JPH09186689A - Device state controlling method and data communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously control the device states of 'operation/standby/stop/ failure', etc., of the plural computers connected with a LAN in all the computers without a time difference. SOLUTION: All the device states 10 of all the computers A to D that a master computer A has is defined as the transmission data of health checks, the broadcast transmissions from a health check transmission mechanism 1 to all the devices are performed at a constant period or when a state is changed, and each computer B to D sends a reply by defining the its own device state as a response signal. The computer A judges the case where the response is not received from the computer B as a failure and the failure is set to the device state 12 of the computer B. By performing the broadcast transmissions for all the device states 10 at the time of the next broadcast transmission from the computer A, the computers C and D are capable of recognizing that the computer B is in a failure state and the device states can be simultaneously controlled in all the computers without a time difference.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device state management method for simultaneously managing the device states such as operation / standby / stop / failure of a plurality of computers connected to a LAN etc. without any time difference, and The present invention relates to a data communication system using the method.

[0002]

2. Description of the Related Art For example, FIG.
It is a figure which shows the conventional state management system shown by the 5th publication, In the figure, 1-6 are terminals A-connected to LAN.
E, the master computer 6 manages the ready state and the down state of each terminal.

In FIG. 13, the master computer performs broadcast transmission and waits for a response from the terminals A to E. When each terminal receives the health check by broadcasting from the master computer, it sets an identification number and returns a response to the master computer. If the terminal is down, no response is returned, so the master computer determines that the terminal is down.

[0004]

Since the conventional state management system operates as described above, a master computer for monitoring the system is required, and only the master computer knows the states of all terminals. Then, there was a problem that other terminals do not know the status of another terminal.

Broadcast communication cannot be performed in the case of a terminal connected via a router (a relay that can relay signals having different transmission speeds and is generally set so that broadcast communication cannot be performed). Or
There was a problem that the response might be delayed and timed out, and it might not be possible to check the health.

In some cases, the broadcast may not be temporarily notified to the terminal due to some trouble. In that case,
There is a problem that the terminal is considered to be a failure and the state change is not recognized.

Further, when the master computer fails, the state of the terminal cannot be managed.

The term "device state change" as used herein means switching between a computer in an operating state and a computer in a standby state (system switching).
And, as a result of "failure occurrence""startup" etc.,
"Stop ← → Operation""Operation ← → Standby""Standby ← → Stop"
That is, the state of a device (computer) such as "operation ← → failure" changes.

The present invention has been made in order to solve the above problems, and an apparatus state management method by which all computers can simultaneously manage the apparatus states of all the computers without a time difference, and this method is used. The purpose is to obtain the existing data communication system.

Further, even if there is a computer that cannot receive broadcast communication due to a router device or a computer whose communication line speed is slow and data transmission / reception takes time,
The purpose is to be able to manage the device status without being affected by the LAN configuration.

It is another object of the present invention to be able to instantly be notified of a state change and to perform reliable device state management even when a device abnormality is not notified due to a transmission error during broadcast transmission.

It is another object of the present invention to be able to perform device state management without stopping the device state management function of the entire system even if the master computer that has transmitted all device states fails.

Also, in general data transmission, a device for eliminating unnecessary response timeout time by utilizing the device state of another computer possessed by the own computer, or a device for logically disconnecting control according to the device state of the destination computer. The purpose is to be able to manage the state.

[0014]

[Means for Solving the Problems]

(1) A device state management method according to the present invention is a system in which a plurality of computers are connected to a communication line such as a LAN,
One computer becomes the master, and this master computer broadcasts the device status of all computers as health check transmission data to slave computers periodically or when the state changes, and the slave computers receive all the above devices. Depending on the status, all the device statuses other than the own computer held by the own computer are updated, and the device status of the own computer is returned as a response signal, and the master computer receives the above response signal and the computer that does not return a response is in a failure state. This is a method in which the device states of all the computers are updated and the updated all device states are used as the next transmission data.

