Transaction synchronization in a disconnectable computer and network
AssigneeNovell, Inc.
InventorsPatrick T. Falls, Brian J. Collins, Stephen P. W. Draper
Life of this patent
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Abstract
A method and apparatus are disclosed for synchronizing transactions in a disconnectable network. Each transaction includes operations that were performed on a database replica on one computer while that computer was disconnected from another computer and hence from that other computer's replica. Transaction synchronization, which occurs after the computers are reconnected, transfers information from each computer to the other computer and applies updates to both replicas as appropriate. Transaction logs and clash handling tools may be used with the invention.
Claims34
A method for synchronizing transactions in a system, the system including at least two computers capable of being connected by a network link, each of the computers including a storage device containing a distributed hierarchical database replica, a device controller in signal communication with the storage device, a replica manager in signal communication with the device controller and the network link, and a database manager in signal communication with the replica manager, the method comprising the computer-implemented steps of:
- routing database transactions with the database managers through the replica managers to the device controllers;
- connecting at least two computers with the network link;
- and
- using each of at least two replica managers to route a transaction to another replica manager after the two computers are connected by the network link.
A system comprising at least two computers capable of being connected by a network link, each of said computers comprising:
- a storage device containing a replica, said replica containing entries of a distributed hierarchical database;
- a device controller in signal communication with said storage device;
- a replica manager in signal communication with said device controller and said network link;
- and
- a database manager in signal communication with said replica manager, said database manager on each computer configured to route database transactions to said device controller only through said replica manager, and said replica managers configured to route such transactions to each other after said computers are connected by said network link.
A computer-readable storage medium having a configuration that represents data and instructions which cause a first computer and a second computer in a system to perform method steps for synchronizing transactions, the system including at least two computers capable of being connected by a network link, each of the computers including a storage device containing a distributed hierarchical database replica, a device controller in signal communication with the storage device, a replica manager in signal communication with the device controller and the network link, and a database manager in signal communication with the replica manager, the method comprising the steps of:
- routing database transactions with the database managers through the replica managers to the device controllers;
- connecting at least two computers with the network link;
- and
- using each of at least two replica managers to route a transaction to another replica manager after the two computers are connected by the network link by:
- identifying a first transaction that targets an entry in the first replica, which resides on the first computer;
- transferring an update based on the first transaction over the network connection from the first computer to the second computer;
- applying the first transaction update to the second replica, which resides on the second computer;
- identifying a second transaction that targets an entry in the second replica;
- transferring an update based on the second transaction over the network connection from the second computer to the first computer;
- and
- applying the second transaction update to the first replica.
Dependencies are inferred from the claim text.