YDB

Yandex Black October: How Architectural Flaws and Capacity Mismanagement Turned Data Center Losses Into a 11-Day Fintech Coma

In October 2026 three Yandex data centers in Central Russia were physically destroyed within days, triggering the collapse of Yandex Cloud and multiple core services. Between the first and third site failures engineers had 74 hours to restore quorum and rebalance workloads yet failed to do so because Control Plane components remained tied to the lost zone and spare capacity had been eliminated to cut costs. Core banking and BNPL systems entered Read-Only mode after losing quorum, forcing a complete stop-the-world reconciliation that lasted until 22 October. Backups stored inside the same regional S3 buckets proved unusable, resulting in a seven-day RPO and primary-key collisions after restoration. The incident exposed that Metro-Cluster designs had been incorrectly treated as full Disaster Recovery and that aggressive AP microservice patterns created logical split-brain conditions outside the database layer.

Yandex B2B Tech Integrates Hybrid Full-Text and Vector Search in Single YDB Query

Yandex B2B Tech has added hybrid search to its YDB database, allowing full-text and vector approaches to run together inside one SQL query. The update helps small and medium businesses as well as large corporations locate exact document identifiers while also matching semantic meaning in descriptions, even when wording differs. Full-text search handles precise elements such as policy numbers, codes, and names, whereas vector search identifies conceptual similarity. Results from both methods are merged and ranked within the same transaction, keeping all data inside a single database instance. This removes the need to maintain a separate search engine and vector store or to reconcile information between them. The technology is aimed at chatbots, recommendation systems, and AI assistants that process technical content where both exact codes and human-readable problem descriptions matter equally. Hybrid search is now available in the on-premises YDB 26.3 release and in the cloud-based Managed Service for YDB.