Reliable messaging using clocks with synchronized rates

• US 20060075133A1
• Filed: 12/07/2004
• Published: 04/06/2006
• Est. Priority Date: 09/21/2004
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Langworthy, David E., Kakivaya, Gopala Krishna R.
• Granted Patent: US 7,536,436 B2
• Time in Patent Office: Days
• US Class Current: 709/237
• CPC Class Codes: H04L 1/1621 Group acknowledgement, i.e. the acknowledgement message defining a range of identifiers, e.g. of sequence numbers
• CPC Class Codes: H04L 1/1685 the supervisory signal being transmitted in response to a specific request, e.g. to a polling signal
• CPC Class Codes: H04L 1/1848 Time-out mechanisms
• CPC Class Codes: H04L 1/188 Time-out mechanisms
• CPC Class Codes: H04L 1/1883 using multiple timers
• CPC Class Codes: H04L 63/04 for providing a confidential data exchange among entities communicating through data packet networks
• CPC Class Codes: H04L 63/06 for supporting key management in a packet data network cryptographic mechanisms or cryptographic arrangements for key management H04L9/08
• CPC Class Codes: H04L 69/28 Timers or timing mechanisms used in protocols
• CPC Class Codes: H04L 69/326 in the transport layer [OSI layer 4] H04L69/16 takes precedence
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

The present invention extends to methods, systems, and computer program products for reliable messaging using clocks with synchronized rates. In some embodiments, a message source adds at least an interaction ID and TTL value to a message. The message source begins a countdown timer having duration of the TTL value. The message source transmits the message to the destination computer system. The message source detects expiration of a retransmission interval corresponding to the message. The message source determines if the message requires acknowledgment. In other embodiments, a message destination receives a message that includes at least an interaction ID and TTL value. The message destination determines that the message is to be processed. The message destination begins a countdown timer having duration of the TTL value. The message destination processes the message and updates an interaction cache location that corresponds to the interaction ID.

Claims

1. At a message source that is network connectable along with one or more other computer systems, including a destination computer system, to a network, the message source and the destination computer system having synchronized clock rates, a method for reliably exchanging messages with the destination computer system, the method comprising:

an act of adding at least an interaction ID and TTL value to a message, the interaction ID identifying a message interaction between the message source and the destination computer system and the TTL value indicating when the message is to expire;

an act of beginning a countdown timer for the message, the countdown time having duration of the TTL value;

an act of transmitting the message to the destination computer system;

an act of detecting expiration of a retransmission interval corresponding to the message; and

an act of determining if the message requires acknowledgment.

2. The method as recited in claim 1, further comprising an act of adding a message offset number to the message prior to transmitting the message.

3. The method as recited in claim 1, further comprising an act of adding and instance ID the message prior to transmitting the message.

4. The method as recited in claim 1, wherein the act of adding at least an interaction ID and TTL value to a message comprises an act of adding a TTL value that is a specified multiple of the round trip latency between the message source and the destination computer system.

5. The method as recited in claim 1, wherein the act of adding at least an interaction ID and TTL value to a message comprises an act of formulating a message to adhere to message policies selected from among one or more protocol invariants and one or more protocol pre-conditions.

6. The method as recited in claim 1, wherein the act of determining if the message requires acknowledgment comprises an act of determining that the message does not require acknowledgment.

7. The method as recited in claim 6, wherein the act of determining that the message does not require acknowledgment comprises an act of determining that the message has been acknowledged by the destination computer system.

8. The method as recited in claim 7, wherein the act of determining that the message has been acknowledged by the destination computer system comprises an act of receiving an acknowledgment message that identifies the interaction ID corresponding to the message.

9. The method as recited in claim 8, wherein the act of determining that the message has been acknowledged by the destination computer system comprises an act of receiving a message offset number corresponding to the message.

10. The method as recited in claim 6, wherein the act of determining that the message does not require acknowledgment comprises an act of determining that the countdown timer has expired.

11. The method as recited in claim 1, wherein the act of determining if the message requires acknowledgment comprises an act of determining that the message does require acknowledgment.

12. The method as recited in claim 11, wherein the act of determining that the message does require acknowledgment comprises:

an act of determining that an acknowledgement for the message has not been received; and

an act of determining that a countdown timer for the message has not expired.

13. The method as recited in claim 11, further comprising:

an act of recomputing the TTL value to be the interval remaining on the countdown timer.

14. The method as recited in claim 13, further comprising:

an act of retransmitting the message to the destination computer system.

15. The method as recited in claim 1, further comprising:

an act of sending an ACKACK to the destination computer system, the ACKACK indicating to the destination computer system that the message source no longer requires acknowledgment of the message.

