Data transfer scheme using caching technique for reducing network load

• US 20030061337A1
• Filed: 09/25/2002
• Published: 03/27/2003
• Est. Priority Date: 09/27/2001
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Kanai, Tatsunori, Sato, Hideaki, Toyama, Haruhiko, Miyazawa, Takayuki, Yoshida, Hideki, Yoshii, Kenichiro, Kimura, Yasuhiro, Seki, Toshibumi
• Granted Patent: US 7,441,248 B2
• Time in Patent Office: Days
• US Class Current: 709/223
• CPC Class Codes: H04L 67/288 Distributed intermediate devices, i.e. intermediate devices for interaction with other intermediate devices on the same level
• CPC Class Codes: H04L 67/564 Enhancement of application control based on intercepted application data
• CPC Class Codes: H04L 67/568 Storing data temporarily at an intermediate stage, e.g. caching
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]

Abstract

In a data transfer device, presence/absence of a prescribed header in the received request message is analyzed, and information indicating the presence/absence of the prescribed header, or information indicating either presence or absence of the prescribed header when the prescribed header is either present or absent as a result of analysis is stored. Then, when a reply message corresponding to the request message is received, the presence/absence of the prescribed header is checked by referring to the stored information, and the reply message is transferred according to a result of checking.

Claims

1. A data transfer device, comprising:

a request receiving unit configured to receive a request message;

an analysis unit configured to analyze presence/absence of a prescribed header by analyzing the request message received by the request receiving unit;

a storing unit configured to store information indicating the presence/absence of the prescribed header, or information indicating either presence or absence of the prescribed header when the prescribed header is either present or absent as a result of analysis by the analysis unit;

a reply receiving unit configured to receive a reply message corresponding to the request message;

a checking unit configured to check the presence/absence of the prescribed header by referring to the storing unit when the reply message is received by the reply receiving unit; and

a transfer unit configured to transfer the reply message according to a result of checking by the checking unit.

2. The data transfer device of claim 1, wherein the transfer unit transfers the reply message without making any change when the checking unit checks that the prescribed header is present.

3. The data transfer device of claim 1, further comprising:

a judgement unit configured to judge whether the reply message contains data requested by the request message in an original form or not when the checking unit checks that the prescribed header is absent;

wherein the transfer unit transfers the reply message that contains the data in the original form when the judgement unit judges that the data in the original form is contained.

4. The data transfer device of claim 3, further comprising:

a memory unit configured to store in advance at least one set of data that can be requested by the request message and a compressed information obtained by compressing the data in correspondence; and

a management unit configured to generate a new reply message when the judgement unit judges that the data in the original form is not contained, by searching through the memory unit by using the compressed information contained in the reply message, reading out the data corresponding to the compressed information, and changing the compressed information contained in the reply message by the data corresponding to the compressed information;

wherein the transfer unit transfers the new reply message generated by the management unit.

5. The data transfer device of claim 1, wherein the transfer unit transfers the reply message by attaching a specific header different from the prescribed header when the checking unit checks that the prescribed header is present.

6. The data transfer device of claim 5, wherein the transfer unit attaches the specific header which is a header for prohibiting caching of data contained in the reply message at a device capable of handling HTTP protocol.

7. The data transfer device of claim 1, further comprising:

a header attaching unit configured to attach the prescribed header to the request message when the absence of the prescribed header is detected as a result of analysis by the analysis unit.

8. The data transfer device of claim 1, wherein the analysis unit analyzes the presence/absence of the prescribed header which indicates that the request message has passed through another data transfer device.

9. A data transfer device, comprising:

a request receiving unit configured to receive a request message;

an analysis unit configured to analyze the request message received by the request receiving unit;

a storing unit configured to store an analysis result obtained by the analysis unit;

a reply receiving unit configured to receive a reply message corresponding to the request message; and

a processing unit configured to carry out a processing with respect to the reply message by referring to the analysis result stored by the storing unit when the reply message is received by the reply receiving unit.

