Final answer:
sstableloader uses the Gossip protocol to learn the cluster's topology, allowing nodes in the Apache Cassandra database to synchronize their state information.
Step-by-step explanation:
The sstableloader utility uses the Gossip protocol to learn the topology of the cluster. This protocol allows nodes within the Apache Cassandra database cluster to communicate with each other to propagate and synchronize information about the state of the cluster and its nodes. Gossip is a peer-to-peer communication protocol that enables the exchange of state information between nodes, which is crucial in a distributed system like Cassandra for maintaining consistency and handling failures.