JP2000020336A - Duplex communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent system destruction by preventing the simultaneous processing operation of active and reserve host devices by executing switching to the reserve host device after stopping the operation of the active host device where stall is generated. SOLUTION: A reserve host device 2 transmits a message for fault occurrence detection through an inter-system communication path 3 to an active host device 1. When the active host device 1 does not return a response message to the reserve host device 2 in response to this transmission and the reserve host device 2 recognize the fault occurrence of not updating active system operation condition data stored in shared disk devices 4 and 5, the reserve host device 2 sends operation stop request data through a LAN transmission line 25 to a communication server 6, a power source controller 7 controls the stop of electrification to the active host device 1 and stops operation and afterwards, switching to the reserve host device 2 is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a duplex communication system having an active host system and a standby host system. More particularly, the active host system sends a response message for failure detection to a standby host system due to a stall or the like. The present invention relates to a redundant communication system in which, when a return is not made and the operation status data is not updated, the operation of the active host device is stopped, and thereafter, the operation is switched to the standby host device.

[0002]

2. Description of the Related Art Hitherto, a duplex communication system having an operation system and a standby system host device of this type is applied to a communication network such as a local area network (LAN) which requires reliability. The active host device performs normal data processing. The standby host device monitors the processing operation in the active host device. When a failure (down) occurs in the active host device by this monitoring, the active host device is automatically switched to the standby host device, and the processing operation is continued. As such a switching control method between the active system and the standby system, for example, a “down monitoring system of a duplex configuration system” in Japanese Patent Application Laid-Open No. 1-195544 is known.

FIG. 4 is a block diagram showing a configuration of such a conventional duplex communication system. The redundant communication system includes, via a LAN or the like, an active host device 1 that normally executes data processing, and a standby system that monitors the occurrence of a failure in the active host device 1 and switches to continue the processing operation when the failure occurs. A host device 2, an inter-system communication path 3 for transmitting (transmitting / receiving) a message and a response message for the standby host device 2 to monitor the occurrence of a failure in the active host device 1, and an active host device 1 and a standby host It has shared disk devices 4 and 5 for storing operation status data indicating the operation status of the device 2. In this example, two shared disk devices 4 and 5 that perform the same operation status data writing and reading operations are arranged in order to enhance system reliability.

The active host device 1 receives a failure detection message sent from the standby host device 2 through the inter-system communication path 3 and returns a response message. An operating status setting / acquisition unit 9 for transmitting the operating status data processed by the host device 1 to the shared disk devices 4 and 5 at regular intervals and updating the data is provided. The standby host device 2 also has the same health check unit 10 and operating status setting / acquisition unit 11 as the active host device 1. Shared disk devices 4, 5
Is the operating status storage file 1 that operates similarly
2 and 13 are provided.

Next, the operation of the conventional example will be described. The active host device 1 and the standby host device 2 transmit and receive a message and a response message through the inter-system communication path 3. The standby host device 2 monitors the operation of the active host device 1 based on the transmission / reception of the message and the response message and the active operating status data stored in the operating status storage files 12 and 13 of the shared disk devices 4 and 5. . Based on this monitoring, the standby host device 2 determines whether to switch the processing operation of the active host device 1 to the standby host device 2 and continue. In the standby host device 2, first, the health check unit 10 periodically sends a failure detection message to the active host device 1 via the inter-system communication path 3. The health check unit 8 of the active host device 1 receives this message, and returns a response message for failure detection to the standby host device 2.

In the active host device 1, the active operating status data processed here is processed by the operating status setting / acquisition unit 9.
Are updated at regular intervals to the operating status storage files 12, 13 of the shared disk devices 4, 5. When a failure occurs in the active host device 1, a message cannot be received, or a response message cannot be transmitted even if a message is received. Therefore, the standby host device 2
In this case, the response message cannot be received, and the non-reception causes the standby host device 2 to operate the operation status setting / acquisition unit 1.
1 reads the operating system operation status data stored in the operation status storage files 12 and 13 of the shared disk devices 4 and 5.

