System for flexible distributed processing and transaction processing suitable for nested transaction

• US 5,778,179 A
• Filed: 04/07/1997
• Issued: 07/07/1998
• Est. Priority Date: 12/26/1991
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation), Toshiba Corporation
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Kanai, Tatsunori, Shirakihara, Toshio
• Primary Examiner(s): Lall, Parshotam S.
• Assistant Examiner(s): Coulter, Kenneth R.
• Application Number:
  US08/827,895
• Time in Patent Office: 456 Days
• Field of Search: 395/200.33, 395/680, 395/675
• US Class Current: 709/203
• CPC Class Codes: G06F 15/17 using an input/output type connection, e.g. channel, I/O port

Abstract

A flexible distributed processing system capable of dealing with sophisticated conditions for selecting a server process. In the system, each of the services provided by all server processes is registered in the service manager in correspondence with an executability condition for judging whether each service is executed, such that the service manager selects one of the server processes which is providing the desired service indicated by the inquiry transmitted from the client process and which is judged to be executable according to the executability condition registered at the service manager, and the client process requests the desired service the selected one of the server processes. The system can utilize a transaction processing for a nested transaction in which a commit processing for the processes of the sub-transactions which are incapable of executing the nested transaction, is completed concurrently with a completion of the commit processing for the top level transaction.

Claims

1. A method of distributed processing among processors having a plurality of server processes for providing services and a service manager for managing the services provided by the server processes, the method comprising the steps of:

registering each of the services provided by said plurality of server processes of the processors to the service manager in correspondence with an executability condition for determining whether the respective server process is capable of executing a particular service;

transmitting an inquiry concerning a desired service to be received by a client process to the service manager on one of the processors;

selecting one of the server processes which is providing the desired service indicated by the inquiry transmitted at the transmitting step and which is determined to be a server process which is capable of being used to execute the desired service according to the executability condition registered at the service manager on said one of the processors; and

requesting the desired service from the client process to said one of the server processes selected at the selecting step.

2. The method of claim 1, wherein the executability condition is given in a form of an executability judgement procedure for judging the executability of each service.

3. The method of claim 2, wherein the executability judgement procedures for the services provided by said plurality server processes are stored in memory means, and the executability condition for each server process is registered at the registering step by reading an appropriate one of the executability judgement procedures stored in the memory means according to an address in the memory means specified by said each server process.

4. The method of claim 1, wherein the executability condition is defined in terms of arguments of each service for specifying details of said each service.

5. The method of claim 1, wherein each processor also has a communication processing means for communicating with the communication processing means of an other processor, such that the desired service is requested from the client process to the server process at the requesting step through the communication processing means of a processor on which the client process is located.

6. The method of claim 1, wherein each processor also has a communication processing means for communicating with the communication processing means of an other processor, such that the inquiry is transmitted from the client process to the service manager at the transmitting step through the communication processing means of a processor on which the client process is located.

7. The method of claim 1, wherein each processor also has a communication processing means for communicating with the communication processing means of an other processor, such that the inquiry is transmitted from the communication processing means of a processor on which the client process is located to the service manager at the transmitting step and the desired service is requested from the communication processing means of a processor on which the client process is located to the service process at the requesting step, in response to a request for receiving the desired service given from the client process to the communication processing means of a processor on which the client process is located.

8. The method of claim 1, wherein when there are more than one server processes providing the desired service and judged to be executable according to the executability condition registered in the service manager, said one of the server processes is selected at the selecting step according to a prescribed selection procedure.

9. The method of claim 8, wherein the prescribed selection procedure indicates a selection according to priority level assigned to each server process in advance.

10. The method of claim 8, wherein the prescribed selection procedure indicates a random selection.

11. The method of claim 8, wherein the prescribed selection procedure indicates a selection according to a predetermined order among the server processes.

12. The method of claim 8, wherein the prescribed selection procedure indicates a selection according to priority level assigned to each server process which is higher for the server processes which has not been selected at the selecting step for a longer period of time.

13. The method of claim 8, wherein the prescribed selection procedure indicates a selection according to priority level assigned to each server process which is higher for the server processes which exert smaller load to the respective processor.

