JP2000148644A - Method and system for transferring information, and recording medium stored with information transfer program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase hit ratio by obtaining only information valid for lock- ahead decision from among information obtained once by a proxy computer, and referring to information related with the contents of information of look- ahead object. SOLUTION: When an information request for information reference is issued from a client computer (S1), a proxy computer obtains requested information from a server computer (S2), transfers it to the client computer (S3), and stores look-ahead reference information which is necessary for deciding information for look-ahead at the time of look-ahead (S4). Then, the proxy computer decides on the information for look-ahead by referring to the stored look-ahead reference information (S5) and conducts look-ahead from the server computer (S6). When an information request is issued from the client computer (S7) and the requested information is made corresponding to the look-ahead information, the proxy computer transfers the information to the client computer (S8).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information transfer method and system, and a storage medium storing an information transfer program. More particularly, the present invention relates to a client computer that issues a request on an information communication network and uses a service and a client computer. Improving responsiveness to information transfer requests from clients in a server / client system consisting of a proxy computer that intervenes between a server computer, a client computer, and a server computer on the service providing side and performs proxy access to requests from client computers For this purpose, the present invention relates to an information transfer method and system for realizing a look-ahead method for performing information transfer prior to a request from a client in a proxy computer, and a storage medium storing an information transfer program.

[0002]

2. Description of the Related Art As a method of shortening a response time to an information request from a client, there is a method called "look-ahead". Information accessed on the Internet or an intranet is described in a hypertext format. In this format, as shown in FIG. 7, links to other related information are provided. After the requested information is displayed, the user sees the information on this link and, if necessary,
Request the transfer of the information. The user repeats such an operation one after another.

[0003] Observing the link information with a proxy computer and obtaining in advance the link destination information before receiving a request from a client computer is called "prefetching". If the request from the client computer is information obtained in advance, it is transferred to the client computer as it is. If the information is other than information obtained in advance, the proxy computer transfers the information from the server computer to obtain the information, and transfers it to the client computer.

[0004] The prefetching operation will be described below. FIG.
FIG. 3 is a diagram for explaining a conventional prefetch operation. When a request for information A is made from the client computer to the proxy computer (step 11), the proxy computer requests information A from the server computer (step 12), and transfers the information A from the server computer to the proxy computer (step 11). Step 13). The proxy computer transfers the information A provided from the server computer to the client computer (step 14), and requests (prefetches) information linked from the information A to the server computer (step 15). The server computer transfers the information requested from the proxy computer (Step 16).

When a request for information B is issued from the client computer to the proxy computer (step 1).
7) If the requested information B has already been transferred by prefetching, the proxy computer transfers the requested information B to the client computer (step 18). Otherwise, the proxy computer requests the server computer for the information B (step 19). ). This allows
The server computer transfers the information B to the proxy computer as in step 13 described above (step 20), and the proxy computer transfers the information B to the client computer (step 21).

[0006]

However, in general, the access information on the Internet or an intranet includes a large number of linked information, and since there are a large number of links from the linked information, the information to be prefetched is very small. Is a large number. Also, it is very difficult to predict in advance what kind of request the user will make. Therefore, in order to perform effective prefetching, the probability that the client makes a request for the prefetched information (hit ratio)
Need to be higher.

[0007] In order to perform effective prefetching within a limited resource range, it is necessary to narrow down an effective prefetching target. However, the information to be prefetched is only information of the link destination to the information, and has no information such as the size, format, and attribute of the information. Therefore, there is actually no information for performing effective narrowing. It is useful if there is information on the contents of the file such as the target file size, attribute, and update time as information for determining the prefetch target.

Further, there is a problem that it takes a lot of time to inquire the contents of the target information to the server computer at the time of selecting the prefetch target, which is not suitable for high-speed operation. The present invention has been made in view of the above points, and it is desirable to obtain only information useful for prefetch determination from information once obtained by a proxy computer, and refer to the information on the contents of the prefetch target information. Accordingly, an object of the present invention is to provide an information transfer method and system capable of improving a hit ratio and a storage medium storing an information transfer program.

