ydb-platform/nbs
Nov 2025 – May 2026
6 Months active
Languages Used
C++Python
Technical Skills
C++Pythonbackend developmenterror handlingperformance optimizationsystem design
Ivan Efimov
PROFILE
Ivan Efimov
Worked on the ydb-platform/nbs repository, delivering features and fixes that improved reliability, performance, and maintainability in distributed storage systems. Over six months, implemented enhancements such as configurable retry logic for error handling, a latency testing suite for network SSDs, and adaptive resource management in the VolumeBalancer. Used C++ and Python to introduce non-blocking remounts, memory-aware service activation, and dynamic timing for maintenance workflows. Addressed stability by refining error responses and limiting concurrent operations, while supporting robust testing with unit tests. The work demonstrated a focus on backend development, system design, and actor model programming to optimize cloud storage operations.
Overall Statistics
Feature vs Bugs
70%Features
Repository Contributions
11Total
Bugs
3
Commits
11
Features
7
Lines of code
1,851
Activity Months6
Your Network
159 peopleSame Organization
@yandex-team.ru127
Work History
May 2026
2 Commits • 1 Features
May 1, 2026May 2026 performance summary for the ydb-platform/nbs repository. Focus was on stabilizing and improving the Volume Balancer to minimize disruption during Hive downtime and improve responsiveness through adaptive timing. Key work included implementing a Gentle Preemption mechanism to safely transition during remote mounting, and switching the VolumeBalancer iteration timeout from a fixed interval to a dynamic UpdateCountersInterval. These changes enhance reliability in distributed storage management and maintenance workflows, with clear business value in reducing downtime risk and preserving data integrity.
2 Commits • 1 Features
May 1, 2026May 2026 performance summary for the ydb-platform/nbs repository. Focus was on stabilizing and improving the Volume Balancer to minimize disruption during Hive downtime and improve responsiveness through adaptive timing. Key work included implementing a Gentle Preemption mechanism to safely transition during remote mounting, and switching the VolumeBalancer iteration timeout from a fixed interval to a dynamic UpdateCountersInterval. These changes enhance reliability in distributed storage management and maintenance workflows, with clear business value in reducing downtime risk and preserving data integrity.
May 2026
April 2026
4 Commits • 3 Features
Apr 1, 2026April 2026 monthly summary for ydb-platform/nbs: Delivered four focused improvements that enhance dataplane performance, resource efficiency, and architectural flexibility. Implemented non-blocking remount for TSession, introduced memory-constrained host gating, fixed volume balancer pull delay growth, and decoupled response routing for volume start/stop. These changes reduce dataplane stalls, optimize memory usage on constrained nodes, improve balancing reliability, and enable more modular interactions between actors.
April 2026
4 Commits • 3 Features
Apr 1, 2026April 2026 monthly summary for ydb-platform/nbs: Delivered four focused improvements that enhance dataplane performance, resource efficiency, and architectural flexibility. Implemented non-blocking remount for TSession, introduced memory-constrained host gating, fixed volume balancer pull delay growth, and decoupled response routing for volume start/stop. These changes reduce dataplane stalls, optimize memory usage on constrained nodes, improve balancing reliability, and enable more modular interactions between actors.
March 2026
1 Commits • 1 Features
Mar 1, 2026March 2026: Implemented a safety cap on VolumeBalancer to limit the maximum number of in-progress volume operations, reducing overload risk and improving stability under concurrent pushes/pulls. This change enhances resource management and reliability in ydb-platform/nbs, tied to NBS-6929 and commit 387016a4206c5574127656ce29381be9a80f1334.
1 Commits • 1 Features
Mar 1, 2026March 2026: Implemented a safety cap on VolumeBalancer to limit the maximum number of in-progress volume operations, reducing overload risk and improving stability under concurrent pushes/pulls. This change enhances resource management and reliability in ydb-platform/nbs, tied to NBS-6929 and commit 387016a4206c5574127656ce29381be9a80f1334.
