daos-stack/daos
Jan 2025 – May 2026
14 Months active
Languages Used
CPythonMarkdown
Technical Skills
Bug FixingCode MaintenanceConcurrency ControlDistributed SystemsMemory ManagementSystem Programming
Mohamad Chaarawi
PROFILE
Mohamad Chaarawi
Worked extensively on the daos-stack/daos repository, delivering features and fixes across distributed storage, file systems, and backend infrastructure. Focused on enhancing data integrity, performance, and reliability, this developer implemented improvements such as EC-aware chunk sizing, robust error handling, and resource management for both C and Python components. Addressed concurrency and memory management challenges, optimized aggregation and object storage logic, and strengthened CI/CD pipelines through targeted test stability enhancements. Leveraged skills in C programming, system programming, and Python scripting to refine client-server interactions, enforce storage policies, and document internal APIs, resulting in more predictable, maintainable, and resilient storage operations.
Overall Statistics
Feature vs Bugs
46%Features
Repository Contributions
28Total
Bugs
13
Commits
28
Features
11
Lines of code
2,184
Activity Months14
Your Network
239 peopleSame Organization
@hpe.com178
Work History
May 2026
1 Commits
May 1, 2026In May 2026, delivered a targeted data integrity fix in the DAOS object storage path by resetting the IOD iteration count per IOD instead of cumulatively, ensuring accurate detection of valid entries and reliable data processing. This change addresses DAOS-623 and was implemented in commit 847f4495dea8bf3d7c116c2f27bf81284e97ecd0, with per-IOD counter reset and sign-off by Mohamad Chaarawi. Business value: increases reliability and correctness of object storage data handling, reduces risk of silent data gaps, and improves data quality across storage pipelines. Technical impact: refined IOD loop logic, easier testing/maintenance, and demonstrated strong collaboration and code-quality discipline.
1 Commits
May 1, 2026In May 2026, delivered a targeted data integrity fix in the DAOS object storage path by resetting the IOD iteration count per IOD instead of cumulatively, ensuring accurate detection of valid entries and reliable data processing. This change addresses DAOS-623 and was implemented in commit 847f4495dea8bf3d7c116c2f27bf81284e97ecd0, with per-IOD counter reset and sign-off by Mohamad Chaarawi. Business value: increases reliability and correctness of object storage data handling, reduces risk of silent data gaps, and improves data quality across storage pipelines. Technical impact: refined IOD loop logic, easier testing/maintenance, and demonstrated strong collaboration and code-quality discipline.
May 2026
April 2026
4 Commits • 2 Features
Apr 1, 20262026-04 monthly summary for daos-stack/daos: Delivered two core capabilities and improved test robustness. Key features: (1) DFuse Read/Write Path Improvements and Documentation, including EOF handling and improved error management. (2) Tests Stability and Reliability Improvements to reduce false negatives by skipping certain FI error messages in logging tests and ignoring server network errors in client tests. Major bugs fixed include pre-read EOF guard/overflow handling, zero-initialization of mock_read buffers, and improved error handling in DFuse write paths. Impact: stronger reliability of DFuse IO under real workloads, fewer flaky tests, faster feedback loops, and higher confidence in deployments. Technologies demonstrated: C/C++, DFuse, DAOS, FI-based testing, enhanced developer documentation, and test harness improvements.
April 2026
4 Commits • 2 Features
Apr 1, 20262026-04 monthly summary for daos-stack/daos: Delivered two core capabilities and improved test robustness. Key features: (1) DFuse Read/Write Path Improvements and Documentation, including EOF handling and improved error management. (2) Tests Stability and Reliability Improvements to reduce false negatives by skipping certain FI error messages in logging tests and ignoring server network errors in client tests. Major bugs fixed include pre-read EOF guard/overflow handling, zero-initialization of mock_read buffers, and improved error handling in DFuse write paths. Impact: stronger reliability of DFuse IO under real workloads, fewer flaky tests, faster feedback loops, and higher confidence in deployments. Technologies demonstrated: C/C++, DFuse, DAOS, FI-based testing, enhanced developer documentation, and test harness improvements.
