Publication of informational messages to software applications in a computing environment

• US 20050283353A1
• Filed: 05/27/2005
• Published: 12/22/2005
• Est. Priority Date: 05/28/2004
• Status: Active Grant

• Current Assignee: eBay Inc.
• Original Assignee: eBay Inc.
• Inventors: Kao, Daniel T., Billingsley, Eric, Wong, Laura, Tai, Shio-Hsien
• Granted Patent: US 7,571,195 B2
• Time in Patent Office: Days
• US Class Current: 703/23
• CPC Class Codes: G06Q 10/10 Office automation; Time management
• CPC Class Codes: G06Q 30/06 Buying, selling or leasing transactions

Abstract

A “push” based publication model in which messages are sent automatically to communicate event related data to other system applications when an event occurs that causes a change to a persistent data store. A shadow table stores records relating to information stored in the main table. Each record is assigned a sequentially ordered identification code. A high water mark table stores the identification number of the last message published for a group of messages, and thus points to where publication last stopped. By using sequentially ordered codes, it is readily apparent from a gap in the sequence codes whether a record/message is missing. The shadow table may be configured as an Index Ordered Table to eliminate a query “hop” from the index table to the shadow table. The persistent store is queried to identify changes in persistent store structure, and the message structure is modified automatically to reflect any changes.

Claims

1. A method for publishing information to independent software applications operating in a computer system, the method comprising:

detecting occurrence of an event in which a persistent store of data is modified;

storing, in a memory of the computer system, a new record for each event, each record comprising information relating to the event and a respective next sequential identification code;

preparing a corresponding message for each record of a plurality of records, each message comprising certain information relating to a respective event that is to be communicated to the independent software applications;

transmitting each message to at least one independent software application of the computer system to publish information relating to corresponding events; and

storing, in the memory, the respective sequential identification code of the last record published by transmission of a respective corresponding message.

2. The method of claim 1, further comprising:

reading from the memory the respective sequential identification code of the last record published in a respective corresponding message; and

reading from the memory a next sequential record having an identification code that is next in a sequence relative to the respective sequential identification code read from the memory;

preparing a next corresponding message for the next sequential record; and

transmitting the next corresponding message to at least one independent software application of the computer system to publish information relating to a corresponding event.

3. The method of claim 1, further comprising:

storing, in the memory, the identification code of the next sequential record.

4. The method of claim 1, further comprising:

storing data in a main table of a persistent store responsive to occurrence of an event.

5. The method of claim 4, further comprising:

storing data in a shadow table of a persistent store responsive to occurrence of the event.

6. The method of claim 5, wherein the shadow table is configured as an index ordered table.

7. The method of claim 5, wherein the shadow table stores certain information that is also stored in the main table.

8. The method of claim 7, wherein a view is used for accessing data stored in the shadow table and the main table, and preparing a corresponding message for each record comprises reading data from the view.

9. The method of claim 7, wherein preparing a corresponding message for each record of a plurality of records comprises reading data from the main table.

10. The method of claim 1, further comprising:

interrupting the transmission of messages when a number of messages transmitted corresponding to the number of records in the plurality of records reaches a predetermined message publication limit; and

11. The method of claim 10, further comprising:

resuming the transmission of messages after expiration of a predetermined period of time.

12. The method of claim 1, wherein a number of records in the plurality of records is determined by a predetermined limit.

13. The method of claim 1, further comprising;

receiving a request for retransmission of a message corresponding to a particular record, the particular record being identified in the request by a particular respective identification code; and

retransmitting the message corresponding to the particular record.

22. A computer program product embodied on one or more computer-readable media, the computer program product comprising computer readable program code configured to carry out the method of claim 1.

14. A method for publishing information to independent software applications operating in a computer system, the method comprising:

storing, in a memory of the computer system, a new record for each of a plurality of events, a persistent store of data being modified with the occurrence of each event, each record comprising information relating to a corresponding event and a respective identification code, the respective identification codes being assigned to the records in a predictable sequence corresponding to an order of storing of the records;

preparing a corresponding message for each record of a first plurality of records, each message comprising information relating to a respective event that is to be communicated to the independent software applications;

transmitting, in a first plurality of messages, each message of the first plurality of messages to at least one independent software application of the computer system to publish information relating to corresponding events; and

storing, in the memory, the last sequential identification code of the records corresponding to the messages transmitted in the first plurality of messages.

