JP2009266138A - Communication system, server system, relay system, and communication method and program used for them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication system which can surely synchronize a state between server systems even if communication between a standby system and an active system is failed. <P>SOLUTION: The communication system is constituted of two server systems 1a and 1b and a plurality of terminals 2a to 2c, and one of the server systems operates as the active system while the other operates as the standby system. In the communication system, communication from the terminals 2a to 2c to the active server system 1a is carried out through the standby server system 1b, and communication contents to the active server system 1a are temporarily held in the standby system 1b to synchronize the respective states of the active server system 1a and standby system 1b by processing the temporarily held communication contents after confirming the completion of the processing of the communication contents in the active server system 1a. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a communication system, a server device, a relay device, a communication method used therefor, and a program therefor, and more particularly to a communication system that enables server switching by group communication using a data sharing tool executed in a client-server configuration. About.

  By reducing the cost of broadband communication lines, intranet and Internet communications have evolved from voice calls to advanced communications that combine videophones, whiteboards for collaborative work, and data sharing tools such as application sharing. The number of participants is 1: 1, and a combination of two or more people is widely used.

  FIG. 23 shows a system for realizing communication using the above data sharing tool. FIG. 23 shows a system configured by a client-server system. In this system, the server 7 has two roles. The first role is to make each client 9a-9d have the same event generation order such as writing to the whiteboard and reflecting application sharing operation in each client 9a-9d. Is to aggregate the contents of the messages once and distribute them. Another role is to manage communication-related data such as the content being communicated, participant information, and the status as management data 8.

  Since the server 7 has a role as described above, if the server 7 stops its function during communication, communication cannot be continued. In order to prevent communication interruption due to a device failure or the like, it is conceivable to prepare a backup server device (standby system) in addition to an operating server device (active system). In order to execute this, since the data managed by the server 7 changes during communication, the state of the active server device and the state of the standby server device must always be synchronized during communication. An example of the state synchronization method of the apparatus is described in Patent Document 1.

In the method described in Patent Document 1, communication from a transmission terminal to an active system device is performed via a standby system device. Then, the standby system device always synchronizes the states of the two devices during communication by transferring the received communication contents to the active device and performing data processing similar to that of the active device.
JP 2006-229919 A

  In the communication system related to the present invention described above, since no consideration is given to data loss due to a communication failure between the standby server and the active server, the communication failure between the standby server and the active server fails. As a result, there is a problem that state synchronization between devices fails.

  Further, in the communication system related to the present invention, since all communication passes through the remote standby server while the communication contents arrive at all the clients via the active server from the client, the standby server is When installed in a remote location from the active server, there is a problem that a delay until an operation on a certain client is reflected on all clients increases.

  SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-described problems, and a communication system and a server apparatus that can reliably execute state synchronization between server apparatuses even when a communication failure occurs between a standby system and an active system. It is to provide a relay apparatus, a communication method used for them, and a program thereof.

The communication system according to the present invention includes two server devices and a plurality of terminal devices, and operates one of the server devices as an active system and the other of the server devices as a standby system. A communication system,
Communication from the terminal device to the active server device is performed via the standby server device,
In the standby server device, the communication content to the active server device is temporarily stored, and after the processing of the communication content in the active server device is confirmed, the temporary storage is performed. The state of each of the active server device and the standby server device is synchronized by processing the communication contents.

Another communication system according to the present invention includes two server devices, a plurality of terminal devices, and a relay device, and operates one of the server devices as an active system and the other of the server devices. A communication system operating as a standby system,
Communication from the terminal device to the active server device is performed via the relay device,
In the relay device, the communication content between the terminal device and the active server device is temporarily stored, and the communication content processing in the active server device is completed for the communication content. The statuses of the active server device and the standby server device are synchronized by transmitting to the standby server device after confirmation.

The server device according to the present invention includes two server devices and a plurality of terminal devices, and operates one of the server devices as an active system and the other of the server devices as a standby system. A server device used in a communication system,
Perform communication from the terminal device to the active system via the standby system,
When operating as the standby system, the communication content to the active system is temporarily stored, and after confirming that the processing of the communication content in the active system is completed, the temporarily stored communication content is processed. By doing so, the states of the active system and the standby system are synchronized.

The relay device according to the present invention includes two server devices, a plurality of terminal devices, and a relay device, and operates one of the server devices as an active system and the other of the server devices as a standby system. A relay device used in a communication system operated as
Perform communication from the terminal device to the active server device via its own device,
The communication content between the terminal device and the active server device is temporarily saved, and the communication content is confirmed after the communication content processing in the active server device is completed. By transmitting to the standby server device, the states of the active server device and the standby server device are synchronized.

The communication method according to the present invention includes two server devices and a plurality of terminal devices, and operates one of the server devices as an active system and the other of the server devices as a standby system. A communication method used in a communication system,
Communication from the terminal device to the active server device is performed via the standby server device,
In the standby server device, the communication content to the active server device is temporarily stored, and after the processing of the communication content in the active server device is confirmed, the temporary storage is performed. The state of each of the active server device and the standby server device is synchronized by processing the communication contents.

Another communication method according to the present invention includes two server devices, a plurality of terminal devices, and a relay device, and operates one of the server devices as an active system and the other of the server devices. A communication method used for a communication system operated as a standby system,
Communication from the terminal device to the active server device is performed via the relay device,
In the relay device, the communication content between the terminal device and the active server device is temporarily stored, and the communication content processing in the active server device is completed for the communication content. The statuses of the active server device and the standby server device are synchronized by transmitting to the standby server device after confirmation.

The program according to the present invention is composed of two server devices and a plurality of terminal devices, and operates such that one of the server devices operates as an active system and the other of the server devices operates as a standby system. A program to be executed by a central processing unit in a server device used in the system,
Perform communication from the terminal device to the active system via the standby system,
From the active system, a process of notifying the standby system of a message indicating that the processing of communication contents has been completed when operating as the active system, a process of temporarily storing communication contents when operating as the standby system, and Including a process of deleting the temporarily stored communication content when receiving the message and performing state synchronization in the standby system,
When operating as the standby system, the communication content to the active system is temporarily stored, and after confirming that the processing of the communication content in the active system is completed, the temporarily stored communication content is processed. Thus, the states of the active system and the standby system are synchronized.

Another program according to the present invention includes two server devices, a plurality of terminal devices, and a relay device, and operates one of the server devices as an active system and waits for the other of the server devices. A program to be executed by a central processing unit in a relay device used in a communication system operated as a system,
Communication from the terminal device to the active server device is performed via the relay device,
From each of the server devices, a message indicating that the processing of the communication content has been completed is notified to the relay device,
A process for temporarily storing the communication content; a deletion of the temporarily stored communication content when the message is received from the active server device; and a transmission of the temporarily stored communication content to the standby server device. Processing to be executed,
The communication content between the terminal device and the active server device is temporarily saved, and the communication content is confirmed after the communication content processing in the active server device is completed. The state of each of the said active system and the said standby system is synchronized by making it transmit to the server apparatus of a standby system, It is characterized by the above-mentioned.

