Range replication is the duplication of ranges on multiple nodes so that if one node fails, the range’s data is still accessible via another node. In CockroachDB, each range is replicated three times by default. This replication allows CockroachDB to be highly available and remain online even when a node goes down, because the data lives in two other places (and two nodes are required to achieve quorum). When a failure happens, CockroachDB automatically redistributes data to the surviving nodes.