
Lianyukang contributed to the apache/doris repository by engineering robust storage, compaction, and snapshot management features for distributed cloud databases. Leveraging C++ and Java, he implemented adaptive compaction algorithms, parallel transaction recycling, and centralized snapshot APIs to improve data integrity, throughput, and operational safety. His work included optimizing thread pools, enhancing observability with detailed logging and metrics, and introducing configuration-driven controls for security and resource management. He also authored user-facing documentation and test suites to ensure reliability and ease of deployment. The depth of his contributions reflects a strong focus on scalable backend development, concurrency, and cloud-native data management.
February 2026 monthly performance summary for the apache/doris development stream. Focused on strengthening observability, reliability, and data integrity in cloud mode, with targeted fixes and validations that support production stability and scalable operation.
February 2026 monthly performance summary for the apache/doris development stream. Focused on strengthening observability, reliability, and data integrity in cloud mode, with targeted fixes and validations that support production stability and scalable operation.
January 2026 (2026-01) summary for apache/doris focusing on delivering business-impactful features, fixing correctness bugs, and improving admin usability. Key outcomes include a corrected Tablet Stats ID flow, performance-boosting optimizations for sparse wide table compaction, and a new admin-facing privilege configuration for cluster snapshots. These efforts collectively improve observability, performance of large-scale tables, and operational safety for cluster administration.
January 2026 (2026-01) summary for apache/doris focusing on delivering business-impactful features, fixing correctness bugs, and improving admin usability. Key outcomes include a corrected Tablet Stats ID flow, performance-boosting optimizations for sparse wide table compaction, and a new admin-facing privilege configuration for cluster snapshots. These efforts collectively improve observability, performance of large-scale tables, and operational safety for cluster administration.
December 2025 (apache/doris) highlights: Delivered two major features to improve durability and efficiency of data maintenance, and fixed critical bugs affecting stability under heavy workloads. Key features include: 1) Improved compaction and migration efficiency via guards against exceeding FDB transaction limits, and new parallelism configs for snapshot migration and compaction; 2) Efficient batch delete with memory safety, introducing a delete task limit to prevent OOM during large-scale deletions and associated tests. Major bugs fixed: 1) Recycler OOM by limiting queued delete tasks, 2) Race condition in clean_txn_label during versioned write mode cleanup, 3) Corrected cumulative compaction picker to trim by max score after filtering. Overall impact: Increased throughput and stability for maintenance operations, reduced risk of OOM and transaction limit breaches, and more predictable performance under large-scale data churn. Demonstrated skills: concurrency and parallelism tuning, memory management and safe batch operations, robust bug-fix discipline, testing, and code quality. Repository: apache/doris
December 2025 (apache/doris) highlights: Delivered two major features to improve durability and efficiency of data maintenance, and fixed critical bugs affecting stability under heavy workloads. Key features include: 1) Improved compaction and migration efficiency via guards against exceeding FDB transaction limits, and new parallelism configs for snapshot migration and compaction; 2) Efficient batch delete with memory safety, introducing a delete task limit to prevent OOM during large-scale deletions and associated tests. Major bugs fixed: 1) Recycler OOM by limiting queued delete tasks, 2) Race condition in clean_txn_label during versioned write mode cleanup, 3) Corrected cumulative compaction picker to trim by max score after filtering. Overall impact: Increased throughput and stability for maintenance operations, reduced risk of OOM and transaction limit breaches, and more predictable performance under large-scale data churn. Demonstrated skills: concurrency and parallelism tuning, memory management and safe batch operations, robust bug-fix discipline, testing, and code quality. Repository: apache/doris
November 2025: Delivered security hardening, TLS reliability, and storage-optimization improvements for apache/doris. Key changes include: (1) SSL handshake stability: prevented infinite loops during handshake failures with progress checks and SslEngineHelper, reducing TLS hang risk; (2) SSL renegotiation disabled in MySQL channel to eliminate renegotiation-related vulnerabilities; (3) Configurable key bounds stripping for recycle rowset metadata to shrink compaction logs and improve storage efficiency. These workstreams collectively improve production stability, security posture, and operational efficiency, with clear configuration options and minimal expected performance impact.
