ReplicaSentry

ReplicaSentry is a web app for monitoring and validating database replication health across Postgres, MySQL, and MongoDB. It goes beyond “lag charts” by continuously checking data correctness via lightweight sampling, checksum comparisons, and schema/DDL drift detection. It alerts on silent failures: replica applying but missing rows, divergent sequences, broken foreign keys, or replication filters that drop data. It also provides runbooks and one-click diagnostics (identify the first diverging transaction, table, or shard) so on-call engineers can act fast. This is not a magic fix-it tool—cross-region replication issues are messy and often require manual intervention—but it can drastically shorten time-to-detection and time-to-triage. Pricing is per cluster with higher tiers for more frequent validation and longer retention.