Previewing file information over a network

• US 9,489,456 B1
• Filed: 11/17/2006
• Issued: 11/08/2016
• Est. Priority Date: 11/17/2006
• Status: Active Grant

• Current Assignee: CA, Inc. (d/b/a CA Technologies) (Broadcom, Inc.)
• Original Assignee: Blue Coat Systems Incorporated (Gen Digital Inc.)
• Inventors: Vidwans, Hrishikesh A.
• Primary Examiner(s): Yen, Syling
• Application Number:
  US11/561,123
• Time in Patent Office: 3,644 Days
• Field of Search: 707/2, 707/705, 707/736, 707/737, 707/741, 707/748, 707/754, 707/999.01, 370/392, 370/400, 370/408, 711/137
• US Class Current: 1/1
• CPC Class Codes: G06F 12/0813 with a network or matrix configuration
• CPC Class Codes: G06F 16/172 Caching, prefetching or hoarding of files
• CPC Class Codes: G06F 16/183 Provision of network file services by network file servers, e.g. by using NFS, CIFS network file access protocols H04L67/1097
• CPC Class Codes: G06F 16/951 Indexing; Web crawling techniques
• CPC Class Codes: G06F 2212/1044 Space efficiency improvement
• CPC Class Codes: G06F 2212/154 Networked environment
• CPC Class Codes: G06F 2212/163 Server or database system
• CPC Class Codes: G06F 2212/463 File
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/0643 Management of files
• CPC Class Codes: G06F 3/0652 Erasing, e.g. deleting, data cleaning, moving of data to a wastebasket
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]

Abstract

A process for opening and reading a file over a network, including a WAN. An edge file gateway receives a request from an application to open a file cached with the edge file gateway at one point on a network and stored on a file server connected to a central server at another point on the network. The edge file gateway forwards the request to open the file to the central server, along with any offsets and lengths stored from any previous requests to read the file. The central server responds by sending any file data described in the offsets and lengths to the edge file gateway. When the edge file gateway receives a read request, the edge file gateway stores the offset and length for the request, if a predefined storage limit is not exceeded, and attempts to satisfy the request from cached file data.

Claims

1. A computer-implemented method, comprising:

receiving, at a network device, a request from a remote client application to open a file stored on a file server, wherein the network device and the file server are connected by a network;

accessing, in response to the request, a cache to select one or more data segments of the file to pre-fetch from the file server, wherein each of the one or more data segments are identified by an offset position in the file and a length of the data segment;

conditionally pre-fetching the selected data segments from the file on the file server, wherein;

the selected data segments that are pre-fetched are based on previous requests to read identified data segments of the file, one or more offset positions and lengths of which are stored in the cache in association with a cached version of the file; and

the pre-fetched, selected data segments only include data segments described by the one or more offset positions and lengths of previous requests to read identified data segments of the file;

storing the pre-fetched, selected data segments into the cache;

after pre-fetching and caching the selected data segments, receiving, from the remote client application, a request to read data from the file, wherein the request comprises an offset position in the file and a length of the data segment to be read;

accessing the requested data segment in the cache if the cache contains the data segment described in the one or more parameters;

fetching the requested data segment from the file on the file server, if the cache does not contain the data segment described in the parameters;

providing the requested data segment to the remote client application in response to the read request; and

conditionally storing, in the cache, the offset position in the file and the length of the data segment of the request to read the data segment from the file in association with the cached version of the file based one or more predefined storage limits.

2. The method of claim 1, wherein the conditional pre-fetching does not occur if the network device has a lease on the file stored on the file server or if the file data in the cache is known to be current with the file server'"'"'s file.

3. The method of claim 1, wherein the entire file is fetched from the file server if the request to read would cause a predefined file limit to be exceeded.

4. The method of claim 3, wherein the predefined file limit would be exceeded if a specified percentage of the entire file'"'"'s length would be exceeded by the sum of the read request'"'"'s offset position and length and all previously stored offset positions and lengths for the file.

5. The method of claim 3, wherein the predefined file limit would be exceeded if a specified percentage of the entire file'"'"'s length would be exceeded by the read request'"'"'s length.

6. The method of claim 1, wherein the predefined storage limit would be exceeded if a specified number of bytes would be exceeded by the sum of the bytes used to store the read request'"'"'s offset position and length and the bytes used to store all previously stored offset positions and lengths for the file.