(2) Further, in the above (1), when the master computer periodically broadcasts the health check transmission data, the slave computer generates an error if the transmission data is not received for a predetermined time. This is a method in which it is considered that a predetermined countermeasure is taken.

(3) Further, in the above (1) or (2), when the slave computer has a state change in its own computer,
In this method, the state change is broadcasted.

(4) Further, in the above (1) or (2), when the slave computer has a state change in its own computer,
By broadcasting the status change, after a predetermined time from this transmission, the status change is retransmitted to other computers one by one, and the device status of other computers is confirmed by the presence or absence of the response signal. is there.

(5) Further, in any one of the above items (1) to (4), when there is no response signal from the slave computer, the master computer has a one-to-one correspondence with the computer after a lapse of a predetermined time. This is a method for retransmitting and reconfirming all device states.

(6) Further, in any one of the above items (1) to (5), when the slave computer cannot receive all the device states due to the health check for a certain period of time, the slave computer of the slave computer is in a predetermined order. This is a method in which one operates as a master computer.

(7) In any one of the above items (1) to (6), the computer refers to all device states held by the computer when transmitting general data other than the health check, This is a method in which the transmission data is not transmitted to a computer in a state of failure / stop.

(8) Further, the data communication system uses the apparatus state management method according to any one of the above (1) to (7).

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. In FIG. 1, computers A to D are LANs.
1 is a health check transmission mechanism that broadcasts the entire device state 10 and receives individual device states 11 to 14 from each computer as a response in a system configuration in which the computers can communicate with each other.

Reference numeral 2 is a health check receiving mechanism for returning the device state of the computer itself when receiving all device states 10. Reference numeral 3 is a device state transmitting mechanism for broadcasting the device state of the computer itself. 10 is the device state 11 to 1 of each computer
All device states that collectively hold 4 are stored in the memory. 11 to 14 are device states such as operation / standby / stop / failure corresponding to the computers A to D. All the computers A to D have the same configuration.

Next, the operation will be described with reference to the flowchart of FIG. (1) The computer A (master computer), which is predetermined to operate the health check transmission mechanism 1, voluntarily broadcasts the entire device state 10 at a constant cycle or when the state changes. (S1) (2) Each of the computers B to D responds if the health check receiving mechanism 2 receives a broadcast signal. This response uses the device status of its own computer as a response signal.

(3) The computer A receives the response status of each of the computers B to D by the health check transmission mechanism 1, and each computer B receives the response state.
It is determined whether or not there is a response from ~ D. (S3) (4) As a result of receiving the response states (device states 11 to 14) from the computers B to D, the computer A responds from the computers C and D, and when there is no response from the computer B, the computer B The failure is detected by the health check transmission mechanism 1, the computer B is set to the failure state, and the all-device state 10 is updated. (S4)

(5) All device states 10 thus obtained
Is transmitted again as a next transmission data after a fixed time. (S5) (6) On the other hand, when the computers C to D receive the all-device state 10, the health check receiving mechanism 2 sets the device states of the computers other than the own computer to the internal all-device state 10.
(S6)

(7) At the same time, the computers C to D return the device statuses of their own computers to the sender (computer A). (S
7) (8) Computer A receives the device states of computers C and D, sets the device states, and updates all device states 10. (S
8)

As a result, the computer A and the computers C to D can have the same all device states, and the failure of the computer B can be known.

Next, the operation when the computer B is changed from the failure state to the operation state will be described with reference to the flowchart of FIG. (1) When the failure of the computer (computer B) is recovered, (T
1) (2) The device status transmission mechanism 3 broadcasts the device status of its own computer (computer B) to all devices. (T
2) (3) Other computers A, C, D are health check receiving mechanism 2
Then, the “failure recovery” of the computer B is set to the state of all devices. (T3)

As a result, the device state of the computer B can be grasped by all the devices at the same time when the state changes, regardless of the health check cycle.

