JPH10275133A - Reexecution processing method for process - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inform a user that a process is rolled back by specifying the terminal having started the process and informing the specified terminal that reexecution processing has been performed when the process is reexecuted. SOLUTION: A process management part 11 when detecting a fault occurring to a process in execution informs other computers which are performing decentralized processes that the fault has occurred. At the same time, rollback and restarting processing for the process is performed according to checkpoint information held in a storage device 14 and after this rollback and restarting processing, that is reported to a rollback information part 15. The rollback information part 15 once receiving the report from the process management part 11 refers to a terminal information management part 12 to specify the terminal having started the rollback restarted process and informs the terminal that the process is rolled back and restarted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process re-execution processing method, and more particularly to a process re-execution for notifying a user of the occurrence of rollback / restart in a distributed system using a distributed checkpoint. It relates to a processing method.

[0002]

2. Description of the Related Art As a method of improving the reliability of program execution in a computer, there is known a method of executing a program based on a checkpoint. This is because, during the execution of a program, the status or the like (hereinafter, referred to as “checkpoint information”) of a process which is the execution body of the program is acquired regularly or irregularly according to a predetermined checkpoint timing. When this occurs, the program is re-executed (rollback / restart) based on the checkpoint information acquired at the most recent checkpoint. here,
A checkpoint refers to a point in time when a process for acquiring checkpoint information is performed when the execution of a program is viewed over time.

In a program that operates independently, checkpoint information may be obtained only at checkpoints in the middle of the process. However, in a case where a plurality of programs operate in a relationship such as communication between processes. In, it is not sufficient to simply obtain the state of a process in accordance with a checkpoint. That is, in order to prevent inconsistency when re-executing, it is necessary to acquire a plurality of pieces of checkpoint information that are mutually related for each checkpoint. Hereinafter, for convenience, a checkpoint for each process is referred to as a local checkpoint, and a set of local checkpoints for processes that are interrelated is referred to as a distributed checkpoint. In the distributed checkpoint, when a failure occurs, it is necessary to return to the most recent checkpoint for a plurality of processes and execute again. The case where rollback / restart based on checkpoints is applied to a distributed system in this way is referred to as a distributed checkpoint / restart method.

[0004] Rollback / restart is performed in the following cases. (1) When processing is performed while generating a checkpoint by a single program a) When the process is interrupted due to a hardware failure or a machine fault due to a bug in the OS b) Due to a bug in the application The process is interrupted due to a program fault. (2) In the environment where distributed processing is performed while generating distributed checkpoint information for a plurality of processes, a failure occurs in other related processes. Knowing, you can understand that the process has rolled back.

[0005] However, in the case of (1) b), the user cannot recognize the occurrence of the failure of the computer.
I do not understand that the process has rolled back. In the case of (2) above, for example, in the case of a server failure in a client / server system, the process is rolled back and restarted even though the computer used by each user has no abnormality. Would be. In such a case, the user does not know what happened.

[0006] As described above, in the conventional distributed checkpoint / restart method, no notification to the user when the process is rolled back or restarted is taken into account. There was a problem that the user could not directly understand whether or not.

[0007]

In the checkpoint / restart method, when a rollback occurs due to a program fault of a user program itself or a failure of another process under distributed processing, the fact is notified to each user. The problem was that users were not sure what happened to the running process.

[0008] The present invention has been made in view of the above points, and a checkpoint / restart method includes:
It is intended to provide a method for notifying a user that a process has been rolled back.

[0009]

The invention according to claim 1 is
When executing the process while acquiring the checkpoint information of the process on the distributed computer system, the process and the terminal that has started the process are recorded as predetermined information in association with each other, and the process is executed again. A re-execution processing method for a process, characterized in that when performing a process, a terminal that has started the process is specified, and the specified terminal is notified that re-execution processing has been performed.

Therefore, according to the present invention, when a failure occurs in a computer, when a rollback / restart process of a process is performed in a distributed checkpoint / restart method, the user is notified that the process has rolled back. Will be able to know.

[0011] According to a second aspect of the present invention, when at least one process among the process groups performing the distributed processing performs the re-execution processing based on the distributed checkpoint, each of the process groups is activated. Each of the identified terminals is identified, and a notification that the re-execution processing has been performed is given to each of the identified terminals.