After a lapse of a predetermined time, the operating status data stored in the operating status storage files 12 and 13 of the shared disk devices 4 and 5 is read again to determine whether the operating status data has been updated. Confirm. If the active system operation status data is not updated, the standby host device 2 determines that a failure has occurred in the active host device 1,
The processing is continued by switching from the active host device 1 to the standby host device 2.

In such an active / standby switching control method, when the active host device 1 is stalled, a response message cannot be transmitted to the standby host device 2, and the shared disk devices 4, 5 Although the operating status data stored in the operating status storage files 12 and 13 cannot be updated, the processing operation may continue. In this case, when switching from the active host device 1 to the standby host device 2, the active host device 1 and the standby host device 2 simultaneously perform processing operations, and time-series data processing cannot be performed. The system may be destroyed.

[0009] As examples of improving the switching control system between the active system and the standby system, “System including a hot standby system” in JP-A-63-214842 and “System including a hot standby system” in JP-A-63-288338 A system switching method for a hot standby system is known. In these conventional examples, when a failure occurs in the inter-CPU communication unit disposed between the active system and the standby system, the heartbeat communication (health check) times out and no failure occurs in the active system. In addition, switching from the active system to the standby system is performed.

[0010] Further, "Fault handling method in hot standby system" in JP-A-63-288337.
In the example, if a failure occurs in the communication path and the system control system, normal operation cannot be performed. That is, it is not possible to isolate the occurrence of a failure in the active system and the communication path, and it is not possible to switch between the active system and the standby system.

[0011]

As described above, in the above-described conventional redundant communication system, when the active host device is stalled, the standby host device switches without stopping the processing execution in the active host device. Therefore, there is a disadvantage that normal processing operation cannot be performed, the system is destroyed, and the reliability of the system cannot be obtained.

In these conventional examples, switching from the active system to the standby system is performed even when no failure occurs in the active system. In addition, there is a disadvantage that it is not possible to isolate the occurrence of a failure in the active system and the communication path, and it is not possible to perform system switching, and it is not possible to reliably perform switching control to the standby system.

The present invention solves such a problem in the prior art. Even when the active host device is stalled, the active host device and the standby host device simultaneously execute processing operations. It is therefore an object of the present invention to provide a duplex communication system in which the switching to the standby system host device can be reliably performed, the system destruction is prevented, and the system reliability is improved.

[0014]

In order to achieve the above object, a dual communication system according to the present invention comprises a single active host device and a standby host device connected by an inter-system communication path and a communication network; The processing data of the active host device is stored in the storage means and is switched to the standby host device when a failure occurs in the active host device. The standby host device sends a failure detection message to the active host device. The failure is transmitted to the host device via the inter-system communication path, and the standby host device cannot receive a response message from the active host device and the occurrence of a failure in which the active operation status data stored in the storage means is not updated. When recognizing, the operation system is configured to include a switching unit that stops the operation of the active host device and then switches to the standby host device.

Further, in the redundant communication system of the present invention, a plurality of active host devices and at least one standby host device having different processing operations are connected by an inter-system communication network and a communication network, and The processing data of the device is stored in the storage means, and when a failure occurs in the active host device, the device is switched to the standby host device. The standby host device sends a failure detection message to a plurality of active host devices. Each of the devices was transmitted through the inter-system communication network, and the standby host device recognized that a failure occurred in which the response message from the active host device could not be received and the active system operation status data in the storage unit was not updated. In this case, after the operation of the active host device in which the failure has occurred is stopped, switching to the standby host device is executed. It is constituted with a replacement unit.

Further, after the switching means executes the switching to the standby host device, the standby host device continues the processing operation, and the standby host device after the faulty active host device is restored. When a failure occurs in the device, the operation of the standby host device is stopped, and thereafter the switching to the active host device is executed.

The switching means includes a communication server for transmitting a signal requesting a stop of the operation of the active host device via the communication network when the standby host device recognizes the occurrence of the failure, and an operation from the communication server. An operation stop control device that performs control to stop the operation of the active host device based on the stop request signal is provided.

