May 2025 monthly summary for the apache/incubator-gluten project. Focused on reliability and data correctness across the ClickHouse backend, Kafka integration, and Delta Lake MergeTree pathways. Delivered targeted fixes and a new optimization, with expanded test coverage to validate end-to-end data integrity and performance improvements.

April 2025: Strengthened Gluten's ClickHouse backend integration with native Delta Lake features, improved data-path reliability, and targeted bug fixes. Delivered several high-impact capabilities that enable faster, more reliable analytics workloads and expanded Delta Lake compatibility for ClickHouse deployments.

For 2025-03, delivered a focused Kafka integration enhancement in the apache/incubator-gluten repository, combining feature work with a stability fix to enable reliable streaming ingestion and improve data source handling. The work centers on Kafka Stream Reading within the SerializedPlanParser, ensuring read operations correctly populate split information and handle Kafka data sources more robustly. A related fix to stabilize Kafka unit tests was included in the same change, improving CI reliability. These efforts translate to stronger streaming analytics capabilities, reduced data ingestion errors, and clearer operational signals for gluten-powered pipelines, aligned with business goals of accuracy, latency, and uptime.

February 2025: Delivered two major features for apache/incubator-gluten that jointly enhance data engineering reliability and performance. First, Delta Optimized Writer Transformer across Delta versions (2.0, 2.3, 3.2) with shim providers and classes enabling optimized Delta write paths; includes test coverage for optimize write functionality, including partitioned writes. Second, Monotonically increasing ID support for the ClickHouse backend, featuring a new C++ implementation integrated into the Java/Scala codebase to generate unique, monotonically increasing IDs by combining partition IDs and record counts.

January 2025 highlights include a critical bug fix for KylinStorageScanExec and the rollout of Kafka batch data source support, reflecting a strong focus on robustness and scalability. Key outcomes include improved test coverage and maintainability for the query execution engine, plus integration updates across ClickHouse, Substrait, and Spark to enable batch processing with Kafka.

December 2024 monthly summary focusing on delivering correctness and stability for the apache/incubator-gluten project. Highlights include NaN handling in corr for the ClickHouse backend and resolving CSE issues in aggregate functions; added tests; improved reliability and maintainability; business value of accurate analytics and reduced debugging time.

November 2024 performance summary: Across apache/incubator-gluten and apache/kylin, delivered targeted features to improve data reliability, metadata caching, task traceability, and CSV handling, while addressing regression-prone parsing and partitioning edge cases. Highlights include enabling and testing the files.per.partition.threshold setting in the ClickHouse backend with correct start offset; introducing CACHE META command for metadata-only caching on MergeTree tables; implementing task ID logging and propagation to unify tracing across backend and local engine; fixing Spark CSV date/datetime parsing; enabling use_excel_serialization for CSV handling in CH backend to improve compatibility and performance.

October 2024: Focused on stability and correctness in the core gluten pipeline. Delivered two critical bug fixes that improve reliability under dynamic executor pools and prevent potential infinite loops in Substrait processing for the ClickHouse backend. These changes reduce runtime errors during cache operations, improve query correctness, and enhance resilience in environments with fluctuating resources. Demonstrated proficiency across Scala-based cache logic and C++-level Substrait processing, with targeted tests to prevent regressions.