JPH0991251A - Communication fault restoration method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restore the state of a system that is secured before occurrence of a fault without enlarging the system constitution by using the specific restoration data for restoration of the fault and answering the input request of a host computer. SOLUTION: An input/output control part 13 of a terminal 1 transfers the data received from an input part 11 to a communication control part 15 and also transfers the data received from the part 15 to an output part 12. The part 13 also writes the data received from the part 11 in sequence into a storage part 14 as the restoration data and then deletes the input data corresponding to its processing out of the restoration data after receiving a processing end message from the part 15. If the part 13 receives the notification of reconnection from the part 15 in a fault restoration mode, the part 13 thereafter produces continuously the answer data from the restoration data to the input request of a host computer 2 until no restoration data exist any more.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to recovery from a communication failure, and more particularly to a communication failure recovery method in a computer system that provides online services.

[0002]

2. Description of the Related Art A recovery method when a communication failure occurs is
This is for automatically connecting to the online system that was used before the communication failure occurred after the communication failure was recovered. As this restoration method, for example, reference 1 (Japanese Unexamined Patent Publication No.
-55647). This is because, in a computer system that provides online services, the connection status with the online service program is stored for each terminal, and when a failure occurs, after recovery from the failure, a recovery command is input from the terminal to the host computer. By doing so, it connects to the online service that was connected before the failure.

Another recovery method is disclosed in Document 2 (Japanese Patent Laid-Open No. 4-239947). This is provided with a communication means, a communication control means, a communication monitoring means and a storage device on the terminal side, and in a normal state, the communication control means passes the user's input data to the communication means and transmits it to the host computer. . When the communication monitoring means detects a communication failure, the input data is stored in the storage device instead of being passed to the communication means. Then, when the communication monitoring means detects the restoration of the failure, the input data of the user stored in the storage device is passed to the communication means.
Therefore, in this method, the input data at the time of failure does not have to be input again after restoration.

[0004]

By the way, in the computer system which provides the online service as described above, when the terminal is connected to the host computer, not only the connection information and the like are held but also the terminal is connected to the host computer. The application program used by the user operates and holds this information. When a failure occurs in such a situation, if you try to recover the situation before the failure, not only the connection information and user input data described above, but also the status of the application program you are using is always retained. Must be present. This means that a large storage capacity is required.

The present invention has been made in order to solve the above-mentioned problems, and requires a large storage capacity in a host computer and does not enlarge the system configuration, and prevents the occurrence of a failure. The purpose is to be able to recover to the state.

[0006]

According to a communication failure recovery method of the present invention, a terminal stores a communication state up to a predetermined time as recovery data, and after communication interruption due to a communication failure, the terminal stores the recovery data. It is used to generate the response to the input request from the host computer. Therefore, even when the failure is recovered, the host computer provides the online service to the terminal without being aware of the communication after the communication failure occurs and the failure is recovered.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In the computer system according to the present invention, the terminal stores, for example, the data input between the reception of the processing end message and the next processing end message in the storage device, and this data is stored at the time of failure recovery. Used to respond to input requests from the host computer. Then, the host computer transmits a processing end message to the terminal each time one processing is ended.

FIG. 1 is a block diagram showing the configuration of a computer system according to the first embodiment of the present invention.
In FIG. 1, reference numeral 1 denotes a terminal, which includes an input unit 11, an output unit 12 for displaying, an input / output control unit 13, a storage unit 14, a communication control unit 15, and a communication unit 16. Reference numeral 2 is a host computer to which the terminal 1 is connected, and includes a communication unit 21, a communication control unit 22, an online service unit 23, and a storage unit 24. An identification number for the host computer 2 to identify each connected terminal is stored in the storage unit 14 of the terminal 1 in advance.

When the terminal 1 tries to connect to the host computer 2, the communication control section 15 reads the identification number stored in the storage section 14. Then, the communication unit 16 transmits a connection request together with this identification number to the host computer 2. Upon receiving the connection request, the host computer 2 confirms the identification number and performs the connection process.

