Method and apparatus for asynchronous transaction processing

• US 6,138,143 A
• Filed: 01/28/1999
• Issued: 10/24/2000
• Est. Priority Date: 01/28/1999
• Status: Expired due to Term

• Current Assignee: SAP SE
• Original Assignee: Genrad Incorporated (Teradyne Incorporated)
• Inventors: Gigliotti, Samuel Scott, Madam, Vijay Kumar
• Primary Examiner(s): Meky, Moustafa M.
• Application Number:
  US09/239,100
• Time in Patent Office: 635 Days
• Field of Search: 709/201, 709/203, 709/205, 709/213, 709/217, 709/218, 709/219, 709/101, 709/224, 707/201, 707/202
• US Class Current: 709/203
• CPC Class Codes: G06F 16/2379 Updates performed during online database operations; commit processing
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users

Abstract

In an asynchronous transaction processing method, system and computer program product, a transaction is initiated by a client object when the client object initiates a transaction context and registers with the transaction context as a participant in the transaction. The client object also publishes an event, the event including a reference to the transaction context, a reference to the client object and information. At least one server object responsive to, or subscribing to, the event registers with the transaction context identified in the event, performs a logical operation using the information provided in the event, places a vote to commit or roll back the transaction with the transaction context and calls back the client object with a response to the event using the reference to the client object included in the event. Upon receiving a call back from the at least one server object responsive to the event, the client object place a vote to commit or roll back the transaction with the transaction context. The client object then requests that the transaction context close the transaction. The transaction context reviews the votes and if all of the transaction participants have voted to commit the transaction, the transaction context commits the transaction data to one or more databases. If at least one participant in the transaction has voted to roll back the transaction, the transaction context signals the client object of the roll back vote and causes the transaction to be rolled back.

Claims

1. A method for asynchronous transaction processing in a distributed computing environment including at least one client object and at least one server object comprising the steps of:

a) initiating a transaction by a client object, the client object initiating a transaction context and registering as a participant with the transaction context;

b) publishing an event by the client object, the event including a reference to the transaction context, a reference to the client object and information;

c) registering with the transaction context as a participant by at least one server object responsive to the event, the at least one server object responsive to the event;

i) performing logical operations using the information provided in the event;

ii) placing a vote to commit or roll back the transaction with the transaction context; and

iii) calling back the client object with a response to the event using the reference to the client object included in the event;

d) upon receiving a call back from the at least one server object responsive to the event, placing a vote to commit or roll back the transaction with the transaction context by the client object;

e) passing a request from the client object to the transaction context to close the transaction;

f) reviewing the votes in the transaction context and;

i) if all of the transaction participants have voted to commit the transaction, the transaction context causes the transaction to be committed to at least one database;

or

ii) if at least one participant in the transaction has voted to roll back the transaction, the transaction context signals the client object of the roll back vote and causes the transaction to be rolled back.

2. The method of claim 1, wherein the transaction context provides a database connection to at least one participant in the transaction.

3. The method of claim 2, wherein when the transaction is committed, the transaction context signals each participant database connection to commit data to a database.

4. The method of claim 1, wherein the client object includes a client encapsulated in an object wrapper.

5. The method of claim 1, wherein the distributed computing environment includes a plurality of most computers.

6. The method of claim 5, wherein publishing an event includes passing the event to an event publisher for further publication into an event channel.

7. The method of claim 6, wherein the event channel passes the event to a plurality of event subscribers, each event subscriber maintaining a list of server objects responsive to the event and wherein for each event published, at least one event subscriber passes the event from the event channel to a subscribing object that is responsive to the event.

8. The method of claim 7, wherein an event subscriber directs an event to a subscribing object on a desired host machine that is identified in the event.

9. The method of claim 8, wherein the desired host computer includes a subscriber thread pool wherein when an event subscriber directs an event to a subscribing class on the desired host computer but no object of that class is running on the desired host computer, the event subscriber calls the subscriber thread pool to instantiate a server object responsive to the event.

10. The method of claim 9, wherein the event subscriber starts a subscriber thread pool for the subscribing class.

11. The method of claim 1, wherein a plurality of server objects are responsive to the event, each responsive server object:

a) registering with the transaction context identified in the event;

b) performing a logical operation using the information provided in the event;

c) placing a vote to commit or roll back the transaction with the transaction context; and

d) calling back the client object with a response to the event using the reference to the client object included in the event;

the client object placing a vote to commit or roll back the transaction with the transaction context after receiving call backs from each responsive server object.

