Method for Solving Coherency Lock Issues in Proxy Services

• US 20150200817A1
• Filed: 01/15/2014
• Published: 07/16/2015
• 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
• Granted Patent: US 9,674,283 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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;

replacing a first client global unique identifier (GUID) with a second client GUID generated by the second server during the establishment of the communication session;

maintaining a GUID map table at the second server associating the second GUID with the first GUID;

granting a first lease for a file accessible by the first server wherein the first lease comprises a lease key; and

generating 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 client 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 wherein the session data path includes at least a proxy server;

replacing a global unique identifier (GUID) associated with the client with a proxy-generated GUID during session negotiation;

establishing a first lease for a file from the first server; and

receiving a first lease break notification for the first lease, wherein the first lease break notification is associated with the proxy-generated GUID.

12. The client device of claim 11, wherein the client GUID is mapped to the proxy-generated GUID.

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

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

requesting a plurality of leases on the file from a first server, wherein the each of the plurality of lease requests comprises a lease key and the proxy-generated 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 client 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 the 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;

receiving a lease grant notification for the first file; and

receiving a lease break notification, wherein the lease break notification is addressed to a proxy-generated client 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 SMB lease request.

19. The method of claim 16, wherein the proxy-generated client GUID is generated at one of a SMB proxy server or a WAAS device.

20. The method of claim 19, wherein the proxy-generated GU ID is mapped to an original client GUID.