daos-stack/daos
Nov 2024 – May 2026
17 Months active
Languages Used
CMakefileShellGoPythonYAML
Technical Skills
API DesignC ProgrammingData StructuresDebuggingDistributed SystemsIterators
Niu Yawei
PROFILE
Niu Yawei
Over 17 months, contributed to the daos-stack/daos repository by building and refining core storage and data management features in C and Go, with a focus on low-level systems programming and distributed systems. Delivered enhancements in memory management, transactional safety, and device management, addressing concurrency, error handling, and performance optimization. Implemented robust solutions for data integrity, storage efficiency, and operational resilience, including improvements to checkpointing, aggregation, and migration workflows. Regularly identified and fixed bugs affecting reliability and resource usage, while introducing configuration flexibility and observability improvements. The work demonstrated depth in debugging, code refactoring, and system-level problem solving.
Overall Statistics
Feature vs Bugs
56%Features
Repository Contributions
64Total
Bugs
24
Commits
64
Features
30
Lines of code
36,300
Activity Months17
Your Network
2178 peopleSame Organization
@intel.com2117
Work History
May 2026
1 Commits
May 1, 2026May 2026 monthly summary for repository daos-stack/daos: Implemented a cap on the merged extent size in the aggregation logic to prevent oversized transactions. This change reduces inefficiencies and errors in large-transaction paths, delivering a stability and performance improvement aligned with DAOS-18901 (PR #18136). Commit reference: 205e513c25ad85a7e1ab890d7c3d7d5289474f5c. Overall impact includes more predictable throughput, improved reliability of the aggregation path, and reduced tail latency in large transactions.
1 Commits
May 1, 2026May 2026 monthly summary for repository daos-stack/daos: Implemented a cap on the merged extent size in the aggregation logic to prevent oversized transactions. This change reduces inefficiencies and errors in large-transaction paths, delivering a stability and performance improvement aligned with DAOS-18901 (PR #18136). Commit reference: 205e513c25ad85a7e1ab890d7c3d7d5289474f5c. Overall impact includes more predictable throughput, improved reliability of the aggregation path, and reduced tail latency in large transactions.
May 2026
April 2026
4 Commits • 1 Features
Apr 1, 2026April 2026 monthly summary for daos-stack/daos focusing on transactional safety, robustness, and observability in the storage stack. Delivered concrete changes that reduce race conditions, harden destruction under concurrency, and improve diagnostic capabilities for data integrity issues. These efforts enhance reliability, data correctness, and operational visibility, supporting higher uptime and faster incident response across the DAOS storage plane.
April 2026
4 Commits • 1 Features
Apr 1, 2026April 2026 monthly summary for daos-stack/daos focusing on transactional safety, robustness, and observability in the storage stack. Delivered concrete changes that reduce race conditions, harden destruction under concurrency, and improve diagnostic capabilities for data integrity issues. These efforts enhance reliability, data correctness, and operational visibility, supporting higher uptime and faster incident response across the DAOS storage plane.
March 2026
5 Commits • 2 Features
Mar 1, 2026March 2026 performance/quality snapshot for daos-stack/daos. Delivered key reliability and efficiency improvements across WAL handling, data integrity checks, DMA-constrained progress, EC aggregation, and test stability. Highlights include removing si_unused_id rollback during WAL commit failures to align with architecture, introducing evtree data integrity assertions, ensuring checkpoint ULT yields under DMA constraints to maintain progress, skipping EC aggregation space reserving checks with proper removal handling to boost aggregation throughput, and extending the create_no_space_loop test timeout to improve reliability. These changes reduce data-risk, improve throughput and reliability, and demonstrate strong low-level systems development and testing skills.
5 Commits • 2 Features
Mar 1, 2026March 2026 performance/quality snapshot for daos-stack/daos. Delivered key reliability and efficiency improvements across WAL handling, data integrity checks, DMA-constrained progress, EC aggregation, and test stability. Highlights include removing si_unused_id rollback during WAL commit failures to align with architecture, introducing evtree data integrity assertions, ensuring checkpoint ULT yields under DMA constraints to maintain progress, skipping EC aggregation space reserving checks with proper removal handling to boost aggregation throughput, and extending the create_no_space_loop test timeout to improve reliability. These changes reduce data-risk, improve throughput and reliability, and demonstrate strong low-level systems development and testing skills.
