JPH1131085A - Duplex system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a system that performs data access in a short time even when system change is performed from an operation system to a standby system. SOLUTION: Data is simultaneously written to memory devices 21 and 22 during the operation of an operation system 10. An I/O device 14 reads data from the device 12 during the operation of the system 10. An I/O device 24 of a standby system 20 reads data from the device 22 of the system 20 when system change is performed from the system 10 to the system 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a redundant system comprising a computer system having a redundant redundant configuration, and more particularly to a data access configuration thereof.

[0002]

2. Description of the Related Art A duplex system in which a standby computer system is provided in addition to an operating computer system to improve the reliability of the system is widely used.

FIG. 2 is a configuration diagram of a conventional duplex system. In the figure, reference numeral 100 denotes an active computer system and 200 denotes a standby computer system, which have the same device configuration. That is, the operation system 100 includes a CPU device 101, a memory device 102, a system connection device 103, an I / O
O system 104, system bus 105, standby system 2
00 is a CPU device 201, a memory device 202, a system connection device 203, an I / O device 20
4. It comprises the system bus 205.

[0004] The CPU devices 101 and 201 are processors that execute arithmetic processing and the like. Memory devices 102, 20
Reference numeral 2 denotes a main storage device for storing an execution program of the computer system, data, and the like. System connection device 10
3 and 203 are operating systems 100 in the redundant system.
This is a control device for connecting the system bus and the standby system 200, and connects the system bus 105 and the system bus 205. The I / O devices 104 and 204 include the CPU device 101,
An apparatus that transfers data between the input / output port and the memory devices 102 and 202 under software control of the software 201. The system buses 105 and 205 are buses for connecting the CPU devices 101 and 201, the memory devices 102 and 202, the system connection devices 103 and 203, and the I / O devices 104 and 204.

In the redundant system configured as described above, while the operating system 100 is operating, the CP of the standby system 200 is
The U device 201 is disconnected from the system bus 205. Then, the CPU device 101 of the operation system 100
Can read and write to each device connected to the operation system 100, and can read and write to each device connected to the standby system 200 using the system connection devices 103 and 203.

When a hardware failure and a software failure are detected in the active system 100, the active system 100 and the standby system 20
0, and the operation state shifts to the old standby system 200. In this case, the active system memory area stored in the memory device 102 connected to the active system 100 and the standby system Since the same program and data are stored in the standby memory area stored in the memory device 202 connected to the
The execution process is continued even if the operation state is shifted to 0.

[0007] The above-mentioned memory double writing configuration means that the operating system 1
In order to match the contents of the memory device 102 connected to the standby system 200 with the contents of the memory device 202 connected to the standby system 200, when writing to the memory device 102 connected to the active system 100 occurs, the same data is written. This is also performed for the memory device 202 connected to the standby system 200.

I / O device 10 connected to operation system 100
4 is a system bus 105 from the active memory area stored in the memory device 102 connected to the active system 100.
The data is read out through an access route A (shown by a broken line in the figure) using
The O device 204 converts the system bus 105 of the active system 100 and the system connection devices 103 and 2 from the active system memory area stored in the memory device 102 connected to the active system 100.
03 and the system bus 205 connected to the standby system 200
Via an access route B (shown by a broken line in the figure),
Data was being read.

[0009]

However, in the above-described conventional redundant system, when the I / O device 204 connected to the standby system 200 reads data from the memory device, the data access to the operating system 100 is performed. Since the data is read from the memory device 102 to be read, there are the following problems.

That is, data read from the memory device 102 of the active system 100 by the I / O device 204 connected to the standby system 200 is performed by the system connection device 203 of the standby system 200 and the system connection device 103 of the active system 100. Data access takes a lot of time to be accessed via
As a result, the performance of the duplex system was reduced.

[0011] From such a point, from the working system to the standby system,
It has been desired to realize a duplex system that can improve the performance of the system without requiring much time for data access even when system switching is performed.

[0012]

The present invention employs the following structure to solve the above-mentioned problems. <Structure of Claim 1> In a redundant system which comprises an active system and a standby system each having a memory device, and writes data to each memory device simultaneously for both the active system and the standby system, Each of the I / O devices of the standby system and the standby system is configured to read data from its own memory device.

