JP2023154868A - Backup system, backup device, backup method, control method of backup device, and program - Google Patents

Abstract

To obtain a backup system capable of suppressing increase of the number of devices composing the system when comparing in a same multiplication degree while enhancing usability of the system.SOLUTION: A backup system 3 includes: a plurality of servers 1A to 1C; and a backup device 2 capable of alternating the process of the plurality of servers 1A to 1C, and succeeds a process of a server in which an abnormality has occurred when an abnormality has occurred in any of the plurality of servers 1A to 1C. Each of the plurality of servers 1A to 1C backs-up data held in each of the servers 1A to 1C among the servers 1A to 1C.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a backup system, a backup device, a backup method, a backup device control method, and a program.

In systems that require high reliability and high availability, servers are multiplexed and data held by servers is backed up in case something goes wrong with a server. For example, in Patent Document 1, in order to suppress the increase in the number of backup devices, which is a problem when a backup device is provided for each server and data is backed up to the backup device, multiple It describes how to back up server data.

JP2009-211635A

However, according to the technology described in Patent Document 1, although it is possible to reduce the number of backup devices when acquiring data backup, it is not possible to continue the processing performed by the server, and the system The problem was that availability was not taken into account.

The present disclosure has been made in view of the above, and provides a backup system that can suppress an increase in the number of devices constituting a system when compared with the same number of multiplexing while increasing system availability. The purpose is to obtain.

In order to solve the above-mentioned problems and achieve the purpose, a backup system according to the present disclosure can replace multiple servers and the processing of the multiple servers, and if an abnormality occurs in one of the multiple servers, If an abnormality occurs, a backup device is provided to take over the processing of the server in which the abnormality has occurred, and each of the plurality of servers is characterized in that data held by each server is backed up between the servers.

According to the present disclosure, it is possible to increase the availability of the system while suppressing an increase in the number of devices configuring the system when compared with the same number of multiplexing systems.

A diagram showing an outline of a backup system according to Embodiment 1 An explanatory diagram of the data backup method in the backup system shown in Figure 1 Sequence diagram for explaining data backup of the server shown in Figure 1 A sequence diagram to explain the operation when an abnormality is detected in the server in the backup system shown in Figure 1. Sequence diagram for explaining backup processing after an error occurs in the server in the backup system shown in Figure 1 Diagram showing the functional configuration of the server shown in Figure 1 Flowchart for explaining the normal operation of the data transmitter shown in FIG. 6 Flowchart for explaining the normal operation of the data receiving section shown in FIG. 6 Flowchart for explaining the operation of the abnormality management unit regarding abnormality notification transmission shown in FIG. Flowchart for explaining the operation of the abnormality management unit regarding abnormality notification reception shown in FIG. 6 Diagram showing the functional configuration of the backup device shown in Fig. 1 Flowchart for explaining the operation of the backup device shown in FIG. 11 A diagram showing an example of the configuration of a computer system that implements the server and backup device of Embodiment 1. Sequence diagram for explaining a data backup method according to Modification 1 of Embodiment 1 Sequence diagram for explaining a data backup method according to Modification 2 of Embodiment 1 Sequence diagram for explaining a data backup method according to Modification 3 of Embodiment 1 Sequence diagram for explaining a data backup method according to Modification 4 of Embodiment 1 A diagram showing the configuration of a backup system according to Embodiment 2

Below, a backup system, a backup device, a backup method, a backup device control method, and a program according to an embodiment of the present disclosure will be described in detail based on the drawings.

Embodiment 1.
FIG. 1 is a diagram schematically showing a backup system 3 according to the first embodiment. The backup system 3 includes a plurality of servers 1A to 1C and a backup device 2. Hereinafter, when there is no need to distinguish each of the servers 1A to 1C, they will be simply referred to as server 1.

Each of the plurality of servers 1 executes an application program to perform predetermined processing in order to realize the functions provided by the system constituted by the server 1. The plurality of servers 1 are devices to be backed up in the backup system 3. Server 1 is operated as an active system. Here, the term standby system is used as a counterpart to the active system. The active system is a system that is in operation during normal times, and the standby system is a system that is on standby during normal times.

The plurality of servers 1 constitute, for example, a monitoring control system. Examples of the processing performed by each server 1 include data collection of monitoring targets, data processing, display of a monitoring screen, generation of commands for monitoring targets, and the like. Examples of monitoring targets include trains, river water levels, traffic control systems, expressway traffic, and equipment that constitutes social infrastructure.

The backup device 2 is operated as a backup system for the plurality of servers 1. One backup device 2 can replace the processing of a plurality of servers 1. Usually, in systems that require high reliability and high availability, a backup system is often provided for each device. In this case, the number of devices is the number of servers 1 multiplied by the number of multiplexed devices, which poses a problem that operation becomes complicated. On the other hand, since one backup device 2 according to the first embodiment functions as a backup system for a plurality of servers 1, it is possible to suppress an increase in the number of devices when compared with the same number of multiplexing. I can do it. When an abnormality occurs in any of the plurality of servers 1, the backup device 2 takes over the processing of the server 1 where the abnormality has occurred. Note that the abnormality referred to here refers to a state in which it is difficult for the server 1 to continue normal processing, such as a failure of the server 1 or a failure of a communication path connected to the server 1.

