Global attribute uniqueness (GAU) using an ordered message service (OMS)
A method and computer program product for providing Global Attribute Uniqueness (GAU) using an Ordered Message Service (OMS) is presented. A database operation is received from a client. A determination is made regarding whether the operation changes a value to a current value and when the operation would change a value to a current value then operation is ended. When the operation would not change a value to a current value the operation is decomposed into ADD messages and DELETE messages. The ADD messages are sent to a GAU manager and GAU state is checked and updated. The updates are committed to GAU state and the Directory Server (DS) is updated. Operation is then returned to the client. DELETE messages are sent to the GAU manager and GAU state is updated. The updates are then committed.
1. A method of synchronizing Directory Servers (DSs) performing Global Attribute Uniqueness (GAU) using an Ordered Messaging Service (OMS), the method comprising:
receiving, at an OMS Manager in a Directory Server that had been disconnected from a main group of Directory Servers (DSs), a leader message from an OMS End-point queue indicating communications have been restored;
providing, by said OMS Manager in the DS that had been disconnected, a temporary group through which synchronization with a Leader DS in the main group will occur;
sending, by said OMS Manager in the DS that had been disconnected, a sync message to the OMS group;
listening, by said OMS Manager in the DS that had been disconnected, on the temporary group for sync messages;
receiving, at an OMS Manager of the Leader DS, the sync message;
sending, by said OMS Manager of the Leader DS, blocks of change log records as sync messages to the temporary group;
receiving, by said OMS Manager in the DS that had been disconnected, the blocks of sync messages;
and using, in the DS that had been disconnected, said blocks of sync messages to bring state tables and a change log into global consistency.
2. The method of claim 1 further comprising discarding, by the DS that had been disconnected, all messages from the OMS group up to and including the sync message.
3. The method of claim 2 further comprising deleting, by the DS that had been disconnected, the temporary group.
4. The method of claim 3 further comprising resuming, by the DS that had been disconnected, normal operation as a part of the main group.
5. A computer readable storage medium having computer readable code thereon for synchronizing Directory Servers (DSs) performing Global Attribute Uniqueness (GAU) using an Ordered Message Service (OMS), the medium comprising:
instructions for receiving, at an OMS Manager in a Directory Server (DS) that had been disconnected from a main group of Directory Servers (DSs), a leader message from an OMS End-point queue indicating communications have been restored;
instructions for providing, by said OMS Manager in the DS that had been disconnected, a temporary group through which synchronization with a Leader DS in the main group will occur;
instructions for sending, by said OMS Manager in the DS that had been disconnected, a sync message to the OMS group;
instructions for listening, by said OMS Manager in the DS that had been disconnected, on the temporary group for sync messages;
instructions for receiving, at an OMS Manager of the Leader DS, the sync message;
instructions for sending, by said OMS Manager of the Leader DS, blocks of change log records as sync messages to the temporary group;
instructions for receiving, by said OMS Manager in the DS that had been disconnected, the blocks of sync messages;
and instructions for using, in the DS that had been disconnected, said blocks of sync messages to bring state tables and a change log into global consistency.
6. The computer readable medium of claim 5 further comprising instructions for discarding, by the DS that had been disconnected, all messages from the OMS group up to and including the sync message.
7. The computer readable medium of claim 6 further comprising instructions for deleting, by the DS that had been disconnected, the temporary group.
8. The computer readable medium of claim 7 further comprising instructions for resuming, by the DS that had been disconnected, normal operation as a part of the main group.