After the connection process, in the terminal 1, if there is data to be transmitted, the communication control unit 15 receives the transmission data from the input / output control unit 13 and the communication unit 16 transmits it. Then, the communication unit 16 receives the data sent from the host computer 2, and the input / output control unit 1
Pass to 3.

Further, the communication control unit 15 monitors the state of the communication unit 16, performs connection processing again when a communication failure is detected, and notifies the input / output control unit 13 when connection is established. The input / output control unit 13 transfers the data input from the input unit 11 to the communication control unit 15, and transfers the data received from the communication control unit 15 to the output unit 12. Further, the input / output control unit 13 sequentially writes the data input from the input unit 11 into the storage unit 14 as the restoration data, and when receiving the processing end message from the communication control unit 15, inputs the input data for the processing from the restoration data. If it is deleted and a disconnection request is received, all the recovery data is deleted.

As described above, since the terminal 1 does not hold all the data and sequentially deletes the unnecessary data, the storage unit 14 does not need to have a large capacity. Then, upon failure recovery, the input / output control unit 13 receives the reconnection notification from the communication control unit 15, and thereafter, until the recovery data is exhausted, response data to the input request from the host computer 2 is returned from the recovery data. create.

On the other hand, in the storage unit 24 of the host computer 2, connection information consisting of the identification number of the terminal identified by the host computer 2 in advance and user information consisting of the user name and password of the online service user are stored. Remembered When the communication control unit 22 receives the connection request from the communication unit 21, the communication control unit 22 performs a connection process. In the connection processing, it is checked whether or not the received identification number of the terminal 1 is included in the connection information prepared in the storage unit 24, and if there is, a message indicating connection completion is sent to the terminal 1 and the online service unit 23 is notified to the terminal. Notify that 1 has connected.

When the connection is established as described above, the communication control unit 22 receives the transmission data from the online service unit 23, and the communication unit 21 transmits this data to the terminal 1. On the other hand, the data sent from the terminal 1 is received via the communication unit 21, and this received data is passed to the online service unit 23. Further, the communication control unit 22 monitors the state of the communication unit 21, and when detecting a communication failure, notifies the online service unit 23 of this and waits for a connection request from the terminal 1.

Upon receiving the connection notification from the communication control unit 22, the online service unit 23 determines whether the user of the terminal 1 has the right to use the online service (login process). In this login process, the terminal 1 is requested to send a user name and password, and the user name and password input and sent to the terminal 1 are stored in the user information of the storage unit 24 of the host computer 2. Find out if it's inside. If these exist, the response of the login process is returned to the communication control unit 22,
Start online service.

Then, in the host computer 2, during the online service, a process end message is passed to the communication control unit 22 every time one process is completed. Then, this processing end message is sent to the terminal 1 by the communication unit 21. When receiving a communication failure notification from the communication control unit 22, the storage area used for the processing of the terminal 1 is released, the processing is stopped, and the terminal 1 waits for connection again.

The operation of the computer system composed of the terminal 1 and the host computer 2 will be described below with reference to the flowcharts of FIGS. Below, in order to explain the communication operation between the terminal 1 and the host computer 2, the operation in the terminal 1 is shown in the flowchart of FIG. 2, and the operation of the host computer 2 is shown in the flowchart of FIG.

In the terminal 1, first, when an instruction for online use is input from the input unit 11, the input / output control unit 13
It is confirmed whether or not there is recovery data in the storage unit 14 (step S101). If the previous time has ended normally, the recovery data has not been written, so there is no recovery data in the storage unit 14. In this case, the communication control unit 15 uses the storage unit 1
The identification number of the terminal 1 stored in 4 and the connection request are passed to the communication unit 16, transmitted to the host computer 2, and a notification of connection completion is sent from the host computer 2 (step S102).