In order for the backup device 2 to take over the processing of the active server 1, an application program for realizing the functions of the target server 1 and data held by the target server 1 are required. The backup device 2 stores application programs for realizing the functions of each of the plurality of servers 1. When the backup device 2 holds backup data of a plurality of servers 1, problems may arise such as the disk capacity of the backup device 2 being compressed or the network load being concentrated. In a system where data on each server 1 is updated frequently, problems such as disk capacity pressure and network load concentration are likely to occur. Therefore, in the backup system 3, each of the plurality of servers 1 backs up data held by each server 1 between the servers 1.

Here, backup between servers 1 will be explained. In FIG. 1, the data of the server 1A is referred to as "data A", and the application program for realizing the functions of the server 1A is referred to as "application A". Similarly, the data of the server 1B will be referred to as "data B", and the application program for realizing the functions of the server 1B will be referred to as "application B". The data of the server 1C will be referred to as "data C", and the application program for realizing the functions of the server 1C will be referred to as "application C". At this time, the backup device 2 stores application A, application B, and application C from the normal time.

In the backup system 3, backup data is not held in the backup device 2, but backup is performed between the servers 1A to 1C so that each of the servers 1A to 1C holds the backup data of the other servers 1. Regarding the backup method performed here, each of data A, data B, and data C may be held in two or more locations in the servers 1A to 1C.

FIG. 2 is an explanatory diagram of a data backup method in the backup system 3 shown in FIG. 1. More specifically, in the first embodiment, the servers 1A to 1C back up data in a circular manner. Here, the circular format means that data held by each server 1 is transferred between multiple servers 1 so that the data movement route between multiple servers 1 forms a circular route that goes around multiple servers 1 and returns to the original location. This is a form of data backup sent to one of the 1. The data movement route forms a circular route, and each server 1 transmits data in the same direction on the circular route. Specifically, the server 1A transmits data A to the server 1C, the server 1C transmits data C to the server 1B, and the server 1B transmits data B to the server 1A. As a result, a circulation route is formed that goes around the servers 1A to 1C and returns to the original location.

FIG. 3 is a sequence diagram for explaining data backup of the servers 1A to 1C shown in FIG. 1. Server 1C sends data C to server 1B, server 1B sends data B to server 1A, and server 1A sends data A to server 1C. Similar processing is repeated. Note that the backup method shown here is an example. For example, the direction in which the servers 1A to 1C transmit data may be reversed. Furthermore, regarding the timing at which each server 1 transmits data, the order of data transmission shown in FIG. You may. Note that here, for simplicity, the data to be transmitted by each server 1 is expressed as "data A, data B, data C," but each server 1 uses the backup data held in the destination server 1. By transmitting only the difference between the two, it is possible to make the data held by itself and the backup data held in the destination server 1 data equivalent.

As explained above, under normal conditions when no abnormality occurs in the server 1, the servers 1A to 1C are in operation, and the backup device 2 is in a standby state. At this time, each of the servers 1A to 1C sends its own data to the other server 1, so that each of the servers 1A to 1C holds its own data and the backup data of the other server 1. state. Since data is backed up between the servers 1, the backup device 2 does not need to hold backup data of a plurality of servers 1 in normal times.

FIG. 4 is a sequence diagram for explaining operations in the backup system 3 shown in FIG. 1 when an abnormality is detected in the server 1A. First, the server 1A detects an abnormality (step S101). The server 1A sends an abnormality notification to the other servers 1B, 1C and the backup device 2 (step S102).

The server 1C that holds the backup data of the server 1A in which the abnormality has occurred transmits data A to the backup device 2 (step S103).

The backup device 2 saves the data A (step S104). The backup device 2 also launches application A, which is an application for implementing the functions of the server 1A where the abnormality has occurred (step S105). The backup device 2 uses data A to take over the processing of the server 1A (step S106).

Note that the backup device 2 also takes over the backup processing that was being performed by the server 1A in which the abnormality occurred. FIG. 5 is a sequence diagram for explaining backup processing after an abnormality occurs in the server 1A in the backup system 3 shown in FIG. 1.

After an abnormality occurs in the server 1A and the backup device 2 takes over the processing that the server 1A was doing, the backup device 2 sends data A to the server 1C as the server 1A used to do, and then sends data A from the server 1B. Receive data B and hold backup data of server 1B. Server 1B transmits data B to backup device 2 instead of server 1A. Server 1C receives data A from backup device 2 instead of server 1A.

The outline of the functions of the backup system 3 has been described above. The detailed functional configuration of each device and the operation of each device will be described below.

FIG. 6 is a diagram showing the functional configuration of servers 1A to 1C shown in FIG. 1. Note that in order to explain the configuration common to the servers 1A to 1C, it will be referred to as the server 1. The server 1 includes a data storage section 10 , a backup data storage section 11 , a data equivalent section 12 , an abnormality management section 13 , and a backup data migration section 14 . The data equalization section 12 includes a data transmission section 121 and a data reception section 122. The abnormality management section 13 includes an abnormality detection section 131 , an abnormality notification transmission section 132 , and an abnormality notification reception section 133 . Note that only the functions necessary to realize the functions of the backup system 3 are shown here, and the server 1 actually has functions other than those shown in FIG. 6.