November 2025: Delivered security hardening, TLS reliability, and storage-optimization improvements for apache/doris. Key changes include: (1) SSL handshake stability: prevented infinite loops during handshake failures with progress checks and SslEngineHelper, reducing TLS hang risk; (2) SSL renegotiation disabled in MySQL channel to eliminate renegotiation-related vulnerabilities; (3) Configurable key bounds stripping for recycle rowset metadata to shrink compaction logs and improve storage efficiency. These workstreams collectively improve production stability, security posture, and operational efficiency, with clear configuration options and minimal expected performance impact.
October 2025 - Apache Doris (apache/doris). Key accomplishments include stabilizing cumu compaction fault injection tests in large clusters and expanding meta-store snapshot capabilities. These improvements enhance reliability, observability, and operational governance, aligning with business goals of stable deployments and safer upgrade paths. Techniques used include test stability improvements, fault injection control, API design for snapshot management, and cross-component integration across cloud-related modules.
October 2025 - Apache Doris (apache/doris). Key accomplishments include stabilizing cumu compaction fault injection tests in large clusters and expanding meta-store snapshot capabilities. These improvements enhance reliability, observability, and operational governance, aligning with business goals of stable deployments and safer upgrade paths. Techniques used include test stability improvements, fault injection control, API design for snapshot management, and cross-component integration across cloud-related modules.
September 2025 milestones center on delivering robust snapshot lifecycle management, transaction ordering, and user-facing documentation, with strong emphasis on reliability, observability, and business value. The team extended the Doris platform with a centralized, property-driven snapshot framework, improved transaction versioning, and surfaced essential observability through metrics and tests, while also expanding user guidance for data recycling. Key business outcomes include safer data backups and restores through standardized snapshot operations, deterministic transaction ordering via versionstamp support, improved developer productivity through richer interfaces and validations, and better user understanding via comprehensive documentation.
September 2025 milestones center on delivering robust snapshot lifecycle management, transaction ordering, and user-facing documentation, with strong emphasis on reliability, observability, and business value. The team extended the Doris platform with a centralized, property-driven snapshot framework, improved transaction versioning, and surfaced essential observability through metrics and tests, while also expanding user guidance for data recycling. Key business outcomes include safer data backups and restores through standardized snapshot operations, deterministic transaction ordering via versionstamp support, improved developer productivity through richer interfaces and validations, and better user understanding via comprehensive documentation.
August 2025 highlights across Doris core and related docs. Implemented Cloud Meta-Service Logging and Lifecycle for Data Changes, enabling write/recycle of compaction and schema-change logs, refined multi-version handling for new tablets during schema changes, and cleanup of versioned tablet metadata. Strengthened observability and cloud-path robustness with enhanced backend logging and HTTP URI normalization for Azure/S3 interactions. Stabilized Show Data tests (P2) to improve reliability, pagination, and data-size calculations. Authored customer-facing documentation for MySQL TLS/SSL configuration and the Doris Recycler, enhancing deployment safety and data lifecycle visibility. Overall impact: stronger data integrity, faster issue resolution, and improved onboarding for operators and customers.
August 2025 highlights across Doris core and related docs. Implemented Cloud Meta-Service Logging and Lifecycle for Data Changes, enabling write/recycle of compaction and schema-change logs, refined multi-version handling for new tablets during schema changes, and cleanup of versioned tablet metadata. Strengthened observability and cloud-path robustness with enhanced backend logging and HTTP URI normalization for Azure/S3 interactions. Stabilized Show Data tests (P2) to improve reliability, pagination, and data-size calculations. Authored customer-facing documentation for MySQL TLS/SSL configuration and the Doris Recycler, enhancing deployment safety and data lifecycle visibility. Overall impact: stronger data integrity, faster issue resolution, and improved onboarding for operators and customers.
July 2025 monthly summary for apache/doris: Delivered adaptive and robust compaction and rowset recovery, enabling dynamic thread pool sizing, automatic rowset cloning during compaction and Merge-on-Read, and improved error logging to enhance data recovery robustness and performance. Implemented CPU-based auto tuning for cumulative compaction threads and per-round task scaling to optimize throughput. Strengthened reliability and diagnosability by enhancing error handling for missing rowset clones and peer backends, and reducing log noise where appropriate. Fixed critical issues including full clone failures when rowsets are missing and related compaction/MOR edge cases, while continuing to improve code quality and test stability.