  The present invention is configured and operated as described above, so that the communication delay between the clients does not change, and even when a communication failure occurs between the standby system and the active system, the state synchronization between the server devices is achieved. Can be reliably executed.

Next, embodiments of the present invention will be described with reference to the drawings. First, an outline of a communication system according to the present invention will be described. The first communication system of the present invention is operated in pairs as a server device (standby system) and a server device (active system).
The server device also has a message transmission means for notifying the standby system that the processing of the communication content in the own device has been completed when operated as an active system, and a message for temporarily storing the communication content when operated as a standby system Temporary storage means, state update means for executing deletion of temporarily stored communication contents and state synchronization in the standby system, and retransmission confirmation means for periodically retransmitting temporarily stored communication contents.

  In the first communication system of the present invention, the configuration as described above is adopted, communication from the terminal device to the server device (active system) is performed via the server device (standby system), and the server device (standby system). However, the communication content is temporarily saved until it can be confirmed that the communication sent to the server device (active system) via the local device has been processed, and the completion of processing on the server device (active system) is confirmed. Synchronize state by processing from.

  Further, in the first communication system of the present invention, the communication contents that cannot be confirmed every predetermined time are retransmitted to the server device (active system). Further, in the first communication system of the present invention, when a failure occurs in the server device (active system), the server device (standby system) executes communication that is temporarily stored without confirming completion of processing. As a result, in the first communication system of the present invention, the state synchronization between the server devices can be reliably executed even when a communication failure occurs between the standby system and the active system.

  Next, in the second communication system of the present invention, a relay apparatus exists between a server apparatus operated as a standby system and a server apparatus operated as an active system and a terminal apparatus. The server device has message transmission means for notifying the relay device that the processing of communication contents has been completed. In addition, the relay device temporarily stores message contents to be transmitted to the server apparatus (active system), deletes the temporarily stored communication contents, and transfers the communication contents to the server apparatus (standby system). Message transfer means, and retransmission confirmation means for periodically retransmitting the stored communication contents.

  The second communication system of the present invention employs such a configuration, and performs communication from the terminal device to the server device (active system) via the relay device. The relay device temporarily saves the communication contents until it can be confirmed that the communication sent to the server device (active system) has completed processing, and the server device (standby) confirms the completion of processing in the server device (active system). Transfer the communication contents to the system.

  Further, in the relay device, the transfer contents to the server device (standby system) are also temporarily stored until the processing completion in the server device (active system) is confirmed, as described above. Further, the relay device retransmits the communication contents whose completion cannot be confirmed every certain time to both the standby and active server devices. Furthermore, in the relay device, when a failure occurs in the server device (active system), the communication that has been temporarily stored without confirming the completion of processing is transmitted to the server device (standby system). Thus, in the second communication system of the present invention, it is possible to realize a system that does not cause deterioration in communication delay between clients even when a standby server is installed at a remote place.

  FIG. 1 is a block diagram showing a configuration example of a communication system according to the first exemplary embodiment of the present invention. 1, the communication system according to the first embodiment of the present invention includes a server device (active system) 1a, a server device (standby system) 1b, and terminal devices 2a to 2c.

  In FIG. 1, an arrow connecting the devices means that communication is performed, but does not mean that each device is directly connected. For example, communication may be enabled by connecting all devices to the same network device, or all devices may be installed at different bases and enabled to communicate via a network. In the terminal devices 2a to 2c, a client for providing an actual communication service to a user operates, and input / output is performed with the user.

  FIG. 2 is a block diagram showing a configuration example of the server apparatus according to the first embodiment of the present invention. In FIG. 2, the server device 1 includes a data processing device 11 and a storage device 12. The server device (active system) 1a and the server device (standby system) 1b shown in FIG. 1 have the same configuration as the server device 1 shown in FIG.

  The data processing device 11 includes a message reception unit 111, a message temporary storage unit 112, a state update unit 113, a switching unit 114, a retransmission confirmation unit 115, a message processing unit 116, and a message transmission unit 117. It consists of The storage device 12 includes a message storage unit 121 and a transmission destination storage unit 122.

  The message receiving unit 111 receives a message from the terminal device 2 or another server device, checks whether the same message has been received by the time of reception, and if it is a new message, Appropriate means is selected for each system (whether it is an active system or a standby system) and the message type, and processing is entrusted. If the message reception unit 111 has received the message before, the message reception unit 111 discards the message without executing the subsequent processing.

  The temporary message storage unit 112 assigns consecutive numbers to the messages received from the message reception unit 111 and temporarily stores them in the message storage unit 121, and then sends the message to the message transmission unit 117.

  The state update unit 113 reads the corresponding message from the message storage unit 121 using the serial number in the processing completion confirmation message received from the message reception unit 111, and deletes the message in the message storage unit 121. Subsequently, the state update unit 113 passes the read message to the message processing unit 116.

  The switching unit 114 notifies the message receiving unit 111 and the message transmitting unit 117 of the change from the standby system to the active system when a message about the down of the server device (active system) 1a is passed from the message receiving unit 111. At the same time, the messages stored in the message storage unit 121 are read out in order of serial numbers and sent to the message processing unit 116. At this time, the read message is deleted from the message storage unit 121.

  The retransmission confirmation unit 115 confirms the message storage unit 121 at regular time intervals, reads the stored message, and sends it to the message transmission unit 117. The message transmission unit 117 transmits a message sent from another means to an appropriate apparatus or discards the message according to the system at that time and the preceding means. In this case, information such as an address necessary for transmission is stored in the transmission destination storage unit 122.

  FIG. 3 is a sequence chart showing the operation of the communication system according to the first embodiment of the present invention, and FIGS. 4 to 8 are flowcharts showing the operation of the server device according to the first embodiment of the present invention. The overall operation of the communication system according to the present embodiment will be described with reference to FIGS.

  In the processing of each device shown in FIG. 3, a CPU (Central Processing Unit) (not shown) which is a main component of each of the server device 1 and the terminal device 2 is stored in the storage device 12 [or memory, etc.]. Realized by executing the program. Similarly, the processing illustrated in FIGS. 4 to 8 is realized by the CPU of the server device 1 executing a program stored in the storage device 12.

  The overall operation of the communication system according to the present embodiment is as follows: synchronization processing while the server device (active system) 1a is operating normally, messages from the server device (standby system) 1b to the server device (active system) 1a There are roughly three types of retransmission processing, switching processing when the server device (active system) 1a goes down.