Further, as the operation stop control device, there is provided a power supply control device for performing control to stop power supply to the active host device based on an operation stop request signal from the communication server.

Further, the operation stop control device is configured to include a control device that controls to stop the operating system executed by the active host device based on an operation stop request signal from the communication server.

Further, as the active host device, a health check unit for transmitting and receiving a failure detection message and a response message to and from the standby host device through an inter-system communication path, An operating status setting / acquisition unit for transmitting the active operating status data and receiving the active operating status data is provided.

Also, the standby system host device transmits and receives a failure detection message and a response message to and from the active host device via an inter-system communication path. An operating status setting / acquisition unit that sends out operating status data, captures operating status data, monitors the occurrence of a fault in the operating host device, and transmits operation stop request data through a communication network when a fault occurs. It is provided as a configuration.

Further, each of the active host devices transmits and receives a failure detection message and a response message to and from the standby host device through the inter-system communication network. And an operation status setting / acquisition unit for transmitting the operation system operation status data and taking in the operation system operation status data.

Also, the standby host device transmits and receives a failure detection message and a response message to and from each of the active host devices via an inter-system communication path, Operating status setting / acquisition that sends out the active operating status data, captures the active operating status data, monitors the occurrence of a failure in the active host device, and transmits operation stop request data through the communication network when a failure occurs. Unit.

Further, a local area network is used as the communication network and the inter-system communication network.

Further, a disk device having an operating status storage file for storing operating status data is used as the storage means.

Further, the communication server has a data conversion section for converting operation stop request data from the standby host device into a predetermined operation stop request signal and transmitting the signal.

Further, the power supply control device has a host stop unit for performing control to stop power supply to the active host device based on an operation stop request signal from the communication server.

Further, at least two disk devices that write and read the same operation status data are used as the disk devices.

In the duplex communication system of the invention having such a configuration, the active host device does not return a response message to the standby host device, and the active operating status data stored in the storage means is updated. When a failure that does not occur occurs, the operation of the active host device is stopped, for example, by turning off the power supply, and thereafter, switching to the standby host device is executed.

Therefore, even if a failure occurs in the inter-CPU communication section between the active system and the standby system described in the conventional example, even if the heartbeat communication (health check) times out, the active system is not connected to the active system. It is not necessary to execute switching when no failure has occurred. That is, unnecessary switching does not occur. Further, it is not impossible to determine whether a failure has occurred in the active system or a communication path. As a result, in the present invention, the active host device and the standby host device do not execute the processing operations at the same time, and the switching to the standby host device is reliably performed, thereby preventing the system from being destroyed. , Its system reliability is improved.

Further, in the redundant communication system of the present invention, any one of the plurality of active host devices having different processing operations is
If a failure occurs without returning the response message to the standby host device and the operating status data in the storage unit is not updated, the operation of the active host device is stopped by, for example, disconnection of power. After that, switching to the standby host device is executed.

As a result, the system is reliably switched to the standby host device, the system can be prevented from being destroyed, the system reliability is improved, and the standby host device is provided to a plurality of active host devices. For example, only one host device is required, and the configuration is simplified.

[0033]

Next, an embodiment of a duplex communication system according to the present invention will be described in detail with reference to the drawings. In the following text and figures, the same reference numerals are given to the same components as those in the conventional example (FIG. 4). FIG. 1 is a block diagram showing a configuration of a duplex communication system according to a first embodiment of the present invention. The redundant communication system includes an active host device 1 that normally executes a processing operation in a LAN, a standby host device 2 that switches and continues processing operation when a failure occurs in the active host device 1, and an active host device. An inter-system communication path 3 for transmitting a message and a response message between the device 1 and the standby host device 2,
It has shared disk devices 4 and 5 for storing operation status data of the active host device 1 and the standby host device 2. In this example, in order to improve the system reliability, two shared disk devices 4 and 5 are arranged to write and read the same operation status data.