The data storage unit 10 stores data of the server 1 itself. For example, the data storage unit 10 of the server 1A stores data A, the data storage unit 10 of the server 1B stores data B, and the data storage unit 10 of the server 1C stores data C. The backup data storage unit 11 stores backup data of other servers 1. For example, in the example shown in FIG. 2, the backup data storage unit 11 of the server 1A stores data B, the backup data storage unit 11 of the server 1B stores data C, and the backup data storage unit 11 of the server 1C stores data B. , stores data A.

The data equalization unit 12 performs an equalization process to fill in the difference between the backup data and the data held by the server 1 itself. Specifically, the data transmission unit 121 of the data equalization unit 12 calculates the difference between the data stored in the data storage unit 10 and the data stored in the data storage unit 10 at the time of the previous data transmission. Send it to another server 1 as backup data. The data receiving unit 122 receives backup data from another server 1 and stores the received backup data in the backup data storage unit 11. The backup data received here is the difference between the previous backup data stored in the backup data storage unit 11 and the data stored in the source server 1 at the time of transmission of the backup data. For this reason, the data receiving unit 122 reflects the received backup data in the backup data storage unit 11, so that the backup data stored in the backup data storage unit 11 and the backup data stored in the server 1 that is the source of the backup data are data can be equivalent.

The abnormality management unit 13 manages abnormalities that occur in the server 1 included in the backup system 3. Specifically, the abnormality management unit 13 includes an abnormality detection unit 131 that detects an abnormality in the server 1 itself, and an abnormality notification that is information for notifying other devices of the abnormality when the abnormality detection unit 131 detects an abnormality. and an abnormality notification receiving section 133 that receives abnormality notifications to notify abnormalities of other servers 1. The abnormality notification includes, for example, information indicating that an abnormality has occurred and information indicating the source of the abnormality.

When the abnormality detection unit 131 detects an abnormality, the abnormality notification transmitting unit 132 transmits an abnormality notification to the other servers 1 and the backup device 2. The abnormality notification receiving unit 133 receives abnormality notifications from other servers 1. When the abnormality notification receiving unit 133 receives the abnormality notification, it outputs the abnormality notification to the backup data migration unit 14.

When an abnormality notification is output from the abnormality notification receiving unit 133, the backup data migration unit 14 determines whether or not it holds the backup data of the server 1 where the abnormality occurred, and if the backup data is held. , transmits the backup data stored in the backup data storage section 11 to the backup device 2. If the backup data of the server 1 that is the source of the abnormality is not held, the backup data migration unit 14 outputs an abnormality notification to the data equalization unit 12.

When the backup data migration unit 14 outputs an abnormality notification, the data equalization unit 12 determines whether the backup data was sent to the server 1 where the abnormality occurred. If the backup data has been sent to the server 1 that is the source of the abnormality, the data equalization unit 12 changes the destination of the backup data to the backup device 2 .

Next, the operation of the server 1 will be explained. During normal times when no abnormality is detected, the server 1 periodically sends backup data to other servers 1. FIG. 7 is a flowchart for explaining the normal operation of the data transmitter 121 shown in FIG. The data transmitter 121 of the server 1 determines whether it is a predetermined backup timing (step S201). For example, a time interval for transmitting backup data is predetermined, and the data transmitter 121 determines whether it is the backup timing based on whether a predetermined time has elapsed since the last time the backup data was transmitted. You can judge whether or not.

If it is backup timing (step S201: Yes), the data transmitting unit 121 generates backup data from the data stored in the data storage unit 10, and transmits the generated backup data (step S202). The backup data may be all the data stored in the data storage unit 10 at the time of the backup timing, or as described above, the data stored in the data storage unit 10 at the time when the backup data was sent last time, The data may be data indicating a difference from the data currently stored in the data storage unit 10. After transmitting the backup data, and if it is not the backup timing (step S201: No), the data transmitter 121 repeats step S201.

FIG. 8 is a flowchart for explaining the normal operation of the data receiving section 122 shown in FIG. The data receiving unit 122 determines whether backup data has been received from another server 1 (step S203). When the backup data is received (step S203: Yes), the data receiving unit 122 stores the received backup data in the backup data storage unit 11 (step S204). After storing the backup data in the backup data storage unit 11 and when the backup data is not received (step S203: No), the data receiving unit 122 repeats the process of step S203.

FIG. 9 is a flowchart for explaining the operation of the abnormality management unit 13 shown in FIG. 6 regarding abnormality notification transmission. The abnormality detection unit 131 of the abnormality management unit 13 checks whether an abnormality has occurred (step S301). The abnormality detection unit 131 determines whether an abnormality has occurred (step S302). If an abnormality occurs (step S302: Yes), the abnormality notification transmitter 132 transmits an abnormality notification to another device (step S303). Specifically, the abnormality notification transmitter 132 transmits an abnormality notification to the other servers 1 and the backup device 2. For example, when the server 1 is the server 1A, the abnormality notification sending unit 132 of the server 1A sends the abnormality notification to the servers 1B, 1C and the backup device 2. If no abnormality has occurred (step S302: No), the abnormality detection unit 131 repeats the process from step S301. The operation in FIG. 9 is repeated.

