Transparent transaction coordination between distributed networks having different communication protocols

• US 5,428,771 A
• Filed: 05/19/1994
• Issued: 06/27/1995
• Est. Priority Date: 09/18/1991
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Freund, Thomas J., Haskin, Roger L., Storey, Robert A., Daniels, Dean S.
• Primary Examiner(s): Bowler, Alyssa H.
• Assistant Examiner(s): GECKIL, MEHMET B
• Application Number:
  US08/245,845
• Time in Patent Office: 404 Days
• Field of Search: 395/575, 395/800, 395/375, 395/600, 395/650, 395/500, 395/200, 370/85.13, 370/85.14, 370/85.17, 370/85.15, 370/85.16
• US Class Current: 718/101
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A mechanism is provided which allows transparent transaction processing to occur between distributed networks using the AIX or SNA protocols. The present invention will convert between the AIX standard of Two Phase Commit/Presumed Abort (2PC/PA) and the SNA standard of Two Phase Commit/Presume Nothing (2PC/PN). The Presumed Abort Protocol will optimize operations by reducing the number of messages between sites participating in the transaction, and the amount of transaction state information maintained at a site. Thus, any messages needed will be generated and transaction status information will be maintained in order to satisfy a Standard 2PC/PN protocol, when sites within a SNA network are participating in an AIX transaction. Further, the present invention will discard, or ignore any extraneous messages which are received while sites within an AIX network are participating in a SNA transaction.

Claims

1. A method wherein a protocol conversion bridge, in a computer operating system, enables a transaction to be processed across first and second interconnected distributed networks, each network having unique transaction processing protocols, said method comprising the computer implemented steps of:

converting a first set of rules that define a first transaction processing protocol for said first network into a second set of rules that define a second transaction processing protocol for said second network;

converting first transaction processing information, based upon said first protocol into second transaction processing information, based upon said second protocol, in accordance with said second set of rules;

causing migration of transaction coordination responsibility from said first network to said second network based upon a migrate transaction coordination request, included in said second transaction processing protocol, transmitted from said second network to said first network;

synchronizing said first and second networks, subsequent to a communications failure therebetween, to generate consistent first transaction state information and second transaction state information between said first and second networks, respectively; and

exchanging, by said conversion bridge, said state information relating to said first transaction processing information and said second transaction processing information, for the transaction being processed across said first and second networks, to recover said first and second transaction processing information.

2. A method according to claim 1 further comprising the step of migrating coordination responsibility for said transaction between said first and second networks, such that the transaction can be processed according to either said first or second protocol.

3. A method according to claim 2 wherein said step of converting a set of rules comprises:

generating messages required by said first or second distributed network to complete a commit phase of processing said transaction; and

ignoring messages generated by said first or second network, which are not required by the respective other distributed network to complete the commit phase of processing said transaction.

4. A method according to claim 3 wherein said step of converting first transaction processing information comprises:

converting first transaction processing state information, associated with said first protocol, into second transaction processing state information, associated with said second protocol; and

converting a first transaction identifier corresponding to said first transaction state information into a second transaction identifier corresponding to said second transaction processing state information.

5. A method according to claim 4 wherein said step of exchanging status information comprises:

comparing said first transaction processing state information with said second transaction processing state information; and

exchanging said first and second transaction processing state information between said first and second distributed networks.

6. A method according to claim 5 wherein said step of exchanging said first and second transaction processing state information further comprises:

combining said first or second transaction processing state information into a high level flow of transaction processing state information, capable of being received by the respective one of said first or second distributed networks; and

separating said first or second transaction processing state information into discrete transaction processing state information capable of being received by the respective one of said first or second distributed networks.

7. A method according to claim 6 wherein said step of converting a first transaction identifier comprises:

mapping the first transaction identifier into the second transaction identifier, by accessing at least one look up table; and

tracking the first transaction identifier from said first distributed network such that synchronization between said first and second distributed networks is maintained.

8. A method according to claim 7 wherein said step of tracking comprises:

incrementing the second transaction identifier at the conclusion of processing of the transaction; and

updating state information maintained within said at least one look up table at the conclusion of processing of the transaction.

9. A method according to claim 8 wherein said step of migrating coordination responsibility comprises recognizing a command, by said first or second distributed network, requiring migration of transaction coordination.

10. A method according to claim 9 wherein said step of recognizing comprises the step of receiving said migration command immediately prior to receiving a command to commit the transaction.

11. A protocol conversion bridge in a computer operating system that enables a transaction to be processed across first and second interconnected distributed networks, each network having unique transaction processing protocols, said bridge comprising:

means for converting a first set of rules that define a first transaction processing protocol for said first network into a second set of rules that define a second transaction processing protocol for said second network;

means for converting first transaction processing information, based upon said first protocol into second transaction processing information, based upon said second protocol, in accordance with said second set of rules;

means, within said protocol conversion bridge, for causing migration of transaction coordination responsibility from said first network to said second network based upon a migrate transaction coordination request, included in said second transaction processing protocol, transmitted from said second network to said first network;

means for synchronizing said first and second networks, subsequent to a communications failure therebetween, to generate consistent first transaction state information and second transaction state information between said first and second networks, respectively; and

means, in said bridge, for exchanging said state information relating to said first transaction processing information and said second transaction processing information, for the transaction being processed across said first and second networks, to recover said first and second transaction processing information.

12. A system according to claim 11 further comprising means for migrating coordination responsibility for said transaction between said first and second networks, such that the transaction can be processed according to either said first or second protocol.

13. A system according to claim 12 wherein said means for converting a set of rules comprises:

means for generating messages required by said first or second distributed network to complete a commit phase of processing said transaction; and

means for ignoring messages generated by said first or second network, which are not required by the respective other distributed network to complete the commit phase of processing said transaction.

14. A system according to claim 13 wherein said means for converting first transaction processing information comprises:

means for converting first transaction processing state information, associated with said first protocol, into second transaction processing state information, associated with said second protocol; and

means for converting a first transaction identifier corresponding to said first transaction state information into a second transaction identifier corresponding to said second transaction processing state information.

15. A system according to claim 14 wherein said means for exchanging status information comprises:

means for comparing said first transaction processing state information with said second transaction processing state information; and

means for exchanging said first and second transaction processing state information between said first and second distributed networks.

16. A system according to claim 15 wherein said means for exchanging said first and second transaction processing state information further comprises:

means for combining said first or second transaction processing state information into a high level flow of transaction processing state information, capable of being received by the respective one of said first or second distributed networks; and

means for separating said first or second transaction processing state information into discrete transaction processing state information capable of being received by the respective one of said first or second distributed networks.

17. A system according to claim 16 wherein said means for converting a first transaction identifier comprises:

means for mapping the first transaction identifier into the second transaction identifier, by accessing at least one look up table; and

means for tracking the first transaction identifier from said first distributed network such that synchronization between said first and second distributed networks is maintained.

18. A system according to claim 17 wherein said means for tracking comprises:

means for incrementing the second transaction identifier at the conclusion of processing of the transaction; and

means for updating state information maintained within said at least one look up table at the conclusion of processing of the transaction.

19. A system according to claim 18 wherein said means for migrating coordination responsibility comprises means for recognizing a command, by said first or second distributed network, requiring migration of transaction coordinations.

20. A system according to claim 19 wherein said means for recognizing comprises means for receiving said migration command immediately prior to receiving a command to commit the transaction.