  First, an overview of synchronization processing of the communication system according to the present embodiment will be described with reference to FIG. In a state where communication is being performed, the terminal device 2 transmits a message to the server device (standby system) 1b according to the user's tool operation (a1 in FIG. 3). It is assumed that the address of the server device (standby system) 1b is given to the terminal device 2 in advance.

  The server device (standby system) 1b that has received the message from the terminal device 2 performs processing such as temporary storage (a2 in FIG. 3) and transmits the message to the server device (active system) 1a (a3 in FIG. 3). .

  When the server apparatus (active system) 1a receives a message, it performs message processing inherent to the application (a4 in FIG. 3). The result is transmitted to all the terminal devices 2 (a5 in FIG. 3) and received by each terminal device 2 (a6 in FIG. 3). The server device (active system) 1a transmits a processing completion confirmation message to the server device (standby system) 1b after transmission to the terminal device 2 is completed (a7 in FIG. 3). The server apparatus (standby system) 1b that has received the message synchronizes the state as the server apparatus by executing the temporarily stored message (a8 in FIG. 3).

  Next, details of the synchronization processing will be described with reference to FIGS. FIG. 4 is a detailed description of the process of a2 in FIG.

  When receiving a message from the outside (step S1 in FIG. 4), the message receiving unit 111 of the data processing device 11 of the server device (standby system) 1b selects a means for entrusting message processing. First, the message receiving unit 111 determines whether or not the own device is an active system (step S2 in FIG. 4), and confirms whether or not the message transmission source is the terminal device 2 since it is a standby system (FIG. 4). 4 step S3). Here, it is assumed that information on whether the own apparatus is an active system or a standby system is given in advance.

  If the message transmission source is the terminal device 2, the message reception unit 111 sends the message to the message temporary storage unit 112. The message temporary storage unit 112 assigns a serial number that can be uniquely identified to the message (step S4 in FIG. 4), and stores the message with the serial number in the message storage unit 121 (step S5 in FIG. 4).

  The message temporary storage unit 112 sends the message to the message transmission unit 117 after storing the message. The message transmission unit 117 transmits the message sent from the message temporary storage unit 112 to the server device (active system) 1a (step S6 in FIG. 4). In this case, it is assumed that the address of the server device (active system) 1a necessary for transmission is stored in the transmission destination storage unit 122.

  Next, message processing (processing a4 in FIG. 3) in the server apparatus (active system) 1a will be described with reference to FIGS. Since the server device (active system) 1a is also the same as the server device (standby system) 1b, the operation at the time of message reception is the same up to the steps S1 and S2 in FIG.

  The message receiving unit 111 of the data processing apparatus 11 of the server apparatus (active system) 1a determines that the message is an active system, and then checks the serial number of the received message to determine whether the message has already been received (FIG. 5). Step S7). In the message receiving unit 111, it is possible to determine whether or not the message has been received by holding the serial number of the message received last time.

  If the message reception unit 111 has received the message, the message reception unit 111 discards the message (step S12 in FIG. 5) and ends the process. Further, if the message reception unit 111 is a new message, the message reception unit 111 sends the message to the message processing unit 116, and executes the original processing of the application (step S8 in FIG. 5).

  The message processing unit 116 transmits the processing result and the serial number of the processed message to the message transmission unit 117 in order to reflect the result of the original processing of the application to the communicating terminal device 2. The message transmission unit 117 determines whether or not the own device is an active system, and transmits the processing result to all the terminal devices 2 in communication (step S9 in FIG. 5).

  After the transmission to all the terminal devices 2 is completed, the message transmission unit 117 checks whether or not the address of the server device (standby system) 1b is stored in the transmission destination storage unit 122 (step S10 in FIG. 5). If stored, a processing completion confirmation message including the serial number assigned to the processing message is transmitted to the server device (standby system) 1b (step S11 in FIG. 5). It is assumed that the addresses of all the terminal devices 2, server device (active system) 1a, and server device (standby system) 1b necessary for transmission are stored in the transmission destination storage unit 122.

  Next, processing completion confirmation message reception processing (processing a8 in FIG. 3) in the server device (standby system) 1b will be described with reference to FIGS. The operation when the processing completion confirmation message is received is the same in steps S1 to S3 in FIG.

  When the message receiving unit 111 of the data processing device 11 of the server device (standby system) 1a determines that the transmission source is not the terminal device 2, it further determines whether it is a processing completion confirmation message (step S13 in FIG. 6). If the message reception unit 111 is a processing completion confirmation message, the message reception unit 111 sends the message to the state update unit 113.

  The status update unit 113 reads the stored message corresponding to the serial number included in the message from the message storage unit 121 and deletes the message in the message storage unit 121 (step S14 in FIG. 6). The state update unit 113 sends the read message to the message processing unit 116.

  The subsequent processing is the same as the operation in the server device (active system) 1a shown in FIG. 5, and the message is processed by the message processing unit 116 (step S15 in FIG. 6), whereby the server device (active system) 1a. The same processing is executed, and the state is synchronized.

  Although the processing result of the message processing unit 116 and the serial number of the processed message are transmitted to the message transmission unit 117, the message transmission unit 117 determines whether or not the own device is an active system. The processing result is discarded without being transmitted to the terminal device 2 (step S16 in FIG. 6). In this case, the processing completion confirmation message is not transmitted to the server device (active system) 1a.

  Next, message retransmission processing will be described with reference to FIG. In the server device (standby system) 1b, the following operations are executed at predetermined time intervals.

  First, the retransmission confirmation unit 115 confirms whether a message is stored in the message storage unit 121. When the message is stored (step S21 in FIG. 7), the retransmission confirmation unit 115 reads the messages from the message storage unit 121 in the order of serial numbers (step S22 in FIG. 7), and sends the message to the message transmission unit 117.

  The message transmission unit 117 transmits the message from the retransmission confirmation unit 115 to the server device (active system) 1a (step S23 in FIG. 7). If no message is stored in the message storage unit 121, the retransmission confirmation unit 115 ends without performing any processing.

  Finally, the switching process will be described with reference to FIGS. The message receiving unit 111 of the data processing device 11 of the server device (standby system) 1b detects that the server device (active system) 1b is down for some reason during communication (step S31 in FIG. 8).

  As a detection method of this down, for example, the server device (active system) 1a is checked for life and death by the terminal device 2 or other dedicated device, and the device that detects the down takes the server device (standby system) 1b down. It is conceivable to send a notification message.

  Alternatively, it may be determined that the server apparatus (standby system) 1b itself performs alive confirmation or the message retransmission process is repeated a predetermined number of times for the same message. Further, the server device (active system) 1b itself may send a message to notify the server device (standby system) 1b that the server device (standby system) 1b itself is in the event of insufficient processing capacity or partial failure.

  When the message receiving unit 111 receives a message notifying the down as described above, the message receiving unit 111 sends the message to the switching unit 114. When the switching unit 114 detects that the message is down, the switching unit 114 notifies the message reception unit 111 and the message transmission unit 117 that the own device has been switched from the standby system to the active system (step S32 in FIG. 8).

