Transaction state data replication by transaction forwarding in replicated database systems

• US 6,347,322 B1
• Filed: 11/09/1998
• Issued: 02/12/2002
• Est. Priority Date: 11/09/1998
• Status: Expired due to Term

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Green, Gary Michael, Bogantz, Robert L., Hester, Sidney Dean
• Primary Examiner(s): Homere, Jean R.
• Assistant Examiner(s): Wassum, Luke S
• Application Number:
  US09/188,465
• Time in Patent Office: 1,191 Days
• Field of Search: 707/10, 707/202, 707/204, 707/201
• US Class Current: 1/1
• CPC Class Codes: G06F 16/2308 Concurrency control transaction processing G06F9/466
• CPC Class Codes: G06F 16/2322 using timestamps
• CPC Class Codes: G06F 16/27 Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

A transaction processing system comprises a querying system and a logical database having an active database and a backup database. The querying system transmits a message for a transaction to the logical database for processing. The message is transmitted to the active database where the message is processed. The active database creates transaction state data based, in part, on the message. The active database transmits a response message to the querying system and forwards the original message to the backup database. The backup database processes the original message and creates its own transaction state data. The transaction state data in the backup database operationally matches the transaction state data in the active database so that if the active database fails, the backup database includes the requisite transaction state data necessary to complete the transaction. The querying system processes the response message and transmits a termination message to the logical database for processing. The termination message is transmitted to the active database and processed. The termination message is forwarded to the backup database from the active database and similarly processed. The transaction is then complete and both databases are fully replicated.

Claims

1. A method for processing a transaction in a replicated database system comprising a plurality of replicated databases, said plurality of replicated databases comprising an active database and at least one backup database, said transaction comprising a plurality of sequential messages that must be performed to complete said transaction, said method comprising the steps of:

receiving at least one message for said transaction from a querying system in said active database;

processing said at least one message for said transaction in said active database, said active database creating corresponding response messages based on said at least one message and creating transaction state data for said active database so that said active database can process subsequently received messages of said transaction;

transmitting said response messages to said querying system;

forwarding said at least one message for said transaction and control header data from said active database to said at least one backup database, said control header data enabling said backup database to process said at least one message consistent with said active database; and

processing said at least one message of said transaction in said at least one backup database, said at least one backup database creating transaction state data for said backup database so that said backup database can directly process subsequent messages of said transaction in the event of failure of said active database.

2. The method of claim 1, wherein said step of processing said at least one message for said transaction in said at least one backup database further comprises the step of creating a suppressed response message in said at least one backup database based on said at least one message.

3. The method of claim 1, wherein said step of processing said at least one message for said transaction in said at least one backup database does not comprise the step of creating a response message in said at least one backup database based on said at least one message forwarded by said active database.

4. The method of claim 1, wherein said control header data comprises unique transaction identification data representative of said transaction.

5. The method of claim 1, wherein said control header data comprises time stamp data.

6. The method of claim 1, wherein said steps are repeated for a plurality of transactions.

7. The method of claim 6, further comprising the step of serializing said plurality of transactions so that said plurality of transactions are processed in the same order in said at least one backup database as in said active database.

8. A method for processing a transaction in a replicated database system comprising a plurality of replicated databases, said plurality of replicated databases comprising an active database and at least one backup database, said transaction comprising a plurality of sequential messages that must be performed to complete said transaction, said method comprising the steps of:

transmitting a first message for said transaction from a querying system to said replicated database system;

processing said first message for said transaction in said active database, said active database creating a response message based on said first message and creating transaction state data for said active database so that said active database can process subsequently received messages of said transaction;

transmitting said response message to said querying system;

forwarding said first message for said transaction and control header data from said active database to said at least one backup database, said control header data enabling said backup database to process said first message consistent with said active database;

processing said first message for said transaction in said at least one backup database, said at least one backup database creating transaction state data for said backup database so that said backup database can process subsequent messages of said transaction;

transmitting a second message for said transaction from said querying system to said database system;

processing said second message for said transaction in said active database using said active database transaction state data;

forwarding said second message for said transaction and control header data from said active database to said at least one backup database, said control header data enabling said backup database to process said second message consistent with said active database; and

processing said second message for said transaction in said at least one backup database using said backup database transaction state data.

9. The method of claim 8, wherein said step of processing said first transaction message of said transaction in said at least one backup database further comprises the step of creating a suppressed response message in said at least one backup database based on said first transaction message.

10. The method of claim 8, wherein said step of processing said first transaction message of said transaction in said at least one backup database does not comprise the step of creating a response message in said at least one backup database based on said first transaction message forwarded by said active database.

11. The method of claim 8, wherein said control header data comprises unique transaction identification data representative of said transaction.

12. The method of claim 8, wherein said control header data comprises time stamp data.

13. The method of claim 8, wherein said steps are repeated for a plurality of transactions.

14. The method of claim 13, further comprising the step of serializing said plurality of transactions so that said plurality of transactions are processed in the same order in said at least one backup database as in said active database.

15. The method of claim 8, wherein said step of processing said first message for said transaction in said active database comprises the step of storing said active database transaction state data in said active database.

16. The method of claim 8, wherein said step of processing said first message of said transaction in said at least one backup database comprises the step of storing said backup database transaction state data in said at least one backup database.

17. The method of claim 8, wherein said step of processing said first message for said transaction in said active database comprises the step of accessing at least one of a plurality of records in said active database.

18. The method of claim 17, wherein said step of processing said first message of said transaction in said at least one backup database comprises the step of accessing at least one of a plurality of records in said at least one backup database.