FIG. 10 is a flowchart for explaining the operation of the abnormality management unit 13 shown in FIG. 6 regarding reception of an abnormality notification. The abnormality notification receiving unit 133 checks whether there is an abnormality notification to be received (step S401). The abnormality notification receiving unit 133 determines whether there is an abnormality notification to be received (step S402). If there is no abnormality notification (step S402: No), the abnormality notification receiving unit 133 repeats the process from step S401.

If there is an abnormality notification (step S402: Yes), the abnormality notification receiving unit 133 outputs the abnormality notification to the backup data migration unit 14, and the backup data migration unit 14 retains the backup data of the server 1 where the abnormality has occurred. It is determined whether or not (step S403). If the backup data of the server 1 in which the abnormality has occurred is held (step S403: Yes), the backup data migration unit 14 transmits the backup data of the server 1 in which the abnormality has occurred to the backup device 2 (step S404), Finish the process.

If the backup data of the server 1 where the abnormality has occurred is not held (step S403: No), the backup data migration unit 14 outputs an abnormality notification to the data equalization unit 12, and the data equivalent unit 12 It is determined whether backup data has been sent to server 1 (step S405). If the backup data has not been sent to the server 1 where the abnormality has occurred (step S405: No), the data equalization unit 12 ends the process. If the backup data has been sent to the server 1 where the abnormality has occurred (step S405: Yes), the data equalization unit 12 changes the destination of the backup data to the backup device 2 (step S406), and ends the process. The operation in FIG. 10 is repeated.

FIG. 11 is a diagram showing the functional configuration of the backup device 2 shown in FIG. 1. The backup device 2 includes an input processing section 21 , a switching control section 22 , a backup data storage section 23 , and an application program storage section 24 .

The input processing unit 21 is connected to a plurality of servers 1, and receives an abnormality notification from the server 1 where an abnormality has occurred, or receives backup data from the server 1 that holds backup data of the server 1 where an abnormality has occurred. or When receiving an abnormality notification, the input processing unit 21 outputs the received abnormality notification to the switching control unit 22 . When receiving backup data, the input processing unit 21 causes the backup data storage unit 23 to store the received backup data.

When the input processing unit 21 outputs the abnormality notification, the switching control unit 22 performs a switching process to take over the processing of the server 1 where the abnormality has occurred, based on information included in the abnormality notification indicating the server 1 where the abnormality has occurred. Specifically, the switching control unit 22 selects an application program for realizing the function of the server 1 in which the abnormality has occurred from among the plurality of application programs stored in the application program storage unit 24, and switches the selected application Load and run the program. Thereby, the switching control unit 22 can start an application for realizing the function of the server 1 where the abnormality has occurred. At this time, the switching control unit 22 uses the backup data of the server 1 in which the abnormality has occurred, which is stored in the backup data storage unit 23, to take over the processing of the server 1 in which the abnormality has occurred.

The backup data storage unit 23 does not normally hold backup data, and when the input processing unit 21 receives backup data from the server 1, the received backup data is stored. In the backup system 3, if an abnormality occurs in any of the multiple servers 1, the other servers 1 that hold the backup data of the server 1 where the abnormality has occurred will send the backup data to the backup device 2. When an abnormality occurs in any of the plurality of servers 1 in the backup system 3, the data storage unit 23 stores backup data of the server 1 where the abnormality has occurred.

The application program storage unit 24 stores a plurality of application programs for realizing the functions of the server 1 to be backed up in the backup system 3. The application program storage unit 24 stores a plurality of application programs even during normal times when no abnormality occurs. In the example shown in FIG. 1, the application program storage unit 24 stores three application programs represented by application A, application B, and application C.

Next, the operation of the backup device 2 will be explained. FIG. 12 is a flowchart for explaining the operation of the backup device 2 shown in FIG. 11. The input processing unit 21 checks whether there is a received abnormality notification (step S501). The input processing unit 21 determines whether or not there is a received abnormality notification based on the confirmation result (step S502). If there is no abnormality notification (step S502: No), the input processing unit 21 repeats the process from step S501. If there is an abnormality notification (step S502: Yes), the input processing unit 21 outputs the abnormality notification to the switching control unit 22, and determines whether backup data of the server 1 in which the abnormality has occurred has been received (step S503). ). If backup data has not been received (step S503: No), the input processing unit 21 repeats the process of step S503. When the backup data is received (step S503: Yes), the input processing unit 21 stores the received backup data in the backup data storage unit 23 (step S504).

The switching control unit 22, which has received the abnormality notification output by the input processing unit 21, transfers the backup data of the server 1 where the abnormality has occurred and the application program based on the information included in the abnormality notification indicating the server 1 where the abnormality has occurred. is read and the application is started (step S505). Specifically, the switching control unit 22 reads an application program from the application program storage unit 24 and reads backup data from the backup data storage unit 23. Thereby, the backup device 2 can take over the processing of the server 1 where the abnormality has occurred.

Next, the hardware configurations of the server 1 and the backup device 2 of this embodiment will be explained. The server 1 and backup device 2 of this embodiment are realized by, for example, a computer system.

An example of the configuration of a computer system that implements the server 1 and the backup device 2 will be described. FIG. 13 is a diagram showing a configuration example of a computer system that implements the server 1 and the backup device 2 of the first embodiment. As shown in FIG. 13, this computer system includes a control section 101, an input section 102, a storage section 103, a display section 104, a communication section 105, and an output section 106, which are connected via a system bus 107. There is.