Therefore, according to the present invention, when a failure occurs in one of the processes in the process group performing the distributed processing and the rollback / restart processing is performed according to the distributed checkpoint, The user can know that the rollback / restart processing has been performed in the terminal that has started the process group related to the process.

Further, according to a third aspect of the present invention, when the executed process executes a predetermined transaction and the transaction is committed, the transaction is associated with the process that executed the transaction. When performing the re-execution processing of the process, the terminal that has started the process is specified, and the fact that the re-execution processing has been performed on the specified terminal and the corresponding transaction are recorded as predetermined information. Is notified.

Therefore, according to the present invention, in the case of a database system, it becomes possible to know a transaction that has been invalidated by a rollback of a process. Further, in the invention according to claim 4, when there is a user input operation to the executed process, the process and the content of the input operation to the process are recorded as predetermined information in association with each other. When performing the re-execution process of the process, specify the terminal that has started the process,
The specified terminal is notified of the fact that the re-execution processing has been performed and the content of the corresponding input operation.

Therefore, according to the present invention, in an environment such as a window system, it is possible to know an input operation invalidated by a rollback / restart process of a process among input operations by a user.

The invention according to claim 5 is characterized in that when checkpoint information on the process is generated, the recorded predetermined information is deleted. Therefore, according to the present invention, when checkpoint information is generated, unnecessary information is deleted, so that unnecessary resources are not notified to the user and efficient use of resources is performed. It becomes possible.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. [First Embodiment] FIG. 1 is a diagram showing a configuration of a computer system according to the present invention.

The computer system according to the present invention comprises a computer 1
And terminals T1, T2, T3,... (Hereinafter sometimes referred to as “terminal T”) are connected via the network 2. Although only the computer 1 is shown in FIG. 1, another computer may be connected via the network 2.

The computer 1 has a function of executing a process which is an execution body of a program (application program or the like) to be executed under the control of the operating system, and is provided with a function realizing means of the present embodiment which will be described later. ing. The function realizing means in the present embodiment may be realized as a program, or all or a part thereof may be realized as hardware. For example, it can be realized as a function inside an operating system of a computer. It can also be realized as a so-called daemon process that runs on an operating system, or as a library that is statically or dynamically linked to a program.

Next, each function implementing means in this embodiment will be described. In the figure, the process management unit 11
Manages the execution of processes such as application programs executed in the computer and the execution state of the processes. Here, the management of the execution state includes, for example, a process of detecting a failure by an included failure detection unit when a failure occurs in the process being executed. In the figure, the process management unit 11 starts processes P1, P2, and P3 according to a process start request (not shown) from the terminals T1, T2, and T3 to the process management unit 11, and manages the execution of the process group. It shows the state where it is.

When a process start request is received from the terminal T, the process management unit 11 starts the process as described above, and notifies the terminal information management unit 12 of information on which process was started by which terminal. I do.

The terminal information management unit 12 includes the process management unit 1
Based on the notification from No. 1, information on which process was started by which terminal (hereinafter, referred to as “process-terminal information”) is held. FIG. 2 is a diagram illustrating an example of the process-terminal information.

The checkpoint management unit 13 generates and acquires checkpoint information at a predetermined checkpoint timing for the process being executed. This checkpoint information is stored in a storage device such as a local disk.

When the process management unit 11 detects the occurrence of a failure in the process being executed, the process management unit 11 notifies other computers performing the distributed processing that the failure has occurred,
The rollback / restart process of the process is performed according to the checkpoint information held in the storage device 14. When the rollback / restart processing is completed, the process management unit 11 notifies the rollback notification unit 1 of the completion.
Notify 5

Upon receiving the notification from the process management unit 11, the rollback notification unit 15 refers to the terminal information management unit 12, specifies the terminal that has started the rollback / restarted process, Notifies that the process has been rolled back and restarted.

FIG. 3 is a diagram for explaining the operation processing of the process management section 11. The process management unit 11 detects a process failure by the failure detection unit (STE
P31) With respect to the distributed checkpoint, the process management unit of another computer which is performing distributed processing is instructed to perform rollback / restart (STEP32).
Even if there is no detection of a process failure in STEP 31, if a rollback / restart instruction is received from another computer performing distributed processing, or
After the processing of TEP32, the process management unit 11 performs a rollback / restart processing (STEP34).
After performing the rollback / restart processing, the process management unit 11 sends the rollback notification
A notification that the restart has been completed is given (STEP 35).

