Method for continuing data transfer to network cache from server without transferring said data to user terminal irrespective of user interruption of the data transferring request

• US 6,772,193 B1
• Filed: 04/07/2000
• Issued: 08/03/2004
• Est. Priority Date: 04/09/1999
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Igawa, Masaru, Shibata, Koichi, Sakamoto, Shuichi
• Primary Examiner(s): Dharia, Rupal
• Assistant Examiner(s): NGUYEN, QUANG N
• Application Number:
  US09/545,308
• Time in Patent Office: 1,579 Days
• Field of Search: 709/203, 709/216, 709/219, 709/223, 709/226, 709/231, 709/235, 711/113
• US Class Current: 709/203
• CPC Class Codes: G06F 16/9574 of access to content, e.g. by caching

Abstract

In a network cache and a cache control method involving the transfer of a large volume of data as the time of reproduction of multimedia data including video data, a stabilized data transfer is made by eliminating the waste of cached data or a useless cache processing which may be caused by the interruption of a user'"'"'s operation. When a data transfer request from a user terminal connected to a local network is made to a server existing on the internet, a user request processing program starts a cache program. The cache program performs a cache processing independently of the data delivery to the requesting user terminal by the user request processing program so that even if the user'"'"'s request is interrupted, the storage of transferred data into a cache file is performed without ceasing. Also, a required bit rate for data made an object of transfer is analyzed for comparison with a network throughput between the server and the network cache. When the network throughput is larger, the caching of transferred data is not performed so that the discard of data having been cached is not caused. Thereby, it is possible to prevent the cache hit rate from being lowered.

Claims

1. A network system including a user terminal which makes a transfer request for user'"'"'s required data for each file in an access unit to a server having the required data held therein and a network cache which temporarily stores data transferred from the server, said network cache comprising:

user request processing means for detecting the data transfer request from the user terminal and making the data transfer request to the server as proxy for the user terminal;

cache control means for performing a processing for storage of data transferred from the server, while partially transferring the stored data for each file in the access unit to said user terminal; and

data transfer control means for continuing the storage of data transferred to said network cache from the server up to the end of that data in its access unit irrespective of the interruption of the data transfer request from the user terminal and without transferring said data to said user terminal.

2. A network cache according to claim 1, further comprising means for discriminating video data in the data transferred from the server, wherein irrespective of the interruption of a video data transfer request from the user terminal, the storage of the data transferred from the server is continued to said network cache up to the last extremity of that data in its access unit.

3. A network cache according to claim 1, wherein the data transferred from the server is multimedia configuration information indicating the combination of at least two of character data, still picture data and video data, and said network cache further comprises means for analyzing the data transferred from the server, and wherein irrespective of the interruption of a request from the user terminal for transfer of data specified by said multimedia configuration information, the storage of the specified data transferred from the server is continued up to the last extremity of that data in its access unit.

4. A network system according to claim 1 said network cache further comprising:

means for analyzing and holding a required transfer rate for data made an object of transfer;

means for detecting and holding a network throughput between the server and the network cache; and

means for comparing said network throughput and said required transfer rate, the storage of the transferred data being not performed when the ratio of said network throughput to said required transfer rate is larger than a fixed value.

5. A network cache according to claim 4, further comprising means for analyzing a reproduction bit rate of video data required by the user terminal, wherein the storage of video data is not performed when the ratio of said network throughput to said video data reproduction bit rate is larger than a fixed value.

6. A network cache according to claim 4, wherein said network throughput is periodically detected and held.

7. A network cache according to claim 4, wherein said network throughput is detected and held each time a video data transfer request is made to the server.

8. A network cache according to claim 4, further comprising means for analyzing multimedia configuration information to extract a reproduction bit rate of video data specified by said multimedia configuration information, wherein the storage of said video data is not performed in the case where the ratio of a network throughput between a server having said video data held therein and the network cache to said video data reproduction bit rate is larger than a fixed value.

9. A network cache according to claim 4, further comprising means for holding an allowable throughput value for each server in which data required by a user is held, said allowable throughput value being determined from a network throughput value between the server and the network cache, wherein said required transfer rate and said allowable throughput value are compared to make the judgement of whether or not the data transferred from the server should be cached.

25. The network system according to claim 1, wherein said access unit comprises a data file unit.

10. A method for controlling a network cache comprising:

requesting a data transfer request by the network cache from a user terminal as proxy for the user terminal to send the data transfer request for each file in an access unit to a server having data to be provided to the user terminal;

temporarily storing data transferred from the server by the network cache, while partially transferring the stored data for each file in the access unit to said user terminal;

recognizing an interruption of the data transfer request from the user terminal; and

continuing the storage of the transferred data to said network cache from said server up to the end of that data in its access unit in response to the result of recognition of said interruption without transferring said data to said user terminal.