  Subsequently, the switching unit 114 checks whether a message is stored in the message storage unit 121 (step S33 in FIG. 8). When the message is stored, the switching unit 114 reads the message from the message storage unit 121 in the order of the serial number (step S34 in FIG. 8), and sends the message to the message processing unit 116.

  The subsequent operations in steps S35 to S38 are the same as those shown as steps S8 to S11 in FIG. However, in the operation of step S37, since the standby address is not stored in the transmission destination storage unit 122, the message transmission unit 117 ends without transmitting the processing completion confirmation. Also, if no message is stored in the message storage unit 121, the processing is terminated as it is.

  As described above, in this embodiment, the server device (standby system) 1b confirms that the communication transmitted to the server device (active system) 1a via its own device has been processed, and then performs message processing. By performing state synchronization according to the above, it is possible to prevent both the server device (active system) 1a and the server device (standby system) 1b from entering different states even when communication between server devices fails.

  Further, in the present embodiment, the communication contents whose completion cannot be confirmed are retransmitted to the server apparatus (active system) 1a at regular intervals, so that the state synchronization is performed when a failure occurs in the server apparatus (active system) 1a. Therefore, the amount of stored messages that need to be processed by the server device (standby system) 1b can be reduced, and the switching time when a failure occurs can be shortened.

  FIG. 9 is a block diagram showing a configuration of a communication system according to the second exemplary embodiment of the present invention. In FIG. 9, the server device (active system) 1a and the server device (standby system) 1b shown in FIG. 1 are replaced with a server device (active system) 3a and a server device (standby system) 3b having the same name and different contents. . In addition, a relay device 4 is added to the communication system according to the second embodiment of the present invention. Further, the arrows between the devices in FIG. 9 mean that communication is performed as in FIG. 1, but it does not mean that each device is directly connected.

  FIG. 10 is a block diagram showing the configuration of the server device according to the second embodiment of the present invention. In FIG. 10, the server device 3 includes a data processing device 31 and a storage device 32. The server device (active system) 3a and the server device (standby system) 3b shown in FIG. 9 have the same configuration as the server device 3 shown in FIG.

  The data processing device 31 includes a message receiving unit 111, a message processing unit 116, and a message transmission unit 117. The storage device 12 includes a transmission destination storage unit 122.

  These message reception unit 111, message processing unit 116, message transmission unit 117, and transmission destination storage unit 122 are the same as the message reception unit 111, message processing unit 116, message transmission unit 117, and transmission destination storage unit 122 shown in FIG. is there.

  FIG. 11 is a block diagram showing the configuration of the relay device 4 of FIG. In FIG. 11, the relay device 4 includes a data processing device 41 and a storage device 42. The data processing device 41 includes a message reception unit 411, a message temporary storage unit 412, a message transfer unit 413, a server switching control unit 414, a retransmission confirmation unit 415, and a message transmission unit 417. Yes.

  The storage device 42 includes a message storage unit 421, a transferred message storage unit 423, and a transmission destination storage unit 422. The message temporary storage unit 412 and the message storage unit 421 are the same as the message temporary storage unit 112 and the message storage unit 121 in the server device 1 shown in FIG.

  The message receiving unit 411 selects an appropriate means for each state and message type of the relay device 4 at that time, and sends a message. There are three types of states of the relay device 4: “active system operation”, “standby system operation”, and “switching”.

  The message transfer unit 413 reads the corresponding message from the message storage unit 421 using the serial number in the processing completion confirmation message received from the message reception unit 411, and deletes the message in the message storage unit 421. Subsequently, the message transfer unit 413 passes the read message to the message transmission unit 417 and stores the message in the transferred message storage unit 423.

  When the server switching control unit 414 receives a message about the down of the server device (active system) 3a from the message receiving unit 411, the server switching control unit 414 reads the message stored in the message storage unit 421 and the transferred message storage unit 423, and The message is sent to the message transmission unit 417.

  The retransmission confirmation unit 415 confirms the message storage unit 421 and the transferred message storage unit 423 at regular time intervals, reads out any stored messages, and sends them to the message transmission unit 417. The message transmission unit 417 transmits a message sent from another means to an appropriate device according to the state of the relay device 4 at that time and the preceding means.

  FIG. 12 is a sequence chart showing the operation of the communication system according to the second embodiment of the present invention, and FIGS. 13 to 18 are flowcharts showing the operation of the server device according to the second embodiment of the present invention. The overall operation of the communication system according to the present embodiment will be described with reference to FIGS.

  The processing of each device shown in FIG. 12 is performed by a CPU (Central Processing Unit) (not shown), which is a main component of each of the relay device 4, the server device 3, and the terminal device 2. Etc.] is executed by executing the program stored in the above. Similarly, the processes shown in FIGS. 13 to 18 are realized by the CPUs of the server device 3 and the relay device 4 executing the programs stored in the storage devices 32 and 42, respectively.

  The overall operation of the present embodiment is as follows: synchronization processing while the server device (active system) 3a is operating normally, relay device 4 to server device (standby system) 3b and server device (active system) 3a There are roughly three types of message retransmission processing and switching processing when a failure occurs in the server device (active system) 3a.

  First, an overview of synchronization processing of the communication system according to the present embodiment will be described with reference to FIG. This synchronization processing is performed when the state of the relay device 4 is “operating in operation”. Compared to the operation of the first embodiment of the present invention shown in FIG. 3, the operation indicated by the process of b8 is the same as the process operation of a6 in the first embodiment of the present invention.

  When the terminal device 2 transmits a message to the server device (active system) 3a in accordance with the user's tool operation (b1 in FIG. 12) while communication is being performed, the message addressed to the server device (active system) 3a is temporarily After processing such as temporary storage is performed via the relay device 4 (b2 in FIG. 12), the data is transmitted from the relay device 4 to the server device (active system) 3a (b3 in FIG. 12).

  When the server device (active system) 3a receives the message, it performs message processing inherent to the application (b4 in FIG. 12). The processing result is transmitted from the server device (active system) 3a to the terminal device 2 via the relay device 4 (b5 to b7 in FIG. 12).

  In parallel with the above operation, the server device (active system) 3a transmits a processing completion confirmation message to the relay device 4 after the transmission of the message processing result (b9 and b10 in FIG. 12).

  When the relay device 4 receives the processing completion confirmation message, the relay device 4 transmits the message temporarily stored in the above processing to the server device (standby system) 3b (b11 and b12 in FIG. 12).

  The server device (standby system) 3b executes the message transmitted from the relay device 4 to synchronize the state as the server device with the server device (active system) 3a (b13 in FIG. 12).

