JP6421516B2 - Server device, redundant server system, information takeover program, and information takeover method - Google Patents

Description

  The present invention relates to a server device used in a redundant configuration server system, a redundant configuration server system, an information takeover program, and an information takeover method.

  As a network management protocol, SNMP (Simple Network Management Protocol) is known. For example, in a redundant server system configured by a plurality of SIP (Session Initiation Protocol) servers, an apparatus monitoring system that monitors the plurality of SIP servers by SNMP is used.

  As an example, in Patent Document 1, when a failure occurs in a server in a redundant server system, a trap message is transmitted from the server having the failure, or taken over with the server having the failure. A redundant configuration server system is disclosed in which failure information is inherited by performing memory synchronization with a server.

JP 2008-305159 A

  In the system configuration disclosed in Patent Document 1, the statistical information of the application operation at the time of the failure disappears due to the restart of the application, and it is difficult to take over the statistical information at the time of the failure. In addition, when taking over the statistical information by notifying the standby server that a failure has occurred, a temporary failure such as a network interface card (NIC) or a peripheral component interconnect (PCI) bus When the OS occurs and it is necessary to restart the OS, there is a problem that the statistical information of the application operation at the time of the failure cannot be taken over.

  The present invention has been made in view of the above points, and provides a server, a redundantly configured server system, an information takeover program, and an information takeover method capable of reliably obtaining statistical information of application operations at the time of failure. The purpose is to do.

Call control server device of the present invention is used in a redundant configuration server system, a call control server device that executes a first application, to monitor the execution status of the first application, the first application Information collecting means for collecting and storing information on the own server abnormality, which is information indicating an execution state of the call control process when the first application abnormality occurs when an abnormality of the first application is detected, and in the redundant configuration server system and other server monitoring means for monitoring the execution state of the second application in other call control server is running, the other server monitoring means abnormality occurrence of the second application in the other call control server device detects, after the call session control device starts operating switches to the operation system from the standby system, the second applique Has an information collecting means for collecting the other servers abnormal information indicating the execution state of the call control process in the abnormality occurrence of Deployment, wherein the local server abnormality information, abnormality of the first application Information on at least one of the number of call connections at the time, the number of accepted calls, the number of completed calls, and the number of incomplete calls, and the information on when the other server is abnormal is the number of call connections when an abnormality occurs in the second application Including at least one of the number of accepted calls, the number of completed calls, and the number of incomplete calls .

The redundant configuration server system of the present invention is a redundant configuration server system having a first call control server device and a second call control server device, wherein the first call control server device is the first call control server device. Monitor the execution state of the application running on the call control server device, and execute it on the first call control server device when it detects an abnormality in the application running on the first call control server device Information collecting means for collecting and storing abnormal information, which is information indicating an execution state of the call control process when an abnormal application occurs, wherein the second call control server device includes the first call control server device. A monitoring means for monitoring an execution state of an application executed on the call control server device, and a difference between the application executed on the first call control server device. Information recovery for recovering the abnormal time information from the information collecting means of the first call control server device after the second call control server device is switched from the standby system to the active system and starts operating And the abnormal time information includes information on at least one of the number of call connections, the number of accepted calls, the number of completed calls, and the number of incomplete calls when an abnormality occurs in the application. To do.

The information takeover program of the present invention, in the first call control server and a redundant configuration server system consisting of the second call control server device that executes an application, execution of the call control process at the time of occurrence of abnormality in said application an information takeover program for executing processing to take over abnormal information is information indicating the state from the first call control server to said second call control server to the call control server device, the first call control server apparatus, the process of monitoring the execution state of the first of the application running on the call control server device, the first call control server device, is executed in the first call control server device When abnormal occurrence of the application is detected, abnormal time information that is information at the time of abnormal occurrence of the application is collected. A process of storing, the second call control server device, and a process of monitoring an abnormality of the first of the application running on the call control server device, the second call control server device, wherein the Processing for recovering the abnormality information of the first call control server device after detecting an abnormality of the application being executed in one call control server device, switching from the standby system to the active system and starting the operation The abnormal time information includes information on at least one of the number of call connections, the number of accepted calls, the number of completed calls, and the number of incomplete calls when the abnormality of the application occurs. .

