JP2012022383A - Duplexing control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a duplexing control system with which the file writing from an application is not inhibited during a file equalization processing and the file reading property of the application during file equalization processing is hardly deteriorated.SOLUTION: During the time in which data of a (N-1)th buffer 104 of a control system module 10 for which the writing is inhibited is added to a file 22 of a standby system module 20, a N-th buffer 104 holding data to which an application 13 requests the writing of a file of the control system module 10 is sequentially generated into the control system module 10. During the time in which the data of the N-th buffer 104 is added into the file 22 of the standby system module 20, when no writing request from the application 13 is generated, the equalization processing of all files is completed.

Description

  In the present invention, when shifting from single operation only by the control system module to duplex operation by returning the standby system module, the file written and read by the application of the control system module is equivalent to the file of the standby system module. The present invention relates to a redundant control system.

  In the duplex control system, similar processes are operated in parallel on two CPU modules having the same configuration. One CPU module outputs a signal to an external device. The operation mode of the CPU module at this time is called a control system operation mode, and the CPU module operating in this mode is called a control system module.

  The other CPU module does not output a signal to an external device. The operation mode of the CPU module at this time is called a standby system operation mode, and the CPU module operating in this mode is called a standby system module.

  If the control system module becomes abnormal in the duplex operation state, the operation mode of the standby system module is shifted to the control system operation mode to become a new control system module, and the system is shifted to the single operation state.

  When a new CPU module is added during the transition from the single operation state to the duplex operation state, the CPU module becomes a standby system module that operates in the standby system operation mode. At this time, necessary data from the control system module to the standby system module is equalized. The data to be equalized includes all files written and read by the memory and control module applications.

  The present invention provides a mechanism for file equalization from a control system module to a standby system module when shifting from a single operation state to a duplex operation state. FIG. 8 is a functional block diagram showing a configuration example of a conventional duplex control system.

  The control system module 10 includes a file duplication control unit 11, a control system file 12, and an application 13. The file duplication control unit 11 includes an equalization unit 11A, a writing unit 11B, and a reading unit 11C. The standby module 20 includes a file duplication control unit 21 and a standby file 22. The file duplication control unit 21 includes an equalization unit 21A.

  In this configuration example, the contents of the control system file 12 are written to the standby system file 22 of the standby system module 20 in a state where writing from the application 13 of the control system module 10 to the control system file 12 is prohibited at the time of switching to the duplex operation. Equalize.

  At the time of reading, the application 13 that reads and writes the control system file 12 transmits read request data to the reading unit 11B. The read request data includes file name and read range information. The reading range indicates the position where the file is read (reading start offset from reading start offset to reading end offset).

  At the time of writing, the application 13 transmits write request data to the writing unit 11B. The write request data includes file name, write data, and write range information. The write range indicates a position where the file is written (write start offset to write end offset from the beginning of the file).

  The file duplication control unit 11 of the control system module 10 prohibits writing from the application 12 to the control system file 12 and makes a file equalization request to the equalization unit 11A during the transition process to the duplication operation. The writing unit 11C rejects a write request to a write-protected file.

  The equalization unit 11A of the control system module 10 makes a copy request for the control system file 12 to the equalization unit 21A of the standby system module 20 when receiving a file equalization request from the file duplication control unit 11.

  The equalization unit 21A of the standby system module 20 copies the contents of the control system file 12 to the standby system file 22 based on the equalization request received from the equalization unit 11A of the control system module 10.

  FIG. 9 is a functional block diagram showing another configuration example of the conventional duplex control system. The difference from the configuration example of FIG. 8 is a configuration for equalizing the file without prohibiting the application 13 from writing the file to the control system file 12.

  In this method, during the file equalization at the time of the duplex operation shift, the write request from the application 12 to the control system file 12 is stored in the write request queue 11D formed in the file duplex control unit 11 and actually controlled. It is not written in the system file 12. The file write request data stored in the write request queue 11D after the equalization is completed is written to the control system file 12 and the standby meter file 22.

