JP7848151B2 - Information processing system and recovery method - Google Patents

Description

This disclosure relates to an information processing system and a recovery method.

In recent years, information processing systems equipped with multiple information processing devices, such as digital signage, have been attracting attention. For example, railway cars are equipped with numerous information processing devices that display operational information and corporate advertisements, serving as information processing systems for passengers.

In information processing systems like the one described above, when recovering data stored in a memory device mounted on an information processing device, a technology is widely used in which recovery data is transmitted to the information processing device via a network to perform the data recovery (see Patent Document 1). Furthermore, Patent Document 2 discloses a technology in which two information processing devices are used as a pair, and backup data from one device is written to the other device. If the data on one device is corrupted, the backup data from the other device is copied to the original device, enabling data recovery.

Japanese Patent Publication No. 2007-28183 Japanese Patent Publication No. 2007-122485

When applying an information processing system with multiple information processing devices to railway vehicles or similar applications, the network communication connecting these devices requires the use of wired cables with a low number of cores, considering factors such as reliability and cost. Furthermore, due to limited space for wiring, minimizing the length of the wired cables is desirable. Therefore, daisy-chain connections, where information processing devices are connected in a series, are frequently used.

In the situation described above, if it becomes necessary to recover data stored in the storage device of one of multiple information processing devices, transmitting the recovery data from an external server device to the information processing device, as described in Patent Document 1, presents a problem of increased communication load due to the data having to pass through other information processing devices. In particular, the longer the wiring distance between the server device sending the recovery data and the information processing device to be recovered, the wider the scope of the communication load becomes.

Furthermore, in the technology described in Patent Document 2, since two information processing devices each hold backup data of the other device, the communication load can be reduced. However, because it is necessary to hold backup data for all the data on the other device, each information processing device requires a large capacity in its storage device.

The purpose of this disclosure is to provide an information processing system and recovery method that enable data recovery while reducing communication load and storage capacity.

An information processing system according to one aspect of this disclosure is an information processing system comprising a plurality of information processing devices connected to each other in a daisy-chain configuration, wherein each information processing device includes: a storage unit for storing some common device data shared with some of the other information processing devices; and a processing unit that, for each of the some information processing devices, acquires first access information including information for connecting to the some information processing device and the number of intermediate devices, which is the number of other information processing devices passed through when connecting to the some information processing device; and, in the event of corruption of the some common device data, recovers the corrupted some common device data by copying the some common device data stored in a first recovery source device, which is the some information processing device with the smallest number of intermediate devices, to the storage unit of the device itself, based on the first access information.

According to this invention, data recovery becomes possible while reducing communication load and storage capacity.

This figure shows the hardware configuration of the information processing system according to Embodiment 1 of the present disclosure. This figure shows an example of data stored in a memory device. This figure shows an example of the functional configuration of the information processing device according to Embodiment 1 of the present disclosure. This is a diagram to explain the backup process. This figure shows an example of the data structure of recovery data. This figure shows an example of how recovery data is stored. This is a flowchart illustrating an example of a backup process. This is a diagram illustrating an example of a search process. This is a flowchart illustrating an example of a search process. This is a flowchart illustrating an example of a diagnostic process. This is a diagram illustrating an example of data recovery processing. This is a flowchart illustrating an example of a data recovery process. This figure shows an example of the functional configuration of the information processing device according to Embodiment 2 of the present disclosure. This is a diagram illustrating an example of the update process. This flowchart provides a more detailed explanation of an example of the update process. This figure shows an example of update detection data.

The embodiments of this disclosure will be described below with reference to the drawings. In the following description, the processing may be described with "program" as the operating entity. However, since a program is executed by a processor such as a CPU (Central Processing Unit) and performs defined processing using at least one of the storage unit and interface unit as appropriate, the operating entity of the processing may be the processor (or an information processing device having a processor).

Figure 1 shows the hardware configuration of an information processing system according to Embodiment 1 of this disclosure. The information processing system 100 shown in Figure 1 has a plurality of information processing devices 1. In this embodiment, the information processing system 100 is installed on a railway vehicle, and all information processing devices 1 are connected to each other via daisy-chain connection for communication. An information processing device 1 is a device that displays passenger-oriented information, such as operational information and corporate advertisements, on a display screen such as a liquid crystal display. Although two information processing devices 1 are shown in Figure 1, the number of information processing devices 1 is not limited to two.