July 2025 monthly summary for apache/doris: Delivered adaptive and robust compaction and rowset recovery, enabling dynamic thread pool sizing, automatic rowset cloning during compaction and Merge-on-Read, and improved error logging to enhance data recovery robustness and performance. Implemented CPU-based auto tuning for cumulative compaction threads and per-round task scaling to optimize throughput. Strengthened reliability and diagnosability by enhancing error handling for missing rowset clones and peer backends, and reducing log noise where appropriate. Fixed critical issues including full clone failures when rowsets are missing and related compaction/MOR edge cases, while continuing to improve code quality and test stability.
June 2025 monthly summary: Focused on delivering reliable storage engine improvements, enhanced observability, and updated user/docs for WAL size usage across Doris projects. The work emphasizes business value through increased system reliability, faster diagnostics, and better developer/user experience via comprehensive documentation.
June 2025 monthly summary: Focused on delivering reliable storage engine improvements, enhanced observability, and updated user/docs for WAL size usage across Doris projects. The work emphasizes business value through increased system reliability, faster diagnostics, and better developer/user experience via comprehensive documentation.
In May 2025, delivered key improvements to the Doris CloudStorageEngine compaction subsystem, focusing on stability, observability, and recovery. Implemented thread-safety fixes, robust handling of failing tablets, and enhanced profiling/logging to provide granular visibility across base, cumulative, and full compactions. These changes reduce crashes, speed recovery from problematic tablets, and improve debugging and operations. Business value: more reliable data maintenance, less downtime, and faster issue diagnosis in production data pipelines.
In May 2025, delivered key improvements to the Doris CloudStorageEngine compaction subsystem, focusing on stability, observability, and recovery. Implemented thread-safety fixes, robust handling of failing tablets, and enhanced profiling/logging to provide granular visibility across base, cumulative, and full compactions. These changes reduce crashes, speed recovery from problematic tablets, and improve debugging and operations. Business value: more reliable data maintenance, less downtime, and faster issue diagnosis in production data pipelines.
April 2025: Apache Doris development focused on reliability, performance, and maintainability across the core storage and transaction workflows. Key deliverables include: - Cumulative Compaction Enhancements: fault-injection handling, delete-rowset logic optimization, task submission delay strategy, refined logging, and smarter global lock timing to boost reliability and throughput. Notable commits include fixes and enhancements around cold data compaction fault injection, cumulative points after delete, delay strategy, delete-compaction logging, and global lock timing. - Parallel Transaction Recycling: introduced parallelism with a SyncExecutor to accelerate cleanup of expired transaction information, reducing cleanup latency and improving scan/recycle throughput. - S3 Path Construction Bug Fix: resolved double slashes when vault prefix is empty to ensure correct and robust S3 path construction. - Cloud Storage Engine Cleanup: removed unused debug information related to tablet IDs to simplify code paths and reduce noise in task generation. Business impact: higher reliability and throughput for core storage/compaction, faster and more scalable transaction cleanup, fewer path-related deployment/runtime errors, and a leaner codebase that accelerates future changes. Technologies/skills demonstrated: fault injection and testing, logging and observability improvements, concurrent programming with SyncExecutor, cloud storage path handling, and code maintenance/cleanup.
April 2025: Apache Doris development focused on reliability, performance, and maintainability across the core storage and transaction workflows. Key deliverables include: - Cumulative Compaction Enhancements: fault-injection handling, delete-rowset logic optimization, task submission delay strategy, refined logging, and smarter global lock timing to boost reliability and throughput. Notable commits include fixes and enhancements around cold data compaction fault injection, cumulative points after delete, delay strategy, delete-compaction logging, and global lock timing. - Parallel Transaction Recycling: introduced parallelism with a SyncExecutor to accelerate cleanup of expired transaction information, reducing cleanup latency and improving scan/recycle throughput. - S3 Path Construction Bug Fix: resolved double slashes when vault prefix is empty to ensure correct and robust S3 path construction. - Cloud Storage Engine Cleanup: removed unused debug information related to tablet IDs to simplify code paths and reduce noise in task generation. Business impact: higher reliability and throughput for core storage/compaction, faster and more scalable transaction cleanup, fewer path-related deployment/runtime errors, and a leaner codebase that accelerates future changes. Technologies/skills demonstrated: fault injection and testing, logging and observability improvements, concurrent programming with SyncExecutor, cloud storage path handling, and code maintenance/cleanup.
