EXPLICIT CASUALTY CONTROL IN A CLIENT/SERVER SYSTEM

• US 20080133756A1
• Filed: 11/30/2006
• Published: 06/05/2008
• Est. Priority Date: 11/30/2006
• Status: Active Grant

• Current Assignee: Red Hat, Inc. (International Business Machines Corporation)
• Original Assignee: Red Hat, Inc. (International Business Machines Corporation)
• Inventors: Taylor, Owen
• Granted Patent: US 8,190,746 B2
• Time in Patent Office: Days
• US Class Current: 709/227
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]

Abstract

Embodiments of the present invention provide a protocol for ensuring data integrity of requests made by clients of a social network service. In particular, when a client gets a confirmation from an update request, the confirmation is accompanied by a token that provides information about the update. When tie client next makes a read request it passes the token along with the read request. The node at the social network service receiving the request then waits until it makes sure that it has received any notifications that precede the state represented by the token before it processes the request and replies to the client. The token might be, among other things, a physical timestamp, a counter reflecting transactions committed on a database server, or a vector timestamp. In addition, the same technique can be used to ensure ordering between read requests.

Claims

1. A method of ensuring data requests made by clients of social network service, wherein the social network service comprises a plurality of nodes that service the requests, said method comprising:

receiving an update request from the clients;

providing a confirmation of the update request that is accompanied by a token that provides information about the update; and

receiving a subsequent request from the clients; and

determining whether all notifications that precede the state represented by the token have been received; and

responding to the subsequent request when all notifications that precede the state represented by the token have been received.

2. The method of claim 1, wherein the token comprises a physical timestamp.

3. The method of claim 1, wherein the token comprises a counter reflecting transactions committed by at least one of the nodes in the social network service.

4. The method of claim 1, wherein the token comprises a vector timestamp.

5. The method of claim 1, wherein the token comprises a set of counters with one counter reflecting the state of each node in the social network service.

6. The method of claim 1, wherein the token comprises a Lamport timestamp.

7. A system comprising means configured to perform the method of claim 1.

8. A computer readable medium comprising computer executable instructions for configuring a computer to perform the method of claim 1.

10. The method of claim 1, wherein the token comprises a physical timestamp.

11. The method of claim 1, wherein the token comprises a counter reflecting transactions committed by at least one of the nodes in the social network service.

12. The method of claim 1, wherein the token comprises a vector timestamp.

13. The method of claim 1, wherein the token comprises a set of counters with one counter reflecting the state of each node in the social network service.

14. The method of claim 1, wherein the token comprises a Lamport timestamp.

9. A method of ensuring data requests made by clients of social network service, wherein the social network service comprises a plurality of nodes that service the requests, said method comprising:

receiving a first read request from the clients;

providing a confirmation of the read request that is accompanied by a token that provides information about the first read request; and

receiving a subsequent read request from the clients; and

determining whether all notifications that precede the state represented by the token have been received; and

responding to the subsequent read request when all notifications that precede the state represented by the token have been received.

15. A system comprising means configured to perform the method of claim 9.

16. A computer readable medium comprising computer executable instructions for configuring a computer to perform the method of claim 9.