The information processing device 1 includes a CPU 11, memory 12, storage device 13, and network interface 14.

The storage device 13 is a storage unit that stores a program that defines the operation of the CPU 11 and various data used and generated by that program. The CPU 11 is an example of a processor, and is a processing unit that reads the program stored in the storage device 13, loads it into the memory 12, and executes the read program using the memory 12 as a work area, thereby performing various processes. The network interface 14 is an interface unit that enables communication with other information processing devices 1 via network wiring 101.

Figure 2 shows an example of data stored in the storage device 13. As shown in Figure 2, the storage device 13 stores device-specific data 130, data common to some devices 131, and data common to all devices 132.

The device-specific data 130 is data unique to each of the multiple information processing devices 1. The device-specific data 130 includes, for example, parameters related to the brightness and color settings of a display screen, such as a liquid crystal display, corresponding to an information processing device 1 (hereinafter sometimes referred to as "this device") that has a storage device 13 containing the data.

The partially shared device data 131 is data common to some of the multiple information processing devices 1. For example, the partially shared device data 131 might be an application program executed on an information processing device 1 of the same type as the device itself, given that there are multiple types of information processing devices 1. In this embodiment, the information processing system 100 comprises two or more information processing devices 1 having the same partially shared device data 131.

The all-device common data 132 is data common to all of the multiple information processing devices 1. For example, the all-device common data 132 might be the OS (Operating System).

The data common to some devices 131 and the data common to all devices 132 each include version information indicating the version of their own data.

The following primarily describes the process that occurs when a failure occurs in the storage device 13.

Figure 3 is a block diagram showing an example of the functional configuration of the information processing device 1. As shown in Figure 3, in addition to the hardware configuration shown in Figure 1, the information processing device 1 also has an auxiliary storage device 17 as hardware for storing data, separate from the storage device 13.

The information processing device 1 has a functional configuration that includes an application execution unit 15 that provides services to users (passengers) and a data management unit 16 that manages the data stored in the storage device 13.

The application execution unit 15 is implemented by an application program, application 150. The application execution unit 15 displays, for example, operational information and guidance information to passengers.

The data management unit 16 is implemented by a backup storage program 160, a duplicate data search program 161, a storage device diagnostic program 162, and a data repair program 163. In this embodiment, the backup storage program 160 and the duplicate data search program 161 are stored in the storage device 13, while the storage device diagnostic program 162 and the data repair program 163 are stored in the auxiliary storage device 17 so that they can be executed even if a failure occurs in the storage device 13.

The backup storage program 160 is a program for executing a backup process to back up the device-specific data 130. The identical data search program 161 is a program for executing a search process to find the information processing device 1 that will be the source of the partially device-common data 131. The storage device diagnostic program 162 is a program for executing a diagnostic process to diagnose the state of the storage device 13 and detect any problems related to the storage device 13. The data recovery program 163 is a program for executing a data recovery process to recover data (device-specific data 130, partially device-common data 131, and all-device-common data 132) stored in the storage device 13 if that data is corrupted.

Figure 4 illustrates the backup process performed by the backup storage program 160. In the following explanation and diagrams, multiple information processing devices 1 may be denoted with subscripts such as 1-0, 1-1, 1-2, etc., to distinguish them. Similarly, the configuration and data of each information processing device may also be denoted with the same subscripts. For example, device-specific data 130 of information processing device 1-0 may be referred to as device-specific data 130-0, and storage device 13 of information processing device 1-1 may be referred to as storage device 13-1. Furthermore, the backup process performed by the backup storage program 160 of information processing device 1-0 will be explained here as an example.

The backup process is performed as a pre-processing step for the data recovery process by the data recovery program 163, when the information processing device 1 is first started up and the storage device 13 is operating without failure.

In the backup process, the backup storage program 160 first searches for the nearest information processing device 1 among the other information processing devices 1, specifically the one with the shortest network wiring length 101 connecting to its own device, information processing device 1-0, as step P1. Here, the backup storage program 160 searches for the nearest information processing device 1 that can be connected without going through other information processing devices 1 (in the example shown in the figure, information processing device 1-1). If there are multiple information processing devices 1 that can be connected without going through other information processing devices 1, for example, one of those multiple information processing devices will be searched for as the nearest information processing device 1.