In FIG. 13, the control unit 101 is, for example, a CPU (Central Processing Unit). The control unit 101 executes a computer program in which each process performed by the server 1 and the backup device 2 of this embodiment is written. The input unit 102 includes, for example, a keyboard, a mouse, etc., and is used by a user of the computer system to input various information. The storage unit 103 includes various memories such as RAM (Random Access Memory) and ROM (Read Only Memory), and storage devices such as hard disks, and stores programs to be executed by the control unit 101 and necessary information obtained in the process of processing. Store data etc. The storage unit 103 is also used as a temporary storage area for programs. The display unit 104 is composed of an LCD (Liquid Crystal Display) or the like, and displays various screens to the user of the computer system. The communication unit 105 is a communication circuit or the like that performs communication processing. The communication unit 105 may be configured with a plurality of communication circuits each corresponding to a plurality of communication methods. The output unit 106 is an output interface that outputs data to an external device such as a printer or an external storage device.

Note that FIG. 13 is an example, and the configuration of the computer system is not limited to the example of FIG. 13. For example, the computer system may not include the output unit 106. Further, all of the plurality of computer systems for realizing each of the server 1 and the backup device 2 may not be the computer systems shown in FIG. 13. For example, some computer systems may not include at least one of the display section 104, output section 106, and input section 102 shown in FIG. 13.

Here, an example of the operation of the computer system until the computer program in which the processes of the server 1 and the backup device 2 of the present embodiment are written becomes executable will be described. In a computer system having the above configuration, for example, a computer program is stored in a storage unit from a CD-ROM or DVD-ROM set in a CD (Compact Disc)-ROM drive or a DVD (Digital Versatile Disc)-ROM drive (not shown). 103. Then, when the computer program is executed, the computer program read from the storage unit 103 is stored in an area of the storage unit 103 that serves as a main storage device. In this state, the control unit 101 executes processing as the server 1 or the backup device 2 of this embodiment according to the computer program stored in the storage unit 103.

In the above description, a CD-ROM or a DVD-ROM is used as a recording medium to provide a program that describes the processing in the server 1 and the backup device 2. However, the present invention is not limited to this. Depending on the capacity of the program, for example, a computer program provided via a transmission medium such as the Internet via the communication unit 105 may be used.

The program of this embodiment includes a step in which, when an abnormality occurs in one of the plurality of servers 1 to be backed up, the computer starts an application program for realizing the function of the server 1 where the abnormality has occurred. By causing the backup device 2 to perform the processing of the server 1 where the abnormality has occurred, the backup device 2 executes the steps of acquiring backup data of the server 1 where the abnormality has occurred, and executing the application program using the acquired backup data. Let them take over.

The data storage unit 10 and backup data storage unit 11 shown in FIG. 6 are part of the storage unit 103 shown in FIG. 13. The data equalization section 12, abnormality management section 13, and backup data migration section 14 shown in FIG. 6 are realized using the control section 101 and the communication section 105 shown in FIG. The input processing section 21 shown in FIG. 11 is realized using the control section 101 and the communication section 105 shown in FIG. 13. The switching control section 22 shown in FIG. 11 is realized using the control section 101 shown in FIG. 13. The backup data storage section 23 and the application program storage section 24 shown in FIG. 11 are part of the storage section 103 shown in FIG. 13.

Note that the division of functions in each device shown in FIGS. 6 and 11 is an example, and if the backup system 3 can perform the operations described above, the division of functions in each device can be as shown in FIGS. 6 and 11. Not limited to examples.

<Modification 1>
In the above-described first embodiment, in the backup system 3 having three servers 1A to 1C, all the servers 1A to 1C perform data backup in a circular manner. The number of devices is not limited to three. The backup system 3 only needs to have two or more servers 1. In Modification 1, an example of a method for backing up data in a backup system 3 having four servers 1A to 1D will be described.

FIG. 14 is a sequence diagram for explaining a data backup method according to Modification 1 of Embodiment 1. In modification 1, all the servers 1 included in the backup system 3, ie, four servers 1A to 1D, perform data backup in a circular manner. Specifically, server 1D transmits data D to server 1C, server 1C transmits data C to server 1B, server 1B transmits data B to server A, and server 1A transmits data D to server D. Send data A to. Each server 1 repeats the above data backup operation.

<Modification 2>
In Embodiment 1 and Modification 1 above, in the backup system 3 having three or four servers 1, all the servers 1 perform data backup in a circular format, but the data backup method is , does not have to be in a circular format. The data of each server 1 may be held in two or more servers 1 among the servers 1.

FIG. 15 is a sequence diagram for explaining a data backup method according to the second modification of the first embodiment. In the second modification, data backup is performed between a pair of servers 1 among four servers 1A to 1D. In the example shown in FIG. 15, data backup is performed mutually between servers 1A and 1B, and data backup is performed mutually between servers 1C and 1D. Specifically, the server 1A transmits data A to the server 1B, and the server 1B transmits data B to the server 1A. Server 1C transmits data C to server 1D, and server 1D transmits data D to server 1C. As a result, the data of each server 1 is held in two servers 1.

