JP2926873B2 - Computer system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Overview] Regarding file sharing in a computer system composed of a plurality of loosely-coupled computers, the purpose of the present invention is to provide a file-sharing processing method capable of efficiently performing sharing control. And a control information storage device, wherein the shared file is connected so as to be accessed from each of the computers, and the control information storage device is connected by a mechanism exclusively connected to the computer at the request of each of the computers. Are connected so as to be accessed from each of the computers, hold predetermined shared control information, and the shared control information is obtained from a reservation counter, a used system display, and use status information corresponding to each of the shared files. When each of the computers needs the shared file to process a job input to the computer, the computer controls the shared control information of the shared file. Only when the information and the usage status requested by the job satisfy predetermined conditions, the usage status information of the shared control information is set to a value determined from the usage status of the job, and the value of the reservation counter is increased. And executing the job after the reservation succeeds. When the job starts using the shared file, the value of the reservation counter is reduced, and during the use, the system is used. The display is configured to display a predetermined value indicating that the computer is in use.

[Industrial applications]

The present invention relates to a processing method for sharing files in a computer system including a plurality of loosely coupled computers.

[Conventional technology]

FIG. 5 is a block diagram showing a configuration example of a computer system. Each of the plurality of computers 1 is a system having a function of processing a job submitted independently, and shares a shared file 3 stored in a shared external storage device 2 such as a magnetic disk storage device. Configure a loosely coupled system.

In that case, any computer 1 has a shared file 3
When the data is updated, during a series of reference and update processing for the file until the update is completed, at least the processing target data portion is occupied so as not to be used in other processing, namely, It is well known that exclusive control is necessary to prevent inconsistency in related processing.

For this purpose, the following exclusive control method is used, for example, assuming that a file is occupied as a unit when necessary. That is, the shared control information 5 is provided in the external storage device 4 to which the necessary computer 1 is connected. The external storage device 4 is provided with a switching mechanism 6. The switching mechanism 6 is a known mechanism that issues the occupation command from the computer 1 and connects the external storage device 4 only to the computer 1 until the occupation is released by the release command.

The shared control information 5 includes control information corresponding to each required shared file 3. Each control information includes, for example, a used system display and usage status information. The used system display corresponds to, for example, each computer 1. A bit string composed of one bit and a use state are, for example, one bit, and 0 and 1 indicate whether use is permitted to be shared (hereinafter, referred to as shared) or use requiring exclusive occupation (hereinafter, referred to as exclusive). The initial values are all 0.

The computer 1 processes the job, and when a request to use the shared file 3 is issued from the job, first, the switching mechanism 6 attempts to occupy the external storage device 4 as described above.

As a result, if the occupation succeeds, the shared control information 5 is read out. If the job request is only file reference, the necessary control information of the shared file 3 is checked and the use status column is set to 0.
Then, since the shared file 3 can be used, the bit assigned to itself in the used system display column is set to 1
After updating the shared control information 5 to release the switching mechanism 6, the job processing is resumed.

If the job request is for use with file update, look at the column of used system display and set all bits to 0.
In this case, the shared file 3 can be used. In this case, the shared control information 5 is set so that the bit assigned to itself in the column of the used system display is set to 1 and the column of the use status is set to 1. Is updated, and after the switching mechanism 6 is opened, the processing of the job is restarted.

In the case other than the above, the shared file 3 cannot be used immediately, and it is necessary to wait until a condition satisfying any of the conditions is satisfied.
And after a suitable waiting time, try the above process.

When the necessary shared file 3 is successfully occupied and the processing is completed, the shared control information 5 is occupied again as described above, and the control information of the shared file 3 is displayed in the column of the used system display column. After setting the bit and the bit in the column of the use status to 0, the shared control information 5 is released.