March 2026
3 Commits • 1 Features
Mar 1, 2026March 2026 monthly summary for daos-stack/daos: Key features delivered include Directory Class Policy Enforcement, ensuring directories default to replication class and EC is not used for directories; major bugs fixed include Protoquery Timeout Stabilization for Dead Rank Scenarios and enhanced DFS error handling and memory management. Overall impact: safer and more predictable storage semantics, reduced timeout-related failures, and improved robustness of DFS operations. Technologies demonstrated: policy enforcement in DFS, error handling improvements, memory management, and documentation updates.
3 Commits • 1 Features
Mar 1, 2026March 2026 monthly summary for daos-stack/daos: Key features delivered include Directory Class Policy Enforcement, ensuring directories default to replication class and EC is not used for directories; major bugs fixed include Protoquery Timeout Stabilization for Dead Rank Scenarios and enhanced DFS error handling and memory management. Overall impact: safer and more predictable storage semantics, reduced timeout-related failures, and improved robustness of DFS operations. Technologies demonstrated: policy enforcement in DFS, error handling improvements, memory management, and documentation updates.
March 2026
January 2026
3 Commits • 1 Features
Jan 1, 2026January 2026 monthly summary for daos-stack/daos: Delivered EC Aggregation Performance Optimization by loading the latest epoch writes from VOS after restart, eliminating unnecessary scans of unchanged containers and boosting EC throughput. Strengthened test stability and EL9.7 compatibility for Node Local Tests (NLT) by updating tests to use dd for IO interception, removing reliance on __fxstat checks, and redirecting IL test output to /dev/null, with follow-up fixes to ensure IL tests pass consistently. These changes reduce CI flakiness, improve reliability across Linux distributions, and support smoother upgrade paths. Overall impact: Improved EC workload performance, reduced test overhead and flakiness, and better alignment with modern Linux environments. Demonstrated capabilities in low-level IO handling, VOS integration, and cross-OS test stability. Technologies/skills demonstrated: EC aggregation tuning, VOS epoch write handling, Linux IO primitives (dd), test harness modernization, IL interception strategies, EL9.7 compatibility, CI reliability, cross-team collaboration.
January 2026
3 Commits • 1 Features
Jan 1, 2026January 2026 monthly summary for daos-stack/daos: Delivered EC Aggregation Performance Optimization by loading the latest epoch writes from VOS after restart, eliminating unnecessary scans of unchanged containers and boosting EC throughput. Strengthened test stability and EL9.7 compatibility for Node Local Tests (NLT) by updating tests to use dd for IO interception, removing reliance on __fxstat checks, and redirecting IL test output to /dev/null, with follow-up fixes to ensure IL tests pass consistently. These changes reduce CI flakiness, improve reliability across Linux distributions, and support smoother upgrade paths. Overall impact: Improved EC workload performance, reduced test overhead and flakiness, and better alignment with modern Linux environments. Demonstrated capabilities in low-level IO handling, VOS integration, and cross-OS test stability. Technologies/skills demonstrated: EC aggregation tuning, VOS epoch write handling, Linux IO primitives (dd), test harness modernization, IL interception strategies, EL9.7 compatibility, CI reliability, cross-team collaboration.
December 2025
2 Commits • 1 Features
Dec 1, 2025December 2025 monthly summary for repository: daos-stack/daos. Highlights include two high-impact deliveries that improve resource lifecycle, stability, and error handling for PyDaos and the DAOS client:
2 Commits • 1 Features
Dec 1, 2025December 2025 monthly summary for repository: daos-stack/daos. Highlights include two high-impact deliveries that improve resource lifecycle, stability, and error handling for PyDaos and the DAOS client:
December 2025
November 2025
1 Commits • 1 Features
Nov 1, 2025November 2025 (daos-stack/daos): Delivered a targeted DFS performance and reliability improvement by tuning the default chunk size for erasure coding with RF=3. The change ensures chunk size selection aligns with three-parity EC, enhancing data integrity and performance for DFS containers. Work is tracked under DAOS-18171 and committed in 8afd6820c03bcbae96f8d5e38cf1673df5f8b77f.
November 2025
1 Commits • 1 Features
Nov 1, 2025November 2025 (daos-stack/daos): Delivered a targeted DFS performance and reliability improvement by tuning the default chunk size for erasure coding with RF=3. The change ensures chunk size selection aligns with three-parity EC, enhancing data integrity and performance for DFS containers. Work is tracked under DAOS-18171 and committed in 8afd6820c03bcbae96f8d5e38cf1673df5f8b77f.