11. A method for controlling a network cache according to claim 10, further comprising the steps of;

analyzing a required transfer rate for data made an object of transfer;

detecting a network throughput between the server and said network cache;

comparing said network throughput and said required transfer rate; and

passing the transferred data from the server to the user terminal and making the temporary storage of the transferred data free in response to the result of comparison indicating that the ratio of said network throughput to said required transfer rate is larger than a fixed value.

12. A network cache for use to be provided between a server having user'"'"'s required data held therein and a user terminal making a transfer request for the required data for each file in an access unit to the server and temporarily stores data transferred from the server, comprising:

user request processing means for detecting the data transfer request from the user terminal and making the data transfer request to the server as proxy for the user terminal;

cache control means for performing a processing for storage of data transferred from the server, while partially transferring the stored data for each file in the access unit to said user terminal; and

data transfer control means for continuing the storage of data transferred to said network cache from the server up to the end of that data in its access unit irrespective of the interruption of the data transfer request from the user terminal and without transferring said data to said user terminal.

13. A network cache according to claim 12, further comprising means for discriminating video data in the data transferred from the server, wherein irrespective of the interruption of a video data transfer request from the user terminal, the storage of the data transferred from the server is continued up to the last extremity of that data in its access unit.

14. A network cache according to claim 12, wherein the data transferred from the server is multimedia configuration information indicating the combination of at least two of character data, still picture data and video data, and said network cache further comprises means for analyzing the data transferred from the server, and wherein irrespective of the interruption of a request from the user terminal for transfer of data specified by said multimedia configuration information, the storage of the specified data transferred from the server is continued up to the last extremity of that data in its access unit.

15. A network cache according to claim 12, comprising:

means for analyzing and holding a required transfer rate for data made an object of transfer;

means for detecting and holding a network throughput between the server and the network cache; and

means for comparing said network throughput and said required transfer rate, the storage of the transferred data being not performed when the ratio of said network throughput to said required transfer rate is larger than a fixed value.

16. A network cache according to claim 15, further comprising means for analyzing a reproduction bit rate of video data required by the user terminal, wherein the storage of video data is not performed when the ratio of said network throughput to said video data reproduction bit rate is larger than a fixed value.

17. A network cache according to claim 15, wherein said network throughput is periodically detected and held.

18. A network cache according to claim 15, wherein said network throughput is detected and held each time a video data transfer request is made to the server.

19. A network cache according to claim 15, further comprising means for analyzing multimedia configuration information to extract a reproduction bit rate of video data specified by said multimedia configuration information, wherein the storage of said video data is not performed when the ratio of a network throughput between a server having said video data held therein and the network cache to said video data reproduction bit rate is larger than a fixed value.

20. A network cache according to claim 15, further comprising means for holding an allowable throughput value for each server in which data required by a user is held, said allowable throughput value being determined from a network throughput value between the server and the network cache, wherein said required transfer rate and said allowable throughput value are compared to determine whether or not the data transferred from the server should be cached.

21. A program, stored on a memory for implementing a network cache control method by use of a computer, said method controlling a network cache which makes a data transfer request for each file in an access unit from a user terminal as proxy for the user terminal to send the data transfer request to a server having data to be provided to the user terminal and temporarily stores data transferred from the server, the method comprising the steps of:

recognizing the interruption of the data transfer request from the user terminal; and

continuing the storage of the transferred data to said network cache from said server up to the end of that data in its access unit in response to the result of recognition of said interruption without transferring said data to said user terminal.

22. A program, stored on a memory for implementing a network cache control method by use of a computer according to claim 21, further comprising the steps of:

analyzing a required transfer rate for data made an object of transfer;

detecting a network throughput between the server and said network cache;

comparing said network throughput and said required transfer rate; and

causing the network cache to make the temporary storage of the transferred data free in response to the result of comparison indicating that the ratio of said network throughput to said required transfer rate is larger than a fixed value.

23. A computer-readable medium storing a program for implementing, by use of a computer, operation of a cache which makes a data transfer request from a user terminal as proxy for the user terminal to send the data transfer request for each file in an access unit to a server having data to be provided to the user terminal and temporarily stores data transferred from the server, said program comprising instructions performing, through execution by the computer, the steps of:

detecting an interruption of the data transfer request from the user terminal; and

causing the cache to continue the storage of the transferred data from the server therein up to the end of that data in its access unit in response to the result of detection indicating said interruption without transferring said data to said user terminal.

24. A computer-readable medium storing a program for implementing, by use of a computer according to claim 23, further comprising the steps of:

analyzing a required transfer rate for data made an object of transfer;

detecting a network throughput between the server and said network cache;

comparing said network throughput and said required transfer rate; and

causing the network cache to make the transferred data from the server caching-free in response to the result of comparison indicating that the ratio of said network throughput to said required transfer rate is larger than a fixed value.