<Explanation of Claim 1> In the invention of claim 1,
When the system switching is performed, the old standby I / O device reads data from the old standby memory device. here,
Since the same data is written in the memory device as in the active memory device, the operation after system switching can be performed in the same manner as the operation in the old active system. According to the first aspect of the present invention, by such an operation, even when the old standby system after the system switching is operated, data can be read from the memory device in a shorter time as compared with the related art. Performance can be improved.

<Structure of claim 2> In claim 1, when the system is switched from the active system to the standby system, it is checked whether the data in the memory devices of both the active system and the standby system match. If the data does not match, the old standby I / O
The apparatus is a duplex system including data read control means for controlling data read from the old active memory device.

<Explanation of Claim 2> According to the invention of claim 2, in addition to the invention of claim 1, after the system switching, the data of the memory devices of the old working system and the old standby system do not match by the data read control means. In this case, the old standby I / O device reads data from the old active memory device. By such an operation, when switching to the standby system, for example, even when a hardware failure or the like occurs in the memory device of the old standby system, it is possible to prevent the redundant system itself from going down, and therefore, as a redundant system, Can be improved in reliability.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. << Example 1 >><Configuration> FIG. 1 is a configuration diagram showing Example 1 of a duplex system according to the present invention. The system shown in the figure comprises a computer of an active system 10 and a computer system of a standby system 20 and has the same device configuration. That is, the operation system 10
Are a CPU device 11, a memory device 12, and a system connection device 1.
3, the I / O device 14 and the system bus 15, and the standby system 20 includes the CPU device 21, the memory device 22, the system connection device 23, the I / O device 24, and the system bus 25, similarly to the active system 10. .

The CPU devices 11 and 21 are processors for executing arithmetic processing and the like, and perform access control and the like to the memories of the I / O devices 14 and 24. The I / O device 14 is in the memory device 12 of the active system 10, and the I / O device 24 of the standby system 20 is in the standby system 20.
Access control to read data from the memory device 22.

The memory devices 12 and 22 are main storage devices for storing execution programs, data, and the like of the computer system. The memory regions of the memory devices 12 and 22 include an active memory region and a standby memory region. Each is prepared.

FIG. 3 is an explanatory diagram of a memory area. As shown, the active memory area 301 starts from address 00000000.
The address 20000000 and the standby memory area 302 are set from addresses 80000000 to A00000000, and data is stored in this area.

The system connection devices 13 and 23 are control devices for connecting the operation system 10 and the standby system 20 in the redundant system, and connect the system bus 15 and the system 25. The I / O devices 14 and 24 are the CPU device 1
A device for transferring data between an input / output port and the memory devices 12 and 22 by software control of
For example, it is a SCSI device or the like. System bus 15, 25
Are the CPU devices 11 and 21 and the memory device 12
22, system connection devices 13, 23, and I / O devices 14, 2
4 is a bus for connecting the C.I.

<Operation> In the redundant system configured as described above, while the operation system 10 is operating, the CPU device 21 of the standby system 20 is disconnected from the system bus 25 as in the related art. And the CP of the operation system 10
The U device 11 can read and write each device connected to the operation system 10, and can read and write each device connected to the standby system 20 using the system connection devices 13 and 23. .

The I / O device 14 connected to the active system 10 is connected to the system bus 1 from the active memory area 301 stored in the memory device 12 connected to the active system 10.
In the access route A using 5 (shown by a broken line in the figure),
Read data.

In this state, if a hardware failure or a software failure is detected in the active system 10, the active system 1
0 and the standby system 20 are switched, and the operation state shifts to the old standby system 20. Here, in this specific example, the I / O device 24 connected to the old standby system 20 is
The data is read from the standby memory area 302 stored in the access route B (shown by a broken line in the figure) via the system bus 25.

