d.
Transfer processing of WWW information is performed with the W proxy server.

Thus, WWW information having a certain relationship can be collectively held in a certain WWW proxy server, and as a result, the user can obtain the necessary WWW information.
W information can be efficiently extracted from one WWW proxy server.

Therefore, the hit rate can be further improved, the traffic can be increased, and the response time to the user can be shortened.

In the cache management device according to the above-described embodiment, the arrangement of each component may be changed as long as the same operation and function can be realized, and each component may be freely combined. .

Each function and each element of the cache management device according to the above-described embodiment are, for example, a magnetic disk (floppy disk, hard disk, etc.), an optical disk (CD-ROM, DVD) as a program that can be executed by a computer. Etc.), it is also possible to write and apply to a recording medium such as a semiconductor memory or to transmit by a communication medium and apply to a computer such as a server, a network system, or a proxy server. The computer that realizes each of the above functions reads the program recorded on the recording medium, and executes the above-described processing by controlling the operation of the program.

[0081]

As described in detail above, when the present invention is applied, in a network system having a plurality of WWW proxy servers arranged for load distribution,
Information possessed by the cache storage device of the proxy server can be efficiently provided to the user.

As a result, the efficiency of disk occupancy in the cache storage device can be improved, and the user response speed can be improved by improving the cache hit rate. Similarly, an effect of preventing unnecessary traffic from being generated can be obtained by improving the cache hit rate.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a network system including a cache management device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing an operation when a user terminal accesses a WWW proxy server.

FIG. 3 is a flowchart showing an operation when information in a cache storage device of the WWW proxy server is moved.

[Explanation of symbols]

 1, 2 WWW proxy server 3 New element 3a, 4b Information communication unit 3b Table creation unit 3c Cache search unit 3d Cache transfer processing unit 4 Cache information management server 4a Cache information storage unit 4c Cache information Search unit 4d Cache information determination unit 5 Internal network 6 External network 7 Gateway 8 User terminal 9, 10 Local network 11, 12 Cache storage device 13 Cache information table 14 Web proxy category table

Claims (6)

[Claims] 1. A cache management device for managing information stored in cache storage means of a plurality of proxy servers, wherein the plurality of proxy servers and information stored in the cache storage means of each of the proxy servers are stored. A storage unit for storing the associated cache arrangement information; and if the access target information is not stored in the cache storage unit of the accessed proxy server among the plurality of proxy servers, the storage unit is different from the accessed proxy server. A cache search unit for inquiring whether or not information to be accessed is stored in a cache storage unit of the proxy server; and, in response to an inquiry from the cache search unit, referring to the cache arrangement information and accessing the proxy server. Another proxy server cache storage hand Cache information search means for notifying the accessed proxy server of the proxy server storing the access target information and accessing the proxy server if the access target information is stored in the row. Cache management device. 2. The cache management device according to claim 1, wherein the storage unit stores, as proxy category information, a category to which information to be stored in the cache storage unit of each proxy server belongs, in addition to the cache arrangement information. Referring to the storage content of the cache storage unit of each proxy server and the proxy category information, information belonging to a category to be stored in the cache storage unit of another proxy server is included in the cache storage unit of a certain proxy server. A cache information determining unit that determines whether or not there is a proxy server to be stored when the cache information determining unit determines that there is information belonging to a category to be stored in a cache storage unit of another proxy server; A cache that moves this information to the cache storage means A cache management device comprising a transfer processing means. 3. In a network system including a plurality of proxy servers each having a cache storage unit, cache arrangement information in which the plurality of proxy servers are associated with information stored in the cache storage unit of each proxy server is stored. A storage unit for storing, and a cache storage unit of a proxy server different from the accessed proxy server when the access target information is not stored in the cache storage unit of the accessed proxy server among the plurality of proxy servers. A cache search unit for inquiring whether or not information to be accessed is stored in a cache server; and a cache of a proxy server different from the accessed proxy server by referring to the cache arrangement information in response to an inquiry from the cache search unit. For storage means A network system comprising: cache information search means for notifying the accessed proxy server of the proxy server storing the information of the access target and accessing the proxy server if the information of the access target is stored. . 4. The network system according to claim 3, wherein the storage unit stores, as proxy category information, a category to which information to be stored in the cache storage unit of each proxy server belongs, in addition to the cache arrangement information. Referring to the stored contents of the cache storage unit of each proxy server and the proxy category information, there is information belonging to a category to be stored in the cache storage unit of another proxy server in the cache storage unit of another proxy server. Cache information determining means for determining whether or not there is information belonging to a category to be stored in the cache storage means of another proxy server by the cache information determining means; A cache that moves this information to storage means A network system characterized by adding a queue movement processing means. 5. A storage function for causing a computer to store cache arrangement information in which a plurality of proxy servers are associated with information stored in cache storage means of each of the proxy servers; If the access target information is not stored in the cache storage unit of the proxy server that has been accessed, an inquiry is made as to whether the access target information is stored in the cache storage unit of a proxy server different from the accessed proxy server. A cache search function, in response to an inquiry by the cache search function, the cache arrangement information is referred to, and if information to be accessed is stored in a cache storage unit of a proxy server different from the accessed proxy server, Memorize the information to be accessed A computer-readable storage medium storing a program for realizing a cache information search function of notifying an accessed proxy server of a proxy server being accessed and accessing the proxy server. 6. A computer-readable recording medium storing the program according to claim 5, wherein the storage function includes information to be stored in a cache storage unit of each proxy server in addition to the cache arrangement information. The category is stored as proxy category information, and the computer is made to refer to the storage content of the cache storage unit of each proxy server and the proxy category information, and stores the cache of another proxy server in the cache storage unit of one proxy server. A cache information determining function for determining whether or not there is information belonging to a category to be stored in the means; and the cache information determining function determines that there is information belonging to a category to be stored in the cache storage means of another proxy server. Should be remembered if Shisaba computer-readable recording medium recording a program which adds a cache movement processing function of moving the information in the cache storage means.