March 2026 monthly summary for ydb-platform/ydb focusing on architectural improvements, data reliability, and onboarding efficiency. Delivered a major VChunk refactor to improve modularity and metadata handling, enhanced data synchronization by allowing erasure of outdated statuses, and updated deployment/docs to accelerate onboarding and operational clarity. These changes reduce maintenance risk, improve data consistency, and shorten time-to-value for platform users.

February 2026 performance and reliability sprint for ydb-platform/ydb. Delivered the fast path block storage service with a flush queue and integrated metrics/tracing for enhanced observability; introduced NBS storage configuration (protobuf-based) to drive configurable disk pools and improved observability; extended NBS 2.0 with a LoadActorAdapter ID retrieval endpoint via gRPC to strengthen partition interactions; launched a new thread-based executor library to accelerate asynchronous task execution and debugging; implemented core block storage enhancements (striping, vchunks, regions) plus batch synchronization/erasure to boost throughput; fixed memory-safety issue in load_actor_adapter by refactoring to use shared_ptr to prevent crashes. These changes drive faster I/O, safer memory handling, and improved operational visibility.

Concise monthly summary for 2026-01: Delivered targeted fixes and features across two repositories to enhance correctness, onboarding, and storage reliability, driving faster time-to-value for developers and more robust operations. Key outcomes include:\n- In ydb-platform/nbs: Bug fix to post-migration disk tag cleanup—removed the source disk ID tag from the destination disk after cross-zone migration to prevent misidentification and ensure compute service correctness post-replication. (Commit f22a0df3431affea5fe365c3b73ea1c620005dc4; related: #4847).\n- In ydb-platform/ydb: Onboarding/Workspace Setup Documentation added to README with instructions for generating a workspace, running locally, and SSH port forwarding, enabling quicker local starts. (Commit 2ac281136b0869baaca9cb6183c55a2f11e2f2e0; #32205).\n- Persistent Buffers: Implemented IO ops for persistent buffers with write/read, improved logging and connection management; included flush/erase and disk reads; added cookies for request tracking. (Commits eaa7bcb815ebb411374dc7ff900d0f108eab3961; 6e070aed6cb89b204496e9f4aca4e69c98834186; #32480, #32925).\n- Robustness: Added basic error handling in Direct Block Group Storage to validate requests and return proper errors, improving API reliability. (Commit 958b6761e0063df56d713ecde8a222250509c790; #33026).

Month: December 2025 | Repository: ydb-platform/nbs Summary focus: Enhance disk management capabilities to improve reliability, scalability, and operational clarity for multi-cell deployments.

November 2025 delivered targeted improvements to volume management, disk provisioning, and build stability across ydb-platform/nbs and ydb. Implemented tag-based volume filtering and tagging support with comprehensive unit tests, introduced a refined cell selection mechanism for disk creation, and cleaned up build dependencies to speed up CI. These changes enhance volume traceability, reduce provisioning errors, and shorten release cycles, improving reliability and developer velocity.

October 2025 performance summary for ydb-platform/nbs: Delivered critical backup management enhancements and refined blockstore metrics, with concrete changes to tooling, build configuration, and data-loading resilience, delivering stronger disaster recovery readiness and clearer operational visibility.

September 2025 (ydb-platform/nbs) delivered four high-impact changes that strengthen tenancy isolation, resilience, observability, and backup efficiency. Key outcomes include per-tenant resource controls for Hive Local Service, improved Blockstore resilience during SchemeShard outages via cached tablet IDs and graceful error handling, extended monitoring context with host labels and IsLocalMountCounter for Blockstore metrics, and binary backups for SchemeShard data (Path Descriptions and Tablet Boot Info) with new config options and serialization support. These changes enable granular resource allocation, minimize operation disruption during outages, improve service metrics and debugging capabilities, and accelerate backup/restore performance. The work demonstrates strong proto/config evolution, caching strategies, metrics instrumentation, and cross-service coordination across components.

July 2025 monthly summary for ydb-platform/nbs focusing on reliability, observability, and robustness improvements in Blockstore and volume mounting modules. Delivered stability wins by preventing unnecessary tablet reboots during demotion, guarding against premature release of trim barriers when Blob Storage flush fails, and expanding logging and tests to improve debuggability. Also strengthened volume mounting reliability with longer InitialAddClientTimeout handling post-unlock and added cross-service logs. These changes reduce outage risk, improve data integrity under error conditions, and provide richer telemetry for faster issue resolution.

June 2025 performance summary for ydb-platform/nbs: Delivered targeted resilience, observability, and admin tooling enhancements that strengthen blockstore reliability and disk management. Blockstore resilience and error handling improvements introduced a configurable limit for WriteBlob errors before terminating a tablet, adjusted default thresholds, and gated compaction writes based on disk space alerts to prevent cascading failures. Disk Manager observability enhancements added S3 availability monitoring with defined reporting intervals, improving operational visibility. Administrative tooling was augmented with a new disk-manager-admin task schedule-blank command for maintenance automation. These changes reduce downtime risk, improve diagnostics, and provide safer operational controls.

May 2025 highlights reliability and maintainability improvements in ydb-platform/nbs. Delivered two critical bug fixes with clear business impact: (1) eliminated a compiler warning by explicitly capturing this in member lambdas across core modules, aligning with modern C++ practices and reducing technical debt; (2) prevented potential IO queue hangs by refactoring ReadBlob error handling in the Blockstore partition actor, enabling continued IO processing and improving resilience. Included improved logging and a new unit test to verify the ReadBlob fix. These changes enhance stability in production, reduce risk of outages, and lay groundwork for safer future changes.

April 2025 monthly summary for ydb-platform/nbs: Implemented cross-service lock-loss resilience for volume lifecycle, enhanced operator control with a new DoNotStopVolumeTabletOnLockLost option, and expanded test coverage. Reverted non-critical locklost changes in NBS to restore stability, and optimized test execution by simplifying test tags. Addressed a shutdown edge case to ensure volumes reliably delete even when lock is lost during mounting. These efforts reduce operational risk, improve reliability of volume remount/delete flows, and optimize CI resources.

Summary for 2024-12: Implemented the Disk Manager Task Execution Limiter (TasksToListLimit) in ydb-platform/nbs to prevent over-execution when inflightTasksByType limits are reached. This change updates the task lister configuration and runner startup, and includes updated tests to ensure correct handling of task execution limits. The enhancement improves reliability, throughput, and scalability of task processing, delivering measurable business value by reducing stalls and optimizing resource utilization.

Delivered key features and stabilizations for ydb-platform/nbs, focusing on SDK compatibility, disk migration reliability, and admin tooling for legacy snapshots. Implemented a DSN construction helper (getDSN) to replace deprecated sugar.DSN and upgraded client support to the new YDB SDK version, enabling better configurability and compatibility. Hardened disk migration with a transaction-aware update path and enhanced tests, reducing race-condition flakiness during rebase/migration operations. Added an admin command in Disk Manager to create snapshots from legacy snapshots, leveraging S3 for temporary storage to ease legacy deprecation. These changes improve stability, operational safety, and readiness for upcoming SDK changes and deprecations.