15. The method of claim 14, further comprising:

reading from the memory the last sequential identification code;

reading from the memory a next sequential record having a next sequential identification code;

preparing a next corresponding message for the next sequential record; and

transmitting, in a second plurality of messages, each message of the second plurality of messages to at least one independent software application of the computer system, the second plurality of messages including the message corresponding to the next sequential record.

16. The method of claim 15, wherein the second plurality of messages excludes any messages corresponding to any records having a sequential identification code preceding the last sequential identification code.

17. A method for publishing information to independent software applications operating in a computer system, the method comprising:

receiving a recovery request from a subscribing application, said recovery request identifying at least one identification code of a record for which retransmission of a corresponding message is requested, the corresponding message including information from the record;

adding to a queue the recovery request; and

intermittently processing a plurality of recovery requests in the queue, the processing for each recovery request comprising retrieving information from a persistent store of data, preparing a message including the retrieve data, and transmitting the message to the subscribing application.

18. The method of claim 17, further comprising:

deleting from the queue a duplicate recovery request identical to another recovery request in the queue.

19. The method of claim 17, further comprising:

retrieving the corresponding message from a cache, if possible;

wherein adding the recovery request to the queue is performed only if retrieving the corresponding message from the cache is not possible.

20. The method of claim 18, further comprising:

awaiting elapse of a predetermined period of time between adding the request for the missing message to the queue and issuing any recovery requests.

23. A computer program product embodied on one or more computer-readable media, the computer program product comprising computer readable program code configured to carry out the method of claim 17.

21. A computer program product embodied on one or more computer-readable media, the computer program product comprising:

computer readable program code configured to store, in a memory of the computer system, a new record for each of a plurality of events, a persistent store being modified with the occurrence of each event, each record comprising information relating to a corresponding event and a respective identification code, the respective identification codes being assigned to the records in a predictable sequence corresponding to an order of storing of the records;

computer readable program code configured to prepare a corresponding message for each record of a first plurality of records, each message comprising information relating to a respective event that is to be communicated to the independent software applications;

computer readable program code configured to transmit, in a first plurality of messages, each message of the first plurality of messages to at least one independent software application of the computer system to publish information relating to corresponding events; and

computer readable program code configured to store, in the memory, the last sequential identification code of the records corresponding to the messages transmitted in the first plurality of messages.

24. A system for publishing information to independent software applications operating in a computer system, the system comprising:

means for storing, in a memory of the computer system, a new record for each of a plurality of events, a persistent store being modified with the occurrence of each event, each record comprising information relating to a corresponding event and a respective identification code, the respective identification codes being assigned to the records in a predictable sequence corresponding to an order of storing of the records;

means for preparing a corresponding message for each record of a first plurality of records, each message comprising information relating to a respective event that is to be communicated to the independent software applications;

means for transmitting, in a first plurality of messages, each message of the first plurality of messages to at least one independent software application of the computer system to publish information relating to corresponding events; and

means for storing, in the memory, the last sequential identification code of the records corresponding to the messages transmitted in the first plurality of messages.

25. A system for publishing information to independent software applications operating in a computer system, the system comprising:

a processor;

a memory operably connected to the processor; and

instructions stored in the memory and executable by the processor to cause said system to;

store, in the memory, a new record for each of a plurality of events, a persistent store being modified with the occurrence of each event, each record comprising information relating to a corresponding event and a respective identification code, the respective identification codes being assigned to the records in a predictable sequence corresponding to an order of storing of the records;

prepare a corresponding message for each record of a first plurality of records, each message comprising information relating to a respective event that is to be communicated to the independent software applications;

transmit, in a first plurality of messages, each message of the first plurality of messages to at least one independent software application of the computer system to publish information relating to corresponding events; and

store, in the memory, the last sequential identification code of the records corresponding to the messages transmitted in the first plurality of messages.