JP2020004323A - Client server system, client, server, and program - Google Patents

Abstract

To ensure that when a server having become unable to receive data transmitted from a client due to an abnormal state returns to a normal state, data transmission to the server is resumed under the initiative of the client.SOLUTION: A client 10 includes a resume demand transmission unit 13 which, when abnormality in a server 20 is detected and a data transmission unit 12 is unable to transmit data, transmits a resume demand including its own client ID for a while until the server 20 is restored to a normal state and also acquires, from the server 20 having returned to a normal state and received the resume demand, a resume request generated in accordance with the resume demand. The server 20 includes a resume demand control unit 23 for causing the client ID included in the resume demand received after being restored to a normal state to be held by a resume demand source holding unit 24, and also notifying the client 10 in accordance with the resume demand to the effect that a resume request has been generated by a resume request generation unit 25.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a client-server system, a client, a server, and a program, and more particularly to restarting data transmission after a server returns to a normal state.

  For example, if an error occurs in the server while the client is transmitting data to the server and the data cannot be transmitted, the data transmission may be required to be resumed when the server is restored.

  For example, in Patent Literature 1, when a server that has not received data from a client due to an overloaded state has recovered to a normal state, the server notifies the client of a data transmission enabled state, A technique has been proposed in which a client resumes data transmission upon receiving a notification from the server.

JP 2001-177552 A JP-T 2007-529080 JP 06-021961 A

  An object of the present invention is to restart data transmission to a server when a server that has stopped receiving data transmitted from a client due to an abnormal state returns to a normal state.

  A client-server system according to the present invention includes a client, a server that receives data transmitted from the client, the client transmits data to the server, and the server transmits the data to the server. Request transmission means for repeatedly transmitting a transmission restart request to the server until an abnormal state in which the data transmitted by the transmission means is not received is received, and the data transmission means receives the data. Transmission is stopped when the server enters an abnormal state, and resumed when the request transmission unit confirms that the server has entered a normal state.

  Further, when the server receives the transmission restart request including the identification information of the client, the server has a holding unit that holds the identification information of the client.

  The server may further include a generation unit configured to generate restartable information when the server enters a normal state.

  In addition, when there are a plurality of clients, the generation unit generates the restartable information for each client.

  Further, the request transmission unit recognizes that the server has been brought into a normal state by generating the restartable information including the identification information of the own client in the server.

  Further, the data transmission means restarts data transmission when the request transmission means recognizes that the server has entered a normal state.

  Further, the generation unit includes a retry interval in the resumable information, and the request transmission unit repeatedly transmits the transmission resumption request at the retry interval when the server returns to an abnormal state until the server returns to an abnormal state. It is characterized by doing.

  Further, the client has management means for managing a data transmission permission / prohibition state in the data transmission means with status information, and the data transmission means is configured to transmit data when the data transmission status is set to a data transmission prohibition state. The transmission of data is stopped.

  Further, the management means sets the status information to a data transmission disabled state when the server is in an abnormal state.

  Further, the request transmitting unit does not transmit the transmission restart request when the status information is set to a data transmission disabled state by a user.

  The client according to the present invention comprises: a data transmission unit for transmitting data to a server; and a transmission restart request until the server enters an abnormal state in which the server does not receive the data transmitted by the data transmission unit. Request transmission means for repeatedly transmitting to the server, the data transmission means stops data transmission when the server becomes abnormal, and the request transmission means brings the server into a normal state. It is characterized by restarting when it is confirmed that

  The server according to the present invention includes a generation unit configured to generate restartable information when receiving a transmission restart request transmitted from the client after a normal state in which data is received from the client and an abnormal state in which the data is not received from the client. It is characterized by the following.

  The program according to the present invention transmits the computer to a data transmitting unit that transmits data to a server, and when the server enters an abnormal state in which the server does not receive the data transmitted by the data transmitting unit, the computer transmits the data until a normal state is received. Request transmission means for repeatedly transmitting a restart request to the server, wherein the data transmission means stops data transmission when the server enters an abnormal state, and the request transmission means returns the server to a normal state. It is characterized in that it is restarted when it is confirmed that it has become unreliable.

  The program according to the present invention is configured to generate a resumable information upon receiving a transmission resumption request transmitted from the client after the computer enters a normal state of receiving data from an abnormal state in which data from the client is not received. Function as a means.