Host computer 2 which has received the connection request
As shown in the flowchart of FIG. 3, first, in the connection information stored in the storage unit 24 by the communication control unit 22,
Check if there is the identification number of the terminal 1 received,
Connected to the terminal 1 and the online service unit 23
(Step S201). The online service unit 23 that has received the connection notification sends a login request for connecting the terminal 1 to the online service to the terminal, and requests the user name and password to be input (step S20).
2).

On the other hand, the terminal 1 receives the login request as shown in the flowchart of FIG. 2 (step S10).
3) Display on the output unit 12 to prompt the user to enter the user name and password. As a result, when the user name and password are input to the terminal 1 (step S104), they are stored in the storage unit 14 of the terminal 1 as restoration data (step S105) and transmitted to the host computer 2 (step S106). ).

On the other hand, when the host computer 2 receives the user name and password as shown in FIG. 3, the host computer 2 confirms whether or not the user information stored in the storage unit 24 matches. The online service is started (step S203). Then, the processing selection request is sent to the terminal 1
To request input of a desired process name or end of service (step S204). As shown in FIG. 2, the terminal 1 to which this processing selection request is sent receives this processing (step S107), and when the user inputs a processing name (step S108), this processing name is sent to the host computer 2. The data is sent (step S109), and at the same time, this is written in the storage unit 14 as restoration data (step S1).
10).

As shown in FIG. 3, when the host computer 2 receives the process name from the terminal 1 (step S205), it determines whether or not this is the end (step S206). Continue online services. If not, the inquiry data is sent out to the terminal 1 by the received process name to request input for the process (step S207).
On the other hand, in the terminal 1, as shown in FIG. 2, when the inquiry data is received, the inquiry data is displayed on the output unit 12 (step S112), and when the response data is input from the user (step S113), the response data is displayed. Is sent to the host computer 2 (step S114), and the recovery data in the storage unit 14 is updated by storing this (step S114).
115).

When the response data is sent from the terminal 1,
As shown in FIG. 3, the host computer 2 receives the inquiry data (step S208), determines whether or not the inquiry data still exists (step S209), and if there is, the inquiry data by the received processing name again. 1 to request input for processing (step S207). The above-described exchange between the terminal 1 and the host computer 2 is repeated until there is no inquiry data regarding the processing being performed. And
When there is no inquiry data (step S20)
9), and this time, this processing is executed (step S210),
When the processing is completed, a processing end message is sent to the terminal 1 (step S211), and the input of the desired processing name or the end of the service is requested again (step S20).
4).

The terminal 1 receives the request for the end of processing and the next instruction input, and displays this on the output unit 12 (step S112). This time, since it is not an inquiry, there is no input of a response, no transmission of this, and no update of the recovery data related to this (step S113-).
115). Then, this time, since the process is completed (step S116), the part written after step S110 in the recovery data in the storage unit 14 is deleted (step S117), and the process returns to step S107 to return from the host computer 2. Receives a request to enter the processing name of the service or the end of service.

The above steps are performed by the user in step S108.
Repeat until the end of service is entered in. When the user inputs an instruction to end the service in step S108, the terminal 1 transmits a disconnection request to the host computer 2 (step S118) based on the determination in step S111 and stores it in the storage unit 14. The recovery data is deleted (step S119), and a series of processing is ended. On the other hand, when the host computer 2 receives the service end instruction in step S205 (FIG. 3), it receives a disconnection request from the terminal 1 (step S205).
212), a disconnection process is performed (step S213), and a series of processes is ended.

The operation when the communication abnormality does not occur during the communication has been described above, but the operation after the communication abnormality occurs and the recovery is described below. The operation after this restoration is shown in step S120 and subsequent steps in FIG. That is, in this invention,
After the communication failure is restored, the terminal 1 performs the restoration process, and the host computer 2 is not involved in the restoration process.

After the communication failure occurs, when the terminal 1 recovers and tries to start communication with the host computer 2, it is determined in step S101 that there is recovery data in the storage unit 14, and therefore step S120. Will be moved to. That is, in the normal communication state, as described above, the recovery data is written and updated every time communication is generated, and when the communication is normally completed, this is deleted. (Step S119). However, if the communication is not normally completed and the communication is abnormal, the process of step S119 is not performed and the restored data remains in the storage unit 14.

