JPS6351303B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a computer network system in which a plurality of host computers and terminals are connected via a network so as to be able to exchange information with each other, and particularly relates to failure countermeasures for host computers.

In conventional computer systems, when a computer in operation breaks down, the line is switched using a switch, the terminal is switched to another computer prepared as a backup device, or the same data is sent to two computers at the same time. Countermeasures have been taken by storing the information in memory, and when one computer fails, the other computer is used.

However, these methods cannot necessarily be said to be optimal measures, as switching in the event of a failure is troublesome, and post-processing after system restoration is time-consuming. In particular, when the number of computers increases, it becomes extremely difficult to take measures against failures.

SUMMARY OF THE INVENTION An object of the present invention is to provide a computer network system in which even if any computer breaks down, it is easy to switch to another computer and the continuation of data processing is not hindered. be.

Therefore, in the present invention, in a computer network system in which a plurality of host computers and terminals are connected to the network via network interfaces, data from the terminals is transferred to an address set in the network interface. At the same time, this host computer transfers the same data to another host computer for storage, and when the first host computer fails, the network interface By changing the address set in the host computer, switching the connection of the terminal to the other host computer, and continuing processing instructions from the terminal using the data stored in the other host computer, It is an attempt to achieve a goal.

In short, data from a terminal is stored in at least two host computers, and when one host computer that operates according to commands from the terminal fails, for example, data from the terminal is stored in the network interface according to commands from the terminal. By changing the set address from one host computer to another, you can easily switch computers, and when the address is changed to another host computer, the data stored in the other host computer can be changed. By processing commands from the terminal using , data processing can be continued without any problems.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 shows the computer network system of this embodiment. The system includes a local area network 1 configured by coaxial cables, network interfaces 2 ₁ , 2 ₂
Host computers 3 ₁ and 3 ₂ are connected via network interfaces 4 ₁ and 4 2 , respectively, and terminals 5 1 and 5 ₂ having input/output devices such as keyboards and CRTs are connected via network interfaces 4 ₁ and 4 ₂ .
are connected to each other.

Each of the network interfaces 2 ₁ , 2
₂ , 4 ₁ and 4 ₂ are each provided with storage areas for storing the addresses of network interfaces 2 ₁ , 2 ₂ , 4 ₁ and 4 ₂ for exchanging information in advance, as well as devices connected to these. In other words, it executes instructions from a host computer or terminal,
Each network interface has a built-in network processor that exchanges information with each other. the network interface 4 ₁ ,
When the address codes of the network interfaces 4 _{1 and} 4 2 for exchanging information are input from the keyboards of the connected terminals 5 ₁ and 5 ₂ , the network processor 4 ₂ stores the addresses in the storage area. to be memorized. Here, the address of network interface ₂₁ is stored in advance in the storage area of network interface ₄₁ .
The addresses of the network interfaces ₂₂ are set in the storage areas of the network interfaces ₄₂ , respectively. Thus, in a normal state, data from the terminal 5 ₁ is processed by the host computer 3 ₁ and data from the terminal 5 ₂ is processed by the host computer 3 ₂ .

Further, the host computer 3 ₁ includes a pair of magnetic disk devices 6 _1A and 6 _1B , and the terminal 5 ₁
The data provided from the computer via the local area network 1 is stored in the magnetic disk device _61A , and is transferred to the host computer ₃₂ via the local area network 1.
Data transferred from the host computer ₃₂ is stored in the magnetic disk device _61B . During this time, the host computer ₃₁
The status of the magnetic disk devices 6 _1A and 6 _1B is monitored, and when a failure is detected in either of them, an abnormality response signal is sent to the terminal 5 ₁ through the network interface 4 ₁ . As a result, when the terminal 5 ₁ receives an abnormal response signal from the host computer 3 ₁ ,
Or, when there is no reception response signal from the host computer 3 ₁ in response to data transmission etc. to the host computer 3 ₁ , it is determined that a failure has occurred on the host computer 3 ₁ side, and a message to that effect is sent, for example.
It is now displayed on CRTs, etc.

