Client-based caching of remote files

• US 8,868,606 B2
• Filed: 05/21/2013
• Issued: 10/21/2014
• Est. Priority Date: 01/15/2009
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: George, Mathew, Kruse, David M., Pinkerton, James T., Jolly, Thomas E.
• Primary Examiner(s): Corrielus, Jean M
• Application Number:
  US13/899,337
• Publication Number:
  US 20130254272A1
• Time in Patent Office: 518 Days
• Field of Search: 707/827, 707/781, 707/821, 707/704, 709/218, 709/203
• US Class Current: 707/781
• 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 computer-implemented method for controlling a client to handle a break notification from a server, the method comprising:

transmitting a lease request over a network that connects one or more clients and servers, wherein the lease request includes a lease identifier provided by a client when the client opened a remote file managed by the server and accessible by other clients;

receiving a lease response over the network, wherein the lease response includes information from the remote file managed by the server;

caching data at the client based upon the information received from the server;

receiving the break notification from the server;

in response to receiving the break notification, flushing cached data and sending an acknowledgement request to the server that indicates that the client has handled the break and requests a new scope of access to the remote file based on application requests on the client; and

receiving an acknowledgement response from the server that indicates whether the server granted the new scope of access to the remote file.

2. The method of claim 1, wherein the break notification includes a current lease state of the lease held by the client and a new lease state available to the client based on the access of one or more other clients to the remote file.

3. The method of claim 1, wherein the client was caching writes to the remote file before the break notification and wherein flushing cached data comprises flushing pending written data to the server before responding to the break notification.

4. The method of claim 1, further comprising, after receiving and handling the break notification, handling application requests from the cache that are compatible with a grant of the new scope of access and sending other requests to the server without caching.

5. The method of claim 1, wherein the lease request is configured to provide one or more cache intentions in the lease request.

6. The method of claim 5, wherein the cache intentions specify a manner in which the client accesses the remote file.

7. The method of claim 1, wherein the lease request comprises a UNC path to the remote file.

8. The method of claim 1, wherein the lease request comprises an Extended Create Parameter (ECP) and the lease response comprises the ECP.

9. A computer-readable storage medium comprising instructions for controlling a client to handle a break notification from a server, wherein the instructions, when executed by at least one processor at the client, cause the at least one processer to perform actions comprising:

transmitting a lease request over a network that connects one or more clients and servers, wherein the lease request includes a lease identifier provided by the client when the client opened a remote file managed by the server and accessible by other clients;

receiving a lease response over the network, wherein the lease response includes information from the remote file managed by the server;

caching data at the client based upon the information received from the server;

receiving the break notification from the server;

in response to receiving the break notification, flushing cached data and sending an acknowledgement request to the server that indicates that the client has handled the break and requests a new scope of access to the remote file based on application requests on the client; and

receiving an acknowledgement response from the server that indicates whether the server granted the new scope of access to the remote file.

10. The computer-readable storage medium of claim 9, wherein the break notification includes a current lease state of the lease held by the client and a new lease state available to the client based on the access of one or more other clients to the remote file.

11. The computer-readable storage medium of claim 9, wherein the client was caching writes to the remote file before the break notification and wherein flushing cached data comprises flushing pending written data to the server before responding to the break notification.

12. The computer-readable storage medium of claim 9, further comprising, after receiving and handling the break notification, handling application requests from the cache that are compatible with a grant of the new scope of access and sending other requests to the server without caching.

13. The computer-readable storage medium of claim 9, wherein the lease request is configured to provide one or more cache intentions in the lease request.

14. The computer-readable storage medium of claim 13, wherein the cache intentions specify a manner in which the client accesses the remote file.

15. The computer-readable storage medium of claim 9, wherein the lease request comprises a UNC path to the remote file.

16. The computer-readable storage medium of claim 9, wherein the lease request comprises an Extended Create Parameter (ECP) and the lease response comprises the ECP.

17. A system comprising:

one or more processors;

a memory coupled to the one or more processors, the memory for storing instructions which, when executed by the one or more processors, performs a method for controlling a client to handle a break notification from a server, the method comprising;

transmitting a lease request over a network that connects one or more clients and servers, wherein the lease request includes a lease identifier provided by a client when the client opened a remote file managed by the server and accessible by other clients;

receiving a lease response over the network, wherein the lease response includes information from the remote file managed by the server;

caching data at the client based upon the information received from the server;

receiving the break notification from the server;

in response to receiving the break notification, flushing cached data and sending an acknowledgement request to the server that indicates that the client has handled the break and requests a new scope of access to the remote file based on application requests on the client; and

receiving an acknowledgement response from the server that indicates whether the server granted the new scope of access to the remote file.

18. The system of claim 17, wherein the break notification includes a current lease state of the lease held by the client and a new lease state available to the client based on the access of one or more other clients to the remote file.

19. The system of claim 17, wherein the client was caching writes to the remote file before the break notification and wherein flushing cached data comprises flushing pending written data to the server before responding to the break notification.

20. The system of claim 17, wherein the lease request is configured to provide one or more cache intentions in the lease request.