JPH03260746A - Data updating method - Google Patents

Abstract

PURPOSE:To improve the data updating efficiency for a duplex storage device by applying the data updating processing only to a primary face during execution of an application program and then applying the data updating processing to a secondary face in the after-processing carried out at the end of the application program. CONSTITUTION:When an application program has a data updating request, an application program executing state control part 2 buffers the updating position data and the updating data via an input/output buffer 3 and updates the primary face data stored in a duplex storage 5. Then the part 2 detects the end of execution of the application program and gives an instruction to a duplex storage control part 4 to set an input/output device to the secondary face. Then the part 2 writes successively the date buffered by the buffer 3 to the secondary face of the storage 5 and updates the data on the secondary face. Thus the secondary face is positioned to the unupdated data during execu tion of the application program and the saving of the updating data is not necessary. Then the data updating efficiency is improved for a duplex storage.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a data update method for updating data on a dual storage device.

[Prior art]

As shown in FIG. 5, the conventional method for updating data on a dual storage device is designed based on a single data update process, and when that data update process is completed, both pieces of data are updated.

[Problem to be solved by the invention]

However, in the above-mentioned conventional technology, when it is necessary to write back the data on the storage device to the contents at the time the application program started due to abnormal termination of the application program, etc., such as in a transaction processing system, the data is updated. Before updating, it is necessary to save the pre-update data in advance. This includes at least reading 1 of the pre-update data.
There is a problem in that processing efficiency cannot be improved because a total of three input/output overheads are required: one write, one write, and one write for discarding before updating, which is unnecessary when the application program ends normally.

The present invention has been made to solve the above problems.

An object of the present invention is to provide a technique that can improve the efficiency of data update processing on a duplex storage device in a computer system in which an application program duplexes and updates data.

Another object of the present invention is to provide a technique that can eliminate the overhead of pre-update data.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a computer system in which an application program duplicates and updates data,
While the application program is running, only the data on one of the storage devices is updated, and when the application program ends, if the application program terminates normally, the data on the other storage device is updated based on the updated data on the input/output buffer. If the data on one storage device is updated, and if the program terminates abnormally, the update target is updated while the application program is running using the pre-update data on the other storage device based on the updated position data on the input/output buffer. The most important feature is that it eliminates the need to save pre-update data by writing back the data on the storage device that was previously updated.

[Effect]

According to the above-mentioned means, the execution state of the application program is managed, data is updated only on the front side while the application program is running, and data is updated on the side side in post-processing when the application program ends. , while the application program is being executed, the sub-plane is positioned as pre-update data and there is no need to save the pre-update data, so the efficiency of data update processing on the dual storage device can be improved.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be specifically described using the drawings.

In addition, in all the figures for explaining the embodiment, parts having the same functions are given the same reference numerals, and repeated explanations thereof will be omitted.

FIG. 1 is a block diagram showing a schematic configuration of an embodiment of a transaction processing system that implements the data update method of the present invention, and FIGS. 2 and 3 show application program execution state management shown in FIG. 1. 3 is a flowchart for explaining the operation of the section.

The transaction processing system of this embodiment, as shown in FIG. ing.

As shown in FIG. 2, the data updating method in the application program execution state management unit 2 secures an input/output buffer 3 for the application program at the start of execution of the application program (step 101).

Next, a value indicating that the application program is being executed is set in the application program execution state management table (step 102), and the duplex storage device control section 4 is instructed to set the input/output device to the front (step 103). When the application program requests data update in this state, the application program execution state management unit 2
buffers the update position data and update data on the input/output buffer 3 (step 104), and updates the data on the front of the duplex storage device 5 (step 105).

In this way, until the application program execution state management section 2 detects the end of execution of the application program, the duplex storage device a
Only the data on the front of No. 5 is updated.

Then, the application program execution state management unit 2 detects the end of execution of the application program (YES in step 106).
Then, it is determined whether the termination is normal or abnormal (step 107), and depending on the result, a value indicating normal termination processing (step 108) or abnormal termination processing is set in the application program execution status management table (step 108). Step 109)
. In the case of normal termination, the application program execution state management section 2 instructs the duplex storage device control section 4 to set the input/output device to the secondary side (step 110), and the application program is buffered in the input/output buffer 3 for the application program. sequentially write the data to the secondary side of the duplex storage device 5 (step 11)
1). When all the data on the secondary side has been updated (YES in step 112), a value indicating the end of termination processing is set in the application program execution state management table (step 113), and the crowded cover sofa 3 is cleared (step 114).

Conversely, in the case of abnormal termination (No in step 107), the application program execution state management section 2 instructs the duplex storage device control section 4 to set the input/output device to the secondary side, as shown in FIG. 201), read into the pre-update data on the secondary side based on the update position data on the input/output buffer 3 (
Step 202).

Next, the duplex storage device control unit 4 is instructed to set the input/output device to the front (step 203).

Write the read pre-update data to the front (step (
204). When all the data writing back on the front side is completed (
YES in step 205), a value for termination processing is set in the application program execution state management table (step 113 in FIG. 2), and the crowded cover sofa is cleared (step 114 in FIG. 2).

As can be seen from the above description, according to this embodiment, unlike the conventional method for updating data on a dual storage device (see FIG. 5: data updating process of a conventional dual storage device), the method shown in FIG. As shown in the data update process on the dual storage device of this embodiment, the execution status of the application program is managed, and while the application program is running, the data update process is performed only for the front side, and when the application program ends, By updating data on the secondary side in post-processing, while the application program is running,
By positioning the secondary side as pre-update data, there is no need to save the pre-update data. In order to recover from a system failure while an application program is running, it is necessary at least to prevent the values set in the application program execution state management table and update position data from being lost, but it is not necessary to save the update data itself. This can be easily realized by applying a relatively small capacity non-volatile memory.

The present invention has been specifically explained above based on examples, but
It goes without saying that the present invention is not limited to the embodiments described above, and can be modified in various ways without departing from the spirit thereof.

〔Effect of the invention〕

As described above, according to the present invention, the execution state of the application program is managed, data is updated only on the front side while the application program is running, and data on the side side is updated during post-processing when the application program ends. By performing the update process,
While the application program is being executed, the sub-plane is positioned as pre-update data and there is no need to save the update data, so it is possible to improve the efficiency of data update processing on the dual storage device.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a schematic configuration of an embodiment of a transaction processing system for implementing the data update method of the present invention, and FIGS. 2 and 3 are application program execution state management shown in FIG. FIG. 4 is an explanatory diagram for explaining the data update processing method on the dual storage device of this embodiment. FIG. 5 is an explanatory diagram for explaining a conventional data update processing method for a dual storage device. In the figure, 1... Application program storage unit, 2... Application program execution state management unit, 3... Input/output buffer, 4
... Duplex storage device control unit, 5... Duplex storage device.

Claims (1)

[Claims] In a computer system where an application program duplicates and updates data, only the data on one of the storage devices is updated while the application program is running, and when the application program terminates normally, the input/output The data on the other storage device is updated based on the updated data on the buffer, and if the data ends abnormally, the data on the other storage device is updated based on the updated position data on the input/output buffer. A method for updating data on a dual storage device, characterized in that it is unnecessary to save the pre-update data by writing back the data on the storage device that is subject to update while an application program is being executed using the pre-update data.