<Modification 3>
Embodiment 1 described above describes an example in which three servers 1 perform data backup in a circular manner, Modification 1 describes an example in which four servers 1 perform data backup in a circular manner, and Modification 2 An example in which four servers 1 mutually perform data backup has been described. In modification 3, an example will be described in which five servers 1 perform data backup in a circular manner.

FIG. 16 is a sequence diagram for explaining a data backup method according to the third modification of the first embodiment. Even when there are five servers 1, the data backup method using the circular format is the same as when there are three or four servers 1.

Server 1E sends data E to server 1D, server 1D sends data D to server 1C, server 1C sends data C to server 1B, and server 1B sends data B to server 1A. Then, the server 1A transmits data A to the server 1E.

<Modification 4>
In Embodiment 1 and Modifications 1 to 3 above, examples have been described in which data backup is performed in either the circular format or the mutual format, but the circular format and the mutual format may be used together. In modification 4, a method will be described in which five servers 1 perform data backup using both the circulation format and the mutual format.

FIG. 17 is a sequence diagram for explaining a data backup method according to the fourth modification of the first embodiment. The servers 1A and 1B perform data backup in a mutual format, and the servers 1C to 1E perform data backup in a circular format.

Server 1A sends data A to server 1B, and server 1B sends data B to server 1A. Server 1E sends data E to server 1D, server 1D sends data D to server 1C, and server 1C sends data C to server 1E.

In Modifications 1 to 4, the operation of each server 1 is the same as in Embodiment 1, except that the destination of backup data is changed, so a detailed explanation will be omitted. Furthermore, the operation of the backup device 2 is also the same as in the first embodiment.

Note that, similar to the first embodiment, the backup methods shown in Modifications 1 to 4 are merely examples. For example, for servers 1 that perform data backup in a circular manner, the direction in which each server 1 transmits data may be reversed. Furthermore, regarding the servers 1 that perform data backup in a circular format, the data transmission destination of each server 1 is an example, and the data movement route between multiple servers 1 forms a circular route that goes around and returns to the original. It's fine if you can. Furthermore, regarding the timing at which each server 1 transmits data, the illustrated order of data transmission is just an example, and the order of transmitting data may be different, or multiple servers 1 may transmit data at the same time. good. Note that here, for the sake of simplicity, the data that each server 1 sends is expressed as "data A, data B, data C, data D, data E", but each server 1 By sending only the difference between the data and the backup data held on the destination server 1, the data held by itself is data-equalized with the backup data held on the destination server 1. be able to.

As explained above, according to Embodiment 1, the backup system 3 includes a plurality of servers 1 which are active systems that operate during normal times, a backup device 2 which is a standby system that is on standby during normal times, Equipped with One backup device 2 can replace the processing of a plurality of servers 1, and when an abnormality occurs in any one of the plurality of servers 1, it takes over the processing of the server 1 where the abnormality has occurred. Since one backup device 2 can replace the processing of multiple servers 1, there is no need to provide a backup device 2 for each server 1, and the number of backup devices 2 can be smaller than the number of servers 1. Therefore, while increasing the availability of the system, it is possible to suppress an increase in the number of devices constituting the backup system 3 when compared with the same number of multiplexes.

Further, according to the first embodiment, each of the plurality of servers 1 can back up data held by each server 1 between the plurality of servers 1. Therefore, the backup device 2 does not need to hold backup data of a plurality of servers 1 during normal times when no abnormality occurs. When an abnormality occurs in any one of the plurality of servers 1, the server 1 that holds the backup data of the server 1 where the abnormality has occurred transmits the backup data to the backup device 2. This allows the backup device 2 to take over the processing of the server 1 in which the abnormality has occurred, using the backup data sent by the server 1.

Note that the backup device 2 according to the first embodiment normally stores a plurality of application programs for realizing the respective functions of the plurality of servers 1. Therefore, if an abnormality occurs in any one of the plurality of servers 1, an application program for implementing the function of the server 1 where the abnormality has occurred can be started immediately. Therefore, it is possible to shorten the time it takes for the backup device 2 to take over the processing of the server 1 where an abnormality has occurred.

Furthermore, as for the method of backing up data between multiple servers 1, data of one server 1 may be stored in multiple servers 1. For example, one example of a data backup method is a circular format. The backup system 3 can perform circular data backup between at least some of the servers 1 included in the backup system 3 . In the circular format, each of the multiple servers 1 transfers the data held by each server 1 such that the data movement path between the multiple servers 1 forms a circular route that goes around the multiple servers 1 and returns to the original location. is transmitted to one of the plurality of servers 1. As a result, a circular data movement path is formed between the plurality of servers 1, and each server 1 transmits its own data to an adjacent server 1 on the circular data movement path. In the circulation type, there is no need to be aware of the number of devices, so it can be applied to systems with various configurations, and has the advantage of being highly versatile.

Furthermore, in the first embodiment, when an abnormality occurs in one of the plurality of servers 1 and the backup device 2 takes over the processing of the server 1 where the abnormality has occurred, the backup device 2 is configured to It is also possible to take over the backup process for the data. Specifically, when the backup device 2 takes over the processing of the server 1A, it sends its own data, data A, to the server 1C instead of the server 1A, and also stores the data B received from the server 1B. be able to. That is, after taking over the processing of the server 1A, the backup device 2 will have the functions of the data storage section 10, backup data storage section 11, and data equalization section 12 shown in FIG. This makes it possible for the backup system 3 to continue data backup even after an abnormality occurs in one of the multiple servers 1.