Further, this duplex communication system is a LAN communication system.
A communication server (CS) 6 for transmitting data transmitted by the standby host device 2 through the transmission line 25 to the power supply control device 7 through the RS-232C interface (I / F); and an operation stop request signal from the communication server 6 Power supply control device 7 that controls the power cutoff for stopping the operation of the active host device 1 when the
And The active host device 1, the standby host device 2, and the communication server 6 are connected to the LAN transmission path 25 and execute data processing in the LAN.

The active host device 1 receives a failure detection message transmitted from the standby host device 2 and returns a response message to the standby host device 2; It has an operation status setting / acquisition unit 9 for transmitting and updating the operation system operation status data to the operation status storage files 12 and 13 of the devices 4 and 5 and taking in the operation system operation status data.

The standby host device 2 has a health check unit 10 for transmitting a failure detection message to the active host device 1 and receiving a response message returned by the active host device 1 after a predetermined time. Further, the operation status data stored in the operation status storage files 12 and 13 of the shared disk devices 4 and 5 sent from the operation host device 1 is read and acquired, and the own device is switched to process. The operation status data when the operation is continued is stored in the operation status storage files 12, 1 of the shared disk devices 4, 5.
3 is provided with an operation status setting / acquisition unit 11 to be sent out.

The communication server (CS) 6 has the L
The operation stop request data transmitted from the standby host device 2 through the AN transmission line 25 is converted into an operation stop request signal, and R
It has a data converter 14 for sending to the power supply controller 7 by S-232CI / F.

The power control unit 7 has a host stop unit 15 that cuts off the power supply to stop the operation of the active host device 1 when receiving the operation stop request signal from the communication server 6. .

Next, the operation of the first embodiment will be described. FIG. 2 is a flowchart showing a processing procedure of the operation of the first embodiment. 1 and 2, the standby host device 2 transmits a failure detection message to the active host device 1 via the inter-system communication path 3 at regular intervals. The active host device 1 receives this message,
In addition, a response message is returned to the standby host device 2 through the inter-system communication path 3. By receiving the response message from the active host device 1, the standby host device 2 recognizes that the active host device 1 is operating normally.

The active host device 1 sends active operating status data to the shared disk devices 4 and 5 at regular time intervals and updates them. After a timeout when the response message from the active host device 1 cannot be received (step S10), the standby host device 2 reads the active operating status data stored in the shared disk devices 4 and 5 (step S11). . Further, after a certain period of time, the standby system host device 2 reads the operating system operation status data stored in the shared disk devices 4 and 5 again (step S1).
2).

Next, the standby system host device 2 executes step S
The active system operation status data read in the process 11 is compared with the active system operation status data read next, and it is determined whether the data content has been updated (step S13). If the active system operation status data is updated in this determination (S13: Yes), the standby system host device 2 normally transmits the active system operation status data to the shared disk devices 4 and 5, and a failure occurs. It is recognized that a failure has occurred in the inter-system communication path 3. In this case, the standby host device 2
Does not switch the processing operation of the active host device 1 (step S14).

If the active system operation status data stored in the shared disk devices 4 and 5 has not been updated (No), the standby host device 2 operates the communication server 6 via the LAN transmission line 25 in step S13. Operation stop request data for stopping the processing operation of the system host device 1 is transmitted (step S15). The communication server 6 sends an operation stop request signal obtained by converting the operation stop request data to the power supply control device 7 (step S1).
6). Upon receiving the operation stop request signal from the standby host device 2, the power supply control device 7 controls the power cutoff for stopping the operation of the active host device 1 (step S1).
7). Next, the standby host device 2 is connected to the LAN transmission path 25.
When it is recognized that the operation of the active host device 1 has stopped, the switching is performed to continue the processing operation (step S18).