The information transfer method according to the present invention executes call control processing when an abnormality occurs in the application in a redundant server system comprising a first call control server device and a second call control server device that execute the application. An information takeover method for taking over abnormal time information, which is information indicating a state, from the first call control server device to the second call control server device, wherein the first call control server device includes the first call control server device. A step of monitoring an execution state of the application executed on the call control server device, and the first call control server device detects occurrence of an abnormality in the application executed on the first call control server device. a step of collecting and storing the abnormality information of the first call control server device when the said second call control server device, the first call A step of monitoring an abnormality of the application or the first call control server device being executed on the control server device, and the second call control server device being executed on the first call control server device Recovering the abnormality information of the first call control server device after detecting an abnormality of the application and switching from the standby system to the active system to start operation, and the abnormality information includes: It includes at least one of information on the number of call connections, the number of accepted calls, the number of completed calls, and the number of incomplete calls when an abnormality occurs in the application.

1 is a block diagram showing a redundantly configured server system that is an embodiment of the present invention. It is a figure which shows an example of the table of statistical information. It is a figure which shows an example of operation | movement of the redundantly configured server system of FIG. It is a figure which shows an example of the table of statistical information. It is a flowchart which shows an example of operation | movement of the information storage part of the server of the redundantly configured server system of FIG. It is a flowchart which shows an example of operation | movement of the other server monitoring part and information collection | recovery part of the server of the redundantly configured server system of FIG. It is a block diagram which shows the redundant structure server system which is a modification of this invention.

  Hereinafter, a server apparatus and a redundantly configured server system according to an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a block diagram showing a server apparatus and a redundant server system using the same according to one embodiment of the present invention. In the following description, a redundant configuration server system composed of a set of active (ACT) servers and standby (SBY) servers will be described as an example.

  The redundant configuration server system 100 includes an ACT server 200, an SBY server 300, and a server management system 400. The ACT server 200 and the SBY server 300 are, for example, SIP servers (call control servers) that include Linux (registered trademark) as an OS (Operating System) and execute a SIP application on Linux. The ACT server 200 and the SBY server 300 are server devices having the same configuration.

  The ACT server 200 includes a communication unit 210, an application execution unit 220, an information storage unit 230, another server monitoring unit 240, and an information collection unit 250. Similarly, the SBY system server 300 includes a communication unit 310, an application execution unit 320, an information storage unit 330, another server monitoring unit 340, and an information collection unit 350.

  The communication units 210 and 310 are connected to be communicable with each other, and are connected to be able to communicate with the server management system 400. The communication units 210 and 310 are communicably connected to the information storage units 230 and 330, the other server monitoring units 240 and 340, and the information collection units 250 and 350, respectively.

  That is, the information storage unit 230, the other server monitoring unit 240, the information collection unit 250, the information storage unit 330, the other server monitoring unit 340, and the information collection unit 350 of the ACT server 200 are the communication unit 210, They are connected to each other via 310. The communication units 210 and 310 can perform communication between the servers 200 and 300 by, for example, connecting to each other by FTP (File Transfer Protocol).

  The application execution units 220 and 320 are, for example, processing units that execute SIP applications. The application execution units 220 and 320 are statistical information about SIP, for example, as in the statistical information table shown in FIG. 2, the number of connections (number of connections in a call state), the number of calls accepted (number of calls accepted after server activation), completion Device management protocol (SNMP) management information base (MIB) including information such as the number of calls (calls that have been successfully completed) and the number of calls that have not been completed (number of calls that have not been completed) (Hereinafter simply referred to as MIB) 225 and 325, respectively.

  The information storage units 230 and 330 monitor the execution states (operation states) of the applications executed in the application execution units 220 and 320 of the own server, respectively. When an abnormality occurs in the execution state of the application, the information storage units 230 and 330 read and save the statistics information of the MIBs 225 and 325 and re-establish the server when the server is an ACT system at that time. Start up, that is, restart the OS and applications. If there is no abnormality other than the application, only the application may be restarted.

  The other server monitoring units 240 and 340 monitor the execution state of the application (APP) executed by the application execution units 220 and 320 of the other server via the communication units 210 and 310. When the other server monitoring units 240 and 340 detect the occurrence of an abnormality in the other server or the abnormality of the application being executed on the other server, the other server monitoring units 240 and 340 An abnormality notification is sent to notify that an abnormality has occurred in the execution state of the application on the other server.