  Hereinafter, processing different from the prior art of FIG. 8 will be described. When the file reading request is received, the reading unit 11C reads data in the reading range from the control system file 12 and notifies the application 13 of the data. However, data to be passed to the application 13 is created in the following procedure during the duplex operation transition process.

  First, data included in the reading range is read from the control system file 12. Next, all the file write request data stored in the write request queue 11D are referred to, and it is determined whether each write request is within the read range of the corresponding file. On the other hand, the file write request data is reflected.

  The writing unit 11B writes the write data in the write range of the target control file 12 when the file write request is received. However, if the file is write-protected, the write request data is stored in the write request queue 11D without being written to the file. In other words, the write request queue 11D stores write request data for the control system file 12 whose file writing is prohibited.

JP 2005-182217 A

The conventional dual control system has the following problems.
In the conventional configuration shown in FIG. 8, writing to the control system file 12 is prohibited and the files are equalized. Therefore, while the file writing is prohibited, the data to be written to the file by the application 13 must be buffered. Furthermore, since the buffer size increases indefinitely in proportion to the file size to be equalized during the file write prohibition period, the application 13 cannot determine the size of the prepared buffer.

  In the conventional configuration shown in FIG. 9, the file can be equalized without prohibiting writing to the control system file 12. However, when the file read request is made, the entire contents of the write request queue 11D must be reflected on the read file data, so that the file read performance deteriorates.

  An object of the present invention is to realize a duplex control system that does not prohibit file writing from an application during file equalization processing and hardly degrades the file reading performance of the application during file equalization processing. It is in.

In order to achieve such a subject, the present invention has the following configuration.
(1) When shifting from single operation using only the control system module to duplex operation by returning the standby system module, the file written and read by the application of the control system module is equalized to the file of the standby system module In the redundant control system
In principle, during the period when the file of the control system module subjected to the write prohibition process is copied to the file of the standby system module, the control is performed on the primary buffer that holds the data requested by the application to write to the file of the control system module. To the system module,
After completion of the file copy processing, writing to the primary buffer is prohibited, and data in the primary buffer is added to the file of the standby module,
During the period of data addition to the primary buffer, a secondary buffer that holds data requested by the application to write to the file of the control system module is generated in the control system module,
Similarly, during the period in which the write-protected (N-1) data of the next buffer is added to the file of the standby system module, the application holds the data requested to be written to the file of the control system module. The next buffer is sequentially generated in the control system module,
Duplexing control characterized in that equalization processing for all files is terminated when no write request is issued from the application during a period in which data in the Nth order buffer is added to a file of the standby module. system.

(2) The speed of equalizing the file of the control system module to the standby system module is higher than the speed of writing to the file of the control system module by the application. Duplex control system.

(3) The buffer generated in the control system module is deleted sequentially after the data is added to the standby system module file and the control system module file (1) or ( The duplex control system according to 2).

(4) When the time required for appending the buffer data generated in the control system module to the file of the standby system module is shorter than the file write prohibition time allowed for the operation of the application The duplication control system according to any one of (1) to (3), wherein writing of the application to the buffer is prohibited, and data of the buffer is added to a file of the standby module.

(5) When reading the data of the file of the control system module, if the entire reading range is not included in the file, the application sequentially searches the N-th buffer from the primary buffer and reads the reading range. The duplex control system according to any one of (1) to (4), wherein data is acquired from a buffer including the data and combined with the read data.

According to the present invention, the following effects can be expected.
(1) The file of the control system module can be equalized to the standby system module without prohibiting the application from writing the file.

(2) Even during file equalization, the application can acquire the latest file data, and there is almost no deterioration in access speed compared to normal file reading. Thereby, the application can read and write the file without considering the duplication of the file.

It is a functional block diagram which shows one Example of the duplication control system to which this invention is applied. It is a flowchart explaining the flow of a file equalization process. It is a flowchart explaining the flow of a file writing process. It is a flowchart explaining the flow of a file reading process. It is a time chart explaining the flow of the equalization process by a write buffer. 6 is a flowchart for explaining another flow of the write buffer append process in the file equalization process shown in FIG. 2. 6 is a flowchart for explaining another flow of the file writing process shown in FIG. 4. It is a functional block diagram which shows the structural example of the conventional duplication control system. It is a functional block diagram which shows the other structural example of the conventional duplication control system.

  Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a functional block diagram showing an embodiment of a duplex control system to which the present invention is applied. The same elements as those in the conventional configuration described with reference to FIG.

  FIG. 1 is an extension of the function of the conventional configuration shown in FIG. Hereinafter, elements added to the configuration of FIG. 8 and changed processes will be described. In the present invention, file writing by an application is limited to additional writing.

  The additional write is a process of adding new write data to the end of the file, and the data once written in the file is not changed later. This process is employed in, for example, data logging.

  The elements added to the configuration of FIG. 8 are configurations in which an equalization control unit 101, a write control unit 102, a read control unit 103, and a write buffer 104 are formed in the file duplication control unit 11 of the control system module 10. .

  The application 13 reads and writes the control system file 12 as in FIG. 8, but transmits read request data to the read control unit 103 at the time of reading. At the time of writing, write request data is transmitted to the write control unit 102. Here, the data to be written is only appending. The read request data and write request data are the same as those in the prior art of FIG.

  The file duplication control unit 11 prohibits writing of the control system file 12 during the duplication operation line transition process, and makes a file equalization request to the equalization unit 11A and the equalization control unit 101. The equalization control unit 101 adds the data held in the write buffer 104 to the data of the standby system file 22 and the control system file 12 when receiving the file equalization request.

  The additional writing of the data in the write buffer 104 to the control system file 12 and the standby system file 22 is performed in the order of primary buffer → secondary buffer. Further, the addition to the control system file 12 is performed by the equalization control unit 101, and the addition to the standby system file 22 is performed by the equalization control unit 101 to the equalization unit 21A of the standby system module 20. . At this time, the corresponding buffer is write-protected. After completion of the processing based on the write request, the corresponding buffer is deleted.

  When receiving the write request data, the write control unit 102 searches for a writable area of the control system file 12 and adds write data to the area. The search order is: control system file → primary buffer → secondary buffer... Nth buffer.

  If all areas are write-protected, create a new buffer. Here, the writing speed to the buffer is set to be equal to or lower than the file equalization speed by the equalization control unit. At the time of file writing, write request data is transmitted to the writing unit 11B.

  When receiving the read request data, the read control unit 103 searches the control system file 12 and the write buffer 104 for data in the read range included in the request, and notifies the application 13 of it. In the search method, it is determined whether the data falls within the reading range based on the respective data sizes in the order of control system file 12 → primary buffer → secondary buffer... Nth buffer.

  At this time, when the data range extends over the control system file 12 and a plurality of buffers, the data acquired from each is combined. When reading a file, read request data is transmitted to the reading unit 11C.

The write buffer 104 is a buffer group that holds the contents written to the control system file 12. There can be a plurality of buffers, and the primary buffer, secondary buffer,... Examples of data held by each buffer are as follows.
(A) File name: File name to which write data is added (b) Write range: Position where write data is written to the file (c) Write data: Data to be added to the file

  The processing flow will be described below with reference to the flowcharts of FIGS. 2 to 4 and the time chart of FIG. In FIG. 2 to FIG. 4, processing steps unique to the present invention are indicated by bold blocks.

  FIG. 2 is a flowchart for explaining the flow of the file equalization processing. FIG. 2A shows a basic flow of file equalization processing. FIG. 2B shows a detailed flow of the processing step S5 unique to the present invention in FIG.

  In FIG. 2A, when the equalization process is started in step S1, the file equalization control unit 11 prohibits writing to the control system file 12 in step S2. In step S3, the file equalization control unit 11 sends a file equalization request to the equalization unit 11A.

  In step S4, the equalization unit 11A adds the contents of the control system file 12 to the standby system file 22 of the standby system module. In step S5, the data in the write buffer 104 is added to the standby file 22 and the control file 12.