12. The method of claim 1, wherein the responsive server object, as part of its logical operation, publishes a second event including a reference to the server object, a reference to the transaction context and information, at least one second server object being responsive to the second event, the second server object:

a) registering as a participant with the transaction context identified in the second event;

b) performing a logical operation using the information provided in the second event;

c) placing a vote to commit or roll back the transaction with the transaction context; and

d) calling back the server object with a response to the event using the reference to the server object included in the second event;

the server object calling back the client object and placing a vote with the transaction context after receiving a call back from the second server objects.

13. The method of claim 1, wherein the distributed computing environment is a distributed manufacturing execution system environment and the at least one client object inputs information to the manufacturing execution system from a manufacturing floor.

14. In a distributed object computing environment including a plurality of host computers connected by an object request broker, a system for asynchronously processing a transaction comprising:

a) at least one client object class including means for instantiating a client object, the client object having means for initiating a transaction including means for initiating a transaction context, means for registering with the transaction context as a participant in the transaction, means for publishing an event having a reference to the client object, a reference to the transaction context and data, a means for placing a vote to commit or roll back the transaction with the transaction context, and a means for requesting that the transaction context close the transaction;

b) at least one server object class including means for instantiating a server object, the server object being responsive to an event published by the client object and having a means for registering with the transaction context identified in the event as a transaction participant, a means for performing a logical operation with the data included in the event, a means for placing a vote to commit or roll back the transaction with the transaction context identified in the event, and a means for making a call back to the client object identified in the event with results of the logical operation;

c) a transaction context class having means responsive to a client object for instantiating a transaction context object having a means for registering participants in a transaction and for recording votes on whether to commit or roll back the transaction, the transaction context including means for committing the transaction to one or more databases.

15. The system of claim 14, wherein the transaction context class further includes means for providing a database connection to at least one participant in the transaction.

16. The system of claim 14, wherein the client object includes a client encapsulated in an object wrapper.

17. The system of claim 14, further comprising at least one event publisher wherein publishing an event includes passing the event to an event publisher for further publication into an event channel.

18. The system of claim 17, further comprising at least one event subscriber, the event subscriber passing an event from the event channel to a subscribing object on a desired host machine that is identified in the event.

19. The system of claim 18, further comprising a plurality of event subscribers wherein each event subscriber receives the event from the event channel and maintaining a list of server object classes responsive to the event and wherein at least one event subscriber passes the event from an event channel to a subscribing object on the desired host computer that is responsive to the event.

20. The system of claim 19, wherein the desired host computer includes a subscriber thread pool wherein when an event subscriber directs an event to a subscribing class on the desired host computer but no object of that class is running on the desired host computer, the event subscriber calls the subscriber thread pool to instantiate a server object responsive to the event.

21. The system of claim 20, wherein the event subscriber starts a subscriber thread pool for the subscribing class.

22. The system of claim 14, wherein a plurality of server objects are responsive to the event, each responsive server object:

a) registering with the transaction context identified in the event;

b) performing a logical operation using the information provided in the event;

c) placing a vote to commit or roll back the transaction with the transaction context; and

d) calling back the client object with a response to the event using the reference to the client object included in the event;

the client object placing a vote to commit or roll back the transaction with the transaction context after receiving call backs from each responsive server object.

23. The system of claim 14, wherein the responsive server object, as part of its logical operation, publishes a second event including a reference to the server object, a reference to the transaction context and information, at least one second server object being responsive to the second event, the second server object:

a) registering as a participant with the transaction context identified in the second event;

b) performing a logical operation using the information provided in the second event;

c) placing a vote to commit or roll back the transaction with the transaction context; and

d) calling back the server object with a response to the event using the reference to the server object included in the second event;

the server object calling back the client object and placing a vote with the transaction context after receiving a call back from the second server object.

24. In a system for asynchronously processing a transaction in a distributed object computing environment including a plurality of host computers connected by an object request broker, a computer program product comprising a computer useable medium having computer readable program code to direct the system to perform at least the following steps:

a) initiating a transaction by a client object, the client object initiating a transaction context and registering as a participant with the transaction context;

b) publishing an event by the client object, the event including a reference to the transaction context, a reference to the client object and information;

c) registering with the transaction context as a participant by at least one server object responsive to the event, the at least one server object responsive to the event;

i) performing logical operations using the information provided in the event;

ii) placing a vote to commit or roll back the transaction with the transaction context; and

iii) calling back the client object with a response to the event using the reference to the client object included in the event;

d) upon receiving a call back from the at least one server object responsive to the event, placing a vote to commit or roll back the transaction with the transaction context by the client object;

e) passing a request from the client object to the transaction context to close the transaction;

f) reviewing the votes in the transaction context and;

i) if all of the transaction participants have voted to commit the transaction, the transaction context causes the transaction to be committed to at least one database;

or

ii) if at least one participant in the transaction has voted to roll back the transaction, the transaction context signals the client object of the roll back vote and causes the transaction to be rolled back.

