US 2006/0190553 A1Published application

Network system, device and program

AssigneeBrother Kogyo Kabushiki Kaisha

InventorAtsushi Kojima

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Abstract

In a network system including a plurality of devices connected to a network, a master device supplies general devices with shared data to be shared by the devices in the system. On each update of the shared data, the master device generates backup data (the shared data before the backup) and successively transmits a backup instruction to all the devices managed thereby, starting from a device of the lowest priority in the system. Each of the devices successively receiving the backup instruction acquires the backup data from a device having an immediately higher priority than itself. By the above operation, reliable backup of the shared data (enabling restoration of the shared data to that of several times ago after the update is repeated several times) is realized without overloading any device in the system even when the storage capacity of each device for storing the backup data is relatively small.

Claims18

Dependent claims

A network system comprising a plurality of devices connected to a network each of which is assigned an ordinal rank in the system in which a device of a highest ordinal rank functions as a master device while devices of the other ordinal ranks function as general devices and shared data to be shared by the plurality of devices is supplied from the master device to the general devices, wherein:

each of the devices includes master device units that operate when the device functions as the master device and general device units that operate when the device functions as a general device, and
the master device units include:
a shared data storing unit that stores the shared data;
a shared data updating unit that updates the shared data stored in the shared data storing unit;
a first on-update backup data supplying unit that supplies the shared data before update to a lower-level device of the highest ordinal rank in devices lower than the device as backup data when the shared data is updated by the shared data updating unit;
an on-restoration backup data acquiring unit that acquires the backup data from a different device when a restoration instruction is given;
and
a shared data restoring unit that restores the shared data to that before update by storing the backup data acquired by the on-restoration backup data acquiring unit in the shared data storing unit as the shared data, and
the general device units include:
a backup data storing unit that stores the backup data;
a backup data updating unit that updates the backup data by acquiring backup data when the backup data is supplied from a different device and storing the acquired backup data in the backup data storing unit;
a second on-update backup data supplying unit that supplies the backup data before update to a lower-level device of the highest ordinal rank in devices lower than the device as backup data when the backup data is updated by the backup data updating unit;
and
an on-restoration backup data supplying unit that supplies the backup data in response to a request from the master device.

11 more elements

A device which is used as a node forming a network system including a plurality of devices connected to a network each of which is assigned an ordinal rank in the system in which a device of the highest ordinal rank functions as a master device while devices of the other ordinal ranks function as general devices and shared data to be shared by the plurality of devices is supplied from the master device to the general devices, wherein:

the device comprises master device units that operate when the device functions as the master device and general device units that operate when the device functions as a general device, and
the master device units include:
a shared data storing unit that stores the shared data;
a shared data updating unit that updates the shared data stored in the shared data storing unit;
a first on-update backup data supplying unit that supplies the shared data before update to a lower-level device of the highest ordinal rank in devices lower than the device as backup data when the shared data is updated by the shared data updating unit;
an on-restoration backup data acquiring unit that acquires the backup data from a different device when a restoration instruction is given;
and
a shared data restoring unit that restores the shared data to that before update by storing the backup data acquired by the on-restoration backup data acquiring unit in the shared data storing unit as the shared data, and
the general device units include:
a backup data storing unit that stores the backup data;
a backup data updating unit that updates the backup data by acquiring backup data when the backup data is supplied from a different device and storing the acquired backup data in the backup data storing unit;
a second on-update backup data supplying unit that supplies the backup data before update to a lower-level device of the highest ordinal rank in devices lower than the device as backup data when the backup data is updated by the backup data updating unit;
and
an on-restoration backup data supplying unit that supplies the backup data in response to a request from the master device.

11 more elements

A computer-readable medium having a computer program stored thereon, said computer program comprising computer-readable instructions that cause a device, as a node forming a network system including a plurality of devices connected to a network each of which is assigned an ordinal rank in the system in which a device of the highest ordinal rank functions as a master device while devices of the other ordinal ranks function as general devices and shared data to be shared by the plurality of devices is supplied from the master device to the general devices, to function as:

master device units that operate when the device functions as the master device;
and
general device units that operate when the device functions as a general device, wherein:
the master device units include:
a shared data storing unit that stores the shared data;
a shared data updating unit that updates the shared data stored in the shared data storing unit;
a first on-update backup data supplying unit that supplies the shared data before update to a lower-level device of the highest ordinal rank in devices lower than the device as backup data when the shared data is updated by the shared data updating unit;
an on-restoration backup data acquiring unit that acquires the backup data from a different device when a restoration instruction is given;
and
a shared data restoring unit that restores the shared data to that before update by storing the backup data acquired by the on-restoration backup data acquiring unit in the shared data storing unit as the shared data, and
the general device units include:
a backup data storing unit that stores the backup data;
a backup data updating unit that updates the backup data by acquiring backup data when the backup data is supplied from a different device and storing the acquired backup data in the backup data storing unit;
a second on-update backup data supplying unit that supplies the backup data before update to a lower-level device of the highest ordinal rank in devices lower than the device as backup data when the backup data is updated by the backup data updating unit;
and an on-restoration backup data supplying unit that supplies the backup data in response to a request from the master device.

12 more elements

Dependencies are inferred from the claim text.