The search method for finding the nearest information processing device 1 is not particularly limited. For example, one search method could involve identifying the location of each information processing device 1 from an image captured from multiple information processing devices 1, and then searching for the nearest information processing device 1 based on that location. Alternatively, if information indicating the positional relationships or connection relationships of the information processing devices 1 is pre-registered in a storage device 13 or similar, that information may be used to search for the nearest information processing device 1.

Next, as step P2, the backup storage program 160 registers the device-specific data 130-0 of its own device as recovery data 133-1 in the storage device 13 of the nearest information processing device 1-1. As a result, backup data of the device-specific data 130 is stored in the nearest information processing device 1-1.

Furthermore, as step P3, the backup storage program 160 stores information for connecting to the nearest information processing device 1-1 as recovery source access information 170-0 in its own auxiliary storage device 17-0. The information for connecting to the information processing device 1 is, for example, the IP address of that information processing device 1.

Figure 5 shows an example of the data structure of the recovery data 133.

The recovery data 133 is the device-specific data 130 of the nearest information processing device 1 (an information processing device 1 that can be connected without going through other information processing devices 1). Therefore, if there are multiple nearest information processing devices 1, the recovery data 133 may include the device-specific data 130 of each of those multiple nearest information processing devices 1. In the example in Figure 5, the recovery data 133 includes the device-specific data 130-a of information processing device 1-a and the device-specific data 130-b of information processing device 1-b. Furthermore, the recovery data 133 may not include any device-specific data 130. In other words, the recovery data 133 of a single information processing device 1 may contain zero or more device-specific data 130.

Figure 6 shows an example of how the recovery data 133 is stored in the information processing device 1.

In the example shown in Figure 6, information processing devices 1-c and 1-d form a recovery pair, with each being the nearest information processing device. Each information processing device 1-c and 1-d registers the device-specific data 130 of its paired device. Specifically, information processing device 1-c stores the device-specific data 130d-c of information processing device 1-d as recovery data 133-c, and information processing device 1-d stores the device-specific data 130c-d of information processing device 1-c as recovery data 133-d.

The recovery pairs described above may be established in all information processing devices 1 of the information processing system 100. In this case, the recovery data 133 of each information processing device 1 will have device-specific data 130 for one information processing device, making it possible to suppress variations in the number of recovery data 133 stored by each information processing device 1.

Figure 7 is a flowchart illustrating in more detail an example of the backup process performed by the backup storage program 160.

In the backup process, the backup storage program 160 first determines whether the recovery source access information 170-0 is stored in the auxiliary storage device 17-0 of its own device (step S1600). If the recovery source access information 170-0 is stored, the backup storage program 160 terminates the process. On the other hand, if the recovery source access information 170-0 is not stored, the backup storage program 160 searches for the nearest information processing device 1 (step S1601). Then, the backup storage program 160 registers the device-specific data 130-0 stored in the storage device 13 of the nearest information processing device 1, information processing device 1-1, as recovery data 133-1 (step S1602).

Next, the backup storage program 160 stores the recovery source access information 170-0, which includes information for connecting to the nearest information processing device 1-1, in the auxiliary storage device 17-0 of its own device (step S1603), and then terminates the process.

Figure 8 illustrates an example of the search process performed by the identical data search program 161. Here, the search process performed by the identical data search program 161 on the information processing device 1-0 is explained as an example.

The search process, similar to the backup process, is performed as a pre-processing step before the data recovery process by the data recovery program 163, and is carried out when the information processing device 1 is first started up and the storage device 13 is operating without failure.

In the search process, the identical data search program 161 first, as procedure Q1, searches for identical data among the partially device common data 131 stored in other information processing devices 1 that are the same as partially device common data 131-0 stored in the device's storage device 13. Here, the identical data search program 161 obtains information indicating the type of partially device common data 131 stored in each of the other information processing devices 1, and searches for partially device common data 131 of the same type as partially device common data 131-0 stored in the device's storage device 13. The type of partially device common data 131 is, for example, the type of application program, and information indicating that type is stored within the partially device common data 131.

