EVENT QUEUING AND DISTRIBUTION SYSTEM

• US 20140280852A1
• Filed: 05/15/2014
• Published: 09/18/2014
• Est. Priority Date: 04/27/2011
• Status: Active Grant

• Current Assignee: Rackspace US Incorporated (Apollo Global Management, Inc.)
• Original Assignee: Rackspace US Incorporated (Apollo Global Management, Inc.)
• Inventors: Griffiths, Kurt Evan
• Granted Patent: US 9,654,566 B2
• Time in Patent Office: Days
• US Class Current: 709/223
• CPC Class Codes: G06F 16/182 Distributed file systems
• CPC Class Codes: G06F 2209/548 Queue
• CPC Class Codes: G06F 9/542 Event management; Broadcasting; Multicasting; Notifications
• CPC Class Codes: H04L 67/141 Setup of application sessions admission control or resource allocation in data switching networks H04L47/70

Abstract

A REST-based event distribution system is described, with particular applicability to the distribution of distributed filesystem notifications over a high-latency best-effort network such as the Internet. In one embodiment, event channels are mapped to URL spaces and created and distributed through the use of HTTP POST and GET requests. The system is optimized for short polling by clients; an event history is maintained to buffer messages and maintain the idempotence of requests. In another embodiment, the events are registered as a SIP event pack allowing for the distribution of filesystem events.

Claims

1. An event distribution system, the system comprising:

a server configured to respond to event requests via a synchronous client-server protocol, the server further including;

a backing store configured to store an event associated with a channel identifier and to allow subsequent retrieval of the event using the same channel identifier, wherein an event is associated with an event identifier;

a communications module operable to receive event requests and send responses, wherein the communications module receives from a client an event request including a last seen event identifier that indicates a most recent event consumed by the client;

an event filtering system operable to evaluate, modify, and block event requests and responses, wherein the event filtering system sends a response including one or more events that were added to the first channel before the most recent event consumed by the client was added to the first channel; and

an event manager coordinating the use of the backing store, communications module, and event filtering system;

wherein the event requests represent interactions with a distributed filesystem storage system.

2. The event distribution system of claim 1, wherein the synchronous client-server protocol is one of HTTP, HTTPS, and SIP.

3. The event distribution system of claim 1, wherein the channel identifier is a URI.

4. The event distribution system of claim 1, wherein the event requests are formatted as one of HTTP POST, HTTP PUT, HTTP GET, and SIP NOTIFY.

5. The event distribution system of claim 1, wherein the event manager uses the event filtering system to block the recording of substantially identical requests in the backing store.

6. The event distribution system of claim 1, wherein the event manager uses the event filtering system to block the sending of substantially identical responses via the communications module.

7. The event distribution system of claim 1, wherein the event manager uses the event filtering system to identify a set of essential parameters that characterize a request, the set of essential parameters including the channel identifier;

and wherein every request including identical parameters returns an identical response via the communications module.

8. The event distribution system of claim 7, wherein the set of essential parameters includes a temporal range;

and wherein a request with identical parameters includes a request made within the defined temporal range.

9. The event distribution system of claim 1, wherein the response includes all events that were added to the first channel before the most recent event consumed by the client was added to the first channel.

10. The event distribution system of claim 1, wherein the response includes one or more events that have occurred in the first channel since the event associated with the last seen event identifier.

11. A method comprising:

storing in a backing store an event associated with a channel identifier, the backing store enabling subsequent retrieval of the event using the same channel identifier, and each event being associated with an event identifier;

receiving an event request including a last seen event identifier that indicates a most recent event consumed by a client, the event request being from the client and representing one or more interactions with a distributed filesystem storage system; and

sending a response including one or more events that were added to the first channel before the most recent event consumed by the client was added to the first channel.

12. The method of claim 11, wherein the sending a response includes responding to the event request via a synchronous client-server protocol.

13. The method of claim 12, wherein the synchronous client-server protocol is one of HTTP, HTTPS, and SIP.

14. The method of claim 11, wherein the receiving an event request includes receiving an event publishing request, wherein the event publishing request includes an event publishing verb and a subject, wherein the event publishing request is transmitted using one of HTTP and HTTPS, and wherein the event publishing verb is one of POST and PUT.

15. The method of claim 11, wherein the channel identifier is a URI.

16. The method of claim 11, wherein the sending a response includes sending a representation of the one or more events.

17. The method of claim 16, wherein the representation of the one or more events is encoded in a format selected from the group consisting of a Javascript array, JSON, BSON, XML, HTML, and plain text.

18. The method of claim 11, wherein the sending a response includes sending all events that were added to the first channel before the most recent event consumed by the client was added to the first channel.

19. The method of claim 11, wherein the sending a response includes sending one or more events that have occurred in the first channel since the event associated with the last seen event identifier.

20. A non-transient computer readable medium containing executable instructions, which when executed on a processor:

storing in a backing store an event associated with a channel identifier, the backing store enabling subsequent retrieval of the event using the same channel identifier, and each event being associated with an event identifier;

receiving an event request including a last seen event identifier that indicates a most recent event consumed by a client, the event request being from the client and representing one or more interactions with a distributed filesystem storage system; and

sending a response including one or more events that were added to the first channel before the most recent event consumed by the client was added to the first channel.