Next, FIG. 4 shows the measures to be taken when the computer A fails.
This will be described with reference to a flowchart of (1) The computers B to D detect whether the health check receiving mechanism 2 has received all the device states 10 from the computer A within a fixed time. (U1) (2) Computers B to D consider that a fault has occurred in computer A or a fault has occurred in LAN. (3) As a result, a communication failure in the entire device can be quickly detected, and a countermeasure for a failure can be taken. For example, an external alarm or internal software may be notified.

By doing so, all the computers can manage the device states of all the computers in the shortest time without a time difference.

As described above, in the first embodiment, the health check transmission mechanism 1 transmits the device states of all the devices as the data of the health check, so that all the devices manage the state of all the devices at the same time without any time difference. You can Also, the health check receiving mechanism 2 and the device status transmitting mechanism 3
However, at the time of a health check response or a change in the status of the computer,
Since the self-device status is transmitted, all computers can obtain the status change of one computer in the shortest time.

Embodiment 2 In the first embodiment, a computer that does not return a response in the health check transmission mechanism 1 is regarded as a failure state. However, in the case of a LAN configuration via a router device, a computer that cannot perform broadcast communication or a communication line speed There may be a computer that is slow and takes time to send and receive data.

In this embodiment, the apparatus state can be grasped even in such a case.
FIG. 5 is a configuration diagram of a main part of this embodiment, in which the rerecognition mechanism 4
This is applied when broadcast cannot be communicated via a router or when there is a low-speed line with a slow communication speed, as shown in FIG. FIG. 6 is a flowchart of the operation.

The operation in this case will be described. (1) Broadcast transmission from the health check transmission mechanism 1 of the computer A, (V1) (2) Each of the computers B to D responds if the health check reception mechanism 2 receives the broadcast signal. (V2)

(3) The computer A receives the response status from each of the computers B to D by the health check transmission mechanism 1 and judges whether or not the response from each of the computers B to D is within a predetermined time. (V3) (4) The computer A does not immediately set the device state of the computer, which has received no response to the broadcast transmission of the entire device state 10 or has a delayed response, to a failure state,
Send all device statuses 10 to the computer once more, and send (V4)

(5) The reconfirmation mechanism 4 judges whether or not there is a response within a predetermined time. (V5) This reconfirmation mechanism 4
Performs a re-health check by increasing the response timeout value and not increasing the LAN communication load at regular time intervals.

(6) As a result of the health check transmission mechanism 1 of the computer A receiving the response states of the computers B to D, the computer B has a response, the computer C has a one-to-one post-transmission response, and the computer B has 1 If there is no response after a lapse of a predetermined time in the pair 1, the failure of the computer B is detected, the computer B is set to the failure state,
Update all device state 10. (V6) (7) Steps V7 to V10 are the same as steps S5 to S8 of the first embodiment shown in FIG.

As described in steps V3 to V6 above, the computer that has really failed does not return a response, so it is considered to be in a failed state. A computer that returns a response with a delay validates the device state and does not regard it as a failure state. A computer that cannot perform broadcast communication returns a response because one-to-one communication is possible by this reconfirmation mechanism, so that the device information is valid.

As described above, since the reconfirmation mechanism 4 performs the health check on the computer which does not respond to the health check by the normal one-to-one communication, the computer which is through the router cannot perform the broadcast communication. , Health check is possible even if the line speed is slow and the response times out, regardless of the LAN configuration,
It is possible to manage the device status corresponding to any computer configuration.

Embodiment 3. In the first embodiment, the device status transmission mechanism 3 broadcasts and notifies the status change when, for example, the status of the computer A itself changes. However, in the case of a state change due to system switching (switching between a computer in the operating state and a computer in the standby state), the computer must immediately operate in the new device state, so do not wait for the broadcast transmission response. It will work. Therefore, it is unknown whether or not all computers have been notified of the change in device status. This embodiment solves such a situation.