Next, the main part of the operation of the first embodiment will be described in detail. When a failure occurs in the inter-system communication path 3, the standby host device 2, when the heartbeat communication (health check) to the active host device 1 times out, the operation status storage file 1 of the shared disk devices 4 and 5.
The operational status data stored in the storage systems 2 and 13 is read. After the elapse of this predetermined time, the standby host device 2 again operates the operating status storage file 1 of the shared disk devices 4 and 5.
The operating system operation status data stored in the storage units 2 and 13 is read, and it is checked whether the data content is updated. When the active host device 1 is operating normally, the active operating status data stored in the operating status storage files 12 and 13 is updated.

If the operating status data stored in the operating status storage files 12 and 13 is normally updated, the standby host device 2 operates normally, and the standby host device 2 operates normally. It recognizes that a failure has occurred in the communication path 3. In this case, switching of the processing operation from the active host device 1 to the standby host device 2 is not executed.

If the active host device 1 stalls thereafter, the standby host device 2 stores the operating status storage files 12 and 13 of the shared disk devices 4 and 5 when the health check for the active host device 1 times out. Read the stored operating system operation status data. After a certain period of time, the standby host device 2 returns to the shared disk device 4,
The operating status data stored in the operating status storage files 12 and 13 is read, and an update of the data content is checked. In this state, the standby host device 2 cannot determine whether the processing operation of the active host device 1 is normal.
In this case, the processing operation of the active host device 1 is stopped. The standby host device 2 transmits to the communication server 6 operation stop request data for requesting to stop the processing operation of the active host device 1.

The data conversion unit 14 of the communication server 6 converts the operation stop request data received through the LAN transmission line 25 into an operation stop request signal, and outputs the operation stop request signal to the RS-232.
The information is transmitted to the power control device 7 through the CI / F. When receiving the operation stop request signal from the communication server 6, the host stop unit 15 of the power supply control device 7 cuts off the power supply to the active host device 1 and stops the processing operation of the active host device 1. Standby host device 2 is LAN transmission path 2
After recognizing that the active host device 1 has stopped the processing operation through 5, the switching of the processing operation from the active host device 1 to the standby host device 2 is executed.

When the standby host device 2 continues the processing operation in place of the active host device 1 due to the switching of the processing operation, the operation status data is transferred to the shared disk device 4 through the operation status setting / acquisition unit 11. , 5 to the operating status storage files 12 and 13 for storage. After the switching to the standby host device 2, for example, when the maintenance operator repairs the failure of the active host device 1 and restarts, the active host device 1 is restored to the standby host device 2. The message is transmitted through the inter-system communication path 3. When the standby host device 2 receives this recovery message, the execution of the process is stopped and a response message is transmitted to the active host device 1. Active host device 1
Receives the response message from the standby host device 2 and resumes the normal processing operation.

As described above, in the first embodiment, the active host device 1 does not return a response message for failure detection due to stall or the like to the standby host device 2 and operates the shared disk devices 4 and 5. If the active system operation status data stored in the status storage files 12 and 13 has not been updated, the operation of the active host device 1 is stopped by the interruption of power supply from the power supply control device 7. As a result, the active host device 1 and the standby host device 2 do not execute processing operations at the same time, and the switching to the standby host device 2 is performed reliably, thereby preventing the system from being destroyed. As a result, system reliability is improved.

FIG. 3 is a block diagram showing the configuration of the second embodiment. The second embodiment has a configuration in which one standby host device is provided for a plurality of active host devices. In the second embodiment, two active host devices 1 and 16 having different processing operations are provided. Further, it has shared disk devices 17 and 18 connected to the active host device 16 and the standby host device 2. Other configurations are the same as those of the first embodiment shown in FIG. That is, it has the shared disk devices 4 and 5, the communication server 6, and the power supply control device 7 together with the active host device 1 and the standby host device 2.

In the second embodiment, an inter-system communication path 3a using a LAN transmission path is provided in place of the inter-system communication path 3 of the first embodiment. A LAN transmission path 25b different from the inter-system communication path 3a is provided between the standby host apparatus 2 and the communication server 6. This is to make it possible to transmit operation stop request data from the standby host device 2 to the communication server 6 even when a failure occurs in the inter-system communication path 3a, thereby improving system reliability.