[0009]

FIG. 1 is a diagram for explaining the principle of the present invention. The present invention (claim 1)
In the proxy computer, in the information transfer method of obtaining information corresponding to the information transfer request from the client computer from the server computer and transferring the information to the client computer, when an information request for information reference is issued from the client computer (Step 1) The proxy computer obtains the requested information from the server computer (Step 2), transfers it to the client computer (Step 3), and determines the prefetch target information for prefetching. The prefetch reference information is stored in advance (step 4), the prefetch target information is determined by referring to the stored prefetch reference information (step 5), prefetching is performed from the server computer (step 6), and the prefetching is performed from the client computer. When an information request is issued (step 7), the requested request is read ahead. If corresponding to the target information, and transfers the information to the client computer (Step 9).

According to the present invention (claim 2), based on the information transferred to the client computer, information linked from the information of the prefetch reference information and information including the information size, attribute, and update time are set as prefetch target candidates. If the prefetch target candidates are listed and stored, the prefetch target candidates are determined by referring to the stored information, and whether or not to perform prefetch is determined. Is read from the server computer.

FIG. 2 is a diagram showing the principle of the present invention. The present invention (Claim 3) is an information transfer system in which the proxy computer 200 acquires information corresponding to an information transfer request from the client computer 100 from the server computer 300 and transfers the information to the client computer 100,
In the proxy computer 200, the client computer 1
When an information request for information reference is issued from 00, the transfer unit 201 acquires the requested information from the server computer 300 and transfers it to the client computer 100.
A prefetching determination information storage unit 202 that stores prefetching reference information including link destinations and information contents necessary for determining prefetching target information when prefetching, and a transfer unit 2
A prefetch information determination unit 203 that determines prefetch target information by referring to prefetch reference information stored in the prefetch determination information storage unit 202 based on the information transferred in step S01.
Prefetching means 204 for prefetching the prefetching target information determined by the prefetching information determining means 203 from the server computer 300, and, when an information request is issued from the client computer 100, the prefetching target information from which the requested request is read. , The prefetch information transfer unit 205 that transfers the prefetch target information to the client computer 100.
And

According to the present invention (claim 4), the prefetch determination information storage means 202 stores prefetch reference information including linked information, a file size, an attribute, and an update time. Means for listing information linked to the prefetch reference information stored in the decision information storage means 202 as candidates for prefetching, and if the listed prefetching candidates are stored in the prefetching determination information storage means 202 A candidate selecting unit that determines whether or not to perform prefetching by referring to the stored information, and, when the prefetching is determined, performs prefetching from the server computer based on the prefetching candidate.

According to the present invention (claim 5), information corresponding to an information transfer request from a client computer is acquired from a server computer, and an information transfer program mounted on a proxy computer for transferring the information to the client computer is stored. A storage medium, wherein, when an information request for information reference is issued from a client computer, the requested information is obtained from a server computer and transferred to the client computer; and the information transferred in the transfer process. Based on the prefetching determination information storage means, the prefetching target information is determined by referring to the link destination and the prefetching reference information including the content of the information necessary for determining the prefetching target information when prefetching is stored. Prefetch information determination process,
A prefetch process for prefetching the prefetch target information determined by the prefetch information determination process from the server computer;
When an information request is issued from a client computer, a prefetch information transfer process for transferring the prefetch target information to the client computer if the requested request corresponds to the read prefetch target information.

According to the present invention (claim 6), in the prefetch information determination process, a list process for listing linked information stored in the prefetch determination information storage means as prefetch target candidates is provided. If the prefetch target candidate has been stored in the prefetch determination information storage means, it is determined whether or not to perform prefetch by referring to the stored information. And a candidate selection process for prefetching from the server computer.

As described above, according to the present invention, when information is acquired from a server computer by a proxy computer, information for linking to the acquired information is acquired in preparation for the next prefetch, and a prefetch candidate is obtained from the acquired information. (Pre-reading target determination information: information such as information size, format, and attributes) is stored. If the corresponding information (or information linked to the information) becomes a target for prefetching in the next prefetching, the stored information (prefetching target determination information: information such as information size, format, attribute, etc.) , As a source of judgment for narrowing down the prefetch target. By using this information, it is possible to obtain not only link information but also useful information on the content of the information at the time of prefetch determination.

