Double-proxy remote data access system

• US 20070174428A1
• Filed: 04/20/2006
• Published: 07/26/2007
• Est. Priority Date: 08/01/2001
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Actona Technologies Limited (Cisco Systems, Inc.)
• Inventors: Cidon, Israel, Zach, Idan, Kaminsky, Daniel, Glixman, Shahar, Bortnikov, Vita, Ben Kiki, Danit, Lev Ran, Etai, Ben Shaul, Israel
• Granted Patent: US 7,711,788 B2
• Time in Patent Office: Days
• US Class Current: 709/218
• CPC Class Codes: G06F 16/1774 Locking methods, e.g. locking methods for file systems allowing shared and concurrent access to files
• CPC Class Codes: G06F 16/192 Implementing virtual folder structures
• CPC Class Codes: G06F 16/9574 of access to content, e.g. by caching
• CPC Class Codes: G06F 9/546 Message passing systems or structures, e.g. queues
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 67/06 specially adapted for file transfer, e.g. file transfer protocol [FTP]
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04L 67/133 Protocols for remote procedure calls [RPC]
• CPC Class Codes: H04L 67/2876 Pairs of inter-processing entities at each side of the network, e.g. split proxies
• CPC Class Codes: H04L 67/563 Data redirection of data network streams
• CPC Class Codes: H04L 67/565 Conversion or adaptation of application format or content adding application control or application functional data H04L67/561
• CPC Class Codes: H04L 67/5651 Reducing the amount or size of exchanged application data
• CPC Class Codes: H04L 67/568 Storing data temporarily at an intermediate stage, e.g. caching
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users

Abstract

A method for enabling access to a data resource, which is held on a file server (25) on a first local area network (LAN) (21a), by a client (28) on a second LAN (21b). A proxy receiver (48) on the second LAN (21b) intercepts a request for the data resource submitted by the client (28) and transmits a message via a wide area network (WAN) (29) to a proxy transmitter (52) on the first LAN (21a), requesting the data resource. The proxy transmitter (52) retrieves a replica of the data resource from the file server (25) and conveys the replica of the data resource over the WAN (29) to the proxy receiver (48), which serves the replica of the data resource from the proxy receiver (48) to the client (28) over the second LAN (21b).

Claims

1. A method for enabling access to a data resource, which is held on a file server on a first local area network (LAN), by a client on a second LAN, the method comprising:

intercepting a request for the data resource submitted by the client, using a proxy receiver on the second LAN;

transmitting a message via a wide area network (WAN) from the proxy receiver to a proxy transmitter on the first LAN, requesting the data resource;

retrieving a replica of the data resource from the file server to the proxy transmitter;

responsive to the message, conveying the replica of the data resource over the WAN from the proxy transmitter to the proxy receiver; and

serving the replica of the data resource from the proxy receiver to the client over the second LAN.

6. A method according to claim 1, wherein conveying the replica of the data resource comprises conveying metadata relating to the data resource.

17. A method according to claim 1, wherein transmitting the message comprises aggregating the message into a batch of messages, and transmitting the aggregated batch.

22. A method according to claim 1, and comprising conveying to the proxy receiver metadata regarding the data resource on the file server and, responsive to the metadata, presenting to the client a virtual directory of the file server.

26. A method according to claim 1, wherein conveying the replica of the data resource over the WAN comprises encapsulating the replica in accordance with a WAN transport protocol and conveying the encapsulated replica.

27. A method according to claim 26, wherein the WAN transport protocol comprises a Transmission Control Protocol (TCP).

29. A method according to claim 1, wherein the request for the data resource is submitted by the client using a call to a native network file system used by the file server, and wherein retrieving the replica of the data resource comprises retrieving the replica of the data resource using the native network file system.

32. A method according to claim 1, wherein conveying the replica of the data resource comprises compressing the replica at the proxy transmitter, conveying the compressed replica over the WAN, and decompressing the compressed replica at the proxy receiver.

33. A method according to claim 32, wherein compressing the replica comprises applying delta compression at the proxy transmitter to the replica responsive to information provided to the proxy transmitter by the proxy receiver.

