Tag: Replication

Replication failures, lag, or divergence in stateful systems.

ID	Title	Description	Category	Technology	Tags
CRE-2025-0020 High Impact: 10/10 Mitigation: 6/10	Self-hosted PostgreSQL HA: WAL Streaming & HA Controller Crisis (Replication Slot Loss, Disk Full, Etcd Quorum Failure)	Detects high-severity failures in self-hosted PostgreSQL high-availability clusters managed by Patroni, Zalando, or similar HA controllers. This rule targets catastrophic conditions that break replication or cluster consensus: - WAL streaming failures due to missing replication slots (usually after disk full or crash events) - Persistent errors resolving HA controller endpoints (etcd/consul) and loss of HA controller quorum - Disk saturation leading to WAL write errors and replication breakage	PostgreSQL High Availability	postgresql	High Availability Patroni Zalando Etcd Replication WAL Storage Quorum Crash Data Loss Timeout
CRE-2025-0070 Critical Impact: 10/10 Mitigation: 6/10	Kafka Under-Replicated Partitions Crisis	Critical Kafka cluster degradation detected: Multiple partitions have lost replicas due to broker failure, resulting in an under-replicated state. This pattern indicates a broker has become unavailable, causing partition leadership changes and In-Sync Replica (ISR) shrinkage across multiple topics.	Message Queue Problems	kafka	Kafka Replication Data Loss High Availability Broker Failure Cluster Degradation