Further, the host computer 3 ₂ includes a pair of magnetic disk devices 6 _2A and 6 _2B , and the terminal 5 ₂
The data provided from the computer via the local area network 1 is stored in the magnetic disk device _62B , and is transferred to the host computer ₃₁ via the local area network 1.
Data transferred from the host computer ₃₁ is stored in the magnetic disk device _62A . During this time, host computer ₃₂
The status of the magnetic disk devices 6 _2A and 6 _2B is monitored, and when a failure is detected in either one, an abnormality response signal is sent to the terminal 5 ₂ through the network interface 4 ₂ . As a result, when the terminal 5 ₂ receives an abnormal response signal from the host computer 3 ₂ ,
Alternatively, when there is no reception response signal from the host computer ₃₂ in response to data transmission to the host computer ₃₂ , it is determined that a failure has occurred in the host computer ₃₂ , and a message to that effect is sent to the CRT, for example.
etc. are now displayed.

Next, the operation of this system will be explained. Now, in a normal state, when data is input from the terminal ₅₁ , the data is processed according to the flowchart shown in FIG. That is, when data is input from the terminal 5 ₁ , the network interface 4 ₁
Data from the terminal ₅₁ is transmitted through the network 1 to the network interface ₂₁ specified by the address of the storage area. Data received at the network interface ₂₁ is input to the host computer ₃₁ . Then, the host computer 3 ₁ stores the data given from the terminal 5 ₁ in the magnetic disk device 6 _1A , and then transfers it to the host computer 3 ₂ via the network interfaces 2 ₁ and 2 ₂ and the local area network 1. As a result, the host computer ₃₂ transfers the data transferred from the host computer ₃₁ to the magnetic disk device _62A.
to be memorized. On the other hand, data input from the terminal 5 ₂ is stored in the magnetic disk device 6 _2B of the host computer 3 ₂ and then transferred to the host computer 3 2.
₁ is transferred to and stored in the magnetic disk device 6 _1B .
In this manner, during normal operations, data input from either terminal 5 ₁ or 5 ₂ is simultaneously stored in the magnetic disk devices of the two host computers 3 ₁ or 3 ₂ .

Here, for example, if host computer ₃₁ fails,
Alternatively, when a failure occurs in the magnetic disk devices 6 _1A and 6 _1B , a message is displayed on the terminal 5 ₁ indicating that the host computer 3 ₁ is out of order, that is, information cannot be exchanged with the host computer 3 ₁ . Therefore,
As shown in the flowchart of Figure 3, from the keyboard of terminal 5 ₁ to network interface 2
When the address code _{No. 2} is input, it is input from the terminal ₅₁ into the storage area of the network interface ₄₁ and the address code is set. As a result, the terminal 5 ₁ is switched to the host computer 3 ₂ via the network interfaces 4 ₁ and 2 ₂ , and henceforth data from the terminal 5 ₁ is processed by the host computer 3 ₂ .

During this time, the failed host computer ₃₁ is repaired. At this point, the repair of the host computer 3 ₁ is completed, and a data request command is sent from the host computer 3 ₁ to the network interfaces 2 ₁ , 2 _{2 .}
When the data is sent to the host computer 3 ₂ via the local area network 1, the host computer 3 ₂ transfers the data stored in the magnetic disk devices 6 _2A and 6 _2B to the host computer 3 ₁ . This allows host computer 3 ₁
stores the data from the host computer 3 ₂ in the magnetic disk devices 6 _1A and 6 _1B , and restores the data.

After this, in the terminal ₅₁ , change the address code of the storage area of the network interface ₄₁ to the address code of the network interface ₂₁ , and switch the terminal ₅₁ to the host computer ₃₁ . The data from ₁ can be processed again by the host computer ₃₁ . In other words, it is possible to return to normal business.

Therefore, according to the system of this embodiment, the host computers 3 ₁ , 3 ₂ and the terminals 5 1 , 5 ₂ are connected to the local area network 1 via the network interfaces 2 _{1 ,} 2 ₂ , _{4 1} , 4 _{2 .} The data input from each terminal 5 ₁ , 5 ₂ is stored in the magnetic disk devices of both host computers 3 ₁ , 3 ₂ respectively.For example, the host computer 3 ₁ being used from the terminal 5 ₁ is When a failure occurs in the host computer ₃₁ , or when the data stored in the magnetic disk devices _61A and _61B of the host computer 31 is destroyed, the destination address of the network interface ₄₁ is changed and the terminal ₅₁ Since the data from the host computer 32 is processed by the host computer ₃₂ , even if one of the host computers ₃₁ , ₃₂ fails or data is destroyed, data processing can be continued by the other host computer.