The active host device 1 is provided with a health check unit 8 and an operation status setting / acquisition unit 9, and the active host device 16 is also provided with a health check unit 19 and an operation status setting / acquisition unit 20. Is provided. Also,
The standby host device 2 is provided with a health check unit 10 and an operation status setting / acquisition unit 11, the communication server 6 is provided with a data conversion unit 14, and the power supply control device 7 is provided with a host stop unit 15. ing. The shared disk devices 17 and 18 are provided with operation status storage files 21 and 22, respectively.

Next, the operation of the second embodiment will be described. Here, the active host devices 1 and 16 are executing different processing operations. The health check unit 10 of the standby host device 2 transmits a failure detection message at regular intervals to the health check units 8 and 19 of the active host devices 1 and 16 via the inter-system communication path 3a of the LAN transmission path. . This message is sent to the active host devices 1, 1
6 are received by the health check units 8 and 19. Upon receiving this message, the health check units 8 and 19 of the active host devices 1 and 16 return a response message to the standby host device 2. As described above, the standby host device 2 monitors the processing operation of the active host devices 1 and 16 by transmitting and receiving the message and the response message between the standby host device 2 and the active host devices 1 and 16.

Further, the operating system host device 1 stores the operating status storage file 1 of the shared disk devices 4 and 5 at regular intervals.
The active status data is sent to the second and the third update.
Similarly, the active host device 16 also updates the operation status storage files 21 and 22 of the shared disk devices 17 and 18 at regular intervals.
Sends the operation status data to the system and updates it.

When the time-out occurs when the response message from the active host device 1 cannot be received, the standby host device 2 receives the active system operation data stored in the operation status storage files 12 and 13 in the shared disk devices 4 and 5. Read status data. Further, after a certain period of time, the standby system host device 2 reads the operational system operation status data stored in the operation status storage files 12 and 13 in the shared disk devices 4 and 5 again. The standby host device 2 compares the two operating status data before and after, and determines whether the data content has been updated.

If the active system operation status data is updated in this judgment, the active system operation status data is normally sent to the shared disk devices 4 and 5 to the active system host device 1 and a failure occurs. It is recognized that a failure has occurred in the inter-system communication path 3a. In this case, the standby host device 2
Does not switch the processing operation of the active host device 16.

If the operating status data stored in the operating status storage files 12 and 13 of the shared disk devices 4 and 5 is not updated, the standby host device 2 is connected to the communication server 6 via the LAN transmission path 25b.
The operation stop request data for stopping the processing operation of the active host device 1 is transmitted to the data conversion unit 14 of FIG. The data conversion unit 14 of the communication server 6 sends an operation stop request signal obtained by converting the operation stop request data to the power supply control device 7. When receiving the operation stop request signal from the standby host device 2, the power supply control device 7 controls the power cutoff to stop the operation of the active host device 1. Next, upon recognizing that the active host device 1 has stopped operating via the inter-system communication path 3a, the standby host device 2 executes switching to continue the processing operation.

The active host device 16 operates similarly to the active host device 1. That is, when a timeout occurs in which the response message from the active host device 16 cannot be received through the inter-system communication path 3a, the standby host device 2 stores it in the operation status storage files 21 and 22 of the shared disk devices 21 and 22. The operating system operation status data is read, and is read after a certain period of time. When the data content is updated, the active host device 1 recognizes that a failure has occurred in the inter-system communication path 3a. In this case, switching of the processing operation from the active host device 1 to the standby host device 2 is not executed.

When the operating status data stored in the operating status storage files 21 and 22 of the shared disk devices 21 and 22 are not updated, the standby host device 2 sends operation stop request data to the communication server 6. I do. The data conversion unit 14 of the communication server 6
An operation stop request signal is sent to the power supply control device 7, and the power supply control device 7 stops the operation by controlling the disconnection of power to the active host device 16. Next, when recognizing that the active host device 16 has stopped operating via the inter-system communication path 3a, the standby host device 2 executes switching to continue the processing operation.