FIG. 7 is a block diagram showing the main part of this embodiment, in which 31 device status transmission mechanisms are provided. FIG.
Is a flowchart of the operation.

Next, the operation will be described. (1) When the master computer A detects a state change such as system switching, (W1) (2) The computer A broadcasts its own state from the health check transmitting mechanism 1. (W2)

(3) Computer A after broadcast transmission
Sends the device status from the device status transmission mechanism 31 to the computers B to D on a one-to-one basis. (W3) (4) Computer A is the device status transmission mechanism 31, and each computer B
Each of the responses from D to D is individually received and it is determined whether or not there is a response. (W4)

(5) When the health check transmission mechanism 1 of the computer A receives the response states of the computers B to D as a result, there is a response from the computers C and D, but no response from the computer B,
The failure of the computer B is detected, the computer B is set to the failure state, and the all-device state 10 is updated. (W5) (6) The computer A notifies the device states of all the computers by the next broadcast transmission. (W6)

Even when the non-arrival of the broadcast transmission occurs due to the accidental failure and the other computers are not notified in this way, the data is retransmitted to all the devices at a fixed time interval one-to-one after that. Avoiding inconsistencies in the device status of A on each computer, reliable notification of important device status changes that require immediacy such as system switching without increasing the communication load on the LAN, and are highly reliable. The device status can be managed.

Embodiment 4 In this embodiment, even if the master computer that performs the health check fails, another computer is used as the master computer to take over the health check transmission.

FIG. 9 is a block diagram of the essential parts of this embodiment, in which a health check transmission takeover mechanism 5 is provided. FIG. 10 is a flowchart of the operation when the master computer fails. Next, the operation will be described. (1) When computers B to D (slave computers) do not receive all the device states from computer A (master computer) within the specified time, (X1) (2) The predetermined next takeover computer B takes over the health check transmission. The mechanism 5 broadcasts all device states.

In this way, even if the computer A fails, it is possible to continuously manage the state of all devices. In the health check transmission and takeover mechanism 5, the order of the computers to take over when the computer A fails is determined in advance, and the health check non-reception time in the health check receiving mechanism 2 is shortened in the higher priority computer. I'll do it. Since the time when the health check is not received differs slightly for each computer, it is possible to avoid taking over the health check transmission from multiple computers at the same time and take over the health check in order.

With this health check transfer mechanism 5, any computer can be a master computer, and the master computer is not required. Further, the device state management of the entire system can be continued without delay, and the reliability of the entire system can be improved.

Embodiment 5 FIG. In this embodiment, data transmission is not performed to a computer that does not need data transmission due to a failure or the like, the communication load is reduced, and the efficiency of data transmission is improved.

FIG. 11 is a block diagram of the essential parts of this embodiment, in which a data transmission control mechanism 6 is provided. FIG.
2 is a flowchart of the operation.

The data transmission control mechanism 6 will be described. In the first embodiment, the operation / standby / stop / stop of each computer is performed.
Although the failure status is managed by all the devices, as shown in FIG. 11, when sending general data from the computer, the data transmission control mechanism 6 is in the device status of the destination computer (operation, failure, stop, etc.). In the case of a failure state or a stop state, theoretical disconnection control is performed, such as immediately returning an error without transmitting data.

The explanation will be given with reference to the flow chart of FIG. 12. (1) When general data transmission is performed from the computer A, the data transmission control mechanism 6 of the computer A refers to the all-device state 10. (Z1) As a result of the reference (2), it is determined whether or not there is a failure computer or a shutdown computer. (Z2) (3) Data is not transmitted to the failure computer or the shutdown computer, and (Z3) (4) Normal data transmission is performed to the motion computer. (Z4)

In this way, computer A is in failure and computer C is in failure.
It is possible to eliminate unnecessary response time-out processing and reduce the load of communication processing when general data is transmitted to. Also, for example, in the transmission from computer A to computer D,
If communication is possible, but the computer D is in a stopped state, the computer D is theoretically separated by not sending the data and making an error, and the test work and maintenance work of a specific computer D can be performed without affecting the system. It can be done smoothly.

