Under what conditions can data consistency violations occur in a database operating in cluster mode?

Data consistency violations in a database operating in cluster mode can occur under the following conditions:

• Synchronization issues between cluster nodes. If data replication is delayed or version conflicts occur, data may diverge.
• Network failures or split-brain scenarios. When part of the cluster loses connection to the rest, parallel changes can occur, leading to conflicts.
• Incorrect configuration of transaction isolation levels. If transactions are not properly isolated, race conditions and data loss are possible.
• Application logic errors or replication mechanism issues. For example, incorrect application of changes or transaction rollbacks.

To prevent consistency violations, mechanisms such as consensus algorithms, strict isolation levels, cluster health monitoring, and proper conflict resolution are used.