  The information collection units 250 and 350 have a nonvolatile storage device (not shown) that retains data even when the OS or the like is restarted. When the information collection units 250 and 350 receive the abnormality notification from the other server monitoring units 240 and 340, the information collection units 250 and 350 read the statistical information of the MIBs 225 and 325 stored in the information storage units 230 and 330 of the other servers, and the read statistics Information is set in the MIBs 225 and 325 of its own server.

  The server management system 400 periodically collects statistical information of the MIBs 225 and 325 of the ACT servers using, for example, SNMP.

  Hereinafter, an example of the operation of each unit will be described with reference to FIGS. 1 and 3, taking as an example a case where an abnormality has occurred in the ACT server 200.

  As described above, before the occurrence of an abnormality, the server management system 400 periodically collects statistical information of the MIB 225 of the server 200 that is currently an ACT system.

  The other server monitoring unit 340 of the SBY server 300 indicates the state of the ACT server 200 and the execution state of the application (APP) executed by the application execution unit 220 of the ACT server 200 via the communication units 210 and 310. Monitoring.

  When an abnormality occurs in the ACT server 200, the information storage unit 230 of the ACT server 200 reads and stores the statistical information of the MIB 225 of the application execution unit 220 of the own server (S31), and restarts the own server. The OS and application are restarted (S32). If there is no abnormality other than the application, only the application may be restarted.

  After the restart, the ACT server 200 operates as an SBY server and starts monitoring the application execution state of the SBY server 300 as a new ACT server.

  The other server monitoring unit 340 of the SBY server 300 detects the occurrence of an abnormality in the other server or the abnormality of the application being executed on the other server, and sends the other to the application execution unit 320, the information collection unit 350, and the server management system 400. An abnormality notification for notifying that an abnormality has occurred in the execution state of the application of the ACT server is transmitted (S33).

  Upon receiving the abnormality notification, the application execution unit 320 of the SBY server 300 immediately sets the virtual IP and starts executing the application as the new ACT server (S34).

  Upon receipt of the abnormality notification, the information collection unit 350 of the SBY server 300 reads (collects) the statistical information of the MIB 225 stored in the information storage unit 230 of the ACT server 200, and uses the read statistical information as its own server. The MIB 325 is set (S35). Note that when the ACT server 200 restarts the OS, the reading and setting operations may be performed by monitoring the state of the ACT server 200 and waiting for the OS of the ACT server 200 to restart. Good.

  After the setting of the statistical information in S35, the MIB 325 of the SBY server 300 includes, for example, statistical information on the application after execution of the application as the new ACT server, such as the statistical information table shown in FIG. A table including application statistical information at the time of occurrence of an abnormality in the ACT server 200 is stored.

  Upon receiving the abnormality notification, the server management system 400 changes the collection destination of statistical information to the new ACT server (SBY server 300 before the occurrence of abnormality) (S36), and starts collecting statistical information. That is, the server management system 400 collects information including application statistical information after the execution of the application as the new ACT server and application statistical information when an abnormality occurs in the ACT server 200.

  Note that the setting of the virtual IP and the start of execution of the application as the new ACT server by the application execution unit 320 of the SBY server 300 in S34 can be performed without waiting for the reading and setting of the statistical information in S35.

  Hereinafter, an example of an operation routine of the information storage units 230 and 330 will be described with reference to FIG.

  First, in S51, it is determined whether or not the own server is an ACT system. If it is determined in S51 that the own server is an ACT system (S51: YES), the process proceeds to S52, and the statistical information of MIBs 225 and 325 previously stored in the information storage units 230 and 330 is deleted. Is done. Then, it progresses to process step S53 and it is determined whether the application of the own server has started normally.

  If it is determined that the local server is not an ACT system (S51: NO), that is, if the local server is an SBY system, the process proceeds to S53, and whether or not the application of the local server is normally activated. Determined.

  If it is determined in S53 that the application is normally activated (S53: YES), the process proceeds to S54, and after waiting for a fixed time, the process proceeds to S51. In S53, when it is determined that the application is not normally started (S53: NO), the process proceeds to S55, and it is determined whether or not the local server is an ACT system before the occurrence of the application abnormality.