March 2026
February 2026
2 Commits • 1 Features
Feb 1, 2026February 2026: Enhancements to Migration Memory Management in the daos-stack/daos repository to improve stability and resource efficiency in migration workflows. Implemented robust error-cleanup memory freeing and resolved a memory leak by freeing the mo_csum_iov structure during migration, reducing memory pressure and improving reliability under migration load.
February 2026
2 Commits • 1 Features
Feb 1, 2026February 2026: Enhancements to Migration Memory Management in the daos-stack/daos repository to improve stability and resource efficiency in migration workflows. Implemented robust error-cleanup memory freeing and resolved a memory leak by freeing the mo_csum_iov structure during migration, reducing memory pressure and improving reliability under migration load.
January 2026
6 Commits • 2 Features
Jan 1, 2026Month 2026-01: Focused on storage efficiency, data integrity, and runtime reliability across the DAOS stack. Delivered configurable blobstore cluster sizing (default 128MB) for md-on-ssd mode via DAOS_BS_CLUSTER_MB. Fixed RDB pool targets management (parsing, VOS file recreation, and SCM size deletion). Hardened transaction commits under concurrency to ensure pinned records are not skipped. Enhanced ULT handling with a deep stack for IV-related ULTs and updated scheduling defaults with improved error reporting. Refactored pool child lookup to reduce noise by using the appropriate retrieval path. These changes improve storage utilization, data integrity, performance stability, and observability.
6 Commits • 2 Features
Jan 1, 2026Month 2026-01: Focused on storage efficiency, data integrity, and runtime reliability across the DAOS stack. Delivered configurable blobstore cluster sizing (default 128MB) for md-on-ssd mode via DAOS_BS_CLUSTER_MB. Fixed RDB pool targets management (parsing, VOS file recreation, and SCM size deletion). Hardened transaction commits under concurrency to ensure pinned records are not skipped. Enhanced ULT handling with a deep stack for IV-related ULTs and updated scheduling defaults with improved error reporting. Refactored pool child lookup to reduce noise by using the appropriate retrieval path. These changes improve storage utilization, data integrity, performance stability, and observability.
January 2026
December 2025
5 Commits • 2 Features
Dec 1, 2025December 2025 monthly summary for daos-stack/daos: Delivered high-impact reliability and performance improvements for pool management. Implemented memory-safety fixes to prevent pool-map null dereferences, added local tx handling on cancel, tuned space reclamation and resource handling, skipped unnecessary VOS pre-allocation during pool removal, and established default checkpoint parameters before pool property propagation. These changes improve stability, reduce overhead, and ensure predictable configuration, delivering tangible business value in uptime, performance, and operational safety.
December 2025
5 Commits • 2 Features
Dec 1, 2025December 2025 monthly summary for daos-stack/daos: Delivered high-impact reliability and performance improvements for pool management. Implemented memory-safety fixes to prevent pool-map null dereferences, added local tx handling on cancel, tuned space reclamation and resource handling, skipped unnecessary VOS pre-allocation during pool removal, and established default checkpoint parameters before pool property propagation. These changes improve stability, reduce overhead, and ensure predictable configuration, delivering tangible business value in uptime, performance, and operational safety.
November 2025
2 Commits • 1 Features
Nov 1, 2025November 2025 monthly summary for daos-stack/daos: Focused on reliability and data integrity through targeted changes in the codebase. Delivered two high-impact fixes and improvements around SPDK I/O monitoring and tree probing, supported by clear commit history and DAOS issue tags.
2 Commits • 1 Features
Nov 1, 2025November 2025 monthly summary for daos-stack/daos: Focused on reliability and data integrity through targeted changes in the codebase. Delivered two high-impact fixes and improvements around SPDK I/O monitoring and tree probing, supported by clear commit history and DAOS issue tags.
November 2025
October 2025
3 Commits • 2 Features
Oct 1, 2025In 2025-10, focused on stabilizing and hardening the container/server handle lifecycle and enhancing hardware visibility to improve reliability, troubleshooting, and multi-pool manageability. Delivered concurrency-safe container opens, safer handle management, and groundwork for propagating handles to child pools, while enabling faster identification of problematic SSDs via SMD data.