  In step S6, the file equalization control unit 11 cancels the prohibition of writing to the control system file 12, and ends the file equalization process in step S7. Details of the write buffer in step S5 are shown in FIG.

  In FIG. 2B, when the write buffer append process is started in step S51, the file duplication control unit 11 issues a file equalization request to the equalization control unit 101 in step S52. In step S <b> 53, the equalization control unit 101 selects a buffer to be equalized and prohibits writing of the buffer.

  In step S54, the equalization control unit 101 requests the equalization unit 21A of the standby module 20 to write buffer data to be equalized. In step S <b> 55, the equalization unit 21 </ b> A of the standby system module 20 adds buffer data to the standby system file 22.

  Next, in step S <b> 56, the equalization control unit 101 adds buffer data to the control system file 12. Then, the equalization control unit 101 deletes the buffer that has been additionally written in step S57.

  If the appending process for all the buffers is completed in the check in step S58, the appending process for the write buffer is terminated in step S59. If the appending of all the buffers has not been completed in the check in step S58, the process returns to step S53 and the same process is repeated.

  FIG. 3 is a flowchart for explaining the flow of the file writing process. When the file writing process is started in step S1, the application 13 transmits write request data to the write control unit 102 in step S2.

  If it is determined in step S3 that the control file 12 is not write-protected, the process advances to step S4, and the write control unit 102 transmits write request data to the write unit 11B. In step S5, the writing unit 11B adds write data to the control system file 12, and ends the writing process in step S6.

  If it is determined in step S3 that writing is prohibited, the process proceeds to step S7. If there is a writable buffer, the write control unit 102 adds write data to the writable buffer in step S8. . If there is no writable buffer in the check in step S7, the write control unit 102 generates a writable buffer in step S9, and the process proceeds to step S8.

  FIG. 4 is a flowchart for explaining the flow of the file reading process. When the file reading process is started in step S1, the application 13 transmits read request data to the reading control unit 103 in step S2.

  If the read range is included in the control system file 12 in the check in step S3, the read control unit 103 transmits read request data to the reading unit 11C in step S4. In step S <b> 5, the reading unit 11 </ b> C reads file data in the reading range from the control system file 12.

  If the reading of the entire reading range is completed in the check in step S6, the reading control unit 103 notifies the application 13 of the reading data in step S7, and the file reading process is ended in step S8.

  If the reading range is not included in the control system file 12 in the check in step S3, the reading control unit 103 searches for a buffer including the reading range in step S9. In step S10, the read control unit 103 reads buffer data from the searched buffer and proceeds to step S6. If it is determined in step S6 that reading of the entire reading range has not been completed, the process returns to step S9 and the same processing is repeated.

  FIG. 5 is a time chart for explaining the flow of equalization processing by the write buffer. It is assumed that the application 13 performs file writing with a file writing cycle of 1 second and a writing amount of 1 MB in one cycle, and the 1000 MB control system file 12 already exists before the duplex operation transition processing. The file equalization speed by the file duplication control unit 11 is 10 MB / sec.

  According to the present invention, as the equalization target shifts from control system file → primary buffer → secondary buffer → tertiary buffer, the size of the equalized data is sequentially reduced, and the equalization time is accordingly increased. Will also decrease.

  The primary buffer stores 100 MB (1 MB / second * 100 seconds) of data requested by the application 13 during a file equalization required time of 100 seconds (1000 MB / 10 MB / sec).

  Next, in the secondary buffer, 10 MB (1 MB / second * 10 seconds) of data requested by the application is accumulated within the time required for equalization of the primary buffer of 10 seconds (100 MB / 10 MB / sec). Is done.

  In this way, the size of the buffer data gradually decreases, and since there is no write request from the application during the equalization of the tertiary buffer, the control system and the standby system after the equalization of the tertiary buffer. The files are completely identical, and all equalization processing ends.

  In the embodiment described above, the file equalization is not completed until there is no file write request from the application during the equalization of the Nth-order buffer, so it takes a long time to complete the equalization. There is a case.

