In a GBase 8a distributed cluster, data consistency between primary and standby nodes is critical for service stability. Three event types — ddlevent , dmlevent , and dmlstorageevent — act as the core messengers for synchronization and recovery. Together with the gcrecover process, they form a layered assurance system. This article analyzes their roles, triggers, and collaborative logic. 1. Core Positioning: Essential Differences All three events are triggered by the GBase 8a kernel to record differences between primary and standby nodes, but they focus on entirely different inconsistency scenarios and processing priorities: Event Type Core Purpose Inconsistency Focus Data Carrier ddlevent Metadata sync & repair Table structure, indexes, partition differences DDL operation logs dmlevent Business data sync & repair Row data differences from INSERT/UPDATE/DELETE DML operation records dmlstorageevent Storage-level emergency repair Storage anomalies dmlevent cannot fix Data/metadata file repair…