How is data integrity ensured when one of the database nodes fails in a cluster architecture?

In a distributed database architecture, data integrity in the event of a node failure is ensured through several mechanisms:

• Data replication: data is duplicated across multiple nodes so that information is not lost if one node fails.
• Consensus mechanisms (e.g., Paxos, Raft): ensure data consistency between nodes, guaranteeing that changes are applied correctly and sequentially.
• ACID-compliant transactions: allow rolling back changes if an operation was not successfully completed.
• Monitoring and automatic failover: upon detecting a node failure, requests are redirected to operational nodes.

Thus, the system maintains data integrity and availability even in the event of individual component failures.