FIG. 4 is a diagram for explaining the operation processing of the terminal information management unit 12. As shown in the figure, the terminal information management unit 12 waits until there is a notification that the process has been started by the process management unit 11 (STEP 4).
1). And. Upon receiving the notification that the process has been started, the correspondence between the process and the terminal that started the process is stored as process-terminal information.

FIG. 5 is a diagram for explaining the operation processing of the rollback notification unit 15. Rollback notification unit 15
Upon receiving the notification from the process management unit 11 that the rollback / restart has been completed (STEP 51), the process refers to the process-terminal information held in the terminal information management unit 12 and determines based on the occurrence of the failure. Identify the terminal that started the rollback / restarted process (ST
(EP52), the terminal is notified to that effect.

FIG. 6 is a diagram showing an example of the screen display of the terminal that has received the notification. The figure shows the display (screen)
, A rollback notification icon 61 is constantly displayed, indicating that the user is working on a work window 62 such as an editor. At that time, when a rollback / restart is generated by the rollback notification unit 15 and a notification indicating that the rollback has been completed is issued, for example, a window is opened as in the PoPUp window 63 and the rollback is performed. Is displayed.

FIG. 7 is a diagram showing another example of the screen display of the terminal notified. FIG. 7A is a diagram showing a process monitoring monitor window, showing a state in which the execution of the process is displayed with time and the message communication is simultaneously displayed. Here, for example, the process P2
When a failure is detected in, the window is switched to a display as shown in FIG. That is, FIG. 9B shows the state in which each process has rolled back to the nearest checkpoint CP in accordance with the distributed checkpoint and restarted, with a mark (dotted line). This mark is deleted from the window at the time of passing the next checkpoint, for example.

As described above, according to the present embodiment, when the rollback / restart processing is performed based on the occurrence of a failure, the fact is displayed on the terminal that has started the process, so that the rollback / restart processing is performed. Be able to know the fact of back restart.

[Second Embodiment] Next, a second embodiment will be described. FIG. 8 is a diagram illustrating a configuration of a computer system according to the present embodiment. After performing the rollback / restart processing, the computer 1 according to the present embodiment notifies the transaction management unit 81 that the rollback has been completed.

The transaction management unit 81 records the ID of the committed transaction in association with the process in which the transaction was executed, and stores it until the next checkpoint. Upon receiving the notification that the rollback has been completed, the rollback notification unit 15 is notified of the correspondence between the stored transaction ID and the process. That is, the transaction notified at this time has been invalidated by the rollback of the process.

Upon receiving the notification from the transaction management unit 81, the rollback notification unit 15 refers to the terminal information management unit 12, specifies the terminal that has started the process based on the process-terminal information, and specifies the terminal. A notification is sent to the terminal to display the ID of the transaction invalidated by the rollback of the process on the display.

After generating the checkpoint information for each process, the checkpoint management unit 82 notifies the transaction management unit 81 that the generation of the checkpoint information has been completed.

FIG. 9 is a diagram for explaining the operation processing of the process management section 11. The process management unit 11 detects a process failure by the failure detection unit (STE
P91), with respect to the distributed checkpoint, instructs the process management unit of another computer which is performing distributed processing to perform rollback / restart (STEP92).
Even if no failure of the process is detected in STEP 91, if a rollback / restart instruction is received from another computer performing distributed processing, or
After the processing in TEP92, the process management unit 11 performs a rollback / restart processing (STEP94).
After performing the rollback / restart processing, the process management unit 11 notifies the transaction management unit 81 that the rollback / restart has been completed (STEP 9).
5).

FIG. 10 is a diagram for explaining the operation processing of the transaction management unit 81. The transaction management unit 81 determines whether or not the transaction has been committed (STEP 101). For example, the determination as to whether or not the transaction has been committed determines that the transaction has been committed when a message to commit is received. . If you determine that it has been committed,
The ID of the transaction and the process that executed the transaction are recorded in association with each other (STEP 10).
2). Next, the transaction management unit 81 determines whether a notification that the checkpoint information has been generated is received from the checkpoint management unit 83 (STEP 1).
03). If it is determined in STEP 103 that the notification has been received, the I
Delete the correspondence between D and the process (STEP 10
4). Next, the transaction management unit 81 determines whether or not a notification of the rollback completion has been received from the process management unit 11 (STEP 105). The correspondence is notified to the rollback notification unit 15 (STEP 106). If it is determined in STEP 105 that the notification has not been received,
Returning to EP101, the above processing is repeated.