Next, as step Q2, the identical data search program 161 stores information for connecting to each of the other information processing devices 1 that store the same data as identical data access information 171-0 in the auxiliary storage device 17-0. In the example in Figure 8, information processing devices 1-0 and 1-2 each store the same partially common device data (partially common device data A) 131-0 and 131-2. In this case, the identical data search program 161 of information processing device 1-1 stores information for connecting to information processing device 1-2 as identical data access information 171-0.

Figure 9 is a flowchart illustrating in more detail an example of the search process performed by the identical data search program 161.

In the search process, the identical data search program 161 first determines whether the same data access information 171-0 is stored in the auxiliary storage device 17-0 of its own device (step S1610). If the same data access information 171-0 is stored, the identical data search program 161 terminates its processing. On the other hand, if the same data access information 171-0 is not stored, the identical data search program 161 starts a loop process (A) that repeats steps S1612 to S1614 for each information processing device 1 included in the information processing system 100 (step S1611).

In loop processing (A), the identical data search program 161 connects to a target information processing device 1, which is one of the information processing devices 1 included in the information processing system 100 (step S1612). The identical data search program 161 determines whether the type of the partially common device data 131 stored in the connected target information processing device 1 is the same as the type of partially common device data 131 stored in its own device (step S1613).

If the types of the common data 131 for some devices are the same, the identical data search program 161 stores the access information for connecting to the target information processing device 1 as identical data access information 171-0 in the auxiliary storage device 17-0 of its own device. Then, the identical data search program 161 adds the number of other information processing devices 1 that are passed through to connect to the target information processing device 1 as the number of intermediary devices to the identical data access information 171-0 (step S1614). On the other hand, if the types of the common data 131 for some devices are not the same, the process in step S1614 is skipped.

Then, when steps S1612 to S1614 are repeated for all information processing devices 1 included in the information processing system 100, the same data search program 161 exits the loop process (A) (step S1615) and terminates its processing.

Figure 10 is a flowchart illustrating an example of the diagnostic process performed by the storage device diagnostic program 162. The diagnostic process begins, for example, when the information processing device 1 is started up.

First, the storage device diagnostic program 162 determines whether or not a malfunction has occurred in the storage device 13 (step S1620). If no malfunction has occurred in the storage device 13, the storage device diagnostic program 162 starts the storage device 13 (step S1626) and terminates the process.

If a problem occurs with the storage device 13, the storage device diagnostic program 162 performs a hardware diagnosis to check the hardware status of the storage device 13 (step S1621). Based on the results of the hardware diagnosis, the storage device diagnostic program 162 determines whether or not the hardware of the storage device 13 is faulty (step S1622).

If the hardware fails, repairing the storage device 13 requires replacing it. Therefore, the storage device diagnostic program 162 executes a degraded operation program (not shown) stored in the auxiliary storage device 17, causing the information processing device 1 to perform degraded operation (step S1623), and then terminates the process. In degraded operation, minimal processing is performed, such as displaying a user-facing default screen like a company logo.

If the hardware is not faulty, it is likely that the data corruption is software-related. Therefore, the storage device diagnostic program 162 executes a data recovery process to recover the data by running the data repair program 163 (step S1624).

Subsequently, the storage device diagnostic program 162 determines whether the data recovery process was successful (step S1625). If the repair is successful, the storage device diagnostic program 162 starts the storage device 13 (step S1626) and terminates the process. If the repair fails, the storage device diagnostic program 162 executes the degraded operation program stored in the auxiliary storage device 17, causing the information processing device 1 to perform degraded operation (step S1623), and terminates the process.

Figure 11 illustrates an example of data recovery processing by the data recovery program 163. In the following scenario, data stored in the storage device 13 of the information processing device 1-0 is corrupted, and the data recovery program 163 of the information processing device 1-0 executes data recovery processing.

As procedure R1, the data recovery program 163 checks the recovery source access information 170-0 stored in the auxiliary storage device 17-0 of the information processing device 1-0 and identifies the nearest information processing device 1-1 as the recovery source information processing device that stores the data for recovering the device-specific data 130-0 and the all-device common data 132-0. Then, for the device-specific data 130-0, the data recovery program 163 recovers it by copying the device-specific data 130 of the information processing device 1-0, which is stored in the recovery data 133-1 of the nearest information processing device 1-1, to the storage device 13-0 of its own device. Furthermore, for the all-device common data 132-0, the data recovery program 163 recovers it by copying the all-device common data 132-1, which is stored in the nearest information processing device 1-1, to the storage device 13-0 of its own device.