  If it is determined that the local server is an ACT system before the occurrence of an application abnormality (S55: YES), the process proceeds to S56, and the statistical information of the MIBs 225 and 325 is stored in the nonvolatile storage devices of the information storage units 230 and 330. After that, the process proceeds to S57. If it is determined that the local server is not an ACT system before the occurrence of an application abnormality (S55: NO), that is, if it is determined that the server is an SBY system, the process proceeds to S57.

  In S57, the OS and application are restarted, and the routine ends.

  Hereinafter, an example of an operation routine of the information collection units 250 and 350 will be described with reference to FIG.

  First, in S61, it is determined whether or not an abnormality notification is received from another server monitoring unit. If it is determined in S61 that an abnormality notification has been received (S61: YES), the process proceeds to S62 to determine whether or not the server is an ACT system.

  If it is determined in S61 that an abnormality notification has not been received (S61: NO), the process proceeds to S63, and the process proceeds to S61 after waiting for a fixed time.

  In S62, it is determined whether or not the own server is an ACT system. In S62, when it is determined that the local server is an ACT system (S62: YES), that is, when system switching is performed as a result of detecting an abnormality of another server that was an ACT system and notifying the abnormality, The process proceeds to S64, an attempt is made to connect to the information storage units 230 and 330 of other servers, and the process proceeds to S65.

  If it is determined in S62 that the local server is not an ACT system (S62: NO), that is, if an abnormality is detected in another server that is an SBY system and an abnormality is notified, the process proceeds to S63. After a predetermined time wait, the process proceeds to S61.

  In S65, it is determined whether or not the connection to the information storage units 230 and 330 of the other servers has been successful. When it is determined that the connection to the information storage units 230 and 330 of the other servers is successful (S65: YES), the step proceeds to S66. In S65, when it is determined that the connection to the information storage units 230 and 330 of the other server has not been successful (S65: NO), the process proceeds to S63, and after waiting for a certain time, the process proceeds to S61.

  In S66, the MIB statistical information stored in S56 of the routine shown in FIG. 5 in the other server is acquired from the information storage units 230 and 330 of the other server, and the statistical information is set in the MIBs 225 and 325 of the own server. That is, after performing the takeover process, the process proceeds to S67. In S66, when the server holding the statistical information restarts the OS, the statistical information is acquired by monitoring the state of the server and waiting for the server OS to restart. It is good.

  In S67, it is determined whether or not the server is an ACT system. If it is determined that the local server is an ACT system (S67: YES), the process proceeds to S68, and after waiting for a predetermined time, the process proceeds to S67 again. In S67, when it is determined that the local server is not an ACT system (S67: NO), the process proceeds to S63, and after waiting for a predetermined time, the process proceeds to S61. That is, after the information takeover process from another server, the process of S67 is repeated as long as no abnormality occurs in the own server and the own server is an ACT system.

  According to the redundant configuration server system of the present embodiment, when an application abnormality occurs in the ACT server, information on the application at the time of the abnormality is temporarily stored in the nonvolatile storage device in the ACT server. . Then, the information on the application at the time of the abnormality is collected by the new ACT server that was the SBY server until the time of the abnormality. With such a configuration, even when the application in which the abnormality has occurred is restarted, it is possible to reliably take over the information when the abnormality of the application has occurred in the new ACT server.

  In addition, since information on the application at the time of the occurrence of the abnormality is temporarily stored in the nonvolatile storage device in the ACT server, due to an intermittent failure of hardware such as a network interface card (NIC), Even when the OS needs to be restarted, it is possible to reliably take over to the new ACT server without losing information on the application when the abnormality occurs.

  Further, according to the redundant configuration server system of the present embodiment, when an application abnormality occurs in the ACT server, immediately after the SBY server detects the abnormality, that is, taking over the statistical information from the ACT server. Switching to the ACT system is performed without waiting. Therefore, the redundantly configured server system according to the present embodiment can provide a seamless service without a break.

  Further, according to the redundant configuration server system of the present embodiment, as described above, the statistical information in the conventional redundant configuration server system is collected by waiting for the restart of the OS of the server in which an abnormality has occurred and collecting the statistical information. It is possible to efficiently take over statistical information without performing communication related to takeover.

  In the above embodiment, the redundant configuration server system including a pair of server devices having the same configuration has been described as an example. However, the redundant configuration server system may be configured by server devices having different configurations.

