JPH0652120A - Telegraphic message processing synchroning method between computers - Google Patents

Abstract

PURPOSE:To permit respective computers to receive telegraphic message respective terminals and to process them in the same order in a computer network system. CONSTITUTION:The computers 1 and 2 have the data bases 3 and 4 of the same content. Terminals 5 and 6 are connected to the computers 1 and 2 through a transmission path network 10. The priority of the computer 1, is assumed to be higher between the computers 1 and 2. The terminals 5 and 6 respectively transmit the telegrams A, B and C and D. The computers 1 and 2 respectively receive the telegrams. The computer 1 adds processing serial numbers to the received telegrams, informs the computer 2 of them, processes the received telegram in accordance with the processing serial numbers and updates the data base 3. The computer 2 rearranges the received telegram in accordance with the informed processing serial numbers, processes the telegraphic message and updates the data base 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for synchronizing message processing between computers, and more specifically, a plurality of computers each have a database having the same contents, and even if some computers stop operation due to a failure or the like. The present invention relates to a processing method for guaranteeing the consistency of database information between computers in a computer network system that allows the remaining normal computers to continue service.

[0002]

2. Description of the Related Art In a computer network system composed of a plurality of terminals and a plurality of computers each having a database of the same contents, each computer normally processes the processing request message from the terminals in parallel, When the above computer stops its operation due to a failure or the like, the remaining normal computers will process the processing request message from the terminal. In this case, in order to keep the database information of each computer consistent, each computer must process the processing request messages from the terminals in the same order, but the delay of the transmission line network between the terminals and each computer Due to time lag or the like, the order in which the processing request messages from a plurality of terminals arrive at each computer may not necessarily match.

FIG. 2 is a diagram for explaining this. 1 and 2 are computers, 3 and 4 are databases having the same contents, 5 and 6 are terminals,
10 is a transmission line network. In the example of FIG. 2, the terminal 5 sends a message A,
When B is transmitted and the terminal 6 transmits the telegrams C and D, the computer 1 arrives at the computer 1 in the order of “A, B, C, D”, but due to the delay time difference of the transmission line network 10, the computer 2 is transmitted. Is "A,
It shows that the data arrives in the order of C, B, D ". When the computers 1 and 2 process the electronic messages in the order of arrival, the contents of the databases 3 and 4 do not match.

Conventionally, in this type of computer network system, the following method has been used in order to make the processing order of electronic messages in each computer the same.

In the first method, as shown in FIG. 3, all terminals (5, 6 ...) In the network system are normally set to 1
Connected to only one computer 1, the processing request message from each terminal is processed by the computer 1, and the processing result is notified from the computer 1 to the computer 2 to which the terminal is not connected, and the computer 2 notifies from the computer 1. By updating the own database 4 according to the processing result, the database information between the computers is made to match.

In the second method, as shown in FIG. 4, a sub-center 7 is provided between the terminals (5, 6 ...) And the computers 1 and 2, and a processing request message from each terminal is once transmitted by the sub-center 7. By receiving and notifying the computers 1 and 2 from the sub-center 7 at the same time, the processing order of the processing request messages in the computers 1 and 2 is matched, and the database information between the computers is matched.

[0007]

In the above prior art, in the first method, when the computer connected to the terminal stops its operation due to a failure or the like, the information on the electronic message being processed by the computer at that time is There is a problem of being lost. Further, when the computer is stopped due to a failure or the like, in order to continue the service by another computer, it is necessary to reconnect all the terminals to the computer, which causes a problem in operability. is there.

On the other hand, in the second method, since the sub-center always notifies each computer of the processing request message from each terminal,
Even if the operation of one computer is stopped due to a failure, the service can be continued by the other computer, and the information of the telegram being processed at the time of the failure will not be lost. However, since the communication between each terminal and each computer passes through the subcenter, the reliability of the network system is greatly affected by the reliability of the subcenter. For this reason, it is necessary to make a redundant device configuration or the like in order to improve the reliability of the sub-center, which causes a problem of a large investment.

The object of the present invention is to enable all computers to directly receive the processing request message from each terminal and process them in the same order without providing a sub-center between the terminals and the computer. It is an object of the present invention to provide a message processing synchronization method between computers, which makes it possible to economically realize a highly reliable computer network system in which the service of another computer can be continued even if the computer becomes an obstacle.

[0010]

In order to achieve the above object, the present invention allows all computers in a computer network system to receive a processing request message from each terminal, and the computers in advance need to receive the processing request messages. That is, the priority order is set, the computer having the highest priority order determines the processing order of the received message, and notifies the other computers of this processing order.

Further, according to the present invention, when the computer with the highest priority stops its operation due to a failure or the like, the computer with the next highest priority determines the processing order of the received message and notifies the other normal computers. That is what I did.

[0012]

Operation: The computer with the higher priority processes the received message according to the processing order determined by itself, and updates its own database. Each of the other computers processes the received message according to the processing order notified from the computer with the higher priority, and updates its own database. As a result, all the computers in the computer network system can process the processing request messages from each terminal in the same order, and the consistency of the database information between the computers can be secured.

Further, according to the present invention, the processing request message from each terminal is received by each of the plurality of computers and is processed in the same manner by each computer. Therefore, even if a failure occurs in some computers, the processing of the message is performed. No content is lost. Furthermore, since each terminal is directly connected to each computer, a sub-center that requires high reliability is unnecessary.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of a computer network system for explaining a method for synchronizing message processing between computers according to the present invention. In FIG. 1, computers 1, 2
Respectively have databases 3 and 4 having the same contents. Further, a communication line 8 is provided between the computers 1 and 2 to notify the processing order of electronic messages. Terminal (5, 6 ...
.) Is connected to both the computers 1 and 2 via the transmission line network 10. In the following description, it is assumed that the computer 1 has a high priority among the computers 1 and 2. There are various methods for determining the priority order among the computers, such as a method of determining by the device address and a method of prioritizing the one declared earlier in time, and any method may be used.