16. The method as recited in claim 15, wherein the act of sending an ACKACK to the destination computer system comprises act of sending an ACKACK including an instance ID that identifies a message processor instance at the destination computer system.

17. The method as recited in claim 15, further comprising:

an act of receiving a REQACKACK from the destination computer system prior to sending the ACKACK, the REQACKACK indicating that the destination computer system needs the progress of the message interaction

18. The method as recited in claim 1, wherein the message source comprises a Web browser and the destination computer system comprises a Web server.

19. The method as recited in claim 1, further comprising:

an act of receiving an endpoint reference that uniquely identifies the a message processor instance at the destination computer system.

20. At a message destination that is network connectable along with one or more other computer systems, including a source computer system, to a network, the message destination and the source computer system having synchronized clock rates, a method for reliably exchanging messages with the source computer system, the method comprising:

an act of receiving a message that includes at least an interaction ID and a TTL value, the interaction ID identifying a message interaction between the message destination and a source computer system and the TTL value indicating a time to live for the message;

an act of determining that the message is to be processed;

an act of beginning a countdown timer having duration of the TTL value, expiration of the countdown timer indicating that the message has expired;

an act of processing the message; and

an act of updating an interaction cache location that corresponds to the interaction ID.

21. The method as recited in claim 20, wherein the act of receiving a message that includes at least an interaction ID and a TTL value comprises an act of receiving a message that includes the interaction ID, the TTL value, and a message offset number.

22. The method as recited in claim 20, wherein the act of receiving a message that includes at least an interaction ID and a TTL value comprises an act of receiving a message that adheres to message policies selected from among one or more protocol invariants and one or more protocol pre-conditions.

23. The method as recited in claim 20, further comprising an act of receiving an instance ID for the message.

24. The method as recited in claim 23, further comprising:

an act of determining that the received instance ID matches the current instance ID of a message processor at the message destination.

25. The method as recited in claim 23, wherein the act of receiving an instance ID for the message comprises an act of receiving an instance ID in the message.

26. The method as recited in claim 23, wherein the act of receiving an instance ID for the message comprises:

an act of sending a REQACKACK to the source computer system; and

an act of receiving an ACKACK that includes the instance ID from the source computer system.

27. The method as recited in claim 23, further comprising:

an act of determining that the interaction represented by the interaction ID is not included in an interaction cache prior to sending the REQACKACK; and

an act of updating the interaction cache with data included in the ACKACK.

28. The method as recited in claim 20, wherein the act of determining that the message is to be processed comprises an act of extracting a status for the identified message interaction from the interaction cache.

29. The method as recited in claim 28, further comprising an act of comparing a message offset for the received message to the extracted status.

30. The method as recited in claim 20, wherein the act of determining that the message is to be processed comprises:

an act of determining that the message requires acknowledgment; and

an act of determining that the message can be processed.

31. The method as recited in claim 30, further comprising:

an act of sending an ACK to the source computer system.

32. The method as recited in claim 31, wherein the act of sending an ACK to the source computer system comprises an act of sending an ACK that includes one or more ranges of sequence numbers indicating messages that were successfully received.

33. The method as recited in claim 31, further comprising an act of receiving an ACKACK that is responsive to the sent ACK.

34. The method as recited in claim 20, further comprising an act of flushing the message interaction from the interaction cache subsequent to expiration of the countdown timer.

35. The method as recited in claim 21, wherein the source computer system comprises a Web browser and the message destination comprises a Web server.

36. A computer program product for use at a message source that is network connectable along with one or more other computer systems, including a destination computer system, to a network, the message source and the destination computer system having synchronized clock rates, the computer program product for implementing a method for reliably exchanging messages with the destination computer system, the computer program product comprising one or more computer-readable media having stored thereon computer-executable instructions that, when executed by a processor, cause the message source to perform the following:

add at least an interaction ID and TTL value to a message, the interaction ID identifying a message interaction between the message source and the destination computer system and the TTL value indicating when the message is to expire;

begin a countdown timer having duration of the TTL value;

transmit the message to the destination computer system;

detect expiration of a retransmission interval corresponding to the message; and

determine if the message requires acknowledgment.

37. A computer program product for use at a message destination that is network connectable along with one or more other computer systems, including a source computer system, to a network, the message destination and the source computer system having synchronized clock rates, the computer program product for implementing a method for reliably exchanging messages with the source computer system, the computer program product comprising one or more computer-readable media having stored thereon computer-executable instructions that, when executed by a processor, cause the message destination to perform the following:

receive a message that includes at least an interaction ID and a TTL value, the interaction ID identifying a message interaction between the message destination and a source computer system and the TTL value indicating when the message is to expire;

determine that the message is to be processed;

begin a countdown timer having duration of the TTL value;

processing the message; and

update an interaction cache location that corresponds to the interaction ID.