36. A method according to claim 1, and comprising storing the replica of the data resource in a memory of the proxy receiver, and wherein serving the replica of the data resource from the proxy receiver comprises serving the replica of the data resource from the memory of the proxy receiver.

37. A method according to claim 36, and comprising:

intercepting a further request for the data resource from another client on the second LAN;

checking the memory to determine whether the replica of the data resource is present in the memory and valid; and

responsive to the further request and to determining that the replica is present and valid, serving the replica of the data resource from the memory of the proxy receiver to the other client over the second LAN.

48. A method according to claim 36, wherein intercepting the request comprises intercepting a group of one or more requests for first data resources on the file server, and comprising analyzing a pattern of the group of requests, and retrieving replicas of one or more second data resources from the file server to the memory of the proxy receiver, responsive to the pattern.

55. A method according to claim 1, and comprising:

intercepting at the proxy receiver a write request submitted by the client for application to the data resource;

transmitting the write request via the WAN from the proxy receiver to the proxy transmitter; and

passing the write request via the first LAN from the proxy transmitter to the file server.

2-5. -5. (canceled)

7-16. -16. (canceled)

18-21. -21. (canceled)

23-25. -25. (canceled)

28. (canceled)

30-31. -31. (canceled)

34-35. -35. (canceled)

38-47. -47. (canceled)

49-54. -54. (canceled)

56-116. -116. (canceled)

117. A method for enabling access to data resources held on a file server on a first local area network (LAN) by a client on a second LAN, the method comprising:

reading metadata from the file server using a proxy transmitter on the first LAN;

transmitting the metadata via a wide area network (WAN) from the proxy transmitter to a proxy receiver on the second LAN; and

based on the metadata, constructing at the proxy receiver a directory of the data resources on the file server, for use by the client in accessing the data resources.

119. A method according to claim 117, wherein the metadata includes file attributes of the data resources, which file attributes are stored in a directory object on the file server, and wherein reading the metadata comprises reading the file attributes from the directory object.

120. A method according to claim 117, wherein the data resources comprise files, and wherein the metadata includes file attributes that are stored in the files, and wherein reading the metadata comprises reading the file attributes from the files.

121. A method according to claim 117, and comprising intercepting at the proxy receiver a file system request with respect to one of the data resources in the directory submitted by the client over the second LAN, and, responsive to the file system request, serving data from the one of the data resources from the proxy receiver to the client over the second LAN.

118. (canceled)

122-124. -124. (canceled)

125. Apparatus for enabling access to a data resource, which is held on a file server on a first local area network (LAN), by a client on a second LAN, the apparatus comprising:

a proxy transmitter, which is adapted to retrieve a replica of the data resource from the file server over the first LAN; and

a proxy receiver, which is adapted to intercept a request for the data resource submitted by the client on the second LAN, and responsive to the request, to send a message via a wide area network (WAN) to the proxy transmitter on the first LAN, requesting the data resource, thus causing the proxy transmitter to convey the replica of the data resource over the WAN to the proxy receiver, which serves the replica of the data resource to the client over the second LAN.

130. Apparatus according to claim 125, wherein the replica of the data resource comprises metadata relating to the data resource.

141. Apparatus according to claim 125, wherein the proxy receiver is adapted to aggregate the message into a batch of messages and transmit the aggregated batch.

146. Apparatus according to claim 125, wherein the proxy transmitter is adapted to convey to the proxy receiver metadata regarding the data resource on the file server, and wherein the proxy receiver is adapted to present to the client a virtual directory of the file server, responsive to the metadata.

153. Apparatus according to claim 125, wherein the request for the data resource is submitted by the client using a call to a native network file system used by the file server, and wherein the proxy transmitter is adapted to retrieve the replica of the data resource using the native network file system.

156. Apparatus according to claim 125, wherein the proxy transmitter is adapted to compress the replica and to convey the compressed replica over the WAN, and wherein the proxy receiver is adapted to decompress the compressed replica.