At this time, the address set in the network interface ₄₁ is changed by a command from the terminal ₅₁ , and the address set in the network interface ₄₂ is changed by a command from the terminal ₅₂ . Therefore, even if the terminals 5 ₁ , 5 ₂ and the host computers 3 ₁ , 3 ₂ are far apart, the currently used terminal 5
Since switching is possible between ₁ and 5 ₂ , switching in the event of a failure is extremely easy.

Moreover, since the same data is held in the magnetic disk devices of the two host computers 3 ₁ and 3 ₂ , even if the host computers are switched, the data including the data accumulated up to that point will be retained. Since subsequent data processing can be continued, highly reliable data processing is possible.

Another advantage is that a failed host computer can be restored while maintaining the functions of other systems.

In the above embodiment, two host computers 3 ₁ , 3 2 and two terminals 5 ₁ are connected to the local area network ₁ via network interfaces 2 ₁ , 2 ₂ , 4 ₁ , 4 ₂ , respectively. , ₅₂ , but even if there are three or more host computers, it can be handled by adding network interfaces. In FIG. 4, N host computers 3 are connected to a local area network 1 via network interfaces ₂₁ to _2o .
₁ to 3 _o , and N terminals 5 ₁ to 5 _o via network interfaces 4 ₁ to 4 _o.
An example is shown in which . In this case, terminal 5 ₁
The data from the terminal ₅₂ is transferred to the magnetic disk devices 6 _1A and 6 _oB of the host computers 3 1 and 3 _o , and the data from the terminal 5 ₂ is transferred to the magnetic disk devices 6 _1B and 6 _2A of the host computers 3 ₁ and 3 ₂ , and the terminal 5 ₃ Data from the host computers 3 ₂ , 3 ₃ magnetic disk devices 6 _2B ,
6 _3A , etc., so that it is held simultaneously by at least two host computers.

Furthermore, in the above embodiment, the host computer 3
₁ and 3 ₂ , the network interface 4 ₁ and 4 ₂ can be accessed from the keyboard of each terminal 5 ₁ and 5 _2.
address was changed and each terminal 5 ₁ , 5 ₂ was switched to another host computer, but for example, an abnormal response from the host computer exchanging information on each network interface 4 ₁ , 4 ₂ . When a signal is received, if the address set in the storage area is changed and set to another address, the computer can be automatically switched in the event of a failure.

Furthermore, it is not necessary to provide the terminal in a 1:1 relationship with the host computer. For example, one host computer may process data from multiple terminals.

Further, in the above embodiment, each host computer 3 ₁ , 3 ₂ is described as having two magnetic disk devices, but the number of these magnetic disk devices may be one. In this case, the storage area may be allocated so that the data of at least two host computers can be shared. Also,
The storage means is not limited to the magnetic disk device described in the above embodiment.

Furthermore, due to the nature of local area networks,
It is not necessarily necessary to shorten the distance between host computers or terminals.

As described above, the present invention provides a computer network in which even if any computer fails, it is easy to switch to another computer and data processing can be continued including data accumulated up to that point. system can be provided.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention;
FIG. 2 is a flowchart showing data processing in a normal state, FIG. 3 is a flowchart showing data processing in an abnormal state, and FIG. 4 is a block diagram showing another embodiment. 1...Local area network, 2 _1-2
o , 4 ₁ to 4 _o ...Network interface,
3 ₁ ~ 3 _o ... host computer, 5 ₁ ~ 5 _o ......
Terminal, 6 _1A , 6 _1B , 6 _2A ,...6 _oB ...Magnetic disk device.

Claims (1)

[Claims] 1. In a computer network system in which a plurality of host computers and terminals are connected to a network via network interfaces, data from the terminals is set to the network interface. The data is stored in one host computer specified by the address, and the same data is transferred and stored in another host computer by this host computer, so that when the one host computer fails, the network interface The method is characterized in that the address set in the face is changed, the connection of the terminal is switched to the other host computer, and the processing of the command from the terminal is continued using the data stored in the other host computer. computer network system. 2. The computer network system according to claim 1, wherein the address set in the network interface is changed by a command from the terminal.