After the switching to the standby host device 2 as described above, if the failure of the active host devices 1 and 16 is restarted after the failure has been recovered by the maintenance operator, for example, the active host device 1 , 16 transmit a recovery message to the standby host device 2 through the inter-system communication path 3a. When this standby message is received by the standby host device 2, the switched processing operation is stopped, and a response message is transmitted to the active host devices 1 and 16. Upon receiving the response message from the standby host device 2, the active host devices 1 and 16 resume the normal processing operation.

As described above, in the second embodiment, as in the first embodiment, the switching to the standby host device 2 is performed reliably, and the system can be prevented from being destroyed, thereby improving the system reliability. Further, one standby host device 2 is connected to the active host devices 1 and 16 having different processing contents.
The configuration is simplified when a standby host device is installed for each of the active host devices 1 and 16.

In the first and second embodiments, the host stop unit 15 of the power supply control unit 7 controls the disconnection of power to stop the operation of the active host device 1 when a failure occurs. Method is also acceptable. For example, the active host device 1
May be stopped. As a configuration in this case, a control device that captures an operation stop request signal from the communication server 6 when a failure occurs is provided, and the control device stops an operating system executed by a CPU (not shown) of the active host device 1. What is necessary is just to control it.

Further, in the first and second embodiments, when the standby host device 2 is operating as the active host device, the active host devices 1 and 16 return, and When a failure similar to that in the first and second embodiments occurs in the host device 2, the power supply from the power supply control device 7 to the standby host device 2 can be stopped.

In the first embodiment, two shared disk devices 4, 5 and 18 are used, and in the second embodiment, four shared disk devices 4, 5, 17 and 18 are used.
In other words, in order to enhance system reliability, a plurality of shared disk devices performing the same processing operation are used,
One is acceptable. In this case, a corresponding storage area is set for each of the active host devices 1 and 16 and the standby host device 2, and the operating status data is written and read for each of the storage regions.

In the second embodiment, one standby host device 2 is used for the active host devices 1 and 16. However, when a large number of active host devices 1 and 16 are arranged, For example, it is also possible to arrange two standby host devices so as to cope with a case where a plurality of active host devices have failed simultaneously.

[0065]

As is apparent from the above description, according to the duplex communication system of the present invention, the active host device
The response message is not returned to the standby host device, and
When a failure in which the active system operation status data is not updated occurs, the operation of the active host device is stopped, and thereafter, switching to the standby host device is executed.

As a result, the active host device and the standby host device do not execute the processing operations at the same time, and the switching to the standby host device is reliably performed, thereby preventing the system from being destroyed. And the system reliability is improved.

According to the redundant communication system of the present invention, any one of the plurality of active host devices having different processing operations does not return a response message to the standby host device, and operates in the storage means. When a failure in which the system operation status data is not updated occurs, the operation of the active host device is stopped, and after that, switching to the standby host device is executed.

As a result, the active host device and the standby host device do not execute processing operations at the same time as described above, and the switching to the standby host device is executed reliably, and the system is prevented from being destroyed. Became possible,
System reliability is improved. Further, for example, only one standby host device is required for a plurality of active host devices, and the configuration can be simplified.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a duplex communication system according to a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating a processing procedure of an operation according to the first embodiment.

FIG. 3 is a block diagram showing a configuration of a second embodiment.

FIG. 4 is a block diagram showing a configuration of a conventional duplex communication system.