7. The method of claim 1, wherein the network is a wide area network.

8. An apparatus comprising logic encoded in one or more tangible storage media for execution and when executed configured to:

receive, at a network device, a request from a remote client application to open a file stored on a file server, wherein the network device and the file server are connected by a network;

access a cache to select one or more data segments of the file to pre-fetch from the file server, wherein each of the one or more data segments are identified by an offset position in the file and a length of the data segment;

conditionally pre-fetch the selected data segments from the file on the file server, wherein;

the selected data segments that are pre-fetched are based on previous requests to read identified data segments of the file, one or more offset positions and lengths of which are stored in the cache in association with a cached version of the file; and

the pre-fetched, selected data segments only include data segments described by the one or more offset positions and lengths of previous requests to read identified data segments of the file;

store the pre-fetched, selected data segments into the cache;

after pre-fetching and caching the selected data segments, receive, from the remote client application, a request to read data from the file, wherein the request comprises an offset position in the file and a length of the data segment to be read;

access the requested data segment in the cache if the cache contains the data segment described in the one or more parameters;

fetch the requested data segment from the file on the file server, if the cache does not contain the data segment described in the parameters;

provide the requested data segment to the remote client application in response to the read request; and

conditionally store, in the cache, the offset position in the file and the length of the data segment of the request to read the data segment from the file in association with the cached version of the file based one or more predefined storage limits.

9. The apparatus of claim 8, wherein the conditional pre-fetching does not occur if the network device has a lease on the file stored on the file server or if the file data in the cache is known to be current with the file server'"'"'s file.

10. The apparatus of claim 8, wherein the entire file is fetched from the file server if the request to read would cause a predefined file limit to be exceeded.

11. The apparatus of claim 10, wherein the predefined file limit would be exceeded if a specified percentage of the entire file'"'"'s length would be exceeded by the sum of the read request'"'"'s offset position and length and all previously stored offset positions and lengths for the file.

12. The apparatus of claim 10, wherein the predefined file limit would be exceeded if a specified percentage of the entire file'"'"'s length would be exceeded by the read request'"'"'s length.

13. The apparatus of claim 8, wherein the predefined storage limit would be exceeded if a specified number of bytes would be exceeded by the sum of the bytes used to store the read request'"'"'s offset position and length and the bytes used to store all previously stored offset positions and lengths for the file.

14. The apparatus of claim 8, wherein the apparatus is configured to be resident on a wide area network.

15. At least one non-transitory medium, the medium comprising instructions that, when loaded and executed by a processor, configure the processor to:

receive, at a network device, a request from a remote client application to open a file stored on a file server, wherein the network device and the file server are connected by a network;

access a cache to select one or more data segments of the file to pre-fetch from the file server, wherein each of the one or more data segments are identified by an offset position in the file and a length of the data segment;

conditionally pre-fetch the selected data segments from the file on the file server, wherein;

the selected data segments that are pre-fetched are based on previous requests to read identified data segments of the file, one or more offset positions and lengths of which are stored in the cache in association with a cached version of the file; and

the pre-fetched, selected data segments only include data segments described by the one or more offset positions and lengths of previous requests to read identified data segments of the file;

store the pre-fetched, selected data segments into the cache;

after pre-fetching and caching the selected data segments, receive, from the remote client application, a request to read data from the file, wherein the request comprises an offset position in the file and a length of the data segment to be read;

access the requested data segment in the cache if the cache contains the data segment described in the one or more parameters;

fetch the requested data segment from the file on the file server, if the cache does not contain the data segment described in the parameters;

provide the requested data segment to the remote client application in response to the read request; and

conditionally store, in the cache, the offset position in the file and the length of the data segment of the request to read the data segment from the file in association with the cached version of the file based one or more predefined storage limits.

16. The medium of claim 15, wherein the conditional pre-fetching does not occur if the network device has a lease on the file stored on the file server or if the file data in the cache is known to be current with the file server'"'"'s file.

17. The medium of claim 15, wherein the entire file is fetched from the file server if the request to read would cause a predefined file limit to be exceeded.

18. The medium of claim 17, wherein the predefined file limit would be exceeded if a specified percentage of the entire file'"'"'s length would be exceeded by the sum of the read request'"'"'s offset position and length and all previously stored offset positions and lengths for the file.

19. The medium of claim 17, wherein the predefined file limit would be exceeded if a specified percentage of the entire file'"'"'s length would be exceeded by the read request'"'"'s length.

20. The medium of claim 15, wherein the predefined storage limit would be exceeded if a specified number of bytes would be exceeded by the sum of the bytes used to store the read request'"'"'s offset position and length and the bytes used to store all previously stored offset positions and lengths for the file.

21. The medium of claim 15, wherein the network is a wide area network.