When there is restoration data in the storage unit 14, the terminal 1 judges that this is the start of communication after restoration due to a communication abnormality (step S101), and issues a connection request to the host computer 2. Send (Step S1
20), this is repeated until a response is received (step S1)
21). When there is a response from the host computer, this time it waits for a login request (step S122).

When there is a login request from the host computer 2, a login response consisting of the user name and password is generated from the recovery data stored in the storage unit 14 (step S123), and this is sent to the host computer 2. And transmits (step S124). The login response written in step S106 is included in the restoration data.
It remains unerased until it is erased in step S119.

When the login response is transmitted (step S1)
24), it is confirmed whether or not the restored data still exists in the storage unit 14 (step S125). If there is no restored data, the process goes to step S107 to communicate with the host computer 2 as described above. Here, if the recovery data is still present, this is step S110, step S
115, it is the restoration data stored in step S117, and it means that the communication failure occurred while receiving the online service.

When the login response is transmitted (step S1)
24), the process selection request is sent from the host computer 2 (FIG. 3: step S204). When this processing selection request is received (step S126),
A process selection response is created from the recovery data stored in the storage unit 14 (step S127), and this is sent to the host computer 2 (step S128). If the recovery data in the storage unit 14 is other than the login response, this is first the data written in step S110, which is the process selection response.

When the process selection response is sent out (step S1)
28), there is an inquiry from the host computer 2,
When this is received (step S129), it is confirmed again whether or not the restored data still exists in the storage unit 14 (step S130). Here, if there is no recovery data, the response to the inquiry is input as in step S113 (step S131), the recovery data is rewritten (step S132), and this inquiry response is sent to the host computer 2 (step S134). ).

If it is determined in step S130 that the restored data is still present, this is the one stored in step S115, the inquiry response is created from this (step S133), and the inquiry response is sent out (step S134). Steps S129 to S1 above
The steps up to 34 are performed until the inquiry data from the host computer 2 are exhausted, and when the inquiry is completed (step S135), the above situation is rewritten to the recovery data (step S136), and step S107.
To return to normal operation.

[0034]

As described above, according to the present invention, the terminal stores, for example, the data input between the reception of the processing end message and the next processing end message in the storage device. The data is stored, and the recovered data is used to respond to the input request of the host computer at the time of failure recovery. In this way, since not all the data is held, even a terminal with a small storage capacity can store the restored data. And
In the host computer, the online service is provided to the terminal without being aware of whether the communication is after the communication failure occurs and the failure is recovered. Therefore, there is an effect that the host computer can be restored to the state before the occurrence of the failure without enlarging the system configuration such as requiring a large storage capacity.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration of a computer system according to a first embodiment of this invention.

FIG. 2 is a flowchart showing an operation in the terminal 1 of FIG.

FIG. 3 is a flowchart showing an operation of the host computer 2 of FIG.

[Explanation of symbols]

1 ... Terminal, 2 ... Host computer, 11 ... Input unit, 1
2 output section, 13 ... I / O control section, 14, 24 ... storage section,
15, 22 ... Communication control unit, 16, 21 ... Communication unit, 23 ...
Online service department.

Claims (3)

[Claims] 1. A computer system having a terminal connected to a host computer and receiving an online service from the host computer, wherein the terminal stores a communication state up to a predetermined point in time as recovery data, and communication interruption due to communication failure occurs. Then, a communication failure recovery method characterized by generating a response to an input request from the host computer using the recovery data. 2. The communication failure recovery method according to claim 1, wherein the host computer sends a processing end message to the terminal each time one processing ends when the online service is provided to the terminal. When the terminal receives the message indicating that the process is complete, the terminal stores the communication status up to this point as recovery data. 3. The communication failure recovery method according to claim 2, wherein, when the terminal receives the processing end message, the terminal stores the communication state up to the time when the last processing end message is received. A communication failure recovery method characterized by deleting.