March 2026
February 2026
1 Commits
Feb 1, 2026February 2026 monthly update for ydb-platform/nbs: reliability-focused delivery with a targeted stability fix in the Blockstore Client. Disabled EnableListBasedRetryRules to prevent broad retriable errors that could disrupt release scenarios, improving release stability and customer experience. This aligns with ongoing reliability initiatives and reduces risk during customer releases.
February 2026
1 Commits
Feb 1, 2026February 2026 monthly update for ydb-platform/nbs: reliability-focused delivery with a targeted stability fix in the Blockstore Client. Disabled EnableListBasedRetryRules to prevent broad retriable errors that could disrupt release scenarios, improving release stability and customer experience. This aligns with ongoing reliability initiatives and reduces risk during customer releases.
January 2026
1 Commits
Jan 1, 2026January 2026 monthly summary for ydb-platform/nbs: Delivered a critical robustness improvement in Disk Management by ensuring that token creation for a deleted disk returns a non-retriable error, thereby reducing unnecessary retries and stabilizing disk-related workflows. The change is complemented by a unit test to lock in the behavior and prevent regressions. Commit: 3f58188980b32a28be78db1148509167b2398a63 ([NBS-6176]: Fix retrying deleted disk mount from DM (#4721); Closes #4167).
1 Commits
Jan 1, 2026January 2026 monthly summary for ydb-platform/nbs: Delivered a critical robustness improvement in Disk Management by ensuring that token creation for a deleted disk returns a non-retriable error, thereby reducing unnecessary retries and stabilizing disk-related workflows. The change is complemented by a unit test to lock in the behavior and prevent regressions. Commit: 3f58188980b32a28be78db1148509167b2398a63 ([NBS-6176]: Fix retrying deleted disk mount from DM (#4721); Closes #4167).
January 2026
November 2025
2 Commits • 2 Features
Nov 1, 2025Month: 2025-11 — Focused on reliability and performance testing enhancements for ydb-platform/nbs. Key features delivered: (1) DurableClient retry logic extension with an optional whitelist for non-retriable errors, enabling safer retry behavior and reduced noise; (2) Latency testing suite for network SSDs within the fio performance framework, allowing manual triggering to measure latency across configurations. These changes are governed by the new feature flag EnableListBasedRetryRules to control rollout. Business impact: improved resilience of storage operations, clearer failure modes, and faster latency insights for optimization. No major bugs fixed this month; emphasis was on delivering robust features and strengthening testing infrastructure. Technologies demonstrated: C++, proto-based feature flags, configurable retry rules, fio-based performance testing, manual test triggers, and cross-language documentation in PRs.
November 2025
2 Commits • 2 Features
Nov 1, 2025Month: 2025-11 — Focused on reliability and performance testing enhancements for ydb-platform/nbs. Key features delivered: (1) DurableClient retry logic extension with an optional whitelist for non-retriable errors, enabling safer retry behavior and reduced noise; (2) Latency testing suite for network SSDs within the fio performance framework, allowing manual triggering to measure latency across configurations. These changes are governed by the new feature flag EnableListBasedRetryRules to control rollout. Business impact: improved resilience of storage operations, clearer failure modes, and faster latency insights for optimization. No major bugs fixed this month; emphasis was on delivering robust features and strengthening testing infrastructure. Technologies demonstrated: C++, proto-based feature flags, configurable retry rules, fio-based performance testing, manual test triggers, and cross-language documentation in PRs.
Activity
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Quality Metrics
Correctness96.4%
Maintainability81.8%
Architecture85.4%
Performance81.8%
AI Usage23.6%
Skills & Technologies
Programming Languages
C++Python
Technical Skills
C++C++ developmentPythonactor modelactor model programmingbackend developmentcloud storageconfiguration managementdistributed systemserror handlingperformance optimizationsoftware engineeringsystem designsystem programmingtesting
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