October 2025
3 Commits • 2 Features
Oct 1, 2025In 2025-10, focused on stabilizing and hardening the container/server handle lifecycle and enhancing hardware visibility to improve reliability, troubleshooting, and multi-pool manageability. Delivered concurrency-safe container opens, safer handle management, and groundwork for propagating handles to child pools, while enabling faster identification of problematic SSDs via SMD data.
September 2025
6 Commits • 5 Features
Sep 1, 2025September 2025 monthly summary for daos-stack/daos focused on delivering configuration clarity, stability improvements, performance optimizations, and operational resilience. This month consolidated enhancements across server configuration, space management, scrubber efficiency, WAL/aggregation behavior, and runtime monitoring, with an emphasis on business value and reliability.
6 Commits • 5 Features
Sep 1, 2025September 2025 monthly summary for daos-stack/daos focused on delivering configuration clarity, stability improvements, performance optimizations, and operational resilience. This month consolidated enhancements across server configuration, space management, scrubber efficiency, WAL/aggregation behavior, and runtime monitoring, with an emphasis on business value and reliability.
September 2025
August 2025
3 Commits • 1 Features
Aug 1, 2025Month: 2025-08 — Delivered durable persistence enhancements and stability fixes in the daos-stack/daos project, emphasizing data integrity, upgrade safety, and multi-pool reliability. Implemented inline VOS checkpointing to ensure data integrity when external checkpointing mechanisms are unavailable, and introduced a WAL header version 2 with pool UUID and compatibility bits, including an automatic upgrade path from V1 to V2 on pool open for backward compatibility. Also fixed a stability issue in RDB recreation by resetting rdb_blob_sz to 0 in recreate_pooltgts to prevent incorrect recreation when multiple pools are present.
August 2025
3 Commits • 1 Features
Aug 1, 2025Month: 2025-08 — Delivered durable persistence enhancements and stability fixes in the daos-stack/daos project, emphasizing data integrity, upgrade safety, and multi-pool reliability. Implemented inline VOS checkpointing to ensure data integrity when external checkpointing mechanisms are unavailable, and introduced a WAL header version 2 with pool UUID and compatibility bits, including an automatic upgrade path from V1 to V2 on pool open for backward compatibility. Also fixed a stability issue in RDB recreation by resetting rdb_blob_sz to 0 in recreate_pooltgts to prevent incorrect recreation when multiple pools are present.
July 2025
2 Commits
Jul 1, 2025July 2025 monthly summary for daos-stack/daos: Implemented two critical fixes to improve reliability and data integrity. Pool reintegration robustness enhancement ensures reintegration continues when ds_pool_child is not yet started by returning a retryable -DER_STALE error, improving stability after hardware replacements. WAL checkpoint integrity improvement flushes the WAL header before unmapping checkpointed regions, reducing risk of data loss or corruption if the engine is interrupted. These changes reduce downtime, improve resilience, and strengthen data integrity during maintenance and workloads.
2 Commits
Jul 1, 2025July 2025 monthly summary for daos-stack/daos: Implemented two critical fixes to improve reliability and data integrity. Pool reintegration robustness enhancement ensures reintegration continues when ds_pool_child is not yet started by returning a retryable -DER_STALE error, improving stability after hardware replacements. WAL checkpoint integrity improvement flushes the WAL header before unmapping checkpointed regions, reducing risk of data loss or corruption if the engine is interrupted. These changes reduce downtime, improve resilience, and strengthen data integrity during maintenance and workloads.
July 2025
April 2025
5 Commits • 3 Features
Apr 1, 2025April 2025: Four core changes in daos-stack/daos focused on reliability, maintenance tooling, and space management. Key outcomes include more robust SSD error handling, NUMA-aware allocation resilience, offline device replacement tooling, and enhanced space management to reduce false ENOSPACE. These changes improve availability, simplify repairs, and optimize capacity utilization across clusters.
April 2025
5 Commits • 3 Features
Apr 1, 2025April 2025: Four core changes in daos-stack/daos focused on reliability, maintenance tooling, and space management. Key outcomes include more robust SSD error handling, NUMA-aware allocation resilience, offline device replacement tooling, and enhanced space management to reduce false ENOSPACE. These changes improve availability, simplify repairs, and optimize capacity utilization across clusters.