  According to the first aspect of the present invention, when a server that has stopped receiving data transmitted from a client due to an abnormal state returns to a normal state, data transmission to the server is restarted by the client. be able to.

  According to the second aspect of the present invention, it is possible to specify a client requesting resumption of transmission.

  According to the third aspect of the present invention, the client can recognize that the data transmission can be resumed.

  According to the fourth aspect of the invention, the restart of data transmission can be controlled for each client.

  According to the invention described in claim 5, the client can know that the server is in a normal state without receiving a notification from the server.

  According to the invention described in claim 6, the client can initiatively resume the data transmission.

  According to the seventh aspect of the present invention, when a plurality of clients are present, it is possible to avoid the occurrence of congestion caused by the plurality of clients transmitting the transmission restart request simultaneously by adjusting the retry interval for each client. it can.

  According to the invention of claim 8, execution of data transmission can be controlled by the state information.

  According to the ninth aspect of the present invention, it is possible to manage whether or not data transmission is possible by the status information.

  According to the tenth aspect, when data transmission is stopped by a user's intention, data transmission can be prevented from being restarted against the user's intention.

  According to the eleventh aspect, when a server that has stopped receiving data transmitted from a client due to an abnormal state returns to a normal state, data transmission to the server is restarted by the client. be able to.

  According to the twelfth aspect of the present invention, when a server that has stopped receiving data transmitted from a client due to an abnormal state returns to a normal state, data transmission to the server is restarted by the client. be able to.

  According to the thirteenth aspect, when a server that has stopped receiving data transmitted due to an abnormal state returns to a normal state, data transmission to the server can be restarted by the computer. .

  According to the fourteenth aspect of the present invention, when returning to the normal state after the data transmitted from the client is not received due to the abnormal state, the data transmission can be restarted by the client. .

FIG. 1 is a block diagram showing an embodiment of a client server system according to the present invention. FIG. 3 is a hardware configuration diagram of a client according to the present embodiment. FIG. 3 is a sequence diagram of data communication between the client and the server in the present embodiment.

  Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing an embodiment of a client server system according to the present invention. FIG. 1 shows a configuration in which a client 10 and a server 20 are connected to the Internet 1. The client 10 is connected to the Internet 1 via a firewall (FW) 2 to block unauthorized access from outside.

  FIG. 2 is a hardware configuration diagram of a computer forming the client 10 in the present embodiment. The client 10 according to the present embodiment can be realized by a general-purpose hardware configuration existing before, such as a personal computer (PC). That is, the client 10 is an input / output controller that connects the CPU 31, the ROM 32, the RAM 33, the hard disk drive (HDD) 34, the mouse 35 and the keyboard 36 provided as input means, and the display 37 provided as display means shown in FIG. 38, a network interface (IF) 39 provided as communication means is connected to the internal bus 40.

  Returning to FIG. 1, the client 10 includes a communication processing unit 11, a data transmission unit 12, a restart request transmission unit 13, a transmission state management unit 14, and a data storage unit 15. Note that components not used in the description of the present embodiment are omitted from FIG. The communication processing unit 11 processes data communication with the server 20 via the Internet 1. The data transmission unit 12 extracts the data stored in the data storage unit 15 and transmits the data to the server 20. When the server 20 enters an abnormal state in which the server 20 does not receive the data transmitted by the data transmitting unit 12, the restart request transmitting unit 13 repeatedly transmits a transmission restart request to the server 20 until the server 20 enters a normal state of receiving the data. The transmission state management unit 14 manages the data transmission enable / disable state in the data transmission unit 12 based on state information. In the present embodiment, the state in which data transmission is possible is set to “valid”, and the state in which data transmission is not possible is set to “invalid” in the state information.

  Each of the components 11 to 14 in the client 10 is realized by a cooperative operation of a computer forming the client 10 and a program operated by a CPU 31 mounted on the computer. Further, the data storage unit 15 is realized by the HDD 34 mounted on the client 10. Alternatively, the RAM 33 or an external storage means may be used via a network.

  Although a plurality of clients 10 are connected to the Internet 1, all of them need only have the above-described components, and FIG. 1 shows a block configuration of only one client 10.

