Network computer system and method for executing data synchronization process thereof

• US 6,345,308 B1
• Filed: 02/26/1999
• Issued: 02/05/2002
• Est. Priority Date: 02/27/1998
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Abe, Masaki
• Primary Examiner(s): Burgess, Glenton B.
• Assistant Examiner(s): Benson, Walter
• Application Number:
  US09/257,937
• Time in Patent Office: 1,075 Days
• Field of Search: 707/101, 707/202, 707/204, 709/203, 709/248, 714/4, 713/2
• US Class Current: 709/248
• CPC Class Codes: G06F 16/275 Synchronous replication
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04L 67/34 involving the movement of software or configuration parameters network booting or remote initial program loading [RIPL] G06F9/4416
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: Y10S 707/99942 Manipulating data structure, e.g. compression, compaction, compilation

Abstract

The network computer (“NC”) stores a replica list in a local storage by an initial downloading of a synchronization list in a server computer as well as resource replicas that are necessary for mobile operation of the NC. When the NC returns to an on-line state to the server, the replication between the resource replicas in the NC and the server resources is performed with reference to the synchronization list and the replica list in the local storage. Even if a synchronous object in the server synchronization list has been modified during the mobile operation of the network computer, the NC can determine the modification in the replication process. This results in a reliable and flexible network computer system.

Claims

1. A network computer system, comprising:

a server computer;

a plurality of network computers;

at least one network for coupling between the server computer and the plurality of network computers, wherein

the server computer stores original resources having data including at least an OS and a synchronization list for identifying synchronous objects for synchronization of the original resources to each one of the plurality of network computers,

the OS includes a synchronization process for the synchronization of the original resources, and

wherein each of the plurality of the network computers includes a local storage for storing downloaded replicas of the original resources from the server computer to the network computer and a downloaded replica list of the synchronization list of the server computer for identifying synchronous objects for executing the synchronization,

the synchronization list includes optional information for determining execution of the synchronization between the server computer and the local storage, and

the local storage is used to store the replicas of the resources stored in the server computer and the replica list of the synchronization list stored in the server computer;

means for operating the each of the plurality of network computers by using resource replicas stored in the local storage without accessing to the server computer;

means for comparing the synchronization list in the server computer and the replica list in the local storage at a synchronization stage in an on-line connection to the server computer; and

means for executing the synchronization between the resources in the server computer and the resource replicas in the each of the plurality of network computers using a result of a comparison by the comparing means.

2. The computer system according to claim 1, wherein the synchronization executing means includes means for determining execution of the synchronization by determining whether the synchronization list in the server computer is changed after an initial synchronization of resources to the each one of the plurality of network computers.

3. The computer system, according to claim 2, wherein

the synchronization executing means updates the replica list in the local storage by downloading the contents in the synchronization list when it is modified off-line.

4. The computer system according to claim 3, wherein

the synchronization list includes synchronizing object resources and an optional information included for each of the respective resources for determining which one of the respective resources has priority for synchronization when it is determined that data in the server computer and the local storage have been modified off-line.

5. The computer system according to claim 4, wherein

the synchronization executing means determines execution of synchronization by determining modifications of the data in the server computer and in the local storage using the optional information.

6. The computer system according to claim 5, wherein

the synchronization executing means determines execution of the synchronization by using the optional information in the synchronization list.

7. The computer system according to claim 6, wherein the computer system is operable in a first mode operation and a second mode operation, wherein

the first mode operation uses resource replicas stored on the local storage during an off-line state from the server computer;

and

the second mode operation is performed by connecting the server computer through an on-line network.