  After the execution of the synchronization process is completed, the server apparatus (standby system) 3b transmits a process completion confirmation message to the relay apparatus 4 (b14 in FIG. 12). When the relay device 4 receives the processing completion confirmation message from the server device (active system) 3a, the relay device 4 performs processing such as deletion of the stored message that has become unnecessary (b15 in FIG. 12).

  Next, details of the synchronization processing will be described with reference to FIGS. FIG. 13 shows the details of the process b2 described above. Compared to the operation of the first embodiment of the present invention shown in FIG. 4, the operations shown in steps S44 and S45 of FIG. 13 are the same as the operations of the first embodiment of the present invention.

  When receiving a message from the outside (step S41 in FIG. 13), the message receiving unit 411 of the data processing device 41 of the relay device 4 selects a means for entrusting message processing.

  First, the message receiving unit 411 checks whether or not the transmission source is the terminal device 2 (step S42 in FIG. 13). If the message reception unit 411 is a message from the terminal device 2, the message reception unit 411 next checks whether or not the state of the own device is “standby system operation” (step S43 in FIG. 13). In this case, since the state of the own device is “operating in operation”, the message receiving unit 411 sends the message to the message temporary storage unit 412.

  The message temporary storage unit 412 assigns a serial number that can be uniquely determined to the message (step S44 in FIG. 13), and stores the message with the serial number in the message storage unit 421 (step S45 in FIG. 13). Thereafter, the temporary message storage unit 412 sends the message to the message transmission unit 417.

  The message transmission unit 417 confirms the state of the own device (step S46 in FIG. 13). Since it is “operating in operation”, the message is transmitted to the server device (active system) 3a (step S47 in FIG. 13).

  Next, details of message processing (processing b4 and b9 in FIG. 12) in the server apparatus (active system) 3a will be described with reference to FIG. Compared to the operation of the first embodiment of the present invention shown in FIG. 5, the operations shown in steps S61 to S63 and S67 of FIG. 15 are the same as the operations of the first embodiment of the present invention. It is.

  When the message transmission unit 117 of the server device (active system) 3a determines that the own device is the active system, the processing result is temporarily transmitted to the relay device 4 in order to transmit the processing result to all the terminal devices 2. (Step S64 in FIG. 15). After transmitting the processing result, the message transmission unit 117 further transmits a processing completion confirmation message to the relay device 4 (step S65 in FIG. 15).

  Next, details of the operation at the time of reception of the processing result message addressed to the terminal device 2 in the relay device 4 (processing of b6 in FIG. 12) will be described with reference to FIG.

  After receiving the message (step S41 in FIG. 13), the message receiving unit 411 is not a message from the terminal device 2 (step S42 in FIG. 13) but a message addressed to the terminal device 2 (step S49 in FIG. 13). Is sent to the message transmission unit 417. The message transmission unit 417 transmits the message to all the terminal devices 2 based on the information in the transmission destination storage unit 422 (step S50 in FIG. 13).

  Next, details of the process completion confirmation message reception process (process b11 in FIG. 12) in the relay apparatus 4 will be described with reference to FIGS. 13 and 14. FIG.

  After receiving the message (step S41 in FIG. 13), the message reception unit 411 is not a message from the terminal device 2 (step S42 in FIG. 13), but is not a message addressed to the terminal device 2 (step S49 in FIG. 13). Since it is a message (step S51 in FIG. 14), the transmission source is confirmed (step S53 in FIG. 14). Since the message reception unit 411 is a message from the server device (active system) 3 a, the message reception unit 411 sends the message to the message transfer unit 413.

  The message transfer unit 413 reads the corresponding stored message from the serial number included in the message from the message storage unit 421 and deletes the message from the message storage unit 421 (step S54 in FIG. 14). The message transfer unit 413 sends the read message to the message transmission unit 417.

  The message transmission unit 417 transmits the message to the server device (standby system) 3b (step S55 in FIG. 14). Further, the message transfer unit 413 stores the message in the transferred message storage unit 423 (step S56 in FIG. 14).

  Next, details of message processing (processing of b13 in FIG. 12) in the server apparatus (standby system) 3b will be described with reference to FIG. The processing in steps S61 and S62 in FIG. 15 is the same as the message processing in the server apparatus (active system) 3a, but is not the active system (step S63 in FIG. 15), so the message processing result is not transmitted. (Step S66 in FIG. 15). Thereafter, the processing completion confirmation message is transmitted to the relay device 4 (step S65 in FIG. 15).

  Finally, details of the process completion confirmation message reception process (process b15 in FIG. 12) in the relay apparatus 4 will be described with reference to FIGS.

  The processing in steps S41, S42, S49 in FIG. 13 and step S51 in FIG. 14 is the same as that upon reception of the processing completion confirmation message from the server device (active system) 3a, but the server device (active system) 3a. (Step S53 in FIG. 14), the message transfer unit 413 deletes the corresponding stored message from the serial number included in the message from the transferred message storage unit 423 (step S57 in FIG. 14).

  Following the description of the synchronization processing described above, the message retransmission processing will be described with reference to FIG. In the relay device 4, the following operation is executed at predetermined time intervals.

  Each processing of the content confirmation (step S71 in FIG. 16), message reading (step S72 in FIG. 16), and message transmission (step S73 in FIG. 16) by the retransmission confirmation unit 415 is shown in FIG. This is the same as the operation in the first embodiment.

  Subsequently, the retransmission confirmation unit 415 confirms whether or not the message is stored in the transferred message storage unit 423 (step S74 in FIG. 16). When the message is stored, the retransmission confirmation unit 415 reads only one stored message according to the serial number (step S75 in FIG. 16), and sends the message to the message transmission unit 417. The message transmission unit 417 transmits the message to the server device (standby system) 3b (step S76 in FIG. 16).

  Subsequently, the retransmission confirmation unit 415 confirms whether or not the retransmitted message remains in the transferred message storage unit (step S77 in FIG. 16). If the retransmitted message is still in the transferred message storage unit, the retransmission confirmation unit 415 repeats from reading the message. The retransmission confirmation unit 415 ends the operation when there is no message in the transferred message storage unit 423 or when the retransmitted message does not remain in the transferred message storage unit 423.

  Finally, the switching process will be described with reference to FIGS. Compared to the operation of the switching process of the first embodiment of the present invention shown in FIG. 8, the operation shown in step S81 is the same as the operation of the first embodiment of the present invention.

  After detecting the down of the server device (active system) 3a, the message receiving unit 411 sets the state of the own device to “switching” (step S82 in FIG. 17), and sends the server device (operating) to the message transmitting unit 417 and the server switching control unit 414. System) 3a down notification.

  The message transmission unit 417 notifies the server device (standby system) 3b of server switching (step S83 in FIG. 17). The server switching control unit 414 checks whether or not there is a message in the transferred message storage unit 423 (step S84 in FIG. 17), and if there is a message, reads one message according to the serial number (step S85 in FIG. 17). The message is sent to the message transmission unit 417. The message transmission unit 417 sends the message to the server device (standby system) 3b.