FIG. 11 is a diagram for explaining the operation processing of the rollback notification unit. Rollback notification unit 15
Waits for the notification of the ID of the invalidated transaction from the transaction management unit 81 (S
TEP111). When the notification of the ID is received, the terminal that has started the process is specified based on the process-terminal information by referring to the terminal information management unit 12 (STEP 112). Then, the rollback notifying unit 15 notifies the display of the terminal to display the ID of the rolled back transaction.
FIG. 12 is a diagram illustrating an example of the screen display of the terminal that has received the notification. The figure shows the display (screen)
The rollback notification icon 121 is always displayed, indicating that the user is working on the work window 122 such as an editor. In such a situation, when a rollback / restart occurs and the invalidated transaction is notified by the rollback notification unit 15, for example, the PoPUp window 1
A window is opened as shown at 23, and a message indicating that the transaction has been canceled is displayed.

FIG. 13 is a diagram for explaining the operation processing of the checkpoint management unit 82. For example, the checkpoint management unit 82 generates checkpoint information at a predetermined checkpoint timing determined by a timer mechanism of the OS, stores the checkpoint information in the storage device 14 (STEP 131), and notifies the transaction management unit 81 of the fact. (Step 132).

According to this embodiment, when the rollback / restart processing is performed, not only the processing result but also the I / O of the transaction invalidated by the rollback / restart in the database system.
Since D is also notified and displayed, the user can know the fact.

[Third Embodiment] FIG. 14 is a diagram showing a configuration of a computer system according to the third embodiment. In the present embodiment, a user input operation (user action)
And the correspondence of the process to the operation is recorded, and if rollback / restart processing is performed,
The correspondence is notified to the terminal.

In the figure, a user action management unit 1
Reference numeral 41 records the correspondence between the user's input operation and the process in which the operation has been performed, and stores it until the next checkpoint. Then, when the notification that the rollback is completed is received, the correspondence between the stored user action and the process is notified to the rollback notification unit.

Here, the user action includes an input request from a process, a control command for the process, and the like.
The input request includes, for example, a case where data is directly input to the input field from a keyboard or the like, and the control command includes, for example, a window moving operation. Such a user action is recorded in a predetermined format in a memory or the like under the management of the user action management unit 141.

When the rollback notification unit 15 receives the correspondence between the invalidated input operation and the process from the user action management unit 141, the rollback notification unit 15 refers to the process-terminal information stored in the terminal information management unit 12. By
The terminal that has started the process is specified, and a notification is sent to the terminal so that the input operation disabled by the rollback of the process is displayed on the display.

FIG. 15 shows a user action management section 141.
FIG. 9 is a diagram for explaining the operation processing of FIG. The user action management unit 141 traces the user's input operation for the running process, and records the correspondence between the input operation and the process in which the operation was performed (STEP 15).
1). Next, the user action management unit 141 determines whether a notification that the checkpoint information has been generated is received from the checkpoint management unit 142 (STE).
P152). If it is determined in STEP 152 that the notification has been received, the recorded correspondence between the input operation and the process is deleted (STEP 153).

After deleting the record or in STEP 15
If it is determined in step 2 that no notification has been received, the user action management unit 141 determines whether or not a notification that the rollback has been completed has been received from the process management unit (STEP 154). If it is determined in STEP 154 that the notification has been received, the correspondence between the input operation and the process is notified to the rollback notification unit 15 (STEP 155). That is, the recorded input operation is invalidated by the rollback.

FIG. 16 is a diagram for explaining the operation processing of the rollback notifying section 15. Rollback notification unit 1
5 waits until the correspondence between the invalidated input operation and the process is notified from the user action management unit 141 (STEP 161). The rollback notification unit 15
If it is determined that the notification has been received, the terminal that has started the process is specified by referring to the process-terminal information stored in the terminal information management unit 12 (ST
(EP162), and notifies the terminal to display the input operation invalidated by the rollback of the process (STEP163).