March 2025
1 Commits
Mar 1, 2025March 2025 monthly summary for daos-stack/daos focusing on reliability of blobstore IO lifecycle. Implemented a critical bug fix to ensure IO contexts are properly cleared for unplugged/faulty devices and refined the faulty detection logic to trigger only when the blobstore is in NORMAL or OUT state. Also added cleanup of leftover IO contexts during setup to prevent issues when a device is re-integrated after being unplugged. The change reduces risk of stale IO contexts causing I/O errors during device plug-in reattachment and strengthens startup/reintegration paths.
1 Commits
Mar 1, 2025March 2025 monthly summary for daos-stack/daos focusing on reliability of blobstore IO lifecycle. Implemented a critical bug fix to ensure IO contexts are properly cleared for unplugged/faulty devices and refined the faulty detection logic to trigger only when the blobstore is in NORMAL or OUT state. Also added cleanup of leftover IO contexts during setup to prevent issues when a device is re-integrated after being unplugged. The change reduces risk of stale IO contexts causing I/O errors during device plug-in reattachment and strengthens startup/reintegration paths.
March 2025
February 2025
4 Commits • 2 Features
Feb 1, 2025February 2025 monthly summary for the daos-stack/daos development effort. Focused on delivering key functionality, stabilizing critical paths, and improving test reliability to drive business value in storage operations.
February 2025
4 Commits • 2 Features
Feb 1, 2025February 2025 monthly summary for the daos-stack/daos development effort. Focused on delivering key functionality, stabilizing critical paths, and improving test reliability to drive business value in storage operations.
January 2025
7 Commits • 5 Features
Jan 1, 2025January 2025 monthly summary for daos-stack/daos. This period delivered key stability and efficiency improvements across GC references, logging and observability, VOS space management, and pool service scalability. Key outcomes include improved garbage collection correctness, reduced log noise for everyday operation, better space efficiency and resource budgeting across targets, and lowered overhead for pool space queries. The work strengthens reliability, performance, and maintainability, and demonstrates proficiency in C/C++, DAOS internals (VOS, IV, pool service), and debugging/observability tooling.
7 Commits • 5 Features
Jan 1, 2025January 2025 monthly summary for daos-stack/daos. This period delivered key stability and efficiency improvements across GC references, logging and observability, VOS space management, and pool service scalability. Key outcomes include improved garbage collection correctness, reduced log noise for everyday operation, better space efficiency and resource budgeting across targets, and lowered overhead for pool space queries. The work strengthens reliability, performance, and maintainability, and demonstrates proficiency in C/C++, DAOS internals (VOS, IV, pool service), and debugging/observability tooling.
January 2025
December 2024
4 Commits • 2 Features
Dec 1, 2024December 2024 monthly summary for repository daos-stack/daos. Focused on reliability, reporting accuracy, and performance optimization across core data paths. Implemented feature enhancements for pool reporting and DMA memory management, and delivered targeted fixes to improve iteration semantics and phase2 garbage collection efficiency.
December 2024
4 Commits • 2 Features
Dec 1, 2024December 2024 monthly summary for repository daos-stack/daos. Focused on reliability, reporting accuracy, and performance optimization across core data paths. Implemented feature enhancements for pool reporting and DMA memory management, and delivered targeted fixes to improve iteration semantics and phase2 garbage collection efficiency.
November 2024
4 Commits • 1 Features
Nov 1, 2024November 2024 monthly summary for the daos-stack/daos repository. Focused on MD-on-SSD Phase 2 enhancements and a stability fix, delivering significant improvements in memory management, API usability, and data integrity, while laying groundwork for future performance gains and easier operations.
4 Commits • 1 Features
Nov 1, 2024November 2024 monthly summary for the daos-stack/daos repository. Focused on MD-on-SSD Phase 2 enhancements and a stability fix, delivering significant improvements in memory management, API usability, and data integrity, while laying groundwork for future performance gains and easier operations.
November 2024
Activity
Loading activity data...
Quality Metrics
Correctness87.6%
Maintainability82.8%
Architecture83.6%
Performance79.0%
AI Usage21.8%
Skills & Technologies
Programming Languages
CGoMakefilePythonShellYAML
Technical Skills
API DesignBackend DevelopmentBug FixBug FixingCC ProgrammingC programmingCachingCode RefactoringCommand-line Interface DevelopmentConcurrencyConcurrency ControlConfiguration ManagementData IntegrityData Management
Repositories Contributed To
Overview of all repositories you've contributed to across your timeline