Method and apparatus for implementing three tier client asynchronous transparency

• US 6,442,552 B1
• Filed: 06/30/2000
• Issued: 08/27/2002
• Est. Priority Date: 06/30/2000
• Status: Expired due to Term

• Current Assignee: Valtrus Innovations Limited (f/k/a Dolya Holdco 9 Limited) (Key Patent Innovations Limited)
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Guerraoui, Rachid, Frolund, Svend
• Primary Examiner(s): Mizrahi, Diane D.
• Application Number:
  US09/608,124
• Time in Patent Office: 788 Days
• Field of Search: 707/10, 707/200, 707/201, 707/202, 707/203, 707/204, 707/205, 707/103, 707/4, 709/229
• US Class Current: 707/613
• CPC Class Codes: G06F 16/95 Retrieval from the web
• CPC Class Codes: H04L 67/01 Protocols
• CPC Class Codes: Y10S 707/99934 Query formulation, input preparation, or translation

Abstract

A client method for providing three tier asynchronous client transparency includes sending a request and a count from a client to a first application server of an application server group. The request and count are resent to the group, if no corresponding decision is received within a pre-determined time period. The request is resent with an incremented count to a selected one of the first application server and the group, if the corresponding decision indicates that the result has not been committed. An application server method attempts to write a server identity to a write-once register in response to receipt of a client tier originated request. An attempt is made to write the computed result and a determined outcome as a first decision to the write-once register. The transaction identified by the request is terminated consistent with a second decision indicated by the write-once register. The result of the second decision is provided to the client-tier.

Claims

1. A computer method for providing a three tier asynchronous client transparency comprising the steps of:

a) sending a request and a count from a client to a first application server of an application server group; and

b) resending the request and count to the application server group, if no corresponding decision is received within pre-determined time period.

2. The method of claim 1 further comprising the step of:

c) incrementing the count and resending the request and incremented count to a selected one of the first application server and the application server group if the outcome of the decision indicates that the result has not been committed.

3. The method of claim 2 further comprising the step of:

d) providing a result of the decision to an end-user, if the outcome indicates that the result has been committed.

4. The method of claim 1 further comprising the steps of:

c) attempting to write a first application server identifier to a write-once register entry associated with the request, wherein each instance of the request corresponds to a unique write-once register entry.

5. A computer method for providing a three tier asynchronous client transparency comprising the steps of:

a) sending a request and a count from a client to a first application server of an application server group; and

b) incrementing the count and resending the request and incremented count to a selected one of the first application server and the application server group, if a corresponding decision indicates that the result has not been committed.

6. The method of claim 5 further comprising the step of:

c) resending the request and count to the application server group, if no corresponding decision is received within pre-determined time period.

7. The method of claim 5 further comprising the step of:

c) providing a result of the decision to an end-user, if the outcome indicates that the result has been committed.

8. The method of claim 5 further comprising the steps of:

c) attempting to write a first application server identifier to a write-once register entry associated with the request, wherein each instance of the request corresponds to a unique write-once register entry.

9. A computer method for providing a three tier asynchronous client transparency comprising the steps of:

a) receiving a request originating from a client tier; and

b) attempting to write a first application server identifier to a first portion of a write-once register entry associated with the request in response to receipt of the request by the first application server.

10. The method of claim 9 further comprising the steps of:

c) computing a result for the request;

d) determining an outcome for the result; and

e) attempting to write the result and outcome as a first decision to a second portion of the write-once register entry.

11. The method of claim 10 further comprising the step of:

d) attempting to terminate a transaction identified by the write-once register entry in accordance with a second decision indicated by the second portion of the write-once register entry.

12. The method of claim 11 wherein the first and second decisions are identical.

13. The method of claim 11 further comprising the steps of:

e) repeating step d) until receiving acknowledgment of the termination of the transaction.

14. The method of claim 11 further comprising the steps of:

f) providing the second decision to the client tier.

15. A computer method for providing a three tier asynchronous client transparency comprising the steps of:

a) selecting an active transaction of a suspected application server of an application server tier;

b) attempting to write a decision having an aborted first outcome to a write-once register entry associated with the selected active transaction; and

c) issuing commands to a database tier to terminate the transaction in accordance with a second outcome indicated by the write-once register entry.

16. The method of claim 15 wherein the first and second outcomes are identical.

17. The method of claim 15 further comprising the step of:

d) adding the selected active transaction to a cleared list;

e) repeating steps a)-d) for each active transaction of the suspected application server.

18. The method of claim 17 further comprising the step of:

f) repeating steps a)-e) for each suspected application server of the application server tier.

19. A computer readable storage medium storing processor executable instructions, wherein the instructions instruct the processor to perform a computer method for providing a three tier asynchronous client transparency comprising the steps of:

a) attempting to write a first server identifier to a first portion of a write-once register entry associated with a received request originating from a client tier;

b) computing a result for the request.

20. The computer readable storage medium of claim 19, wherein the instructions further instruct the processor to perform the steps of:

c) querying a database to determine an outcome for the result;

d) attempting to write the result and outcome as a first decision to a second portion of the write-once register entry; and

e) commanding the database to terminate the transaction identified by the request in accordance with a second decision indicated by the second portion of the write-once register entry.