[0016]

FIG. 3 shows a network configuration to which the present invention is applied. The system shown in FIG. 1 is a client computer 100 that requests and obtains information, obtains an information request from the client computer 100, transfers the request, and transmits the obtained information to the client computer 100.
, A server computer 300 that provides information corresponding to a request, and a network 400 that connects the proxy computer 200 and the server computer 300.

FIG. 4 shows the configuration of the proxy computer of the present invention. The proxy computer 200 has an information storage device 210, selects information necessary for prefetch selection from information transferred from the server computer 300 to the information storage device 210, and stores the information in the prefetch determination information management table 211. A method of transferring information among the client computer 100, the proxy computer 200, and the server computer 300 in the above configuration will be described below.

It is assumed that the proxy computer 200 performs prefetch processing. FIG. 5 is a sequence chart (part 1) for explaining the information transfer processing of the present invention. Step 101) The client computer 100 requests information A to the proxy computer 200.

Step 102) Proxy computer 200
Transfers the request acquired from the client computer 100 to the server computer 300. Step 103) The server computer 300 transfers the information A corresponding to the request acquired from the proxy computer 200 to the proxy computer 200. Step 104) The proxy computer 200 transmits the information A obtained from the server computer 300 to the client computer 1
Transfer to 00.

Step 105) Proxy computer 200
Stores the prefetch target determination information (information size, format, attribute) of the information A obtained from the server computer 300 and transferred to the client computer 100 in the prefetch determination information management table 211 of the information storage device 210. Step 106) The proxy computer 200 lists information linked from the information A as a prefetch candidate.

Step 107) If the prefetch target determination information is stored in the prefetch target determination information table 211 among the listed information, the information is read. Step 108) The proxy computer 200 determines whether the read information matches the file size, format, and attribute of the information A stored in the prefetch target determination information table 211, and determines the matching prefetch information.

Step 109) Proxy computer 200
Requests the server computer 300 for the determined prefetch information. Step 110) The server computer 300 transfers the requested information to the proxy computer 200. Hold the transferred information. In the above step 105, for example, the first read information shown in FIG. 7 and the contents of the information including the information size, format, and attribute of the information are stored in the prefetch determination information management table 211, and
06, the linked information (information A → information A
a,..., information A → information Az) are listed. In this way, if the information among the listed link destination information matches the content of the information stored in the prefetch determination information management table 211, the information is read from the server computer 300 in step 109.

Next, a case where another information (information B) is requested from the client computer 100 after the above processing is completed will be described. FIG. 6 is a sequence chart (part 2) for explaining the information transfer processing of the present invention. Step 201) The client computer 100 requests information B to the proxy computer 200.

Step 202) Proxy computer 200
Determines whether the requested information B is the prefetch information obtained from the server computer 300 in the above-described step 110, and if not, requests the server computer 300 for the information B. Move to Step 203) The requested information B is stored in the server computer 3.
If the information corresponds to the pre-read information already transferred from 00, the proxy computer 200 transfers the pre-read information to the client computer 100 as information B.

Step 204) Proxy computer 200
Acquires the requested information B from the server computer 300. Step 205) The proxy computer 200 transmits the information B acquired from the server computer 300 to the client computer 1
Transfer to 00. In the present invention, a method for determining prefetch information is not particularly defined, but the following method is an example of determining effective prefetch information.

Since information having a large size takes a long time to transfer, information of a certain size or more is to be prefetched. -Judgment is made based on information attributes (text, still image, moving image, audio, etc.). If a client does not frequently access a large-capacity operation, text and still images are prefetched.

Although the above embodiment has been described based on a series of operations in FIGS. 5 and 6, a disk device connected to a computer used as a proxy computer by constructing this processing as a program, The present invention can be easily realized by storing the program in a portable storage medium such as a floppy (registered trademark) disk or a CD-ROM and installing the program when implementing the present invention.

The present invention is not limited to the above embodiment, but can be variously modified and applied within the scope of the claims.

[0029]

As described above, according to the present invention, of the information once obtained by the proxy computer, only the information useful for the prefetch determination is stored, and the information on the contents of the prefetch target information is referred to. , The hit rate can be improved, and the efficiency of the prefetching method can be increased.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining the principle of the present invention.

FIG. 2 is a principle configuration diagram of the present invention.

FIG. 3 is a network configuration diagram to which the present invention is applied.