[Problems to be solved by the invention]

With the above processing, exclusive control of the shared file 3 can be performed. However, if the necessary shared file 3 is not successfully occupied after the execution of the job is started, waiting until the occupation succeeds. During the time, the various resources of the computer allocated to the job are wasted and are disadvantageously degraded.

An object of the present invention is to provide a computer system capable of efficiently performing shared control.

[Means for solving the problem]

 FIG. 1 is a block diagram showing the configuration of the present invention.

FIG. 1 shows a configuration of a file sharing processing method, which includes a shared file 3, a plurality of computers 10, and a control information storage device 11, and the shared file 3 is connected so as to be accessed from each computer 10, The information storage device 11 is connected so as to be accessed from each computer 10 by the switching mechanism 6 which is a mechanism exclusively connected to the computer in response to a request from each computer 10, holds predetermined shared control information 12, and Control information
12 is a reservation counter corresponding to each shared file 3
13, a use system display 14, and use status information 15. When each computer 10 needs the shared file 3 for processing of a job input to the computer, the respective computers 10 share control information of the shared file. Only when the usage status 12 and the usage status requested by the job satisfy predetermined conditions, the usage status information 15 of the shared control information is set to a value determined from the usage status of the job, and the value of the reservation counter 13 is increased. By executing the reservation, the processing of the job is started after the reservation is successful, and when the job starts using the shared file 3, the value of the reservation counter 13 is reduced, and the used system is displayed during the use. A predetermined value indicating that the computer is in use is displayed in 14.

[Action]

With this processing method, the shared file necessary for job execution is reserved only when the conditions are available, and the job is started after the reservation is completed. As a result, there is no need to reserve resources unnecessarily, and the processing efficiency of the computer system can be improved.

〔Example〕

FIG. 2 is a block diagram showing the configuration of the system according to the embodiment of the present invention. The three computers 8a, 8b and 8c constitute a loosely coupled system, and each of the computers 8a, 8b and 8c is connected to an input device 9 respectively.
When a job input consisting of a job control statement is received from a, 9b, 9c, it is stored in the job storage device 20 so as to form a queue, and each of the computers 8a, 8b, 8c becomes a resource state capable of processing the job. Then, the job control statement is extracted from the job storage device 20 and analyzed, and if it is a job to be processed by itself, the job is executed as follows.

For this reason, the job storage device 20 is also connected to the control information storage device.
It has a switching mechanism similar to that of 11, and allows each computer to occupy the job storage device when storing and retrieving job control statements. The external storage device 2 and the control information storage device 11 in FIG. 2 are the same as those in FIG.

FIG. 3 shows an example of the processing flow in the job processing of each of the computers 8a, 8b and 8c.
At 31, for example, one job is extracted in the order of arrival, and the job control statement is analyzed.

According to the analysis, if it is specified in the processing step 32 that the job is not to be processed by the own computer, the job is returned to the queue in the processing step 40, and the process returns to the processing step 30 to proceed to the processing of the next job. . If it is a job to be processed by its own computer, it is identified in processing step 33 if a shared file is used and reserved.

If the reservation has not been made, a reservation process is performed in processing step. The reservation process occupies the control information storage device 11 and controls the required shared file control information of the shared control information 12.
First, if the column of the usage status information 15 is 0 as in the conventional case, when the shared file is used only for reference, the shared file 3 can be used, and the reservation counter 13 of the present invention is reserved by +1. .

In the case of use with updating, the shared file 3 can be used only when all the bits are 0 by looking at the column of the used system display. In this case, the reservation counter 13 is incremented by one. The usage status information 15 is set to 1 to indicate "exclusive". It is assumed that the reservation has been successful only when the reservation counter can be incremented by any of the above.

The above reservation process is tried for all the shared files requested by the job, and if all succeeds,
The sharing control information for all those shared files is updated as described above.

Next, in processing step 35, it is determined whether or not the reservation was successful, and if unsuccessful, processing returns to processing step 30 via processing step 40. If successful, start execution of the job step as follows. During processing of the job queue as described above, the switching mechanism is controlled so that the job storage device 20 is occupied by the computer. Cancel.