Furthermore, as step R2, the data recovery program 163 checks the identical data access information 171-0 stored in the auxiliary storage device 17-0 of the information processing device 1-0, and identifies the information processing device with the fewest number of intermediate devices, namely the information processing device 1-2, which stores the same partial device common data 131 as the partial device common data 131-0 stored in its own device. Then, the data recovery program 163 recovers the partial device common data 131-0 by copying the partial device common data 131-2 stored in the information processing device 1-2 with the fewest number of intermediate devices to the storage device 13-0 of its own device.

Figure 12 is a flowchart illustrating in more detail an example of data recovery processing by the data recovery program 163. The data recovery program 163 is activated during the diagnostic process by the storage device diagnostic program 162 (specifically, at step S1624 in Figure 10). In this embodiment, to reduce communication volume, the data recovery program 163 identifies corrupted data from the device-specific data 130, some device-common data 131, and all-device-common data 132, and recovers only that corrupted data. The method for determining whether data is corrupted is not particularly limited, but for example, hash values for each data type are registered in advance, and the program determines whether the hash value obtained at the time of determination matches the registered hash value.

First, the data recovery program 163 determines whether the common data 132-0 for all devices is corrupted (step S1630). If the common data 132-0 is corrupted, the data recovery program 163 connects to the nearest information processing device 1-1 based on the recovery source access information 170-0 (step S1631). The data recovery program 163 recovers the corrupted common data 132-0 by copying the common data 132-0 stored in the information processing device 1-1 to the storage device 13 of the information processing device 1-0 (step S1632). If the common data 132-0 is not corrupted, steps S1631 and S1632 are skipped.

Next, the data recovery program 163 determines whether the device-specific data 130-0 is corrupted (step S1633). If the device-specific data 130-0 is corrupted, the data recovery program 163 connects to the nearest information processing device 1-1 based on the recovery source access information 170-0 (step S1634). The data recovery program 163 recovers the corrupted device-specific data 130-0 by copying the device-specific data in the recovery data 133-1 stored in the information processing device 1-1 to the storage device 13 of the information processing device 1-0 (step S1635). If the device-specific data 130-0 is not corrupted, steps S1634 and S1635 are skipped.

Furthermore, the data recovery program 163 determines whether the partially shared device data 131-0 is corrupted (step S1636). If the partially shared device data 131-0 is corrupted, the data recovery program 163 connects to the information processing device 1-2 via the shortest route based on the same data access information 171-0 (step S1637). Then, the data recovery program 163 recovers the corrupted partially shared device data 131-0 by copying the partially shared device data 131-0 stored in the information processing device 1-2 to the storage device 13 of the information processing device 1-0 (step S1685), and terminates the process. Note that if the partially shared device data 131-0 is not corrupted, steps S1636 and S1637 are skipped.

As described above, according to this embodiment, the storage device 13 of the information processing device 1 stores some common device data 131 that is common to some of the information processing devices 1 of other information processing devices 1. The identical data search program 161 acquires identical data access information 171 (first access information) for each of the above some information processing devices, which includes information for connecting to that some information processing device and the number of intermediate devices, which is the number of other information processing devices that are passed through when connecting to that some information processing device. If the some common device data 131 is corrupted, the data repair program 163 recovers the corrupted some common device data by copying the some common device data stored in the information processing device with the fewest intermediate devices (first recovery source device) to the storage device 13 of the device itself, based on the identical data access information 171. Therefore, the some common device data 131 that is common to some of the information processing devices 1 of other information processing devices 1 can be recovered by copying the some common device data 131 from the information processing device with the fewest intermediate devices, that is, from the information processing device 1 with the fewest intermediate devices that stores the same some common device data 131 as the device itself. Therefore, data recovery becomes possible while reducing communication load and storage capacity.