[Explanation of symbols]

 1,16 Active host device 2 Standby host device 3,3a Inter-system communication path 4,5,17,18 Shared disk device 6 Communication server 7 Power control device 8,10,19 Health check unit 9,11 Operation status setting / Acquisition unit 12,13,20-22 Operation status storage file 14 Data conversion unit 15 Host suspension unit 25,25b LAN transmission path

Claims (15)

[Claims] 1. An active host device and a standby host device are connected by an inter-system communication path and a communication network.
And, in a redundant communication system that stores processing data of the active host device in the storage means and switches to the standby host device when a failure occurs in the active host device, the standby host device includes a message for detecting failure occurrence. Is transmitted to the active host device through the inter-system communication path, and the standby host device cannot receive a response message from the active host device, and the active operating status stored in the storage means. A redundant communication system, comprising: a switching unit that, when recognizing a failure that data has not been updated, stops the operation of the active host device and then switches to the standby host device. 2. A plurality of active host devices and at least one standby host device having different processing operations are connected by an inter-system communication network and a communication network, and
Store the processing data of the active host device in the storage means,
In a redundant communication system for switching to a standby host device when a failure occurs in an active host device, the standby host device sends a failure detection message to each of the plurality of active host devices. When the standby host device recognizes that a failure has occurred in which the standby system host device cannot receive the response message from the active system host device and the active system operation status data in the storage unit has not been updated, the failure occurs. A redundant communication system, comprising: a switching unit that switches to the standby host device after the operation of the active host device is stopped. 3. The standby host after the switching unit executes the switch to the standby host device, the standby host device continues the processing operation, and the active host device in which the failure has occurred is restored. 3. The duplex communication system according to claim 1, wherein when a failure occurs in the device, the standby host device is stopped, and thereafter, the switching to the active host device is performed. 4. A communication server for transmitting a signal requesting stop of operation of an active host device via a communication network when the standby host device recognizes that a failure has occurred, as the switching means; The duplex communication system according to claim 1 or 2, further comprising: an operation stop control device that controls to stop the operation of the active host device based on the operation stop request signal. 5. The power supply control device according to claim 4, wherein the operation stop control device includes a power supply control device that controls a power supply to an active host device based on an operation stop request signal from a communication server. The duplicated communication system according to claim 1. 6. The operation stop control device according to claim 1, further comprising a control device for performing control for stopping an operating system executed by an active host device based on an operation stop request signal from a communication server. 4. The duplex communication system according to 4. 7. A health check unit for transmitting and receiving a failure detection message and a response message to and from a standby host device via an inter-system communication path as the active host device; Send out the system operation status data,
In addition, the operation status setting that captures the operation system operation status data /
The duplex communication system according to claim 1, further comprising: an acquisition unit. 8. The standby system host device, comprising: a health check unit for transmitting and receiving a failure detection message and a response message to and from an active host device via an inter-system communication path; Send out the operation status data,
And an operation status setting / acquisition unit that captures the operation status data of the operation system, monitors the occurrence of a failure in the operation host device, and transmits operation stop request data through a communication network when the failure occurs. The duplex communication system according to claim 1. 9. A health check unit for transmitting / receiving a failure detection message and a response message to / from a standby host device through an inter-system communication network with each of the active host devices; And send the operational status data
In addition, the operation status setting that captures the operation system operation status data /
The duplex communication system according to claim 2, comprising: an acquisition unit. 10. A health check unit for transmitting / receiving a failure detection message and a response message to / from each of the standby host devices via an inter-system communication path with each of the active host devices; And send the operational status data
And an operation status setting / acquisition unit that captures the operation status data of the operation system, monitors the occurrence of a failure in the operation host device, and transmits operation stop request data through a communication network when the failure occurs. The duplex communication system according to claim 2. 11. The duplex communication system according to claim 1, wherein a local area network is used as the communication network and the inter-system communication network. 12. The duplex communication system according to claim 1, wherein a disk device having an operation status storage file for storing operation status data is used as the storage unit. 13. The duplex server according to claim 4, wherein the communication server has a data conversion unit for converting operation stop request data from a standby host device into a predetermined operation stop request signal and transmitting the signal. Communications system. 14. The power supply control device according to claim 4, further comprising: a host stop unit for performing control to stop power supply to an active host device based on an operation stop request signal from a communication server. Duplex communication system. 15. The duplex communication system according to claim 12, wherein at least two disk devices that write and read the same operation status data are used as said disk devices.