October 2025
1 Commits
Oct 1, 20252025-10 monthly summary for daos-stack/daos: delivered a critical bug fix to the MPI-aware dfuse client that honors MPI daemonization and avoids forcing foreground execution, improving compatibility with MPI launchers and batch systems. This release stabilizes dfuse under MPI-based workflows and reduces manual work for users running with MPI.
1 Commits
Oct 1, 20252025-10 monthly summary for daos-stack/daos: delivered a critical bug fix to the MPI-aware dfuse client that honors MPI daemonization and avoids forcing foreground execution, improving compatibility with MPI launchers and batch systems. This release stabilizes dfuse under MPI-based workflows and reduces manual work for users running with MPI.
October 2025
September 2025
3 Commits • 2 Features
Sep 1, 2025September 2025 DAOS monthly summary focusing on delivering RF3-aware EC auto object class selection, DFUSE handle sharing capabilities, and CI reliability improvements. This work strengthens data placement efficiency, reduces connection setup overhead, and improves test determinism, aligning technical delivery with business value in data resilience, deployment reliability, and developer productivity.
September 2025
3 Commits • 2 Features
Sep 1, 2025September 2025 DAOS monthly summary focusing on delivering RF3-aware EC auto object class selection, DFUSE handle sharing capabilities, and CI reliability improvements. This work strengthens data placement efficiency, reduces connection setup overhead, and improves test determinism, aligning technical delivery with business value in data resilience, deployment reliability, and developer productivity.
June 2025
1 Commits • 1 Features
Jun 1, 2025June 2025 monthly summary for daos-stack/daos focused on delivering core DFS reliability and performance improvements. The primary delivery was a targeted enhancement to DFS chunk sizing that aligns with EC cell constraints and enforces sensible minimums, improving predictability and efficiency for large objects.
1 Commits • 1 Features
Jun 1, 2025June 2025 monthly summary for daos-stack/daos focused on delivering core DFS reliability and performance improvements. The primary delivery was a targeted enhancement to DFS chunk sizing that aligns with EC cell constraints and enforces sensible minimums, improving predictability and efficiency for large objects.
June 2025
May 2025
2 Commits • 1 Features
May 1, 2025Month: 2025-05 | Repository: daos-stack/daos. This period focused on strengthening developer experience through precise documentation and stabilizing the test pipeline, with no customer-facing API changes.
May 2025
2 Commits • 1 Features
May 1, 2025Month: 2025-05 | Repository: daos-stack/daos. This period focused on strengthening developer experience through precise documentation and stabilizing the test pipeline, with no customer-facing API changes.
April 2025
1 Commits • 1 Features
Apr 1, 2025April 2025 monthly summary for daos-stack/daos focusing on business value and technical achievements. Key features delivered: - EC object storage: default chunk size aligns with full stripe access when chunk_size is not set for DFS objects using EC object classes. This aligns access patterns with stripe boundaries, enabling more efficient I/O. Major bugs fixed: - (No major bugs listed in input data for this month.) Overall impact and accomplishments: - Delivered a performance-oriented enhancement for EC object storage that improves throughput and predictability for large-object workloads, contributing to better scalability and resource utilization. - The change is backward-compatible with existing clients and reduces stripe-misalignment risk in EC workloads. Technologies/skills demonstrated: - Systems optimization (EC storage backend, DFS chunk sizing), performance tuning, and alignment with stripe-based I/O patterns. - Collaborative work tracked in DAOS-17147 with commit bf51e0b4defb4a8f5ae487760e1915650b036b2f and linked to PR #16000. Top 3-5 achievements: - EC object storage default chunk size now aligns with full stripe access, improving throughput for EC object classes when chunk_size is unset (commit bf51e0b4defb4a8f5ae487760e1915650b036b2f). - Linked work to DAOS-17147 and PR #16000, establishing a reusable approach for stripe-aligned chunk sizing. - Improved performance consistency and resource utilization for EC workloads in daos-stack/daos. - Contributed code and documentation in the daos repository, supporting ongoing scalability efforts.