The processing request message from each terminal (5, 6 ...) Is notified to both the computers 1 and 2. The notification of the processing request message from each of the terminals (5, 6 ...) To the computer 1 and the computer 2 may be performed sequentially (notifying the computer 1 and then the computer 2). Any existing method may be used depending on the notification method between the computers. In FIG. 1, similarly to FIG. 2, the terminal 5 outputs the electronic messages A and B, the terminal 6 outputs the electronic messages C and D, and the computer 1 outputs A, B, and
It shows that the data has arrived in the order of C, D and in the order of A, C, B, C at the computer 2.

FIG. 5 shows a processing flow of the computer 1. When the computer 1 having a high priority receives a processing request message from the terminal (step 101), first, a serial number for performing processing (processing sequence number) is given in the order of arrival of the message (step 102). The arrival order of the electronic messages on the computer 1 is A, B, C, D, and the processing serial numbers are in the order of arrival.
, Is added. Next, the computer 1 notifies the other computer 2 of the processing serial number assigned to each electronic message via the communication line 8 (step 103), and also processes each electronic message in accordance with the processing serial number to make its own database 3 Is updated (step 104). Note that the computer 1 is the other computer 2
At the time of notifying the processing serial number to the other computer, the processing serial number and the information for identifying the electronic message (the electronic message indicator, the requesting terminal number, etc.) are also included so that the processing serial number in the other computer 2 can be associated with the received electronic message. To notify you.

FIG. 6 shows a processing flow of the computer 2. When the computer 2 having a low priority receives a message from the terminal (step 201), it retains it once in the buffer. The order of arrival of electronic messages on computer 2 is A, C, B, D
Is. After that, when the notification of the processing sequence number of the electronic message is received from the computer 1 having a high priority through the determination in step 202 (step 203), the received electronic messages on the buffer are rearranged according to the processing sequence number specified by the computer 1. (Step 204), the processing of the electronic message is executed in accordance with the rearranged order, and the own database 4 is updated.
Here, the received telegrams A, C, B, C are rearranged as A, B, C, D by the telegram indicators a, b, c, d from the computer 1 and the processing serial numbers ,, and are processed in this order. To be done.

In this way, the computer 1 processes the received message in the processing order determined by itself, while the computer 2 determines the processing sequence number determined by the computer 1 even if the arrival of the received message differs from that of the computer 1. According to the above, since the received message is processed in the same order as that of the computer 1, it is guaranteed that the information in the databases 3 and 4 of the computers 1 and 2 always matches. Further, in the computers 1 and 2, each terminal (5, 6 ...)
Since the processing request message from each terminal is received, even if one of the computers stops operating due to a failure or the like, the information of the processing request message from the terminal is not lost.

Next, referring to FIG. 6, the processing in the computer 2 when the computer 1 is stopped due to a failure will be described. The computer 2 receives the failure stop notification from the computer 1 with a high priority (YES in step 202), and if it is the computer with the highest priority among the normally operating computers (YES in step 211), the subsequent reception The processing serial number is given to the electronic message and the processing serial number is notified to another computer (steps 212 and 213), the received electronic message is processed according to the processing serial number, and the own database 4 is updated (step 205). If there is another computer having a higher priority than itself among the computers in normal operation, the computer 2 will be notified of the processing serial number from the computer in step 203. This ensures the consistency of the database information among the remaining computers.

[0020]

According to the first aspect of the present invention, all computers in the computer network system process the processing request messages from the terminals in the same order even without going through a sub-center or the like which requires high reliability, Consistency of database information between computers can be secured. In addition, since each computer in the computer network system receives the same message from each terminal and processes it, even if some computer fails, the information of the message that was being processed at the time of failure will be lost. Nor.

According to the second aspect of the present invention, even when the computer with the highest priority has stopped operating due to a failure or the like, the processing request message from the terminal is transmitted to each of the remaining normal computers in the computer network system. Process in the same order,
Since the consistency of the database information between those computers can be similarly ensured, the service can be continued.

As described above, according to the inventions of claims 1 and 2, it is possible to economically realize a highly reliable computer network by using a relatively inexpensive general computer.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a computer network system configuration for explaining a message processing synchronization method between computers according to the present invention.

FIG. 2 is a diagram illustrating a problem of a message processing order in a computer network system having a plurality of terminals and a plurality of computers.

FIG. 3 is an example of a conventional computer network system configuration, and is a diagram in which all terminals are connected to one computer.

FIG. 4 is a diagram showing an example of a conventional computer network system configuration, in which a sub-center is provided between a terminal and a computer.

FIG. 5 is a diagram showing an example of a processing flow in a computer with a high priority in the method of the present invention.

FIG. 6 is a diagram showing an example of a processing flow in a computer with a low priority in the method of the present invention.

[Explanation of symbols]

 1, 2 Computer 3,4 Database 5,6 Terminal

Claims (2)

[Claims] 1. A computer network system comprising a plurality of terminals and a plurality of computers each holding a database of the same contents, and which enables other computers to continue service even if some computers stop operating. In, set the priority order in advance between multiple computers,
Each computer receives the processing request message from the terminal, and the computer with the highest priority determines the processing order of the received processing request message and notifies the other computers with lower priorities of the processing order. The processing request message is processed in the determined processing order, and each low priority computer processes the received processing request message according to the processing order notified from the high priority computer. A method for synchronizing message processing between computers. 2. When the computer with the highest priority has stopped operating, the processing order of the processing request message received by the computer with the next highest priority is determined and notified to each of the other computers. The method for synchronizing message processing between computers according to claim 1.