  The server 20 is a server computer that receives and stores data transmitted from each client 10. The server 20 in the present embodiment can be realized with a general-purpose hardware configuration. Therefore, the hardware configuration of the server 20 may be configured in the same manner as in FIG. The server 20 according to the present embodiment includes a communication processing unit 21, a data receiving unit 22, a restart request control unit 23, a restart request source holding unit 24, a restart request generating unit 25, a restart request holding unit 26, and a data storage unit 27. are doing. Note that components not used in the description of the present embodiment are omitted from FIG.

  The communication processing unit 21 processes data communication with the client 10 via the Internet 1. The data receiving unit 22 receives the data transmitted by the data transmitting unit 12 of the client 10 and stores the data in the data storage unit 27. The resumption request control unit 23 controls resumption of data transmission in response to receiving the transmission resumption request transmitted by the resumption request transmission unit 13 of the client 10. The restart request source holding unit 24 holds the client ID included in the transmission restart request received by the restart request control unit 23. The restart request generation unit 25 generates a restart request when the server 20 recovers to a normal state. The restart request corresponds to restartable information generated for each client 10 corresponding to the client ID held by the restart request source holding unit 24. The restart request holding unit 26 holds the restart request generated by the restart request generation unit 25.

  Each of the components 21 to 23 and 25 in the server 20 is realized by a cooperative operation of a computer forming the server 20 and a program operated by a CPU mounted on the computer. Each of the holding units 24 and 26 and the data storage unit 27 are realized by an HDD mounted on the server 20. Alternatively, a RAM or an external storage means may be used via a network.

  In addition, the program used in the present embodiment can be provided not only by communication means but also stored in a computer-readable recording medium such as a CD-ROM or a USB memory. The program provided from the communication unit or the recording medium is installed in the computer, and various processes are realized by the CPU of the computer sequentially executing the program.

  In the client-server system according to the present embodiment, data stored in client 10 is transmitted to server 20 for storage. If any abnormality occurs in the server 20 while data is being transmitted from the client 10 to the server 20, the server 20 cannot receive the data transmitted from the client 10, but after that, the server 20 is in a normal state. Automatically restores the data transmission from the client 10 when the data is restored. A feature of the present embodiment is that the automatic restart of data transmission can be executed under the initiative of the client. Hereinafter, the process of restarting data transmission according to the present embodiment will be described with reference to the sequence diagram shown in FIG.

  In the client 10, the data transmission unit 12 extracts data to be transmitted from the data storage unit 15 and transmits the data to the server 20 (Step 101).

  When the server 20 is in a normal state, the data receiving unit 22 of the server 20 receives the data transmitted from the client 10 and stores the data in the data storage unit 27 (Step 201). Here, the “normal state” in the server 20 is a state in which data transmitted from the client 10 can be normally received, and is a state in which the data is not abnormal. On the other hand, the “abnormal state” refers to a state in which the server 20 cannot receive external data including the client 10. The abnormal state includes not only a case where the server 20 is stopped, but also a state where the processing load and the data communication load on the server 20 are excessive and the data transmitted from the outside cannot be normally received. It is.

  The data transmission unit 12 in the client 10 transmits data to the server 20 in the same manner as in step 101 (step 102), but if the server 20 is in an abnormal state and an abnormality is detected before that (step 202), The data transmission cannot be completed normally.

  As described above, when the data transmission fails, the data transmission unit 12 notifies the transmission state management unit 14 of the failure. Note that the transmission state management unit 14 may always monitor data transmission in the data transmission unit 12 and detect failure of data transmission. When the transmission state management unit 14 detects the failure of data transmission in this way, it changes the state information from valid to invalid to set the data transmission to an invalid state at present (step 103).

  When the data transmission becomes invalid, the restart request transmitting unit 13 transmits a restart request including its own client ID to the server 20 (Step 104). Note that the restart request transmitting unit 13 may be notified by receiving a notification from the transmission state management unit 14 that the data transmission has been changed to the invalid state, or may be in a state managed by the transmission state management unit 14. Information may be constantly monitored.

  When the server 20 is in an abnormal state, as shown in FIG. 3, the server 20 cannot receive the restart request transmitted from the client 10. When detecting that the transmission of the restart request has failed, the restart request transmitting unit 13 repeatedly transmits the restart request at a predetermined retry interval until the server 20 becomes normal (step 105).