  For example, as the minimum required configuration of the redundant configuration server system of the present invention, as in the redundant configuration server system 100 shown in FIG. 7, the ACT server device 200 includes a communication unit 210, an application execution unit 220, and an information storage unit 230. The SBY server 300 may include a communication unit 310, an application execution unit 320, another server monitoring unit 340, and an information collection unit 350. That is, a system comprising an ACT dedicated server having only a function of storing information when an abnormality of the application of the own server occurs when an abnormality occurs, and an SBY dedicated server having only a function of collecting information at the time of occurrence of the abnormality from another server It is good also as a structure.

  In the case of this configuration, the ACT server 200 does not monitor the execution state of the application executed on the SBY server 300 after the restart of the ACT server 200 in the operation description shown in FIG. It becomes.

  By having such a configuration as a minimum, the operation described with reference to FIG. 3 makes it possible to reliably transfer the application information at the time of occurrence of an abnormality to the new ACT server as in the above embodiment.

  Moreover, in the said Example, although the redundantly configured server system which consists of a set of server apparatus was demonstrated to the example, the redundantly configured server system of this invention is not limited to the said structure. For example, a server system having a plurality of ACT servers 200 and SBY systems may be used. In that case, you may combine the above-mentioned ACT system dedicated server and SBY system dedicated server.

  Further, the number of ACT system dedicated servers and SBY system dedicated servers may not be the same. For example, a system configuration having one SBY dedicated server for a plurality of ACT system dedicated servers may be employed.

  In the above embodiment, the SIP server has been described as an example, but other types of server devices such as a VoIP server may be used.

  In the above-described embodiment, the SIP statistical information includes the number of connections, the number of accepted calls, the number of completed calls, and the number of incomplete calls. However, the SIP statistical information includes the number of connections, the number of accepted calls, and the number of completed calls. It is sufficient to include at least one of the number and the number of incomplete calls.

  Further, in the above embodiment, the information storage units 230 and 330 monitor the execution state of the application of the own server, and store the statistical information when the abnormality occurs when an abnormality occurs in the execution state of the application. However, it is not limited to this. For example, the information storage units 230 and 330 monitor the hardware state of the server in addition to the execution state of the application, and store the statistical information at the time of the abnormality when the abnormality occurs in the state. Also good. In this case, the information storage units 230 and 330 may further store information including the execution state of the hardware when the abnormality occurs.

  In the above embodiment, the information collection units 250 and 350 monitor the execution state of the application of the other server, and collect the statistical information at the time of occurrence of the abnormality when the abnormality occurs in the execution state of the application. However, it is not limited to this. For example, the other server monitoring units 240 and 340 monitor the hardware state of the other server in addition to the application execution state, and when the information collection units 250 and 350 detect that an abnormality has occurred in the state, Statistical information at the time of occurrence of the abnormality may be stored. In this case, the information collection units 250 and 350 may further collect information including the execution state of the hardware when the abnormality occurs.

  As described above, by taking over not only the application execution state but also the hardware state as information at the time of occurrence of an abnormality, it becomes possible to take over more detailed information at the time of occurrence of an abnormality.

  The various configurations in the above-described embodiments are merely examples, and can be appropriately selected according to the application and the like.

100 redundant server system 200 ACT server 300 SBY server 210, 310 communication unit 220, 320 application execution unit 230, 330 information storage unit 240, 340 other server monitoring unit 250, 350 information collection unit

Claims (13)