157. Apparatus according to claim 156, wherein the proxy transmitter is adapted to compress the replica by applying delta compression to the replica responsive to information provided to the proxy transmitter by the proxy receiver.

160. Apparatus according to claim 125, wherein the proxy receiver comprises a memory, and is adapted to store the replica of the data resource in the memory, and to serve the replica of the data resource from the memory.

161. Apparatus according to claim 160, wherein the proxy receiver is adapted to:

intercept a further request for the data resource from another client on the second LAN,

check the memory to determine whether the replica of the data resource is present in the memory and valid, and

responsive to the further request and to determining that the replica is present and valid, serve the replica of the data resource from the memory to the other client over the second LAN.

172. Apparatus according to claim 160, wherein the proxy receiver is adapted to:

intercept a group of one or more requests for first data resources on the file server,

analyze a pattern of the group of requests,

responsive to the pattern, cause the proxy transmitter to retrieve replicas of one or more second data resources from the file server and to convey the retrieved replicas to the proxy receiver, and

store the retrieved replicas in the memory.

179. Apparatus according to claim 125, wherein the proxy receiver is adapted to intercept a write request submitted by the client for application to the data resource, and to transmit the write request via the WAN to the proxy transmitter, and wherein the proxy transmitter is adapted to pass the write request via the first LAN to the file server.

126-129. -129. (canceled)

131-140. -140. (canceled)

142-145. -145. (canceled)

147-150. -150. (canceled)

152. (canceled)

154-155. -155. (canceled)

158-159. -159. (canceled)

162-171. -171. (canceled)

173-178. -178. (canceled)

180-240. -240. (canceled)

241. Apparatus for enabling access to data resources held on a file server on a first local area network (LAN) by a client on a second LAN, the apparatus comprising:

a proxy transmitter, located on the first LAN and adapted to read metadata from the file server, to transmit the metadata via a wide area network (WAN) to the second LAN; and

a proxy receiver, located on the second LAN, which is adapted to construct a directory, based on the metadata, of the data resources on the file server, for use by the client in accessing the data resources.

243. Apparatus according to claim 241, wherein the metadata includes file attributes of the data resources, which file attributes are stored in a directory object on the file server, and wherein the proxy transmitter is adapted to read the file attributes from the directory object.

244. Apparatus according to claim 241, wherein the data resources comprise files, and wherein the metadata includes file attributes that are stored in the files, and wherein the proxy transmitter is adapted to read the file attributes from the files.

245. Apparatus according to claim 241, wherein the proxy receiver is adapted to intercept a file system request with respect to one of the data resources in the directory submitted by the client over the second LAN, and, responsive to the file system request, to serve data from the one of the data resources to the client over the second LAN.

242. (canceled)

246-248. -248. (canceled)

249. A computer software product for enabling access to a data resource, which is held on a file server on a first local area network (LAN), by a client on a second LAN, the product comprising a computer-readable medium, in which program instructions are stored, which instructions, when read by a first computer on the first LAN, cause the computer to operate as a proxy transmitter, so as to retrieve a replica of the data resource from the file server over the first LAN, and which instructions, when read by a second computer on the second LAN, cause the second computer to operate as a proxy receiver, so as to intercept a request for the data resource submitted by the client on the second LAN, and responsive to the responsive, to send a message via a wide area network (WAN) to the proxy transmitter on the first LAN, requesting the data resource, thus causing the proxy transmitter to convey the replica of the data resource over the WAN to the proxy receiver, which serves the replica of the data resource to the client over the second LAN.

250-364. -364. (canceled)

365. A computer software product for enabling access to data resources held on a file server on a first local area network (LAN) by a client on a second LAN, the product comprising a computer-readable medium, in which program instructions are stored, which instructions, when read by a first computer on the first LAN, cause the first computer to operate as a proxy transmitter, so as to read metadata from the file server, and to transmit the metadata via a wide area network (WAN) to the second LAN, and which instructions, when read by a second computer on the second LAN, cause the second computer to operate as a proxy receiver, and to construct a directory, based on the metadata, of the data resources on the file server, for use by the client in accessing the data resources.

366-372. -372. (canceled)