Access requests with cache intentions

• US 9,076,012 B2
• Filed: 03/11/2014
• Issued: 07/07/2015
• Est. Priority Date: 01/15/2009
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: George, Mathew, Kruse, David M., Pinkerton, James T., Jolly, Thomas E.
• Primary Examiner(s): Corrielus, Jean M
• Application Number:
  US14/204,697
• Publication Number:
  US 20140244688A1
• Time in Patent Office: 483 Days
• Field of Search: 707/821, 707/781, 707/704, 707/770, 707/722, 711/141, 709/201, 709/203
• US Class Current: 1/1
• CPC Class Codes: G06F 12/0813 with a network or matrix configuration
• CPC Class Codes: G06F 12/0815 Cache consistency protocols
• CPC Class Codes: G06F 12/0866 for peripheral storage systems, e.g. disk cache
• CPC Class Codes: G06F 16/172 Caching, prefetching or hoarding of files
• CPC Class Codes: G06F 16/182 Distributed file systems
• 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 21/6218 to a system of files or objects, e.g. local or distributed file system or database
• CPC Class Codes: G06F 2212/264 Remote server
• CPC Class Codes: G06F 2212/463 File
• CPC Class Codes: G06F 2221/2141 Access rights, e.g. capability lists, access control lists, access tables, access matrices
• CPC Class Codes: H04L 67/01 Protocols
• 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 67/568 Storing data temporarily at an intermediate stage, e.g. caching

Abstract

A lease system is described herein that allows clients to request a lease to a remote file, wherein the lease permits access to the file across multiple applications using multiple handles without extra round trips to a server. When multiple applications on the same client (or multiple components of the same application) request access to the same file, the client specifies the same lease identifier to the server for each open request or may handle the request from the cache based on the existing lease. Because the server identifies the client'"'"'s cache at the client level rather than the individual file request level, the client receives fewer break notifications and is able to cache remote files in more circumstances. Thus, by providing the ability to cache data in more circumstances common with modern applications, the lease system reduces bandwidth, improves server scalability, and provides faster access to data.

Claims

1. A method for sending a lease break notification by a server, wherein the lease break notification breaks a lease at a lease access level, the method for sending the lease break notification comprising:

receiving a first request for access to a file from a first client, the first request for access including a first access level and a first lease identifier that identifies the first client;

granting a first lease to the first client at the first access level, wherein granting the first lease includes sending a lease response that includes information to be cached at the client from the remote file managed by the server;

receiving a second request for access to the file from the first client, the second request for access including a second access level and the first lease identifier, wherein the second access level is higher than the first access level;

collapsing the second request into the first lease based on the common first lease identifier in the first request and the second request, wherein the first lease is upgraded to the second access level;

receiving a third request for access to the file from a second client, the third request for access including the first access level and a second lease identifier that identifies the second client;

granting a second lease to the second client at the first access level; and

sending the lease break notification to the first client, wherein the lease break notification breaks the first lease, and wherein the lease break notification includes the first access level for the second lease.

2. The method of claim 1, wherein the lease access level is comprised of:

read access, write access, and read and write access.

3. The method of claim 1, wherein upon granting the first lease, the server sends the first client file data and metadata corresponding to the file.

4. The method of claim 1, wherein the lease break notification includes the first lease identifier.

5. The method of claim 1, further comprising:

receiving, by the server, an acknowledgement from the first client that the lease has been broken.

6. The method of claim 1, wherein collapsing further comprises comparing the first client to a list of clients in an access control list.

7. The method of claim 6 further comprising confirming that the first client is allowed access to the file at the second access level.

8. A computer system comprising:

a processor; and

a memory communicatively coupled to the processor, the memory having computer-executable instructions that when executed by the processor, provide a method for sending a lease break notification by a server, wherein the lease break notification breaks a lease at a lease access level, the method for sending the lease break notification comprising;

receiving a first request for access to a file from a first client, the first request for access including a first access level and a first lease identifier that identifies the first client;

granting a first lease to the first client at the first access level, wherein granting the first lease includes sending a lease response that includes information to be cached at the client from the remote file managed by the server;

receiving a second request for access to the file from the first client, the second request for access including a second access level and the first lease identifier, wherein the second access level is higher than the first access level;

collapsing the second request into the first lease based on the common first lease identifier in the first request and the second request, wherein the first lease is upgraded to the second access level;

receiving a third request for access to the file from a second client, the third request for access including the first access level and a second lease identifier that identifies the second client;

granting a second lease to the second client at the first access level; and

sending the lease break notification to the first client, wherein the lease break notification breaks the first lease, and wherein the lease break notification includes the first access level for the second lease.

9. The computer system of claim 8, wherein the lease access level is comprised of:

read access, write access, and read and write access.

10. The computer system of claim 8, wherein upon granting the first lease, the server sends the first client file data and metadata corresponding to the file.

11. The computer system of claim 8, wherein the lease break notification includes the first lease identifier.

12. The computer system of claim 8, further comprising:

receiving, by the server, an acknowledgement from the first client that the lease has been broken.

13. The computer system of claim 8, wherein collapsing further comprises comparing the first client to a list of clients in an access control list.

14. The computer system of claim 13 further comprising confirming that the first client is allowed access to the file at the second access level.

20. The computer storage media of claim 9 further comprising confirming that the first client is allowed access to the file at the second access level.

15. One or more computer storage media having computer-executable components that upon execution perform a method for sending a lease break notification by a server, wherein the lease break notification breaks a lease at a lease access level, the method for sending the lease break notification comprising:

receiving a first request for access to a file from a first client, the first request for access including a first access level and a first lease identifier that identifies the first client;

granting a first lease to the first client at the first access level, wherein granting the first lease includes sending a lease response that includes information to be cached at the client from the remote file managed by the server;

receiving a second request for access to the file from the first client, the second request for access including a second access level and the first lease identifier, wherein the second access level is higher than the first access level;

collapsing the second request into the first lease based on the common first lease identifier in the first request and the second request, wherein the first lease is upgraded to the second access level;

receiving a third request for access to the file from a second client, the third request for access including the first access level and a second lease identifier that identifies the second client;

granting a second lease to the second client at the first access level; and

sending the lease break notification to the first client, wherein the lease break notification breaks the first lease, and wherein the lease break notification includes the first access level for the second lease.

16. The one or more computer storage media of claim 15, wherein the lease access level is comprised of:

read access, write access, and read and write access.

17. The one or more computer storage media of claim 15, wherein upon granting the first lease, the server sends the first client file data and metadata corresponding to the file.

18. The one or more computer storage media of claim 15, wherein the lease break notification includes the first lease identifier.

19. The computer storage media of claim 15, wherein collapsing further comprises comparing the first client to a list of clients in an access control list.