<Effects> As described above, according to this example, the I / O device 24 connected to the standby system 20 is connected to the standby system 20 without passing through the system connection devices 13 and 23. Read the data of the memory device 22
The access time is shorter than reading data from the memory device 12 connected to the operating system 10 via the system connection devices 13 and 23, and the performance of the system can be improved.

<< Specific Example 2 >> In the specific example 2, in addition to the configuration of the specific example 1, when system switching is performed, it is determined whether or not the data of the memory devices of both the active system and the standby system match. Collate,
If the data does not match, the old standby I / O device is configured to read data from the old active memory device.

<Structure> FIG. 4 is a diagram showing the structure of a second embodiment of the duplex system according to the present invention. The illustrated system includes a computer of an active system 10a and a computer system of a standby system 20a, and both systems have the same device configuration. Also, C in the active system 10a and the standby system 20a
Since the configurations of the PU devices 11, 21 to the system buses 15, 25 are the same as those in the first embodiment, the description thereof is omitted here.

When the system switching from the active system 10a to the standby system 20a is performed, the data readout control means 17 and 27 provided in the active system 10a and the standby system 20a store the memories of both the active system and the standby system. It is checked whether or not the data of the devices 12 and 22 match, and if the data does not match, the I / O device 24 of the old standby system 20a sets the old active system 1
0a, which is a means for controlling data to be read from the memory device 12a.
This is realized by software control by the CPUs 1 and 21.

<Operation> In the duplex system configured as described above, the operation of the standby system 20a while the operating system 10a is operating is the same as that of the first embodiment. That is, data is simultaneously written to the memory devices 12 and 22 of both systems.

When the system is switched from the active system 10a to the standby system 20a, the data read control unit 27 of the standby system 20a checks whether the data stored in the memory devices 12 and 22 match. I do. Where
Before the system switching, the data read control unit 17 of the active system 10a has confirmed that the data match, so that there is no data mismatch. Therefore, the I / O device 24 of the standby system 20a is controlled by the CPU device 21 so that data is read from the memory device 22. That is, the access route to the memory device 22 is as shown in B. Then, the CPU device 21 of the old standby system 20a
Indicates that when data writing occurs, the memory device 22
And the memory device 1 of the old operating system 10a
Repeat for 2.

On the other hand, after the system switch to the standby system 20a, if the data in the memory device 22 and the data in the memory device 12 do not match due to a hardware failure of the memory device 22, etc., the data read control means 27 Control is performed such that data is read from the O device 24 not from the memory device 22 but from the memory device 12 by the access route C. As a result, even if the memory device 22 of the standby system 20a fails, it is possible to prevent the redundant system itself from going down, and to further improve the reliability of the redundant system.

Also, the old standby system 20a to the old active system 10a
When the system switching is performed, that is, when the state returns to the state before the system switching, the data read control unit 17 of the new active system 10a determines the coincidence of the data in the memory devices 12 and 22, and If they do not match, the I
The / O device 14 controls to read data from the memory device 22 of the standby system 20a.

<Effects> As described above, according to the second embodiment, the data read control means 17 and 27 are provided to check whether the data stored in the active and standby memory devices match. If they do not match, data is read from the memory device on the standby side, so that the reliability of the duplex system can be improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a specific example 1 of a duplex system according to the present invention.

FIG. 2 is a configuration diagram of a conventional duplex system.

FIG. 3 is an explanatory diagram of a memory area in the duplex system of the present invention.

FIG. 4 is a configuration diagram of Example 2 of the duplex system of the present invention.

[Explanation of symbols]

 10, 10a Operating system 12, 22 Memory device 14, 24 I / O device 20, 20a Standby system

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hiroshi Takeuchi 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd.

Claims (2)

[Claims] 1. A redundant system comprising an active system and a standby system each having a memory device, wherein data writing to each of the memory devices is performed simultaneously for both the active system and the standby system. A redundant system, wherein each of the I / O devices of the system and the standby system is configured to read data from the memory device of its own system. 2. The system according to claim 1, wherein when system switching is performed from the active system to the standby system, it is checked whether data in the memory devices of both the active system and the standby system match, and If there is a mismatch, the old standby I / O device is provided with data read control means for controlling to read data from the old active memory device.