14. The method of claim 8, wherein the prescribed selection procedure indicates a selection according to weights assigned to each server process in accordance with the load exerted by each of the server processes to the respective processor.

15. The method of claim 1, wherein the client process memorizes said one of the server processes selected at the selecting step in response to the inquiry transmitted at the transmitting step, such that in a case of requesting a previously requested desired service again, the transmitting step and the selecting step are omitted.

16. The method of claim 1, wherein the client process is located on said one of the processors to which the inquiry is transmitted at the transmitting step.

17. The method of claim 1, wherein the client process is located on an additional processor without the service manager which is different from said one of the processors to which the inquiry is transmitted at the transmitting step.

18. The method of claim 1, wherein each processor has a database associated with the service provided by the server process on said each processor and the executability condition for each service indicates available data in the database associated with said each service.

19. The method of claim 1, wherein a plurality of the processors share a common database to be utilized in the services provided by the server processes on said plurality of the processors.

20. The method of claim 1, wherein the processors include a processor provided with a server process and no service manager.

21. A distributed processing system having a plurality of processors, comprising:

a client process for requesting a desired service to be received, the client process being executed on one processor;

a plurality of server processes for providing services; and

a service manager for managing the services provided by the server processes by registering each of the services provided by said plurality of server processes of the processors to the service manager in correspondence with an executability condition for determining whether the respective server process is capable of executing a particular service the service manager receiving an inquiry concerning the desired service, and selecting one of the server processes which is providing the desired service indicated by the inquiry and which is determined to be a server process capable of executing the desired service according to the registered executability condition such that the desired service is requested to said one of the server processes selected by the service manager.

22. The system of claim 21, wherein the service manager registers the executability condition given in a form of an executability judgement procedure for judging the executability of each service.

23. The system of claim 22, further comprising memory means for storing the executability judgement procedures for the services provided by all server processes, and wherein the service manager registers the executability condition for each server process by reading an appropriate one of the executability judgement procedures stored in the memory means according to an address in the memory means specified by said each server process.

24. The system of claim 21, wherein the service manager registers the executability condition defined in terms of arguments of each service for specifying details of said each service.

25. The system of claim 21, wherein each processor also has a communication processing means for communicating with the communication processing means of other processor, such that when the server process providing the desired service is located on one processor different from another processor on which the client process is located, the client process requests the desired service to the server process through the communication processing means of said another processor on which the client process is located.

26. The system of claim 21, wherein each processor also has a communication processing means for communicating with the communication processing means of other processor, such that when said one of the processors on which the service manager is located is different from another processor on which the client process is located, the client process transmits the inquiry to the service manager through the communication processing means on said another processor on which the client process is located.

27. The system of claim 21, wherein each processor also has a communication processing means for communicating with the communication processing means of an other processor, such that the communication processing means of a processor on which the client process is located transmits the inquiry to the service manager and requests the desired service to said one of the server processes selected by the service manager, in response to a request for receiving the desired service given from the client process to the communication processing means of a processor on which the client process is located.

28. The system of claim 21, wherein when there are more than one server processes providing the desired service and judged to be executable according to the executability condition registered in the service manager, the service manager selects said one of the server processes according to a prescribed selection procedure.

29. The system of claim 28, wherein the prescribed selection procedure indicates a selection according to priority level assigned to each server process in advance.

30. The system of claim 28, wherein the prescribed selection procedure indicates a random selection.

31. The system of claim 28, wherein the prescribed selection procedure indicates a selection according to a predetermined order among the server processes.

32. The system of claim 28, wherein the prescribed selection procedure indicates a selection according to priority level assigned to each server process which is higher for the server processes which has not been selected at the selecting step for a longer period of time.

33. The system of claim 28, wherein the prescribed selection procedure indicates a selection according to priority level assigned to each server process which is higher for the server processes which exert smaller load to the respective processor.

34. The system of claim 28, wherein the prescribed selection procedure indicates a selection according to weights assigned to each server process in accordance with the load exerted by each of the server processes to the respective processor.

35. The system of claim 21, wherein the client process memorizes said one of the server processes selected by the service manager in response to the inquiry, such that in a case of requesting a previously requested desired service again, the transmitting of the inquiry to the service manager and the selecting of said one of the server processes by the service manager in response to the inquiry are omitted.