Furthermore, in this embodiment, the backup storage program 160 registers the device-specific data 130 of the device with the nearest information processing device 1 (second recovery source device), which is an information processing device 1 connected without going through other information processing devices 1, and acquires recovery source access information (second access information) 170, which includes information for connecting to the nearest information processing device. If the device-specific data is corrupted, the data repair program 163 recovers the corrupted device-specific data 130 by copying the device-specific data 130 registered with the nearest information processing device to the device's storage device 13, based on the recovery source access information 170. In this case, the communication load related to the recovery of the device-specific data 130 can be reduced.

Furthermore, in this embodiment, if the all-device common data 132 is corrupted, the data recovery program 163 recovers the corrupted all-device common data 132 by copying the all-device common data 132 stored in the nearest information processing device to the device's storage device 13, based on the recovery source access information 170. In this case, the communication load and storage capacity required for recovering the all-device common data 132 can be reduced.

Furthermore, in this embodiment, when the storage device diagnostic program 162 detects a problem related to the storage device 13, it determines whether the problem is due to corruption of data stored in the storage device 13 or a hardware failure of the storage device 13. If data corruption occurs, the data recovery program 163 recovers the device-specific data 130, some device-common data 131, and all-device-common data 132 stored in the storage device 13. If hardware failure occurs, the storage device diagnostic program 162 causes the information processing device 1 to perform a degraded operation. This enables appropriate processing when a problem occurs.

Furthermore, in this embodiment, the data recovery program 163 identifies the corrupted data from among the device-specific data 130, some device-common data 131, and all-device-common data 132 in the event of data corruption, and recovers only that corrupted data. This reduces the load incurred during data recovery.

This embodiment describes an update process for updating some of the common device data 131. Note that the common device data 132 can also be updated using the same method as in this embodiment.

Figure 13 is a block diagram showing an example of the functional configuration of the information processing device 1 according to this embodiment. The information processing device 1 shown in Figure 13 differs from the information processing device 1 of Embodiment 1 shown in Figure 3 in that an update program 164 is added to the program that implements the data management unit 16. The update process by the update program 164 will be mainly described below.

Figure 14 illustrates an example of the update process performed by the update program 164. Figure 14 shows information processing devices 1-0 to 1-5. Information processing devices 1-0, 1-2, 1-3, and 1-5 have some common device data 131 of the same type (Type A), while information processing devices 1-1 and 1-4 have some common device data 131 of different types (Type B and Type C).

When the common data 131 of any of the information processing devices 1-0 to 1-5 is updated, the update program 164 of the other information processing devices updates its own common data 131 based on the updated common data 131. At this time, in order to reduce the communication load, the update program 164 updates its own common data 131 by copying the common data 131 from the information processing device 1 with the fewest number of intermediate devices to its own storage device 13.

As a result, when any of the Information Processing Units 1 have their partial device common data 131 updated, the partial device common data 131 will be updated sequentially, starting with the Information Processing Unit 1 closest to the one that received the update. For example, in the example shown in Figure 14, if the partial device common data 131 of Information Processing Unit 1-5 is updated, (1) the partial device common data 131 of Information Processing Unit 1-5 is copied to Information Processing Unit 1-4, (2) the partial device common data 131 of Information Processing Unit 1-4 is copied to Information Processing Unit 1-2, and (3) the partial device common data 131 of Information Processing Unit 1-2 is copied to Information Processing Unit 1-1. Thus, the partial device common data 131 is updated sequentially in the order of Information Processing Units 1-4, 1-2, and 1-1. However, at least one of the partial device common data 131 of the same type (in this case, Information Processing Unit 1-5) is updated directly from a server or other device not shown in the diagram.

Figure 15 is a flowchart illustrating an example of the update process in more detail. Here, we will use the example of updating some of the common data 131-0 of the information processing device 1-0 to provide a more detailed explanation of the update process.

Furthermore, at the initial startup of the information processing device 1-0, the same data search program 161 stores the same data access information 171-0, which includes information for connecting to information processing devices 1-2, 1-3, and 1-5 that have some of the same type of common device data 131, in the auxiliary storage device 17 of the device, in the same manner as in Embodiment 1. Subsequently, during operation, the information processing device 1-1 performs update processing by periodically executing the update program 164.

