April 2026 monthly summary for antrea-io/antrea focusing on reliability and IPAM/NetworkPolicy robustness. Key features delivered - Tombstone handling and deletion robustness across controllers: hardened delete paths for StatefulSet, Nodes, and general watch reconnect scenarios to prevent crashes when tombstones are observed and to ensure deleted resources are correctly processed, preserving IPAM state and NetworkPolicy enforcement. Regression tests added. - Flow aggregator stability and IP allocation correctness: mitigated a potential panic in the Flow Aggregator when EndTs is nil and corrected the bitmap index in AllocateRange to prevent double-allocation of IPs; accompanying tests guard against re-allocation and ensure stable record processing. Major bugs fixed - Tombstone processing across delete handlers (StatefulSet, Node, controller delete paths) to prevent crashes and stale IP allocations. - Flow Aggregator: nil EndTs handling, and corrected AllocateRange bitmap indexing to maintain IP pool integrity. Overall impact and accomplishments - Significantly increased reliability of delete-event handling during controller restarts or network partitions, reducing risk of IP exhaustion and NetworkPolicy gaps. - Improved IPAM correctness and resource tracking, preventing stale IP allocations and double-allocation scenarios. - Strengthened test coverage with regression tests focused on tombstone paths and allocation logic, improving long-term maintainability. Technologies/skills demonstrated - Go, Kubernetes controller patterns, informer/tombstone handling, and robust type-safe deletions. - IPAM management, bitmap operations, and allocation logic. - Test-driven development with regression tests and code reviews around critical delete paths.