25. The computer program product of claim 24, wherein a plurality of server objects are responsive to the event, each responsive server object:

a) registering with the transaction context identified in the event;

b) performing a logical operation using the information provided in the event;

c) placing a vote to commit or roll back the transaction with the transaction context; and

d) calling back the client object with a response to the event using the reference to the client object included in the event;

the client object placing a vote to commit or roll back the transaction with the transaction context after receiving call backs from each responsive server object.

26. The method of claim 24, wherein the responsive server object, as part of its logical operation, publishes a second event including a reference to the server object, a reference to the transaction context and information, at least one second server object being responsive to the second event, the second server object:

a) registering as a participant with the transaction context identified in the second event;

b) performing a logical operation using the information provided in the second event;

c) placing a vote to commit or roll back the transaction with the transaction context; and

d) calling back the server object with a response to the event using the reference to the server object included in the second event;

the server object calling back the client object and placing a vote with the transaction context after receiving a call back from the second server object.

27. A method for asynchronous transaction processing in a distributed computing environment including at least one client object and at least one server object comprising the steps of:

a) initiating a transaction by a client object, the client object initiating a transaction context and registering as a participant with the transaction context;

b) publishing an event by the client object, the event including a reference to the transaction context and information;

c) registering with the transaction context as a participant by at least one server object responsive to the event, the at least one server object responsive to the event;

i) performing logical operations using the information provided in the event; and

ii) placing a vote to commit or roll back the transaction with the transaction context;

d) placing a vote to commit or roll back the transaction with the transaction context by the client object;

e) passing a request from the client object to the transaction context to close the transaction;

f) reviewing the votes in the transaction context and;

i) if all of the transaction participants have voted to commit the transaction, the transaction context causes the transaction to be committed to at least one database;

or

ii) if at least one participant in the transaction has voted to roll back the transaction, the transaction context signals the client object of the roll back vote and causes the transaction to be rolled back.

28. The method of claim 27, wherein the transaction context provides a database connection to at least one participant in the transaction.

29. The method of claim 28, wherein when the transaction is committed, the transaction context signals each participant database connection to commit data to a database.

30. The method of claim 27, wherein the client object includes a client encapsulated in an object wrapper.

31. The method of claim 27, wherein the distributed computing environment includes a plurality of host computers.

32. The method of claim 31, wherein publishing an event includes passing the event to an event publisher for further publication into an event channel.

33. The method of claim 32, wherein the event channel passes the event to a plurality of event subscribers, each event subscriber maintaining a list of server objects responsive to the event and wherein for each event published, at least one event subscriber passes the event from the event channel to a subscribing object that is responsive to the event.

34. The method of claim 33, wherein an event subscriber directs an event to a subscribing object on a desired host machine that is identified in the event.

35. The method of claim 34, wherein the desired host computer includes a subscriber thread pool wherein when an event subscriber directs an event to a subscribing class on the desired host computer but no object of that class is running on the desired host computer, the event subscriber calls the subscriber thread pool to instantiate a server object responsive to the event.

36. The method of claim 35, wherein the event subscriber starts a subscriber thread pool for the subscribing class.

37. The method of claim 27, wherein a plurality of server objects are responsive to the event, each responsive server object:

a) registering with the transaction context identified in the event;

b) performing a logical operation using the information provided in the event; and

c) placing a vote to commit or roll back the transaction with the transaction context.

38. The method of claim 27, wherein the responsive server object, as part of its logical operation, publishes a second event including a reference to the transaction context and information, at least one second server object being responsive to the second event, the second server object:

a) registering as a participant with the transaction context identified in the second event;

b) performing a logical operation using the information provided in the second event; and

c) placing a vote to commit or roll back the transaction with the transaction context.

39. The method of claim 27, wherein the distributed computing environment is a distributed manufacturing execution system environment and the at least one client object inputs information to the manufacturing execution system from a manufacturing floor.