10. A data transfer method, comprising:

(a) receiving a request message;

(b) analyzing presence/absence of a prescribed header by analyzing the request message received by the step (a);

(c) storing information indicating the presence/absence of the prescribed header, or information indicating either presence or absence of the prescribed header when the prescribed header is either present or absent as a result of analysis by the step (b);

(d) receiving a reply message corresponding to the request message;

(e) checking the presence/absence of the prescribed header by referring to the information stored by the storing step when the reply message is received by the step (d); and

(f) transferring the reply message according to a result of checking by the step (e).

11. A data transfer method, comprising:

(a) receiving a request message;

(b) analyzing the request message received by the step (a);

(c) storing an analysis result obtained by the step (b);

(d) receiving a reply message corresponding to the request message; and

(e) carrying out a processing with respect to the reply message by referring to the analysis result stored by the step (c) when the reply message is received by the step (d).

12. A computer program product for causing a computer to function as a data transfer device, the computer program product comprising:

a first computer program code for causing the computer to receive a request message;

a second computer program code for causing the computer to analyze presence/absence of a prescribed header by analyzing the request message received;

a third computer program code for causing the computer to store information indicating the presence/absence of the prescribed header, or information indicating either presence or absence of the prescribed header when the prescribed header is either present or absent as a result of analysis by the second computer program code;

a fourth computer program code for causing the computer to receive a reply message corresponding to the request message;

a fifth computer program code for causing the computer to check the presence/absence of the prescribed header by referring to the information stored by the third computer program code when the reply message is received; and

a sixth computer program code for causing the computer to transfer the reply message according to a result of checking by the fifth computer program code.

13. The computer program product of claim 12, wherein the sixth computer program code transfers the reply message without making any change when the fifth computer program code checks that the prescribed header is present.

14. The computer program product of claim 12, further comprising:

a seventh computer program code for causing the computer to judge whether the reply message contains data requested by the request message in an original form or not when the fifth computer program code checks that the prescribed header is absent;

wherein the sixth computer program code transfers the reply message that contains the data in the original form when the seventh computer program code judges that the data in the original form is contained.

15. The computer program product of claim 14, further comprising:

an eighth computer program code for causing the computer to store in advance at least one set of data that can be requested by the request message and a compressed information obtained by compressing the data in correspondence into a memory; and

a ninth computer program code for causing the computer to generate a new reply message when the seventh computer program code judges that the data in the original form is not contained, by searching through the memory by using the compressed information contained in the reply message, reading out the data corresponding to the compressed information, and changing the compressed information contained in the reply message by the data corresponding to the compressed information;

wherein the sixth computer program code transfers the new reply message generated by the ninth computer program code.

16. The computer program product of claim 12, wherein the sixth computer program code transfers the reply message by attaching a specific header different from the prescribed header when the fifth computer program code checks that the prescribed header is present.

17. The computer program product of claim 16, wherein the sixth computer program code attaches the specific header which is a header for prohibiting caching of data contained in the reply message at a device capable of handling HTTP protocol.

18. The computer program product of claim 12, further comprising:

a tenth computer program code for causing the computer to attach the prescribed header to the request message when the absence of the prescribed header is detected as a result of analysis by the second computer program code.

19. The computer program product of claim 12, wherein the second computer program code analyzes the presence/absence of the prescribed header which indicates that the request message has passed through another data transfer device.

20. A computer program product for causing a computer to function as a data transfer device, the computer program product comprising:

a first computer program code for causing the computer to receive a request message;

a second computer program code for causing the computer to analyze the request message received;

a third computer program code for causing the computer to store an analysis result obtained by the second computer program code;

a fourth computer program code for causing the computer to receive a reply message corresponding to the request message; and

a fifth computer program code for causing the computer to carry out a processing with respect to the reply message by referring to the analysis result stored by the third computer program code when the reply message is received.