Embodiment 2.
FIG. 18 is a diagram showing the configuration of a backup system 3-1 according to the second embodiment. In the first embodiment, the backup system 3 having one backup device 2 has been described, but a plurality of backup devices 2 may be prepared.

The backup system 3-1 includes servers 1A to 1C and backup devices 2A and 2B. Hereinafter, parts that are different from Embodiment 1 will be mainly described, and detailed descriptions of parts similar to Embodiment 1 will be omitted. Further, hereinafter, if there is no need to distinguish between the backup devices 2A and 2B, they may be simply referred to as the backup device 2.

Each of the plurality of backup devices 2 can replace the processing of the plurality of servers 1 included in the backup system 3-1. Each of the plurality of backup devices 2 stores an application A, an application B, and an application C, which are a plurality of application programs for realizing the functions of the servers 1A to 1C.

For example, the order in which the plurality of backup devices 2 operate when an abnormality occurs in the server 1 is predetermined, and the backup device 2 that operates in the earliest order is called the first backup device; The backup device 2 that operates next to the device is called a second backup device. Here, it is assumed that the backup device 2A is the first backup device and the backup device 2B is the second backup device. In this case, the backup device 2A, which is the first backup device, operates in the same way as the backup device 2 according to the first embodiment, and when an abnormality occurs in any one of the plurality of servers 1, the abnormality occurs. Inherits the functions of server 1. When the backup device 2A, which is the first backup device, is in operation, the backup device 2B, which is the second backup device, operates in the same way as the backup device 2 according to the first embodiment. When an abnormality occurs in either the server 1 or the backup device 2A, the function of the server or backup device 2A in which the abnormality occurs is taken over.

For example, consider a case where an abnormality occurs in server 1A while servers 1A to 1C are in operation. At this time, the backup device 2A takes over the processing of the server 1A. In this case, the servers 1B and 1C and the backup device 2A are in operation. The backup device 2A starts the application A, acquires the backup data of the server 1A from the server 1C, and takes over the processing of the server 1A. Note that, as described in the first embodiment, the backup device 2A can also take over the data backup process that was performed by the server 1A.

If an abnormality occurs in any of the operating devices while the servers 1B, 1C and the backup device 2A are operating as described above, the backup device 2B is activated. For example, when an abnormality occurs in the server 1B, the backup device 2B starts application B, acquires the backup data of the server 1B from the backup device 2A, and takes over the processing of the server 1B. Note that the backup device 2B can also take over the data backup process that was performed by the server 1B.

Note that if an abnormality occurs in the backup device 2A while the servers 1B, 1C and the backup device 2A are in operation, the backup device 2B takes over the processing of the backup device 2A. Specifically, the backup device 2B starts the application A, acquires data A, which is the backup data of the backup device 2A, from the server 1C, and takes over the processing of the backup device 2A.

As explained above, according to the second embodiment, the backup system 3-1 includes a plurality of backup devices 2A and 2B, and the plurality of backup devices 2 detect an abnormality in one of the plurality of servers 1. If an abnormality occurs, the first backup device takes over the processing of the server 1 where the abnormality has occurred, and when the first backup device is operating, either the operating server 1 or the first backup device If an abnormality occurs in the server 1 or the first backup device in which the abnormality occurs, a second backup device is included. As a result, as in the first embodiment, it is possible to increase the availability of the system while suppressing an increase in the number of devices constituting the system when compared with the same number of multiplexing. Furthermore, even if another abnormality occurs in the backup system 3-1 after the backup device 2 has started operating but before the server 1 in which the abnormality has occurred is restored, the system continues to operate. becomes possible.

In this case, after the backup device 2A, which is the first backup device, operates in place of the server 1 in which the abnormality has occurred, the data storage unit 10, backup data storage unit 11, and data equivalent unit 12 shown in FIG. In addition to the above functions, it may also have the functions of the abnormality management section 13 and the backup data migration section 14.

The configurations shown in the embodiments described above are examples of the contents of the present disclosure, and can be combined with other known technologies, and the configurations can be modified without departing from the gist of the present disclosure. It is also possible to omit or change parts.

For example, in Embodiment 1, an example in which the number of backup devices 2 is one is described, and in Embodiment 2, an example in which there are two backup devices 2 is described, but the number of backup devices 2 may be three or more. Good too. When three backup devices 2 are provided for three servers 1, the number of devices is the same as in the conventional configuration in which a backup system is provided for each device, but the number of multiplexed devices is 2 in the conventional configuration. On the other hand, in the configuration in which three backup devices 2 are provided, the number of multiplexed devices for each server 1 is four. When compared with the same number of multiplexed devices, it is possible to suppress an increase in the number of devices, and when compared with the same number of devices, it is possible to increase the number of multiplexed devices.