As described above, the device state of the destination device is judged during normal transmission and logically separated, and if there is a failure, an error is immediately sent without data transmission. Moreover, it becomes possible to perform computer testing and maintenance work without affecting the system.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a device state management system according to a first embodiment of the present invention.

FIG. 2 is a flowchart of the operation according to the first embodiment of the present invention.

FIG. 3 is a flowchart at the time of failure recovery according to the first embodiment of the present invention.

FIG. 4 is a flowchart when the host computer according to the first embodiment of the present invention fails.

FIG. 5 is a configuration diagram of a device state management system according to a second embodiment of the present invention.

FIG. 6 is a flowchart of a re-recognition mechanism according to the second embodiment of the present invention.

FIG. 7 is a configuration diagram of an apparatus state management system according to Embodiment 3 of the present invention.

FIG. 8 is a flowchart when the state of the host computer changes according to the third embodiment of the present invention.

FIG. 9 is a configuration diagram of an apparatus state management system according to Embodiment 4 of the present invention.

FIG. 10 is a flowchart when the master computer according to Embodiment 4 of the present invention fails.

FIG. 11 is a configuration diagram of a device state management system according to a fifth embodiment of the present invention.

FIG. 12 is a flowchart for stopping transmission to a failure / stop computer according to the fifth embodiment of the present invention.

FIG. 13 is a configuration diagram of a conventional device state management system.

[Explanation of symbols]

1 health check transmission mechanism, 2 health check reception mechanism, 3, 31 device status transmission mechanism, 4 reconfirmation mechanism,
5 Health Check Transmission Handover Mechanism, 6 Data Transmission Control Mechanism 10 All Device State, 11 Computer A Device State, 12
Device status of computer B, 13 Device status of computer C, 14
Device status of computer D.

Claims (8)

[Claims] 1. In a system in which a plurality of computers are connected to a communication line such as a LAN, one computer serves as a master, and this master computer periodically uses the device states of all the computers as health check transmission data. Or when the status changes, broadcast transmission to the slave computer, the slave computer, by the received all device status,
All the device statuses other than the own computer held by the own computer are updated, the device status of the own computer is returned as a response signal, and the master computer receives the above response signal and considers the computer that does not return a response as a failure state. A device state management method in which the device states of all computers are updated and the updated all device states are used as the next transmission data. 2. The apparatus state management method according to claim 1, wherein when the master computer periodically broadcasts health check transmission data, the slave computer is abnormal if the transmission data is not received for a predetermined time. A device status management method in which it is regarded as an occurrence and a prescribed countermeasure is taken. 3. The apparatus state management method according to claim 1, wherein when the slave computer has a state change in its own computer, the slave computer broadcasts the state change. 4. The apparatus state management method according to claim 1, wherein when the slave computer has a state change in its own computer, the slave computer broadcasts the state change, and after a predetermined time from this transmission, a pair of A device status management method in which the status change is retransmitted to another computer in 1 and the device status of the other computer is confirmed by the presence or absence of a response signal. 5. The apparatus state management method according to claim 1, wherein the master computer, when there is no response signal from the slave computer, waits for a predetermined period of time and then sends a pair to the computer. A device status management method in which all device statuses are retransmitted and reconfirmed in step 1. 6. The device state management method according to claim 1, wherein when the slave computer cannot receive all device states by health check for a certain period of time, the slave computer is in a predetermined order. A device status management method that operates one of the above as a master computer. 7. The apparatus state management method according to claim 1, wherein the computer refers to all apparatus states held by the computer when transmitting general data other than a health check. A device state management method in which the transmission data is not transmitted to a computer in a state such as a failure or a stop. 8. A data communication system using the device status management method according to claim 1.