  Therefore, if the application 13 can permit file writing prohibition for a certain period of time, the file equalization time can be reduced by prohibiting writing to the file and buffer only within that time.

  FIG. 6 is a flowchart for explaining another flow of the write buffer append process (FIG. 2B) in the file equalization process shown in FIG. Steps added to FIG. 2B are steps S60, S61, and S62.

  Additional steps S60 and S61 are inserted between step S53 and step S54. In the check in the adding step S60, before adding each buffer to the file, it is determined whether or not the time required for adding the buffer is shorter than the allowable write prohibition time of the application 13. The time required for additional recording is obtained by the buffer data size / the additional recording speed. The write-once speed is uniquely determined by the data transfer method between the control system module and the standby system module and the processing capacity of the device.

  If the required time for additional writing in the buffer is shorter than the write prohibition allowable time of the application 13 in the check in the additional step S60, the process proceeds to additional step S61. . If it is determined in the additional step S60 that the additional writing time is longer than the write prohibition allowable time, all writing is not prohibited and the buffer additional processing is performed from step S54.

  Thereafter, the prohibition of all writing is canceled by an additional step S61 inserted between step S58 and step S59. Note that “all write prohibition” here means prohibition of writing to the control system file and all buffers.

  FIG. 7 is a flowchart for explaining another flow of the file writing process shown in FIG. Steps added to FIG. 4 are steps S10 and S11. The additional step S10 is inserted between step S2 and step S3.

  If all the writing is prohibited when receiving the write request data from the application 13 in the check in the adding step S10, the writing rejection is notified to the application 13 in the adding step S11, and the file writing process is ended in the step S6. . If all writing is not prohibited in the check in the additional step S10, the process proceeds to step S3 and the same processing as in FIG.

  As described above, the process of prohibiting the writing of the application 13 to the control system file 12 and the buffer 104 under a predetermined condition allows the file write prohibition time during the file equalization process to be within the allowable time of the application. it can.

DESCRIPTION OF SYMBOLS 10 Control system module 11 File duplication control part 11A Equalization part 11B Writing part 11C Reading part 12 Control system file 13 Application 20 Standby system module 21 File duplication control part 21A Equalization part 22 Standby system file 101 Equalization control part 102 write control unit 103 read control unit 104 write buffer

Claims (5)

Redundant control that equalizes the file written and read by the application of the control system module to the file of the standby system module when shifting from the single operation only by the control system module to the duplex operation by returning the standby system module In the system,
In principle, during the period when the file of the control system module subjected to the write prohibition process is copied to the file of the standby system module, the control is performed on the primary buffer that holds the data requested by the application to write to the file of the control system module. To the system module,
After completion of the file copy processing, writing to the primary buffer is prohibited, and data in the primary buffer is added to the file of the standby module,
During the period of data addition to the primary buffer, a secondary buffer that holds data requested by the application to write to the file of the control system module is generated in the control system module,
Similarly, during the period in which the write-protected (N-1) data of the next buffer is added to the file of the standby system module, the application holds the data requested to be written to the file of the control system module. The next buffer is sequentially generated in the control system module,
Duplexing control characterized in that equalization processing for all files is terminated when no write request is issued from the application during a period in which data in the Nth order buffer is added to a file of the standby module. system.   2. The duplex control according to claim 1, wherein a speed for equalizing the file of the control system module to the standby system module is higher than a speed of writing the file of the control system module by the application. system.   The buffer generated in the control system module is deleted sequentially after the data is added to the file of the standby system module and the file of the control system module. Redundant control system.   When the time required to append the buffer data generated in the control system module to the file of the standby system module is shorter than the file write prohibition time allowed for the operation of the application, 4. The duplex control system according to claim 1, wherein writing of the application into the buffer is prohibited, and data in the buffer is added to a file of the standby module.   When reading the data of the file of the control system module, if the entire reading range is not included in the file, the application sequentially searches the Nth buffer from the primary buffer and includes the reading range. 5. The duplex control system according to claim 1, wherein data is obtained from a buffer and combined with read data.