  It is also conceivable to perform processing so that data transmission in the data transmission unit 12 is repeatedly performed at a predetermined retry interval until the server 20 becomes normal. However, since the data to be transmitted to the server 20 may have a relatively large capacity, it is not preferable to repeat the transmission of the large-capacity data until the server 20 becomes normal in consideration of the network load. Absent. Therefore, in the present embodiment, an increase in network load is suppressed by setting a restart request having a relatively small capacity relative to data to be transmitted as a transmission target. The restart request can be formed only by including small size information such as the client ID, the identification information of the restart request, and the transmission date and time.

  If the server 20 recovers to the normal state while repeating the transmission of the restart request (step 203), the restart request control unit 23 can receive the restart request transmitted from the client 10 (step 106, 204). Upon receiving the restart request, the restart request control unit 23 causes the restart request source holding unit 24 to hold the client ID included in the restart request (Step 205). When the restart request is held, the restart request generation unit 25 generates a restart request including the client ID held in the restart request source holding unit 24 and causes the restart request holding unit 26 to hold the request (step 207). Even when a plurality of client IDs are stored in the restart request source holding unit 24, a restart request is generated for each client 10. The resumption request control unit 23 stores the client ID in the resumption request source storage unit 24, and then receives the resumption request from the client 10 having the client ID, in order to avoid holding the duplicated client ID. The restart request that has been made is discarded (steps 107 and 206, steps 108 and 208). Instead of discarding, a process may be performed in which a client ID already held under the same client ID is overwritten and saved.

  However, when the restart request corresponding to the client 10 is held in the restart request holding unit 26 and the restart request is normally received from the client 10 (steps 108 and 208), the restart request control unit 23 The client 10 is notified that a restart request for the client 10 has been generated (step 209). In response to this notification, the restart request transmitting unit 13 recognizes that the server 20 has returned to a normal state, and acquires a restart request from the server 20 (step 109).

  In this way, upon receiving the restart request, the restart request transmitting unit 13 notifies the transmission state management unit 14 of that. Note that the transmission state management unit 14 may always monitor the reception status of the restart request transmission unit 13 and detect the reception of the restart request. When detecting the reception of the restart request, the transmission state management unit 14 changes the state information from invalid to valid, thereby setting the data transmission to a valid state at present (step 110).

  When the data transmission becomes valid, the data transmission unit 12 restarts the data transmission that has been stopped because the server 20 has become abnormal. That is, data to be transmitted is extracted from the data storage unit 15 and transmitted to the server 20 as described above (step 101). On the other hand, the data receiving unit 22 of the server 20 in the normal state normally receives the data transmitted from the client 10 and stores the data in the data storage unit 27 (Step 201). In this way, data transmission from the client 10 to the server 20 is restarted.

  According to the present embodiment, when restarting data transmission from client 10 to server 20, data is not transmitted from server 20 to client 10. The notification of the restart request in step 209 is not a notification by the server 20 taking the initiative, but a response to the restart request from the client 10. That is, in the present embodiment, since data transmission can be resumed under the initiative of the client 10, it is necessary to make a hole in the firewall 2 in order to receive a notification from the server 20 that the data has been restored. There is no.

  By the way, it is assumed that the server 20 is in an abnormal state while a plurality of clients 10 are transmitting data to the server 20. In this case, the plurality of clients 10 transmit the restart request to the server 20 as described above. When the server 20 receives a restart request from a plurality of clients 10 at the same time by returning to the normal state, the reception processing and the generation processing of the restart request are concentrated, and a great processing load may be applied. come. Therefore, the restart request generator 25 generates a restart request so as to include the retry interval (step 207). In this case, it is preferable to set a different retry interval for each restart request so that the transmission timing of the restart request in each client 10 is scattered.

  The restart requests are obtained by the corresponding clients 10 (step 109). The retry interval included in the restart request is stored in the client 10 so that the restart request transmitting unit 13 can refer to the retry interval. Then, when the server 20 becomes abnormal again, the restart request transmitting unit 13 refers to the stored retry interval and transmits a restart request at the retry interval. As described above, since the plurality of clients 10 repeatedly transmit the restart request according to the retry interval specified by the server 20, the restart request is executed based on the transmission control in the server 20. . As a result, the server 20 cannot respond at the time of restoration of the normal state this time, but performs the reception processing of the restart request transmitted from the plurality of clients 10 and the generation processing of the restart request at the next recovery from the abnormal state. It can be executed in a distributed manner, thereby avoiding centralized processing.