  After the transmission of the message, the server switching control unit 414 confirms whether or not the transmitted message remains in the transferred message storage unit 423 (step S87 in FIG. 17). When the processing in the server device (standby system) 3b is completed and the processing completion confirmation message is returned to the relay device 4, the message in the transferred message storage unit 423 is deleted.

  The server switching control unit 414 checks the transferred message storage unit 423 at regular intervals (step S88 in FIG. 17) until the message in the transferred message storage unit 423 is deleted (step S88 in FIG. 17). If it is confirmed that the message has been deleted, the server switching control unit 414 processes the next message remaining in the forwarded message storage unit 423 in the same manner as described above.

  When there are no more messages stored in the transferred message storage unit 423, the server switching control unit 414 subsequently checks whether or not a message is stored in the message storage unit 421 (step S89 in FIG. 18). When the messages are stored, the server switching control unit 414 reads the messages in the order of the serial numbers (step S90 in FIG. 18) and deletes the messages in the message storage unit 421.

  The read message is transmitted from the server switching control unit 414 to the message transmission unit 417 and transmitted to the server device (active system) 3a (step S91 in FIG. 18). If the message storage unit 421 becomes empty, the server switching control unit 414 switches the state of the relay device 4 to “standby operation” (step S92 in FIG. 18).

  Other operations associated with the switching process will be described. The server device (standby system) 3b operates as an active system in response to a server switching notification message from the relay device 4. Therefore, when the message transmitted from the relay device 4 is received, the operation proceeds to steps S61, S62, S63, S64, and S65, so that the processing result is transmitted to the terminal device 2.

  When a message arrives from the terminal device 2 to the relay device 4 during the switching process, the operation at the time of reception of the relay device 4 shown in FIG. 13 is “switching”, so steps S41 and S42. , S43, S44, S45, S46 in this order and stored in the message storage unit 421.

  The stored message is read from the message storage unit 421 during the switching process and transmitted to the server device (standby system) 3b. Further, after the switching process is completed, the state of the relay device 4 becomes “standby system operation”, and the operation at the time of message reception from the terminal device 2 is in the order of steps S41, S42, S43, S48, and the server being operated It is transmitted to the device (standby system) 3b.

  As described above, in the present embodiment, the relay device 4 holds the transmission content to both the server device (active system) 3a and the server device (standby system) 3b until the message processing in each server device is completed. Thus, it is possible to prevent a state synchronization failure due to a communication failure between the relay device 4 and the server device.

  Further, in the present embodiment, the server 4 (standby system) 3b is transferred by transferring the communication contents to the server apparatus (standby system) 3b after the relay apparatus 4 completes processing in the server apparatus (active system) 3a. No matter where it is installed, it does not affect the communication time between clients via the server device (active system) 3a.

  Furthermore, in the present embodiment, processing is required for state synchronization when a failure occurs in the server device (active system) 3a by retransmitting the communication contents that cannot be confirmed every certain time to the server device. The amount of stored messages can be reduced, and the switching time when a failure occurs can be shortened.

  Furthermore, in the present embodiment, during the switching process associated with the stoppage of the function of the server device (active system) 3a, the message from the terminal device 2 that has arrived during the switching is temporarily stored, and the message that has already been stored is stored. By giving priority to the process, the terminal device 2 can accept a user operation even during switching.

  Next, the operation of the best mode for carrying out the present invention will be described using specific examples. Such an example corresponds to the above-described first embodiment of the present invention.

  This embodiment considers a central processing unit and a memory as a data processing device, and a hard disk [hereinafter referred to as an HDD (Hard Disk Drive)] as a storage device. When the computer program on the memory is executed by the central processing unit, it functions as each means. Further, the server device, the relay device, and the terminal device are connected to a LAN (Local Area Network) at each installation base, and the LANs are connected to each other via a WAN (Wide Area Network). All networks shall be based on the Internet protocol.

  FIG. 19 is a block diagram showing a network configuration of the communication system according to the first embodiment of the present invention, FIG. 20 is a diagram showing a message from the terminal device in the first embodiment of the present invention, and FIG. FIG. 22 is a diagram showing a message assigned with a serial number in the first embodiment of the present invention, and FIG. 22 is a diagram showing a processing completion confirmation message in the first embodiment of the present invention.

  In the present embodiment, four people communicate using a shared whiteboard using clients on the terminal devices (x, y, z, w) 6a to 6d, respectively. A shared whiteboard is a tool that reflects a graphic or character on a certain terminal on all terminals.

  First, synchronization processing according to the present embodiment will be described. When the user draws a line on the shared whiteboard at the client of the terminal device (x) 6a, the terminal device (x) 6a shares the coordinates including both ends as information representing the line with respect to the server device (standby system) 5b. A message that can be interpreted by the whiteboard (see FIG. 20) is transmitted (a1 in FIG. 3).

  When the server device (standby system) 5b receives the message (step S1 in FIG. 4), since the own device is the standby system (step S2 in FIG. 4) and the message transmission source is the terminal device (x) 6a (step S3 in FIG. 4). ), “0124343” obtained by adding 1 to the serial number “0124342” added to the previous message is added to this message (step S4 in FIG. 4), and temporarily stored in the HDD (not shown) (step S5 in FIG. 4). . FIG. 21 shows a message assigned with this serial number. After this storage is performed, the message given the serial number is transmitted to the server device (active system) 5a (step S6 in FIG. 4).

  When the server apparatus (operating system) 5a receives the message (step S1 in FIG. 4), since the own apparatus is the operating system (step S2 in FIG. 4), it is confirmed whether the message has already been received (step S7 in FIG. 5). Since the serial number of the message received before this message is “0124342”, the server apparatus (active system) 5a determines that the message is a new message and participates in the process of data format check and communication as a shared whiteboard server process. The history data is stored for provision to the user (step S8 in FIG. 5).

  After processing this message, the server device (active system) 5a transmits the message as it is as a processing result to each of the terminal devices (x, y, z, w) 6a to 6d (step S9 in FIG. 5).

  After transmitting the processing result, the server device (active system) 5a confirms that “192.168.1.100” is stored as the address of the server device (standby system) 5b in the HDD transmission destination storage file. (Step S10 in FIG. 5), a processing completion confirmation message (see FIG. 22) is transmitted to the address (Step S11 in FIG. 5). When each terminal device (x, y, z, w) 6a to 6d receives a message (a6 in FIG. 3), a line is displayed on the shared whiteboard of the client.

  When the server device (standby system) 5b receives the processing completion confirmation message (step S1 in FIG. 4), the own device is the standby system (step S2 in FIG. 4), and the transmission source is the server device (active system) 5a (FIG. 4). Since the process completion confirmation message (step S3) (step S13 in FIG. 6), the temporary storage message (see FIG. 21) corresponding to the serial number “0124343” is read and deleted from the HDD (step S14 in FIG. 6).

