Double-proxy remote data access system

• US 7,139,811 B2
• Filed: 07/31/2002
• Issued: 11/21/2006
• Est. Priority Date: 08/01/2001
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Actona Technologies Limited (Cisco Systems, Inc.)
• Inventors: Kaminsky, Daniel, Glixman, Shahar, Cidon, Israel, Zach, Idan, Bortnikov, Vita, Ben Kiki, Danit, Lev Ran, Etai, Ben Shaul, Israel
• Primary Examiner(s): VU, VIET DUY
• Application Number:
  US10/485,178
• Publication Number:
  US 20040255048A1
• Time in Patent Office: 1,574 Days
• Field of Search: 709/202, 709/203, 709/213, 709/217, 709/219, 709/223, 707/10, 707/100, 707/104
• US Class Current: 709/217
• 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:

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

conveying the replica of the data resource over a wide area network (WAN) from the proxy transmitter to a cache held by a proxy receiver on the second LAN;

intercepting at the proxy receiver a file system request for the data resource submitted by the client over the second LAN;

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

responsive to the file system request and to determining that the replica is present and valid, serving the replica of the data resource from the cache of the proxy receiver to the client over the second LAN,

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 proxy transmitter to the cache of the proxy receiver, responsive to the pattern, and

wherein analyzing the pattern comprises calculating for each of the second data resources on the file server a relation of an expected usage of the replicas of the second data resources at the proxy receiver to an expected modification rate of the second data resources at the file server.

2. 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:

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

conveying the replica of the data resource over a wide area network (WAN) from the proxy transmitter to a cache held by a proxy receiver on the second LAN;

intercepting at the proxy receiver a file system request for the data resource submitted by the client over the second LAN;

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

responsive to the file system request and to determining that the replica is present and valid, serving the replica of the data resource from the cache of the proxy receiver to the client over the second LAN,

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 proxy transmitter to the cache of the proxy receiver, responsive to the pattern, and

wherein retrieving the replicas of the one or more second data resources comprises analyzing a relation of an available bandwidth of the WAN to an expected usage of the replicas of the second data resources at the proxy receiver, and determining, responsive to the relation, when to retrieve a replica of the second data resource.

3. 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 located on the first LAN, and which is adapted to retrieve a replica of the data resource from the file server, and to transmit the replica of the data resource over a wide area network (WAN) to the second LAN; and

a proxy receiver, which is located on the second LAN and comprises a cache, and which is adapted to receive the replica of the data resource from the proxy transmitter to the cache, to intercept a file system request for the data resource submitted by the client over the second LAN, to check the cache to determine whether the replica of the data resource is present in the cache and valid, and, responsive to the file system request and to determining that the replica is present and valid, to serve the replica of the data resource from the cache to the client over the second LAN,

wherein the proxy receiver is adapted to intercept a group of one or more requests for first data resources on the file server, to analyze a pattern of the group of requests, and to retrieve replicas of one or more second data resources from the proxy transmitter to the cache, responsive to the pattern, and

wherein the proxy receiver is adapted to calculate for each of the second data resources on the file server a relation of an expected usage of the replicas of the second data resources at the proxy receiver to an expected modification rate of the second data resources at the file server, and to retrieve the replicas from the proxy transmitter to the cache, responsive to the calculation.

4. 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 located on the first LAN, and which is adapted to retrieve a replica of the data resource from the file server, and to transmit the replica of the data resource over a wide area network (WAN) to the second LAN; and

a proxy receiver, which is located on the second LAN and comprises a cache, and which is adapted to receive the replica of the data resource from the proxy transmitter to the cache, to intercept a file system request for the data resource submitted by the client over the second LAN, to check the cache to determine whether the replica of the data resource is present in the cache and valid, and, responsive to the file system request and to determining that the replica is present and valid, to serve the replica of the data resource from the cache to the client over the second LAN,

wherein the proxy receiver is adapted to intercept a group of one or more requests for first data resources on the file server, to analyze a pattern of the group of requests, and to retrieve replicas of one or more second data resources from the proxy transmitter to the cache, responsive to the pattern, and

wherein the proxy receiver is adapted to analyze a relation of an available bandwidth of the WAN to an expected usage of the replicas of the second data resources at the proxy receiver, and to determine, responsive to the relation, when to retrieve a replica of the second data resource.