Unique ID management in disconnected database replication

Abstract

A system for managing identifiers in a database replication network includes a database including data items, and a global ID space including a number of identities (IDs) for identifying data items. A replica of the database includes an existing range of IDs allocated to the replica from the global ID space, and a replica ID manager for requesting a new range of IDs from the ID space when a threshold is reached. The replica ID manager adjusts the threshold based upon usage of IDs by the replica, calculates a size of the new range of IDs based upon an ID usage rate of the replica, and includes the size in the request. An ID administrator associated with the global ID space allocates a new range of IDs to the replica in response to the request, thereby providing unique global IDs to data items in replicas of the database.

1 . A system for managing identifiers in a database replication network, comprising: 
 a database comprising a plurality of data items;    an ID space including a number of identities (IDs) for identifying data items included in the database;    a replica of at least a portion of the data items in the database, the replica comprising an existing range of IDs allocated to the replica from the ID space;    a replica ID manager associated with the replica for requesting a new range of IDs from the ID space when IDs in the existing range of IDs reaches a predetermined threshold; and    an ID administrator associated with the ID space, the ID administrator configured for receiving requests for ranges of IDs, the ID administrator configured for allocating a new range of IDs to the replica in response to the request from the replica ID manager, a size of the new range of IDs being selected based upon an ID usage rate of the replica.    
   
   
       2 . The system of  claim 1 , wherein the ID administrator is a subsystem of the database.  
   
   
       3 . The system of  claim 2 , wherein the database further comprises an interface for receiving the request from the replica ID manager and for transferring the new range of IDs to the replica ID manager.  
   
   
       4 . The system of  claim 1 , wherein the ID administrator is resident at a different site than the database, and wherein the database and the ID administrator comprise interfaces for communicating with each other via a communications link.  
   
   
       5 . The system of  claim 1 , wherein the replica ID manager is configured for assigning IDs from the replica ID space to data items in the replica to identify the respective data items.  
   
   
       6 . The system of  claim 1 , wherein the ID administrator is configured for allocating the new range of IDs such that the new range of IDs excludes any IDs previously allocated to a replica.  
   
   
       7 . The system of  claim 1 , wherein the ID administrator is configured for calculating the size of the new range of IDs based upon the ID usage rate of the replica.  
   
   
       8 . The system of  claim 1 , wherein the replica ID manager is configured for calculating the size of the new range of IDs based upon the ID usage rate of the replica, and wherein the replica ID manager includes the size in the request for a new range of IDs.  
   
   
       9 . The system of  claim 1 , wherein the replica ID manager is configured for adjusting the predetermined threshold based upon a usage rate of IDs by the replica.  
   
   
       10 . A system for managing identifiers in a database replication network of a database, comprising: 
 a database comprising a plurality of data items;    an ID space including a number of identities (IDs) for identifying data items included in the database;    a replica of at least a portion of the data items in the database, the replica comprising an existing range of IDs allocated to the replica from the ID space;    an ID manager associated with the replica for monitoring usage of IDs by the replica, the ID manager configured for submitting a request for a new range of IDs, the request comprising a size of the new range of IDs based upon usage of IDs by the replica; and    an ID administrator associated with the ID space, the ID administrator configured for receiving the request from the ID manager and for allocating a new range of IDs to the replica in response to the request, the new range of IDs comprising the size requested by the ID manager.    
   
   
       11 - 19 . (canceled)  
   
   
       20 . A method for managing identifiers allocated to a plurality of replicas of a database comprising a data space including a plurality of data items, and a global ID space comprising a plurality of identities (IDs) for identifying data items, the method comprising: 
 providing a replica of the database, the replica comprising a replica ID space comprising a plurality of IDs allocated from the global ID space;    monitoring usage of IDs by the replica; and    submitting a request for a new range of IDs from the global ID space when the IDs from the plurality of IDs remaining unused by the replica reaches a predetermined threshold, the request comprising a size of the new range of IDs being requested, the size being based upon a usage rate of IDs by the replica.    
   
   
       21 . The method of  claim 20 , wherein the size of the new range of IDs is selected based upon at least one of an average usage rate of IDs, a current usage rate of IDs, and a rate of change of usage rate of IDs over time by the replica.  
   
   
       22 . The method of  claim 20 , wherein the replica comprises a first replica, and wherein the first replica intermittently communicates with a second replica of the database for synchronizing data between the first and second replicas.  
   
   
       23 . The method of  claim 22 , wherein the size of the new range of IDs is selected to provide sufficient numbers of IDs for the first replica to satisfy ID usage by the first replica between successive communications with the second replica.  
   
   
       24 . The method of  claim 23 , wherein the second replica comprises a master copy of the database.  
   
   
       25 . The method of  claim 20 , wherein the replica intermittently communicates with an ID administrator managing the global ID space, and wherein the size of the new range of IDs is selected to provide sufficient numbers of IDs for the replica to satisfy ID usage by the replica between successive communications with the ID administrator.