Distributed File System Consistency Mechanism Extension for Enabling Internet Video Broadcasting

• US 20100082774A1
• Filed: 12/07/2009
• Published: 04/01/2010
• Est. Priority Date: 09/09/2005
• Status: Active Grant

• Current Assignee: William M. Pitts
• Original Assignee: William M. Pitts
• Inventors: Pitts, William M.
• Granted Patent: US 8,504,597 B2
• Time in Patent Office: Days
• US Class Current: 709/219
• CPC Class Codes: G06F 16/148 File search processing
• CPC Class Codes: G06F 16/156 Query results presentation
• CPC Class Codes: G06F 16/1734 Details of monitoring file system events, e.g. by the use of hooks, filter drivers, logs
• 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 16/24578 using ranking
• CPC Class Codes: G06F 16/9535 Search customisation based on user profiles and personalisation
• CPC Class Codes: H04H 20/82 using signals not modulated onto a carrier
• CPC Class Codes: H04N 21/222 Secondary servers, e.g. proxy server, cable television Head-end provisioning of proxy services in data packet switching networks H04L67/56
• CPC Class Codes: H04N 21/6125 involving transmission via Internet transmission by internet of broadcast information H04H60/82
• CPC Class Codes: H04N 21/654 Transmission by server directed to the client
• CPC Class Codes: H04N 21/84 Generation or processing of descriptive data, e.g. content descriptors systems specially adapted for using meta-information in broadcast systems H04H60/73

Abstract

The consistency callback mechanisms employed by local file systems such as NTFS and distributed file systems such as DDS, NFS and CIFS are extended to provide a shared memory foundation for efficiently broadcasting real-time high definition video from a source object to large numbers of viewers via the Internet. Distributed applications such as video viewing client applications establish connections to a common distributed file system object, and then each application registers with the underlying distributed file system to receive notifications whenever the video source modifies the source object. The data required to update images maintained by viewing clients is included in notification messages. The distributed file system employs a network of proxy cache nodes. Proxy cache nodes receive notification messages (complete with image update data) and update their cached images of the source object and then retransmit the notification messages towards the viewing clients using IP multicast techniques. In this manner, the distributed file system'"'"'s consistency mechanism efficiently employs network resources to enable the real-time distribution of video content streams.

Claims

1. In a distributed file system, a method of registering an application'"'"'s request for notification of updates to a file, comprising:

providing to the site at which the application is executing a file descriptor identifying the file for which the application requests notification of updates; and

requesting that any notification of an update include the data that is updated in the file.

2. The method of claim 1 wherein the distributed file system is the Internet.

3. The method of claim 1 wherein the content is audio and the applications are audio clients which allow users to hear the audio content.

4. The method of claim 1 wherein the content is video and the applications are video clients which allow users to view the video content.

5. The method of claim 1 wherein providing the file descriptor and requesting that a notification include updated data further comprises an IOCTL system call function having arguments which identify the file.

6. The method of claim 5, wherein the IOCTL system call function returns when there is an update notification.

7. The method of claim 5, wherein the request for update notification includes a notification routine address.

8. The method of claim 7, wherein the IOCTL system call function returns immediately and the notification routine identified by the notification routine address is called when an update notification is received.

9. The method of claim 1 further comprising storing the identified notification descriptor as extended attributes of the identified file that are handled in the same manner as the file'"'"'s regular attributes.

10. The method of claim 9 wherein a request for update notification is received from each of a plurality of applications, and further comprising discarding the extended attributes of the identified file when all of the applications that have provided a request for update notification for the identified file have terminated their connections to the identified file.

11. In a distributed file system, a method of notifying sites of an update to a specified file, comprising:

determining that there has been an update to the file;

determining the sites at which the file is currently being accessed; and

delivering a notification message to each of the determined sites indicating that the file has been updated and containing the updated data from the file.

12. In a distributed file system, a method of notifying an application of an update to a specified file, comprising:

registering at the site at which an application is executing a descriptor identifying the file for which the application requests update notification;

receiving at the site a notification message that an update to the file has occurred and the newly updated data in the file;

delivering the notification to the application.

13. A method of communicating updates to a file located at a first site in a distributed file system to applications running at different sites in the distributed file system, comprising:

for each of a plurality of applications, providing to the site at which the application is running a file descriptor identifying the file for which the application requests notification of updates;

for each file for which a file descriptor is provided, storing the request for update notification as extended attributes of the identified file that are handled in the same manner as the file'"'"'s regular attributes;

receiving an update to the file;

determining the sites at which the file is currently being accessed;

delivering a notification message to each of the determined sites, the notification message indicating that an update has occurred and containing the newly updated data in the file; and

at each site, delivering a notification and the newly updated data to the application that provided the file descriptor.

14. The method of claim 13 wherein providing the file descriptor and the notification descriptor further comprises an IOCTL system call function having arguments which identify the file.

15. The method of claim 14, wherein the IOCTL system call function returns when there is notification that an update has occurred.

16. The method of claim 14, wherein the file descriptor includes a notification routine address.

17. The method of claim 16, wherein the IOCTL system call function returns immediately and the notification routine identified by the notification routine address is called when there is notification that an update has occurred.

18. The method of claim 13 further comprising discarding the extended attributes of the identified file when all of the applications that have provided a file descriptor for the identified file have terminated their connections to the identified file.

19. The method of claim 13 wherein delivering a notification message to each of the determined sites further comprises employing IP multicast to send the notification message to all of the sites.

20. A method of broadcasting content located on a first site in a distributed file system to multiple applications running at a plurality of other sites, comprising:

for each of the plurality of applications, establishing through the site at which the application is running a connection to the first site or to an intermediate which is closer to the first site;

for each intermediate site, establishing a connection to the first site or to another intermediate site until a connection to a source object located on the first site is established for each of the plurality of applications;

returning to each of the applications an object identifier identifying the source object;

buffering a copy of the source object at each site at which an application is running and at each intermediate site;

for each of the plurality of applications, requesting an update notification whenever the source object is modified;

determining when new data is written to the source object;

whenever new data is written to the source object, providing an update notification to each of the plurality of applications by sending the update notification to each of the next level sites through which the plurality of applications are connected to the source object, the update notification including an indication of the new data written to the source object; and

updating each buffered copy of the source object with the new data.

21. The method of claim 20 wherein the distributed file system is the Internet.

22. The method of claim 20 wherein the content is audio and the applications are audio clients which allow users to hear the audio content.

23. The method of claim 20 wherein the content is video and the applications are video clients which allow users to view the video content.

24. The method of claim 20 wherein writing new data to the source object further comprises:

writing first new data indicative of the content of the source object;

waiting a predetermined period of time to allow applications to establish connections to the source object; and

writing subsequent new data to the source object.

25. The method of claim 20 wherein providing an update notification to each of the plurality of applications further comprises employing IP multicast to send the update notification to each of the next level sites through which the plurality of applications are connected to the source object.

26. A method of processing an update notification received from a site one level closer to the source object, comprising:

receiving the update notification; and

updating each buffered copy of the source object with the new data; and

sending the update notification to each of the next level sites through which applications are connected to the source object, the update notification including an indication of the new data written to the source object.

27. The method of claim 26 wherein providing an update notification to each of the next level sites further comprises employing IP multicast to send the update notification to each of the next level sites through which applications are connected to the source object.