36. The system of claim 21, wherein the client process is located on said one of the processors to which the inquiry is transmitted.

37. The system of claim 21, wherein the client process is located on an additional processor without the service manager which is different from said one of the processors to which the inquiry is transmitted.

38. The system of claim 21, wherein each processor also has a database associated with the service provided by the server process on said each processor and the executability condition for each service indicates available data in the database associated with said each service.

39. The system of claim 21, further comprising a common database shared by said plurality of processors and to be utilized in the services provided by the server processes on said plurality of the processors.

40. The system of claim 21. wherein the processors include a processor provided with a server process and no service manager.

41. A method of managing transaction processing in a transaction processing system including first processes capable of executing nested transactions, second processes incapable of executing nested transactions and a transaction manager capable of managing nested transactions, comprising the steps of:

(a) executing sub-transactions of one nested transaction by means of respective of said first and second processes;

(b) carrying out a commit processing only for the first processes which executed sub-transactions in step (a);

(c) executing a top level transaction of said one nested transaction after step (b);

(d) carrying out a commit processing for the top level transaction after step (c); and

(e) completing a commit processing for the second processes which executed sub-transactions in step (a), concurrently with a completion of the commit processing for the top level transaction carried out in step (d).

42. The method of claim 41, wherein the commit processing for the second processes is entirely carried out concurrently with the commit processing for the top level transaction at the step (d).

43. The method of claim 41, wherein a vote phase of the commit processing for the second processes is carried out concurrently with the commit processing for the first processes at the step (b), while a decision phase of the commit processing for the second processes is carried out concurrently with a decision phase of the commit processing for the top level transaction at the step (d).

44. The method of claim 41, wherein a vote phase of the commit processing for the second processes is carried out concurrently with the commit processing for the first processes at the step (b) and an execution of the top level transaction at the step (c), while a decision phase of the commit processing for the second processes is carried out concurrently with a decision phase of the commit processing for the top level transaction at the step (d).

45. The method of claim 41, wherein a vote phase of the commit processing for the second processes is carried out concurrently with an execution of the top level transaction at the step (c), while a decision phase of the commit processing for the second processes is carried out concurrently with a decision phase of the commit processing for the top level transaction at the step (d).

46. The method of claim 41, wherein the transaction processing system has:

one processor on which the first processes and the transaction manager capable of managing nested transactions are provided;

another processor on which the second processes and another transaction manager capable of managing nested transaction are provided; and

a communication connection means for enabling a communication between the transaction manager on said one processor and said another transaction manager on said another processor, such that the commit processing for the second processes is carried out by the transaction manager on said one processor by communication with said another transaction manager on said another processor through the communication connection means.

47. The method of claim 46, wherein said another transaction manager on said another processor carries out a decision phase of the commit processing with respect to the second processes in response to a notification of a commitment of the top level transaction from the transaction manager on said one processor communicated to said another transaction manager on said another processor through the communication connection means.

48. The method of claim 41, wherein the transaction processing system has:

one processor on which the first processes and the transaction manager capable of managing nested transactions are provided;

another processor on which the second processes and another transaction manager incapable of managing nested transaction are provided; and

a communication connection means for enabling a communication between the transaction manager on said one processor and said another transaction manager on said another processor, such that the commit processing for the second processes is carried out by the transaction manager on said one processor by communication with said another transaction manager on said another processor through the communication connection means.

49. The method of claim 48, wherein said another transaction manager of said another processor carries out a decision phase of the commit processing with respect to the second processes in response to a notification of a commitment of the sub-transactions from the transaction manager on said one processor communicated to said another transaction manager on said another processor through the communication connection means.

50. The method of claim 41, wherein the transaction processing system has:

one processor on which the first processes and the transaction manager capable of managing nested transactions are provided;

another processor on which the second processes and another transaction manager are provided; and

a communication connection means for enabling a communication between the transaction manager on said one processor and said another transaction manager on said another processor, such that a vote phase of the commit processing for the second processes is carried out by the transaction manager on said one processor by transmitting a vote request to said another transaction manager on said another processor through the communication connection means.