  The read message is subjected to server processing as shared whiteboard data in the same manner as in the server device (active system) 5a (step S15 in FIG. 6). As a result, the states of both the server device (active system) 5a and the server device (standby system) 5b are synchronized. After the above processing, the server device (standby system) 5b discards the processing result without transmitting a message (step S16 in FIG. 6).

  At this time, the message resending process is executed. However, since there is no temporarily stored message in the server apparatus (standby system) 5b, the process is terminated without performing any process.

  Further, at this point, in the server device (active system) 5a, a partial HDD failure has occurred, so the server device (active system) 5a notifies the server device (standby system) 5b of the occurrence of the failure (step in FIG. 8). S31).

  The server device (standby system) 5b determines that the server device (active system) 5a is down, and switches its own device to the active system (step S32 in FIG. 8). Since there is no temporarily stored message (step S33 in FIG. 8), the server device (standby system) 5b determines that the state synchronization has been completed, and provides the server function as it is as the active system.

  As described above, the present invention performs state synchronization in the server device (standby system) after confirming the completion of processing in the server device (active system), so even if communication between server devices fails, Can be reliably executed.

  In the present invention, since the communication content is transferred to the server device (standby system) by the relay device after the processing of the communication content in the server device (active system) is completed, the client via the server device (active system) The communication time between the clients does not change regardless of the installation position of the server device (standby system).

  The present invention can be applied to improve the availability of a group communication system using a data sharing tool realized in a client-server type.

It is a block diagram which shows the structural example of the communication system by the 1st Embodiment of this invention. It is a block diagram which shows the structural example of the server apparatus by the 1st Embodiment of this invention. It is a sequence chart which shows operation | movement of the communication system by the 1st Embodiment of this invention. It is a flowchart which shows operation | movement of the server apparatus by the 1st Embodiment of this invention. It is a flowchart which shows operation | movement of the server apparatus by the 1st Embodiment of this invention. It is a flowchart which shows operation | movement of the server apparatus by the 1st Embodiment of this invention. It is a flowchart which shows operation | movement of the server apparatus by the 1st Embodiment of this invention. It is a flowchart which shows operation | movement of the server apparatus by the 1st Embodiment of this invention. It is a block diagram which shows the structure of the communication system by the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the server apparatus by the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the relay apparatus of FIG. It is a sequence chart which shows the operation | movement of the communication system by the 2nd Embodiment of this invention. It is a flowchart which shows operation | movement of the server apparatus by the 2nd Embodiment of this invention. It is a flowchart which shows operation | movement of the server apparatus by the 2nd Embodiment of this invention. It is a flowchart which shows operation | movement of the server apparatus by the 2nd Embodiment of this invention. It is a flowchart which shows operation | movement of the server apparatus by the 2nd Embodiment of this invention. It is a flowchart which shows operation | movement of the server apparatus by the 2nd Embodiment of this invention. It is a flowchart which shows operation | movement of the server apparatus by the 2nd Embodiment of this invention. 1 is a block diagram illustrating a network configuration of a communication system according to a first exemplary embodiment of the present invention. It is a figure which shows the message from the terminal device in 1st Example of this invention. It is a figure which shows the message which provided the serial number in 1st Example of this invention. It is a figure which shows the process completion confirmation message in 1st Example of this invention. It is a block diagram which shows the structural example of the communication system relevant to this invention.

Explanation of symbols

1,3 Server device 1a, 3a, 5a Server device (active system)
1b, 3b, 5b Server device (standby system)
2a-2c, 6a-6d terminal device
4 Relay device 11, 31, 41 Data processing device 12, 32, 42 Storage device
100 WAN
111,411 message receiver
112,412 Message temporary storage unit
113 State update unit
114 switching unit
115,415 Retransmission confirmation unit
116 Message processing unit
117,417 Message sending part
121,421 Message storage unit
122,422 Destination storage unit
201-203 LAN
413 Message transfer unit
414 Server switching control unit
423 Transferred message storage

Claims (35)