In March 2025 (2025-03), contributed to Apache Doris by delivering reliability, observability, and concurrency improvements in the cloud compaction workflow, with targeted fixes and enhancements that improve debugging, stability, and production throughput.
In March 2025 (2025-03), contributed to Apache Doris by delivering reliability, observability, and concurrency improvements in the cloud compaction workflow, with targeted fixes and enhancements that improve debugging, stability, and production throughput.
February 2025 highlights for apache/doris: delivered reliability and performance improvements across the recycler, storage, and testing layers. Implemented data integrity protections in rowset recycling, resolved critical null pointer issues in cold compaction on new tablets, introduced S3 vault whitelisting to accelerate deletions, enhanced observability for storage accessors, and expanded test infrastructure to stabilize recycler and delete_rowset_data workflows. These efforts reduce data leakage risk, improve operation reliability, and strengthen deployment confidence.
February 2025 highlights for apache/doris: delivered reliability and performance improvements across the recycler, storage, and testing layers. Implemented data integrity protections in rowset recycling, resolved critical null pointer issues in cold compaction on new tablets, introduced S3 vault whitelisting to accelerate deletions, enhanced observability for storage accessors, and expanded test infrastructure to stabilize recycler and delete_rowset_data workflows. These efforts reduce data leakage risk, improve operation reliability, and strengthen deployment confidence.
January 2025 (apache/doris) summary: Implemented Show Data regression test coverage across cloud environments and various table types to ensure data integrity and accurate size reporting. Hardened the Recycler and Recycling Pipeline with protobuf bounds checks, improved storage interface handling (S3/HDFS), resilience against initialization failures, and safer recycling workflows. Strengthened Test Suite reliability and isolation with timeouts, non-concurrent execution, and cleanup of debug points, reducing flaky tests. These efforts collectively improve data reliability, cloud readiness, and CI confidence, with a clear business value in safer data operations and more predictable deployments.
January 2025 (apache/doris) summary: Implemented Show Data regression test coverage across cloud environments and various table types to ensure data integrity and accurate size reporting. Hardened the Recycler and Recycling Pipeline with protobuf bounds checks, improved storage interface handling (S3/HDFS), resilience against initialization failures, and safer recycling workflows. Strengthened Test Suite reliability and isolation with timeouts, non-concurrent execution, and cleanup of debug points, reducing flaky tests. These efforts collectively improve data reliability, cloud readiness, and CI confidence, with a clear business value in safer data operations and more predictable deployments.
December 2024 (apache/doris): Delivered key features for performance and operability, fixed critical reliability issues, and improved testing and cloud integration. Feature work included cumulative compaction performance and configuration improvements (higher permits and new control flag), and testing utilities/logging enhancements, plus cloud config alignment to reduce stale rowset recycle times. Major bug fixes strengthened test reliability and runtime stability across the system, including cumu compaction test reliability improvements and thread pool/CountdownEvent robustness. These efforts yielded higher background throughput, reduced CI instability, improved observability, and better alignment with cloud integration requirements. Demonstrated skills include concurrency and synchronization, test tooling and Groovy-based fixes, instrumentation, and configuration management.
December 2024 (apache/doris): Delivered key features for performance and operability, fixed critical reliability issues, and improved testing and cloud integration. Feature work included cumulative compaction performance and configuration improvements (higher permits and new control flag), and testing utilities/logging enhancements, plus cloud config alignment to reduce stale rowset recycle times. Major bug fixes strengthened test reliability and runtime stability across the system, including cumu compaction test reliability improvements and thread pool/CountdownEvent robustness. These efforts yielded higher background throughput, reduced CI instability, improved observability, and better alignment with cloud integration requirements. Demonstrated skills include concurrency and synchronization, test tooling and Groovy-based fixes, instrumentation, and configuration management.
November 2024 monthly summary focusing on feature delivery, bug fixes, and impact across Doris repositories. Highlights include documentation-driven performance guidance for group commit to optimize data import, robust correctness and startup resilience improvements, and stability enhancements to data compaction and status testing.
November 2024 monthly summary focusing on feature delivery, bug fixes, and impact across Doris repositories. Highlights include documentation-driven performance guidance for group commit to optimize data import, robust correctness and startup resilience improvements, and stability enhancements to data compaction and status testing.

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