  Further, as described above, the restart request transmitting unit 13 automatically transmits the restart request to the server 20 by setting the state information managed by the transmission state managing unit 14 to be invalid. However, if the status information is set to be invalid by the client user stopping the data transmission function provided by the data transmission unit 12, the resumption request transmission unit 13 activates the data transmission function against the intention of the client user. The restart request may not be transmitted to the server 20 so as not to cause the restart.

1 Internet, 2 firewall (FW), 10 client, 11 communication processing unit, 12 data transmission unit, 13 restart request transmission unit, 14 transmission state management unit, 15 data storage unit, 20 server, 21 communication processing unit, 22 data reception Unit, 23 restart request control unit, 24 restart request source holding unit, 25 restart request generation unit, 26 restart request holding unit, 27 data storage unit, 31 CPU, 32 ROM, 33 RAM, 34 hard disk drive (HDD), 35 mouse , 36 keyboard, 37 display, 38 input / output controller, 39 network interface (IF), 40 internal bus.

Claims (14)

Client and
A server for receiving data transmitted from the client;
Has,
The client,
Data transmission means for transmitting data to the server;
When the server enters an abnormal state in which the server does not receive the data transmitted by the data transmitting unit, a request transmitting unit that repeatedly transmits a transmission restart request to the server until the server returns to a normal state, and
Has,
Wherein the data transmitting means stops data transmission when the server is in an abnormal state, and resumes when the request transmitting means confirms that the server is in a normal state. system.   2. The client server system according to claim 1, wherein the server, when receiving the transmission restart request including the identification information of the client, has a holding unit that holds the identification information of the client.   3. The client server system according to claim 2, wherein the server has a generating unit that generates restartable information when the server enters a normal state.   4. The client-server system according to claim 3, wherein when there are a plurality of clients, the generation unit generates the restartable information for each client.   The method according to claim 1, wherein the request transmission unit recognizes that the server is in a normal state by generating the restartable information including the identification information of the client in the server. The client-server system as described.   5. The client-server system according to claim 4, wherein the data transmission unit restarts data transmission when the request transmission unit recognizes that the server has entered a normal state. The generation means includes a retry interval in the restartable information,
The client server system according to claim 4, wherein, when the server becomes abnormal again, the request transmitting unit repeatedly transmits the transmission restart request at the retry interval until the server becomes normal. The client has a management unit that manages a data transmission availability state in the data transmission unit with state information,
2. The client server system according to claim 1, wherein the data transmission unit stops transmitting data when the status information is set to a data transmission disabled state.   9. The client-server system according to claim 8, wherein when the server is in an abnormal state, the management unit sets the state information to a data transmission disabled state.   9. The client server system according to claim 8, wherein the request transmission unit does not transmit the transmission restart request when the status information is set to a data transmission disabled state by a user. Data transmission means for transmitting data to the server;
When the server enters an abnormal state in which the server does not receive the data transmitted by the data transmitting unit, a request transmitting unit that repeatedly transmits a transmission restart request to the server until the server returns to a normal state, and
Has,
The client according to claim 1, wherein the data transmission unit stops the data transmission when the server is in an abnormal state, and resumes the data transmission when the request transmission unit confirms that the server is in a normal state.   A server comprising: a generation unit configured to generate restartable information when receiving a transmission restart request transmitted from the client after a normal state in which data is received from an abnormal state in which data is not received from the client. Computer
Data transmission means for transmitting data to the server,
When the server enters an abnormal state in which the server does not receive the data transmitted by the data transmitting unit, a request transmitting unit that repeatedly transmits a transmission restart request to the server until the server returns to a normal state,
Function as
The program, wherein the data transmission means stops the data transmission when the server is in an abnormal state, and resumes the data transmission when the request transmission means confirms that the server is in a normal state. A program for causing a computer to function as generating means for generating resumable information when receiving a transmission resumption request transmitted from the client after a normal state in which the computer receives data from an abnormal state in which data is not received from the client. .

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