FIG. 4 is a configuration diagram of a proxy computer according to the present invention.

FIG. 5 is a sequence chart (part 1) for explaining the information transfer processing of the present invention.

FIG. 6 is a sequence chart (part 2) for explaining the information transfer processing of the present invention.

FIG. 7 is a diagram showing links to related information.

FIG. 8 is a diagram for explaining a conventional prefetch operation.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 client computer 200 proxy computer 201 transfer means 202 prefetch determination information storage means 203 prefetch determination means 204 prefetch means 205 prefetch information transfer means 210 information storage device 211 prefetch determination information management table 300 server computer 400 network

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference)

Claims (6)

[Claims] An information transfer method in which a proxy computer acquires information corresponding to an information transfer request from a client computer from a server computer and transfers the information to the client computer, wherein an information request for information reference from the client computer is provided. Is issued, the proxy computer acquires the requested information from the server computer and transfers the acquired information to the client computer, and sets the prefetch reference information necessary for determining the prefetch target information at the time of prefetch. The information is stored, the prefetch reference information is stored, the prefetch target information is determined, the prefetch is performed from the server computer, and the information request is issued when the client computer issues an information request. Corresponds to the prefetch target information,
An information transfer method, wherein the information is transferred to the client computer. 2. Based on the information transferred to the client computer, information linked from the information of the prefetch reference information and information including an information size, an attribute, and an update time are listed as prefetch target candidates. If the prefetched candidate candidates that have been uploaded are stored, it is determined whether or not to perform prefetching by referring to the stored information. If the prefetching is determined, the information of the prefetching target candidates is stored in the server. 2. The information transfer method according to claim 1, wherein prefetching is performed from a computer. 3. An information transfer system in which a proxy computer acquires information corresponding to an information transfer request from a client computer from a server computer and transfers the information to the client computer. When an information request for information reference is issued, a transfer unit that obtains the requested information from the server computer and transfers it to the client computer, and is necessary for determining prefetch target information when prefetching A link destination, a look-ahead determination information storage unit for storing look-ahead reference information including the content of information, and referring to the look-ahead reference information stored in the look-ahead determination information storage unit based on the information transferred by the transfer unit. Prefetch information determining means for determining prefetch target information, and Read-ahead means for performing read-ahead of the read-ahead information from the server computer; and, when an information request is issued from the client computer, if the requested request corresponds to the read-ahead target information, Information transfer means for transferring information to the client computer. 4. The prefetch determination information storage unit stores the prefetch reference information including linked information, a file size, an attribute, and an update time, and the prefetch information determination unit stores the prefetch information in the prefetch determination information storage unit. Means for listing the linked information of the stored prefetch reference information as prefetch target candidates; and if the listed prefetch target candidates are stored in the prefetch determination information storage means, the information is stored. 4. The information transfer according to claim 3, further comprising: a candidate selecting unit that determines whether to perform prefetching with reference to the information, and, when the prefetching is determined, performs prefetching from the server computer based on the prefetching candidate. system. 5. A proxy computer that acquires information corresponding to an information transfer request from a client computer from a server computer and transfers the information to the client computer.
A storage medium storing an information transfer program, wherein when an information request for information reference is issued from the client computer, a transfer process for acquiring the requested information from the server computer and transferring the information to the client computer; and Based on the information transferred in the transfer process, refer to the prefetch reference information including the link destination necessary for determining the prefetch target information at the time of prefetch stored in the prefetch determination information storage unit and the content of the information. A read-ahead information determining process of determining the read-ahead information by performing a pre-read process of pre-reading the pre-read target information determined by the pre-read information determining process from the server computer; and If the requested request corresponds to the read-ahead target information that has been read, the A prefetch information transfer process for transferring read target information to the client computer. A storage medium storing an information transfer program. 6. The look-ahead information determination process includes: a list-up process for listing linked information stored in the look-ahead determination information storage means as a look-ahead candidate; If it is stored in the prefetch determination information storage means, it is determined whether or not to perform prefetch by referring to the stored information. If it is determined that prefetch is to be performed, the server computer is determined based on the prefetch target candidate. 6. A storage medium storing the information transfer program according to claim 5, further comprising: a candidate selection process for performing prefetching from a list.