A communication system composed of two server devices and a plurality of terminal devices, operating one of the server devices as an active system and operating the other of the server devices as a standby system,
Communication from the terminal device to the active server device is performed via the standby server device,
In the standby server device, the communication content to the active server device is temporarily stored, and after the processing of the communication content in the active server device is confirmed, the temporary storage is performed. A communication system characterized by synchronizing the states of each of the active server device and the standby server device by processing the communication contents.   Each of the server devices temporarily stores the communication contents when operating as the standby system, and message transmission means for notifying the standby system of a message indicating that the processing of communication contents has been completed when operating as the active system Message temporary storage means, and state update means for executing deletion of communication contents temporarily stored in the message temporary storage means upon receipt of the message from the active system and state synchronization in the standby system The communication system according to claim 1.   The communication system according to claim 2, wherein the server device includes a retransmission confirmation unit that retransmits the communication content temporarily stored in the message temporary storage unit.   The server device executes the communication contents that are temporarily stored in the message temporary storage means when the operating system goes down while operating as the standby system, and thereby the server device of the active system and 4. The communication system according to claim 3, further comprising switching means for completing the state synchronization of each standby server device.   The communication system according to claim 3 or 4, wherein an identifier that can be uniquely identified is assigned to a communication message from the terminal device when operating as the standby system. A communication system that includes two server devices, a plurality of terminal devices, and a relay device, and operates one of the server devices as an active system and the other of the server devices as a standby system. And
Communication from the terminal device to the active server device is performed via the relay device,
In the relay device, the communication content between the terminal device and the active server device is temporarily stored, and the communication content processing in the active server device is completed for the communication content. A communication system, wherein the statuses of the active server device and the standby server device are synchronized by transmitting to the standby server device after confirmation. Each of the server devices includes message transmission means for notifying the relay device of a message indicating that the processing of the communication content has been completed,
The relay device includes: a message temporary storage unit that temporarily stores the communication content; a deletion of the communication content temporarily stored in the message temporary storage unit when the message is received from the active server device; and the temporarily stored communication The communication system according to claim 6, further comprising message transfer means for executing transmission of contents to the standby server apparatus.   The communication system according to claim 7, wherein the relay device includes a retransmission confirmation unit that periodically retransmits the communication content temporarily stored in the message temporary storage unit.   The relay server device transmits the communication contents temporarily stored in the message temporary storage unit to the standby server device when the active server device is down, thereby transmitting the active server device. 9. The communication system according to claim 8, further comprising server switching control means for completing state synchronization of each of the standby server devices.   10. The communication system according to claim 8, wherein the relay device assigns a uniquely distinguishable identifier to a message to be transmitted to the server device. 11.   The system according to claim 9 or 10, wherein a new message from the terminal device to the active server device is temporarily stored in the relay device during the switching of the server device, and the state synchronization is prioritized. The communication system described. A server device that is composed of two server devices and a plurality of terminal devices, and that is used in a communication system that operates one of the server devices as an active system and operates the other of the server devices as a standby system. There,
Perform communication from the terminal device to the active system via the standby system,
When operating as the standby system, the communication content to the active system is temporarily stored, and after confirming that the processing of the communication content in the active system is completed, the temporarily stored communication content is processed. By doing so, the state of each of the said active system and the said standby system is synchronized, The server apparatus characterized by the above-mentioned.   A message transmitting means for notifying the standby system of a message indicating that processing of communication contents has been completed when operating as the active system, and a message temporary storing means for temporarily storing communication contents when operating as the standby system; 13. A state update unit for executing deletion of communication contents temporarily stored in the message temporary storage unit upon receipt of the message from the active system and state synchronization in the standby system. The server device described in 1.   The server apparatus according to claim 13, further comprising: a retransmission confirmation unit that retransmits the communication content temporarily stored in the message temporary storage unit.   When the active system goes down while operating as the standby system, the state of synchronization between the active system and the standby system is completed by executing the communication contents temporarily stored in the message temporary storage means The server apparatus according to claim 14, further comprising a switching unit that causes the server to switch.   16. The server device according to claim 14, wherein an identifier that can be uniquely identified is assigned to a communication message from the terminal device when operating as the standby system. It is composed of two server devices, a plurality of terminal devices, and a relay device, and is used in a communication system that operates one of the server devices as an active system and operates the other of the server devices as a standby system. A relay device,
Perform communication from the terminal device to the active server device via its own device,
The communication content between the terminal device and the active server device is temporarily saved, and the communication content is confirmed after the communication content processing in the active server device is completed. A relay device that synchronizes the states of the active server device and the standby server device by transmitting to a standby server device. From each of the server devices, a message indicating that the processing of the communication content is completed is notified to the own device,
Message temporary storage means for temporarily storing the communication contents; deletion of communication contents temporarily stored in the message temporary storage means upon reception of the message from the active server apparatus; and the standby system for the temporarily stored communication contents The relay apparatus according to claim 17, further comprising message transfer means for executing transmission to the server apparatus.   19. The relay apparatus according to claim 18, further comprising a retransmission confirmation unit that periodically retransmits the communication content temporarily stored in the message temporary storage unit.   When the active server device goes down, the communication contents that are temporarily stored in the message temporary storage means are transmitted to the standby server device so that the active server device and the standby server device The relay device according to claim 19, further comprising server switching control means for completing state synchronization of each server device.   21. The relay apparatus according to claim 19, wherein an identifier that can be uniquely identified is assigned to a message to be transmitted to the server apparatus.   The new message from the terminal device to the active server device is temporarily saved by the own device during switching of the server device, and the state synchronization is prioritized. Relay device. A communication method comprising two server devices and a plurality of terminal devices, and used in a communication system that operates one of the server devices as an active system and operates the other of the server devices as a standby system. There,
Communication from the terminal device to the active server device is performed via the standby server device,
In the standby server device, the communication content to the active server device is temporarily stored, and after the processing of the communication content in the active server device is confirmed, the temporary storage is performed. A communication method characterized by synchronizing the states of each of the active server device and the standby server device by processing the communication contents. Notifying the standby system of a message indicating that processing of communication contents has been completed when operating the server device as the active system;
Executing temporarily storing communication contents when operating the server device as the standby system, deleting the temporarily stored communication contents when receiving the message from the active system, and performing state synchronization in the standby system 24. The communication method according to claim 23, further comprising the step of:   The communication method according to claim 24, wherein when the server device is operated as the standby system, the communication content temporarily stored is retransmitted to the active system.   When the active server device goes down, the state synchronization can be completed and the communication with the terminal device can be continued by executing the communication contents temporarily stored in the standby server device 26. The communication method according to claim 25.   27. The communication method according to claim 25 or 26, wherein when the server device is operated as the standby system, a uniquely distinguishable identifier is assigned to a communication message from the terminal device. It is composed of two server devices, a plurality of terminal devices, and a relay device, and is used in a communication system that operates one of the server devices as an active system and operates the other of the server devices as a standby system. A communication method,
Communication from the terminal device to the active server device is performed via the relay device,
In the relay device, the communication content between the terminal device and the active server device is temporarily stored, and the communication content processing in the active server device is completed for the communication content. A communication method characterized by synchronizing the states of the active server device and the standby server device by transmitting to the standby server device after confirmation. Each of the server devices notifies the relay device of a message indicating that the processing of the communication content has been completed,
In the relay device, the step of temporarily storing the communication content, the deletion of the communication content temporarily stored when the message is received from the active server device, and the standby server device of the temporarily stored communication content 29. The communication method according to claim 28, further comprising a step of performing transmission to the network.   30. The communication method according to claim 29, wherein the relay device periodically retransmits the temporarily stored communication content.   In the relay device, when the active server device goes down, the active server device transmits the communication contents temporarily stored in the message temporary storage means to the standby server device. 31. The communication method according to claim 30, wherein state synchronization of each of the standby server devices is completed.   32. The communication method according to claim 30, wherein the relay device assigns a uniquely discriminable identifier to a message transmitted to the server device.   The new message from the terminal device to the active server device is temporarily stored in the relay device during the switching of the server device, and the state synchronization is prioritized. The communication method described. In a server apparatus that is composed of two server apparatuses and a plurality of terminal apparatuses, and that is used in a communication system that operates one of the server apparatuses as an active system and operates the other of the server apparatuses as a standby system A program to be executed by a central processing unit of
Perform communication from the terminal device to the active system via the standby system,
From the active system, a process of notifying the standby system of a message indicating that the processing of communication contents has been completed when operating as the active system, a process of temporarily storing communication contents when operating as the standby system, and Processing to delete the temporarily stored communication content when receiving the message and to perform state synchronization in the standby system,
When operating as the standby system, the communication content to the active system is temporarily stored, and after the processing of the communication content in the active system is confirmed, the temporarily stored communication content is processed. To synchronize the states of the active system and the standby system. It is composed of two server devices, a plurality of terminal devices, and a relay device, and is used in a communication system that operates one of the server devices as an active system and operates the other of the server devices as a standby system. A program to be executed by the central processing unit in the relay device,
Communication from the terminal device to the active server device is performed via the relay device,
From each of the server devices, a message indicating that the processing of the communication content has been completed is notified to the relay device,
A process for temporarily storing the communication content; a deletion of the temporarily stored communication content when the message is received from the active server device; and a transmission of the temporarily stored communication content to the standby server device. Processing to be executed,
The communication content between the terminal device and the active server device is temporarily saved, and the communication content is confirmed after the communication content processing in the active server device is completed. A program that synchronizes states of the active system and the standby system by transmitting to a standby server device.

Images