May 2026 focused on reliability hardening in the Apache Flink repository. Delivered a targeted bug fix to HybridSourceReader to preserve the correct ordering of method calls during source switches, ensuring proper management of underlying subsources during transitions and recovery. Implemented a regression test to validate the sequence during recovery. This work strengthens fault-tolerance for hybrid sources and reduces risk of incorrect state transitions during failures.

April 2026 monthly summary for apache/iceberg focusing on a targeted correctness fix in the Flink Iceberg source reader and supporting integration tests. Improved watermark handling to ensure on-time classification for records with minimum event time and added tests to validate the new behavior. This work increases streaming accuracy, reliability, and confidence in Flink-Iceberg workloads while maintaining production readiness.