Transfer of a set of segments between storage clusters of a database system

A transfer segment group task processing module includes:

• at least one first processor;
• and
• at least one first memory that stores operational instructions that, when executed by the transfer segment group task processing module, cause the transfer segment group task processing module to:
• send a first begin segment group transfer instruction to a first storage cluster based on a determination to transfer a set of segments stored via the first storage cluster to a second storage cluster;
• receive a target first ownership sequence number from the first storage cluster based on the first storage cluster processing the first begin segment group transfer instruction;
• send a second begin segment group transfer instruction to the second storage cluster indicating the target first ownership sequence number received from the first storage cluster and further indicating the set of segments;
• receive a transfer complete notification from the second storage cluster based on the second storage cluster processing the second begin segment group transfer instruction to transfer the set of segments from the first storage cluster for storage via the second storage cluster based on the second storage cluster communicating with the first storage cluster;
• send a complete storage instruction to the second storage cluster;
• receive an updated second ownership sequence number received from the second storage cluster indicating updating of second data ownership information of the second storage cluster to indicate ownership of the set of segments by the second storage cluster based on the second storage cluster processing the complete storage instruction to include the set of segments in updated data ownership information of second cluster state data having the updated second ownership sequence number;
• and
• send a commit transfer instruction to the first storage cluster based on updated second ownership sequence number received from the second storage cluster.

A non-transitory computer readable storage medium comprises:

• at least one memory section that stores operational instructions that, when executed by at least one processing module that includes a processor and a memory, causes the at least one processing module to:
• send a first begin segment group transfer instruction to a first storage cluster based on a determination to transfer a set of segments stored via the first storage cluster to a second storage cluster;
• receive a target first ownership sequence number from the first storage cluster based on the first storage cluster processing the first begin segment group transfer instruction;
• send a second begin segment group transfer instruction to the second storage cluster indicating the target first ownership sequence number received from the first storage cluster and further indicating the set of segments;
• receive a transfer complete notification from the second storage cluster based on the second storage cluster processing the second begin segment group transfer instruction to transfer the set of segments from the first storage cluster for storage via the second storage cluster based on the second storage cluster communicating with the first storage cluster;
• send a complete storage instruction to the second storage cluster;
• receive an updated second ownership sequence number received from the second storage cluster indicating updating of second data ownership information of the second storage cluster to indicate ownership of the set of segments by the second storage cluster based on the second storage cluster processing the complete storage instruction to include the set of segments in updated data ownership information of second cluster state data having the updated second ownership sequence number;
• and
• send a commit transfer instruction to the first storage cluster based on updated second ownership sequence number received from the second storage cluster.