When you swap a failed Data Node with a fresh one in GBase 8a, a carefully choreographed sequence ensures data distribution stays consistent: a transitional distribution map isolates the fault, then an automatically rebuilt map restores the original layout while data is moved in the background . The key is a two‑table relay that guarantees a complete, valid mapping exists at every moment.

The Four‑Step Process

Create a transitional distribution map — The DBA manually builds a new distribution that excludes the failed node. The cluster now holds two maps: the original (with the failed node) and the transitional (without it).

Trigger the replacement command — The system automatically creates a third distribution map. This one is identical to the original, except the failed node's IP is replaced by the new node's IP.

Data migration and switchover — The system moves data from the transitional map's nodes to the new node according to the automatically created map.…