1 Commits • 1 Features
Apr 1, 2025April 2025 monthly summary for daos-stack/daos focusing on business value and technical achievements. Key features delivered: - EC object storage: default chunk size aligns with full stripe access when chunk_size is not set for DFS objects using EC object classes. This aligns access patterns with stripe boundaries, enabling more efficient I/O. Major bugs fixed: - (No major bugs listed in input data for this month.) Overall impact and accomplishments: - Delivered a performance-oriented enhancement for EC object storage that improves throughput and predictability for large-object workloads, contributing to better scalability and resource utilization. - The change is backward-compatible with existing clients and reduces stripe-misalignment risk in EC workloads. Technologies/skills demonstrated: - Systems optimization (EC storage backend, DFS chunk sizing), performance tuning, and alignment with stripe-based I/O patterns. - Collaborative work tracked in DAOS-17147 with commit bf51e0b4defb4a8f5ae487760e1915650b036b2f and linked to PR #16000. Top 3-5 achievements: - EC object storage default chunk size now aligns with full stripe access, improving throughput for EC object classes when chunk_size is unset (commit bf51e0b4defb4a8f5ae487760e1915650b036b2f). - Linked work to DAOS-17147 and PR #16000, establishing a reusable approach for stripe-aligned chunk sizing. - Improved performance consistency and resource utilization for EC workloads in daos-stack/daos. - Contributed code and documentation in the daos repository, supporting ongoing scalability efforts.
April 2025
March 2025
1 Commits
Mar 1, 2025March 2025 monthly summary for daos-stack/daos: delivered a targeted fix to the DAOS Object API, improved DFS pipeline error reporting, and expanded test coverage across object classes. These changes enhance reliability, observability, and developer productivity with cross-class compatibility and clearer diagnostics.
March 2025
1 Commits
Mar 1, 2025March 2025 monthly summary for daos-stack/daos: delivered a targeted fix to the DAOS Object API, improved DFS pipeline error reporting, and expanded test coverage across object classes. These changes enhance reliability, observability, and developer productivity with cross-class compatibility and clearer diagnostics.
February 2025
2 Commits
Feb 1, 2025February 2025 monthly summary for daos-stack/daos focusing on reliability, stability, and resource management. Delivered two key improvements: (1) CXI provider initialization stability through a retry mechanism for HG_Init_opt2 controlled by the CRT_CXI_INIT_RETRY environment variable, enabling recovery from transient cart init failures (DAOS-16990). (2) IO descriptor limit hardening by adding a soft limit of 4k to nr ranges for list-io, preventing resource exhaustion when ranges are small (DAOS-17055). These changes reduce initialization failures and protect system resources under high I/O workloads, contributing to higher availability and predictable performance. Technologies demonstrated include environment-driven configuration, retry patterns in cart initialization, and robust descriptor/resource management in client/cart subsystems.
2 Commits
Feb 1, 2025February 2025 monthly summary for daos-stack/daos focusing on reliability, stability, and resource management. Delivered two key improvements: (1) CXI provider initialization stability through a retry mechanism for HG_Init_opt2 controlled by the CRT_CXI_INIT_RETRY environment variable, enabling recovery from transient cart init failures (DAOS-16990). (2) IO descriptor limit hardening by adding a soft limit of 4k to nr ranges for list-io, preventing resource exhaustion when ranges are small (DAOS-17055). These changes reduce initialization failures and protect system resources under high I/O workloads, contributing to higher availability and predictable performance. Technologies demonstrated include environment-driven configuration, retry patterns in cart initialization, and robust descriptor/resource management in client/cart subsystems.
February 2025
January 2025
3 Commits
Jan 1, 2025January 2025 monthly summary for daos-stack/daos: Implemented critical fixes to OID IV race condition handling and retry tracking, along with licensing upkeep. Focused on concurrency correctness, data integrity, and maintainability to improve container reliability and compliance.
January 2025
3 Commits
Jan 1, 2025January 2025 monthly summary for daos-stack/daos: Implemented critical fixes to OID IV race condition handling and retry tracking, along with licensing upkeep. Focused on concurrency correctness, data integrity, and maintainability to improve container reliability and compliance.
Activity
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Quality Metrics
Correctness88.6%
Maintainability82.8%
Architecture82.4%
Performance80.0%
AI Usage22.2%
Skills & Technologies
Programming Languages
CMarkdownPython
Technical Skills
API DevelopmentBug FixingC ProgrammingC programmingCI/CDCode MaintenanceCommand-line Interface (CLI) DevelopmentConcurrency ControlConfiguration ManagementDistributed SystemsDocumentationError HandlingFile I/OLinux commandsMPI
Repositories Contributed To
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