FIG. 17 is a diagram showing an example of the screen display of the terminal that has received the notification. In the figure, the rollback notification icon 171 is always displayed on the display (screen), and the user can use the work window 17 such as an editor.
2 shows a state in which work is being performed. In such a situation, when a rollback / restart occurs and the invalidated transaction is notified by the rollback notification unit 15, for example, a window is opened as a PoPUp window 173, and the data by the input operation is displayed. Is displayed to the effect that has been canceled. As shown in the figure, the user action may display a control command or the like in addition to the input data.

As described above, according to the present embodiment, for example, when a rollback / restart process is performed in an interactive environment such as a window system, the rollback / restart process becomes invalid. Since the input operation is notified, the user can know the content.

[0050]

According to the present invention, when a failure occurs in a computer, when a rollback / restart process of a process is performed in a distributed checkpoint / restart method, a user is notified that the process has rolled back. Will be able to know.

In the case of a database system, it is possible to know a transaction that has become invalid due to a rollback of a process. Further, in an environment such as a window system, it becomes possible to know an input operation invalidated by a rollback / restart process of a process among input operations of a user.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a computer system according to a first embodiment.

FIG. 2 is a diagram showing an example of process-terminal information.

FIG. 3 is a diagram for explaining an operation process of a process management unit.

FIG. 4 is a diagram for explaining an operation process of a terminal information management unit.

FIG. 5 is a diagram for explaining an operation process of a rollback notification unit.

FIG. 6 is a diagram showing an example of a screen display of a terminal that has been notified.

FIG. 7 is a diagram showing another example of the screen display of the terminal that has been notified.

FIG. 8 is a diagram showing a configuration of a computer system according to the second embodiment.

FIG. 9 is a diagram for explaining an operation process of a process management unit.

FIG. 10 is a diagram for explaining an operation process of a transaction management unit.

FIG. 11 is a diagram illustrating an operation process of a rollback notification unit.

FIG. 12 is a diagram showing an example of a screen display of a terminal that has been notified.

FIG. 13 is a diagram for explaining an operation process of a checkpoint management unit.

FIG. 14 is a diagram showing a configuration of a computer system according to a third embodiment.

FIG. 15 is a diagram for explaining an operation process of a user action management unit.

FIG. 16 is a diagram for explaining an operation process of a rollback notification unit.

FIG. 17 is a diagram showing an example of a screen display of a terminal that has been notified.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Computer 11 ... Process management part 12 ... Terminal information management part 13 ... Checkpoint management part 14 ... Storage device 15 ... Rollback notification part 81 ... Transaction management part 141 ... User action management part

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Tatsunori Kanai 1 Toshiba-cho, Komukai-Toshiba-cho, Sai-ku, Kawasaki-shi, Kanagawa Inside the R & D Center of Toshiba Corporation

Claims (5)

[Claims] When executing a process while acquiring checkpoint information of the process on a distributed computer system, the process and the terminal that started the process are recorded as predetermined information in association with each other, When performing the process re-execution processing, a process re-execution processing method characterized by specifying a terminal that has started the process and notifying the specified terminal that the re-execution processing has been performed. . 2. When at least one process in a group of processes performing distributed processing performs re-execution processing based on a distributed checkpoint, a terminal that has started each of the group of processes is specified. 2. The method according to claim 1, wherein each of the identified terminals is notified that the re-execution processing has been performed. 3. When the executed process executes a predetermined transaction and the transaction is committed, the transaction and the process that executed the transaction are recorded as predetermined information in association with each other. When performing the re-execution processing of the process, identifying the terminal that has started the process, and notifying the identified terminal that the re-execution processing has been performed and the corresponding transaction. A method for re-executing the process according to claim 1. 4. When a user performs an input operation on the process to be executed, the process and the content of the input operation on the process are recorded in association with each other as predetermined information, and the process is re-executed. When performing execution processing,
3. The process according to claim 1, wherein the terminal that has started the process is specified, and a notification that re-execution processing has been performed and the content of the corresponding input operation are notified to the specified terminal. Re-execution processing method. 5. A method according to claim 1, wherein when the checkpoint information for the process is generated, the recorded predetermined information is deleted.