When the job step is executed, first, in the processing step 36, for the shared file used in the job step, the reservation counter 13 of the shared control information 12 is decremented by 1, and the bit corresponding to the computer in the used system display 14 is set to 1. After that, the job step is executed in a processing step 37.

When the execution of the job step is completed, processing step 38
Then, the bit of the used system display 14 of the corresponding shared control information 12 and the usage status information 15 are reset. When the same shared file is used again in a later job step, the reservation is made again in the same manner as described above.

At processing step 39, the job is identified as having a subsequent job step, and if not, processing returns to processing step 30 for processing the next job, but if there are subsequent job steps, processing returns to processing step 32.

FIG. 4 is a diagram for explaining an example of job processing, in which three jobs X, Y, and Z each using a shared file FILE.
Are input in this order, job X is composed of two job steps, the first job step is specified to be executed by computer A, the second job step is specified to be executed by computer B,
It is assumed that the job control statement specifies that the shared file FILE is referenced in both job steps.

Job Y and job Z may be executed by any computer. Job Y updates the shared file FILE, and job Z requests reference.

The following description corresponds to (1) to (4) in FIG. 4. First, when the computer A takes out the job X, the computer A makes a reservation in the sharing control information of the FILE and sets the reservation counter to 1.

Next, the computer B takes out the job Y and attempts to reserve the FILE. However, since the job Y has requested the update processing, it must be reserved exclusively. I can not make a reservation because there is.

When the computer C takes out the job Z and reserves the FILE, it succeeds because this is a reference request, and advances the reservation counter to 2.

In order to start the execution of the job X in the computer A, the reservation counter is decremented by 1 to 1 and the display of the used system is set.

In order to start the execution of the job Z in the computer C as well, the reservation counter is decremented by 1 to 0, and the used system display is set.

When the first job step of job X is completed, computer A
To clear the display of the used system, but also in the second job step
Since the FILE is used, the reservation counter is incremented by 1 to 1.

In order for the computer B to start the second job step of the job X, the reservation counter is decremented by 1 to 0, and the used system display is set.

When the second job step of job X is completed, computer B
Turns off the display of the used system.

When the job Z ends, the computer C erases the display of the used system, and the sharing control information of the FILE completely indicates a free state.

For example, computer A takes out job Y here and
When the reservation is made, the reservation is successful and the reservation counter is set to 1; the use status information is set to 1;

〔The invention's effect〕

As is apparent from the above description, according to the present invention, in a computer system including a plurality of loosely coupled computers, sharing control for file sharing can be performed efficiently, so that a remarkable industrial process to improve the processing efficiency of the system is achieved. There is also an effect.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of the present invention, FIG. 2 is a block diagram showing an embodiment of the present invention, FIG. 3 is a flowchart of the processing of the present invention, and FIG. 4 explains the job processing of the present invention. FIG. 5 is a block diagram showing a conventional configuration example. In the figure, 1, 10, 8a, 8b and 8c are computers, 2 and 4 are external storage devices,
3 is a shared file, 5 and 12 are shared control information, 6 is a switching mechanism, 11 is a control information storage device, 13 is a reservation counter, 14 is a used system display, 15 is a use status, 20 is a job storage device,
30 to 40 indicate processing steps.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G06F 15/177 WPI JOIS

Claims (1)

(57) [Claims] In a computer system having shared resources referenced or updated by a plurality of computers, a table for managing a computer on which an input job is executed and a reservation status of a shared resource to be used; Analyzing means for analyzing the computer on which the job is executed, the shared resource to be used, and reference or update to the shared resource based on the job control statement, and updating the table based on the analysis result; If the table can be updated by means,
A computer system characterized by: execution control means for sequentially executing the job using a computer and a shared resource designated by the control statement.