19. A method for processing a transaction in a replicated database system Comprising a plurality of replicated databases, said plurality of replicated databases comprising an active database and at least one backup database, said transaction comprising a plurality of sequential messages that must be performed to complete said transaction, said method comprising the steps of:

transmitting a first message for said transaction from a querying system to said database system;

processing said first message for said transaction in said active database, said active database creating a response message based on said first message and creating transaction state data for said active database so that said active database can process subsequently received messages of said transaction;

transmitting said response message to said querying system;

forwarding said first message for said transaction and control header data from said active database to said at least one backup database, said control header data enabling said backup database to process said first message consistent with said active database;

processing said first message of said transaction in said at least one backup database, said at least one backup database creating transaction state data for said backup database so that said backup database can process subsequent messages of said transaction;

transmitting a second message for said transaction from said querying system to said database system;

if said active database is available, then;

processing said second message for said transaction in said active database using said active database transaction state data;

forwarding said second message for said transaction and control header data from said active database to said at least one backup database, said control header data enabling said backup database to process said second message consistent with said active database; and

processing said second message for said transaction in said at least one backup database using said backup database transaction state data; and

if said active database is not available;

processing said second message for said transaction in said at least one backup database using said backup database transaction state data.

20. The method of claim 19, wherein said control header data comprises unique transaction identification data representative of said transaction.

21. The method of claim 19, wherein said control header comprises time stamp data.

22. The method of claim 19, wherein said steps are repeated for a plurality of transactions.

23. The method of claim 22, further comprising the step of serializing said plurality of transactions so that said plurality of transactions are processed in the same order in said at least one backup database as in said active database.

24. A system for processing a transaction comprising a sequence of messages that must be performed to complete said transaction, said system comprising:

a database system comprising a plurality of replicated databases, said plurality of replicated databases comprising an active database and at least one backup database, said active database comprising an active database processor and said at least one backup database comprising a backup database processor; and

a database querying system comprising a database querying system processor configured to access said database system for processing transactions, said database querying system processor programmed to transmit a first message for one of said transactions to said database system for processing by said active database processor;

wherein said active database processor is programmed to;

update at least one record in said data storage unit of said active database process in response to said first message and create a response message and transaction state data for said active database so that said active database can process messages subsequent to said first message of said one of said transactions;

transmit said response message to said querying system for processing by said querying system processor; and

forward said first message for said one of said transactions and control header data to said at least one backup database for processing by said at least one backup database processor, said control header data enabling said backup database to process said first message consistent with said active database;

and wherein said at least one backup database processor is programmed to process said first message to create transaction state data for completion of said one of said transactions;

and wherein said database querying system is further programmed to transmit a second message for said one transaction to said database system;

and wherein said active database processor is further programmed to;

process said second message using said active database transaction data; and

forward said second message and control header data to said at least one backup database, said control header data enabling said backup database to process said second message consistent with said active database;

and wherein said at least one backup database processor is programmed to process said second message using said backup database transaction state data.

25. The system of claim 24, wherein said at least one backup database processor is programmed to create a suppressed response message in said at least one backup database based on said first transaction message.

26. The system of claim 24, wherein said at least one backup database processor is programmed not to create a response message in said at least one backup database based on said first transaction message forwarded by said active database.

27. The system of claim 24, wherein said control header data comprises unique transaction identification data representative of said transaction.

28. The system of claim 24, wherein said control header data comprises time stamp data.

29. The system of claim 24, wherein said database querying system processor, said active database processor and said at least one backup database processor are programmed to process a plurality of transactions.

30. The system of claim 29, wherein said active database processor is programmed to serialize said plurality of transactions so that said plurality of transactions are processed in the same order in said at least one backup database as in said active database.

31. The system of claim 24, wherein said active database comprises an active database memory for storing said active database transaction state data.

32. The system of claim 24, wherein said at least one backup database comprises a backup database memory for storing said backup database transaction data.

33. The system of claim 24, wherein said database system comprises a plurality of backup databases.

34. The system of claim 24, wherein said active database processor is further programmed to access at least one of a plurality of records in said active database to process said first message.

35. The system of claim 34, wherein said at least one backup database processor is further programmed to access at least one of a plurality of records in said at least one backup database to process said first message.

36. A system for processing a transaction comprising a sequence of operations that must be performed to complete said transaction, said system comprising:

a replicated database system comprising a reliable transaction distributor and a plurality of replicated databases, said reliable transaction distributor distributing messages controlling said operations to said plurality of replicated databases which comprise an active database and at least one backup database, said active database comprising an active database processor and said at lease one backup database comprising a backup database processor; and

a database querying system comprising a database querying system processor configured to access said plurality of replicated databases for processing transactions, said database querying system processor programmed to transmit a first message for one of said transactions to said database system;

wherein said active database processor is programmed to;

process said first message thereby creating a response message and transaction state data for said active database so that said active database can process subsequent messages of said one transaction;

transmit said response message to said querying system for processing by said querying system processor; and

forward said first message for said one transaction and control header data to said at least one backup database for processing by said backup database processor, said control header data enabling said backup database to process said first message consistent with said active database;

and wherein said at least one backup database processor is programmed to process said first message thereby creating transaction state data for said backup database so that said backup database can process subsequent messages of said one transaction;

and wherein said database querying system processor is further programmed to transmit a second message for said one transaction to said database system;

and wherein if said active database is available then said active database processor is further programmed to;

process said second message using said active database transaction data; and

forward said second message and control header data to said at least one backup database, said control header data enabling said backup database to process said second message consistent with said active database;

and wherein said at least one backup database processor is programmed to process said second message using said backup database transaction state data;

and if said active database is not available;

said at least one backup database processor is programmed to process said second message received directly from said reliable transaction distributor using said backup database transaction state data.