In the update process, the update program 164 first obtains version information and update flags for the partially common device data 131 stored in the partially common device data 131 of the partially common device data 131 of the partially common device data 131 of the same type from each of the information processing devices 1 that store partially common device data 131 of the same type, based on the identical data access information 171 of the device itself. A data table summarizing the obtained information is then created in memory 12 as update determination data (step S1640). The update flag indicates the update status and is stored, for example, in the storage device 13 of each information processing device 1. The update flag displays one of the following values: "-" indicating no update is needed, "Update scheduled" indicating an update is needed, or "Updating" indicating an update is in progress. The initial value of the update flag is "-".

Figure 16 shows an example of update determination data. The update determination data 1600 shown in Figure 16 includes fields 1601 to 1604. Field 1601 stores the IP address, which is information for connecting to a device of the same type. Field 1602 stores the number of intermediate devices to reach the device of the same type. Field 1603 stores the version information of the common device data 131 stored in the device of the same type. Field 1604 stores the update flag of the common device data 131 stored in the device of the same type. The IP address and the number of intermediate devices can be obtained from the same data access information 171-0, while the version information and update flag are obtained by the update program 164.

Returning to the explanation of Figure 15, the update program 164 determines, based on the update determination data, whether there is a preceding update device of the same type that stores a version of the partial device common data 131 that is higher than the version of the partial device common data 131 of the current device (step S1641). If no preceding update device exists, the update program 164 terminates processing. On the other hand, if a preceding update device exists, the update flag of the current device is set to "Update Scheduled" (step S1642).

The update program 164 determines whether the partial device common data 131 of the information processing device 1 with the fewest number of intermediate devices has been updated (step S1643). For example, if the version of the partial device common data 131 of the information processing device 1 with the fewest number of intermediate devices is greater than the version of the partial device common data 131 of its own device, the update program 164 determines that the partial device common data 131 of the information processing device 1 with the fewest number of intermediate devices has been updated.

If the partial device common data 131 of the information processing device 1 has already been updated, the update program 164 updates the partial device common data 131 of the information processing device 1 by copying it to the storage device 13 of the device itself (step S1644), and then terminates the process. During the update (while step S1644 is being executed), the update flag of the device is set to "Updating," and when the update is complete, the update flag of the device is set to "-."

If some of the common data 131 for the minimum transit device has not been updated, the update program 164 determines whether or not there is an information processing device 1 with the update flag set to "Updating" (step S1645).

If there is an information processing device 1 with the update flag set to "Updating," the update program 164 waits for a certain period of time (step S1646). Afterward, the update program 164 updates the update determination data based on the same data access information 171 of its own device (step S1647), and returns to the process in step S1643.

If no information processing device 1 has an update flag set to "Updating," the sequential execution of updates is stopped, even if an information processing device 1 has an update flag set to "Scheduled for Update." This occurs, for example, when information processing devices 1-2 and 1-3 are waiting for each other to update their respective partial device common data 131. To resolve this situation, the update program 164 determines whether the partial device common data 131 of the second least transiting information processing device 1, which is the information processing device 1 with the second smallest number of transiting devices in the update determination data, has been updated (step S1648).

If the partial device common data 131 of the information processing device 1 via the second minimum route has already been updated, the update program 164 updates the partial device common data 131 of the information processing device 1 via the second minimum route to the storage device 13 of the device itself (step S1648), and then terminates the process. On the other hand, if the partial device common data 131 of the information processing device 1 via the second minimum route has not already been updated, the update program 164 waits for a certain period of time (step S1646) and then proceeds to the process in step S1647.

Furthermore, in steps S1643 and S1648, instead of copying the entire common data 131 for some devices, only the difference data before and after the update in the common data 131 for some devices may be copied.

As described above, according to this embodiment, if the version of the partial device common data 131 stored in the minimum-transit information processing device 1 is greater than the version of the partial device common data 131 of the device itself, the update program 164 updates the partial device common data 131 of the device itself based on the partial device common data 131 stored in the minimum-transit information processing device 1. In this case, data updates become possible while reducing communication load and storage capacity.

Furthermore, in this embodiment, even if there is an information processing device 1 with the update flag set to "Scheduled for Update," if the sequential execution of the update is stopped, the update program 164 updates the partial device common data 131 of its own device based on the partial device common data 131 of the information processing device via the second minimum. In this case, it becomes possible to perform the update appropriately while suppressing an increase in communication load.