1, 1A to 1E server, 2, 2A, 2B backup device, 3, 3-1 backup system, 10 data storage unit, 11 backup data storage unit, 12 data equivalent unit, 13 abnormality management unit, 14 backup data migration unit, 21 input processing section, 22 switching control section, 23 backup data storage section, 24 application program storage section, 101 control section, 102 input section, 103 storage section, 104 display section, 105 communication section, 106 output section, 107 system bus, Reference Signs List 121 data transmitting unit, 122 data receiving unit, 131 abnormality detecting unit, 132 abnormality notification transmitting unit, 133 abnormality notification receiving unit.

Claims (15)

multiple servers and
a backup device capable of substituting the processing of a plurality of said servers, and in the event of an abnormality occurring in any one of the plurality of said servers, taking over the processing of said server in which the abnormality has occurred;
Equipped with
A backup system characterized in that each of the plurality of servers backs up data held by each server between the servers. Each of the plurality of servers transfers data held by each server to a plurality of servers so that the data movement path between the plurality of servers forms a circular path that goes around the plurality of servers and returns to the original location. 2. The backup system of claim 1, wherein data backup is performed in a circular format that is sent to one of the servers. The backup device includes:
A plurality of application programs for realizing the functions of each of the plurality of servers are normally stored,
3. The backup system according to claim 1, wherein when an abnormality occurs in any one of the plurality of servers, an application program for realizing the function of the server where the abnormality occurs is activated. The backup device does not normally hold backup data of the plurality of servers,
When an abnormality occurs in any one of the plurality of servers, the server holding backup data of the server where the abnormality has occurred transmits the backup data to the backup device,
3. The backup system according to claim 1, wherein the backup device uses the backup data transmitted by the server to take over the processing of the server in which the abnormality has occurred. 3. The backup device according to claim 1, wherein when an abnormality occurs in any one of the plurality of servers, the backup device takes over the data backup process that was being performed by the server in which the abnormality occurred. backup system. comprising a plurality of the backup devices,
The plurality of backup devices include:
a first backup device that takes over the processing of the server where the abnormality occurs when an abnormality occurs in any of the plurality of servers;
When the first backup device is operating, if an abnormality occurs in either the operating server or the first backup device, the server in which the abnormality has occurred or the first backup a second backup device that takes over the processing of the device;
The backup system according to claim 1 or 2, characterized in that it includes: a storage unit that stores a plurality of application programs for realizing the functions of each of the plurality of active servers operating during normal times;
an input processing unit that receives an abnormality notification sent by the server in which the abnormality has occurred when an abnormality occurs in any one of the plurality of servers;
In response to the abnormality notification, an application program for realizing the function of the server in which the abnormality has occurred is started among the application programs stored in the storage unit, thereby taking over the processing of the server in which the abnormality has occurred. a switching control section;
Equipped with
A backup device characterized in that it is a standby system that can replace the processing of a plurality of the servers. Each of the plurality of servers backs up data held by each server between the servers,
A backup method characterized in that a backup device can replace the processing of a plurality of servers, and when an abnormality occurs in any one of the plurality of servers, the backup device takes over the processing of the server in which the abnormality has occurred. Each of the plurality of servers transfers data held by each server to a plurality of servers so that the data movement path between the plurality of servers forms a circular path that goes around the plurality of servers and returns to the original location. 9. A backup method as claimed in claim 8, characterized in that the data backup is performed in a circular manner that is sent to one of the servers. The backup device includes:
A plurality of application programs for realizing the functions of each of the plurality of servers are normally stored,
10. The backup method according to claim 8, wherein when an abnormality occurs in any one of the plurality of servers, an application program for implementing the function of the server where the abnormality has occurred is activated. The backup device does not normally hold backup data of the plurality of servers,
When an abnormality occurs in any one of the plurality of servers, the server holding backup data of the server where the abnormality has occurred transmits the backup data to the backup device,
10. The backup method according to claim 8, wherein the backup device uses the backup data sent by the server to take over the processing of the server in which the abnormality has occurred. 10. The backup device according to claim 8 or 9, wherein when an abnormality occurs in any one of the plurality of servers, the backup device takes over the data backup process that was being performed by the server in which the abnormality occurred. Backup method. When an abnormality occurs in any of the plurality of servers, a first backup device among the plurality of backup devices takes over the processing of the server in which the abnormality has occurred,
A second backup device among the plurality of backup devices is configured such that when the first backup device is in operation, an abnormality occurs in either the operating server or the first backup device. 10. The backup method according to claim 8, further comprising taking over the processing of the server or the first backup device in which the abnormality has occurred. In the backup device, which is a standby system during normal times,
It stores multiple application programs to implement the functions of multiple active servers that are normally running.
If an abnormality occurs in one of the plurality of servers, receiving an abnormality notification sent by the server where the abnormality has occurred;
taking over the processing of the server in which the abnormality has occurred by starting an application program for realizing the function of the server in which the abnormality has occurred among the plurality of application programs in response to the abnormality notification;
A method for controlling a backup device, the method comprising: to the computer,
It stores multiple application programs to implement the functions of multiple active servers that are normally running.
If an abnormality occurs in one of the plurality of servers, receiving an abnormality notification sent by the server where the abnormality has occurred;
taking over the processing of the server in which the abnormality has occurred by starting an application program for realizing the function of the server in which the abnormality has occurred among the plurality of application programs in response to the abnormality notification;
A program characterized by executing.

Images