One new feature in Percona XtraDB Cluster (PXC) in recent releases was the inclusion of the ability for an existing cluster to auto-bootstrap after an all-node-down event. Suppose you lose power on all nodes simultaneously or something else similar happens to your cluster. Traditionally, this meant manually re-bootstrapping the cluster, but not any more.
How it works
Given the above all-down situation, if all nodes are able to restart and see each other such that they all agree what the state was and that all nodes have returned, then the nodes will make a decision that it is safe for them to recover PRIMARY state as a whole.
This requires:
- All nodes went down hard — that is; a kill -9, kernel panic, server power failure, or similar event
- All nodes from the last PRIMARY component are restarted …