The embodiments of this disclosure described above are illustrative for illustrative purposes only and are not intended to limit the scope of this disclosure to those embodiments. Those skilled in the art can implement this disclosure in various other forms without departing from the scope of this disclosure.

1: Information Processing Unit 11: CPU 12: Memory 13: Storage Device 14: Network Interface 15: Application Execution Unit 16: Data Management Unit 17: Auxiliary Storage Device 130: Device-Specific Data 131: Data Common to Some Devices 132: Data Common to All Devices 133: Recovery Data 150: Application 160: Backup Storage Program 161: Identical Data Search Program 162: Storage Device Diagnostic Program 163: Data Repair Program 164: Update Program 170: Recovery Source Access Information 171: Identical Data Access Information

Claims (8)

An information processing system comprising multiple information processing devices connected to each other via daisy-chain connection, enabling them to communicate with one another,
The aforementioned information processing device is
A storage unit that stores some common data shared with some other information processing devices,
An information processing system comprising: for each of the aforementioned partial information processing devices, a first access information is acquired which includes information for connecting to the partial information processing device and the number of intermediate devices which is the number of other information processing devices through which the connection is made; and if the partial device common data is corrupted, a processing unit is used to recover the corrupted partial device common data by copying the partial device common data stored in a first recovery source device, which is the partial information processing device with the smallest number of intermediate devices, to the storage unit of the device itself, based on the first access information. The storage unit stores device-specific data unique to each information processing device,
The processing unit registers the device-specific data in a second recovery source device, which is an information processing device connected to the plurality of information processing devices without going through the other information processing devices, and obtains second access information including information for connecting to the second recovery source device. If the device-specific data is corrupted, the processing unit recovers the corrupted device-specific data by copying the device-specific data registered in the second recovery source device to the storage unit of its own device based on the second access information. The storage unit stores common data for all of the information processing devices,
The information processing system according to claim 2, wherein, if the common data for all devices is corrupted, the processing unit recovers the corrupted common data for all devices by copying the common data for all devices stored in the second recovery source device to the storage unit of its own device based on the second access information. The information processing device includes an auxiliary storage device that stores a program for causing the information processing device to perform a predetermined degraded operation.
The information processing system according to claim 3, wherein, when the processing unit detects a failure related to the storage unit, it determines whether the failure is due to corruption of data stored in the storage unit or a hardware failure of the storage unit, and in the case of data corruption, it restores the partial device common data, device-specific data, and all device common data stored in the storage unit, and in the case of a hardware failure, it executes the program to perform the degraded operation. The information processing system according to claim 4, wherein, in the event of data corruption, the processing unit identifies the corrupted data from among the data common to some devices, the data specific to each device, and the data common to all devices, and recovers only the corrupted data. The processing unit checks the version of the common data for some devices stored in each of the some information processing devices, and if the version of the common data for some devices stored in the first recovery source device is greater than the version of the common data for some devices stored in the storage unit of the device itself, it updates the common data for some devices stored in the storage unit of the device itself based on the common data for some devices stored in the first recovery source device, as described in claim 1. The processing unit updates the common data stored in the storage unit of its own device based on the common data stored in the information processing unit with the second smallest number of intermediate devices, if a certain period of time has elapsed under the following conditions: the common data stored in each of the partial information processing units contains a version of common data for partial devices that is larger than the version of common data for partial devices stored in the storage unit of its own device; the common data for partial devices stored in each of the partial information processing units has not been updated; and the version of common data for partial devices stored in the first recovery source device is not larger than the version of common data for partial devices stored in the storage unit of its own device. A recovery method using an information processing system comprising multiple information processing devices connected to each other via daisy-chain connection,
The aforementioned information processing device is
It stores some common data shared with some other information processing devices,
A recovery method comprising: obtaining first access information for each of the aforementioned partial information processing devices, which includes information for connecting to the partial information processing device and the number of intermediate devices, which is the number of other information processing devices through which the connection is made; and, in the event that the partial device common data is corrupted, recovering the corrupted partial device common data by copying the partial device common data stored in a first recovery source device, which is the partial information processing device with the smallest number of intermediate devices, to the device itself based on the first access information.