Method for solving coherency lock issues in proxy services

• US 9,674,283 B2
• Filed: 01/15/2014
• Issued: 06/06/2017
• Est. Priority Date: 01/15/2014
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Mulchandani, Jitesh, Shrirame, Mangal Vithal, Nagalingam, Magesh Babu, Dharmasanam, Srinivas, Mathison, Paul Theodore, Pachiappan, Suresh
• Primary Examiner(s): Sison, June
• Assistant Examiner(s): COONEY, ADAM A
• Application Number:
  US14/155,450
• Publication Number:
  US 20150200817A1
• Time in Patent Office: 1,238 Days
• Field of Search: 709223, 709226, 709227, 709228, 709229
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]
• CPC Class Codes: H04L 67/142 Managing session states for stateless protocols; Signalling session states; State transitions; Keeping-state mechanisms
• CPC Class Codes: H04L 67/56 Provisioning of proxy services store-and-forward switching systems in data switching networks H04L12/54

Abstract

Methods and systems are provided for negotiating a session with a first server, wherein data within the session travels through at least a second server such as a proxy server; replacing a first client global unique identifier (GUID) with a second GUID generated by the second server; maintaining a GUID map table at the second server mapping the second GUID with the first GUID; requesting a plurality of leases on a file from the first server, wherein the each of the plurality of lease requests comprises a lease key and the second GUID, wherein the lease key is identical for each of the plurality of leases; providing caching services, wherein caching services are associated with a lease state corresponding to one of the plurality of leases; receiving an indication that a second client has made a lease request for the file; breaking the first lease upon receipt of the indication; and communicating a lease break notification to addresses associated with the second GUID.

Claims

1. A method comprising:

establishing a communication session with a first server, wherein data within the session travels through a second server;

detecting a first global unique identifier (GUID) associated with the communication session, wherein the first GUID is created by a client for establishing the communication session;

generating a second GUID for the client for establishing the communication session, wherein the second client GUID is generated by the second server during the establishment of the communication session;

associating, in a GUID map table maintained at the second server, the second GUID with the first GUID;

providing the second GUID to the first server for consummating the communication session;

receiving a first lease for a file accessible by the first server, wherein the first lease comprises a lease key, wherein the first sever generates the lease key in response to the first GUID generated from the client, associates the generated lease key with the second GUID generated by the second server, and sends the lease key to both the client and the second server; and

receiving a first lease break notification, wherein the first lease break notification is associated with the lease key and the second GUID.

2. The method of claim 1, wherein the first lease is a combination of one or more of:

a read lease, a write lease, and a handle lease.

3. The method of claim 1, wherein the first lease break notification is generated in response to an indication that a change has occurred to the file at the first server.

4. The method of claim 1, wherein the first lease break notification is generated in response to an indication that a lease request has been made by a second client.

5. The method of claim 4, further comprising flushing a cached version of the file upon receipt of the first lease break notification.

6. The method of claim 1, wherein the first lease spans multiple opens as well as multiple connections from a first client.

7. The method of claim 1, wherein the second server is one of a SMB proxy server or a Wide Area Application Services (“

WAAS”

) server.

8. The method of claim 7, wherein the first server and the second server are operating with Server Message Block protocol (“

SMB”

).

9. The method of claim 1, wherein the lease key is identical for a plurality of leases for the file.

10. The method of claim 1, further comprising providing caching services, wherein each caching service is associated with a lease state corresponding to each of a plurality of leases.

11. A device operating with Server Message Block protocol (“

SMB”

) comprising;

a memory; and

a processor configured to execute instructions stored in the memory, the instructions comprising;

negotiating a session with a first server by a client device, wherein a session data path includes a proxy server;

detecting a first global unique identifier (GUID) associated with the session and associated with the client device;

generating a second GUID for the client device for establishing the session, wherein the second GUID is generated by the proxy server during the establishment of the session;

associating, in a GUID map table maintained at the proxy server, the second GUID with the first GUID;

receiving a first lease for a file from the first server, wherein the first lease comprises a lease key, wherein the first server generates the lease key in response to receipt of the first GUID generated by the client device, associates the generated lease key with the second GUID generated by the proxy server, and sends the lease key to both the client device and the proxy server; and

receiving a first lease break notification for the first lease, wherein the first lease break notification is associated with the second GUID.

12. The device of claim 11, wherein the first GUID is mapped to the second GUID.

13. The device of claim 11, wherein the client device is a mobile device.

14. The device of claim 11, wherein the processor is further configured to execute instructions comprising:

requesting a plurality of leases on the file from the first server, wherein each of the plurality of leases comprises the lease key and the second GUID, wherein the lease key is identical for each of the plurality of leases; and

providing caching services, wherein each caching service is associated with a lease state corresponding to one of the plurality of leases.

15. The device of claim 14, wherein the processor is further configured to execute instructions comprising:

receiving an indication that a lease request has been made for a leased file at the first server from a second client device; and

flushing one or more caches containing copies of the leased file.

16. A method comprising:

sending a lease request for a first file to a first server, the lease request comprising a first global unique identifier (GUID) associated with a client device;

receiving a lease grant notification for the first file, the lease grant notification comprising a lease key, wherein the lease key is generated by the first server in response to receiving the first GUID from the client device, wherein the server associates the generated lease key with a second GUID generated by a second server in response to detecting the lease request from the client device, wherein the second server associates the second GUID with the first GUID in a GUID map table maintained at the second server, and wherein the second server sends the second GUID to the first server along with the association with the client device; and

receiving a lease break notification from the second server, wherein the lease break notification is addressed to the second GUID.

17. The method of claim 16, wherein the file resides at a campus on one or more connected data servers.

18. The method of claim 16, wherein the lease request is a Server Message Block protocol (SMB) lease request.

19. The method of claim 16, wherein the second server is at one of a Server Message Block protocol (SMB) proxy server or a Wide Area Application Service (WAAS) device.

20. The method of claim 19, wherein the second GUID is mapped to an original client GUID.