A call control server device that is used in a redundantly configured server system and executes a first application,
The own server abnormality time information which is information indicating the execution state of the call control process when the first application abnormality occurs when the execution state of the first application is monitored and the abnormality of the first application is detected. Information collecting means for collecting and storing
Other server monitoring means for monitoring the execution state of the second application being executed by another call control server device in the redundant server system;
After the other server monitoring means detects an abnormality of the second application in the other call control server device and the call control server device is switched from the standby system to the active system and starts operating, Information collecting means for collecting other server abnormality information, which is information indicating an execution state of the call control process when an application abnormality occurs;
Have
The own server abnormality time information includes information on at least one of the number of call connections, the number of accepted calls, the number of completed calls, and the number of uncompleted calls when an abnormality occurs in the first application,
The other server abnormal time information includes information on at least one of the number of call connections, the number of accepted calls, the number of completed calls, and the number of incomplete calls when an abnormality occurs in the second application.
A call control server device.   The call control server apparatus according to claim 1, wherein the information collection means collects and stores the information when the own server is abnormal while the call control server apparatus is in an active state.   The call control server device according to claim 1 or 2, wherein the information collection unit collects the information when the other server is abnormal after waiting for the other call control server device to restart.   When the call control server device is operating as a standby server and the other server monitoring unit detects an abnormality in the second application being executed on the other call control server device, the information collection is performed. 4. The operation of the call control server device is switched to an operation as an active server without waiting for the means to collect the information when the other server is abnormal. Call control server device. A redundantly configured server system having a first call control server device and a second call control server device,
The first call control server device monitors an execution state of an application executed on the first call control server device, and detects an abnormality of the application executed on the first call control server device. Information collecting means for collecting and storing abnormal time information, which is information indicating an execution state of the call control processing when an abnormality occurs in the application executed on the first call control server device ,
The second call control server device is
Monitoring means for monitoring an execution state of an application executed on the first call control server device;
After detecting an abnormality of an application being executed in the first call control server device and the second call control server device is switched from a standby system to an active system and starts operating, the first call control server Information collecting means for collecting the abnormal information from the information collecting means of the apparatus,
The redundant configuration server system, wherein the abnormal time information includes at least one of the number of call connections, the number of accepted calls, the number of completed calls, and the number of incomplete calls when an abnormality occurs in the application.   6. The redundantly configured server system according to claim 5, wherein the information collecting unit collects the abnormal time information after the first call control server device is restarted.   When the second call control server device is operating as a standby server and the monitoring means detects an abnormality of an application being executed on the first call control server device, the information collecting means 7. The redundant configuration server system according to claim 5, wherein the operation of the second call control server device is switched to the operation as an active server without waiting for the recovery of the abnormal time information. In the redundant configuration server system comprising the first call control server device and the second call control server device that execute the application, the abnormal time information that is the information indicating the execution state of the call control process when the application abnormality occurs An information takeover program that causes a call control server device to execute a process of taking over from the first call control server device to the second call control server device,
A process in which the first call control server device monitors an execution state of the application being executed in the first call control server device;
When the first call control server device detects an abnormality of the application being executed on the first call control server device, it collects abnormal time information that is information at the time of the abnormality of the application. Processing to save,
A process in which the second call control server device monitors an abnormality of the application being executed in the first call control server device;
After the second call control server device detects an abnormality of the application being executed in the first call control server device and starts operation by switching from the standby system to the active system, the first call control server device Collecting the abnormal information of the control server device, and
The information at the time of abnormality includes information on at least one of the number of call connections, the number of accepted calls, the number of completed calls, and the number of incomplete calls when an abnormality occurs in the application.   9. The information transfer program according to claim 8, wherein the collecting process causes the second call control server device to execute after the first call control server device is restarted.   When the second call control server device detects an abnormality in the application being executed on the first call control server device, the second call control server device detects the first call control server device. The second call control server device is caused to execute a process of switching the operation of the second call control server device to an operation as an active server without waiting for the recovery of the abnormal time information. The information transfer program according to claim 8 or 9. In the redundant configuration server system comprising the first call control server device and the second call control server device that execute the application, the abnormal time information that is the information indicating the execution state of the call control process when the application abnormality occurs An information takeover method for taking over from the first call control server device to the second call control server device,
The first call control server device monitoring an execution state of the application being executed by the first call control server device;
When the first call control server device detects the occurrence of an abnormality in the application being executed on the first call control server device , it collects and stores information on the abnormality of the first call control server device And steps to
The second call control server device monitoring the application being executed on the first call control server device or an abnormality of the first call control server device;
After the second call control server device detects an abnormality of the application being executed in the first call control server device and starts operation by switching from the standby system to the active system, the first call control server device Collecting the abnormal time information of the control server device,
The information at the time of abnormality includes information on at least one of the number of call connections, the number of accepted calls, the number of completed calls, and the number of incomplete calls when an abnormality occurs in the application.   12. The information transfer method according to claim 11, wherein the collecting step is performed after the first call control server device is restarted.   When the second call control server device detects an abnormality in the application being executed on the first call control server device, the second call control server device detects the first call control server device. The method according to claim 11, further comprising a step of switching the operation of the second call control server device to an operation as an active server without waiting for the recovery of the abnormal time information. Information transfer method.

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