Non-Blocking Concurrency Control
A concurrency model for lakehouse table formats that uses distributed timelines rather than locks or optimistic retries, allowing multiple writers to simultaneously mutate the same table and rows without blocking or failing commits. Native to Apache Hudi 1.0.
Summary
A concurrency model for lakehouse table formats that uses distributed timelines rather than locks or optimistic retries, allowing multiple writers to simultaneously mutate the same table and rows without blocking or failing commits. Native to Apache Hudi 1.0.
Replaces Optimistic Concurrency Control (OCC) as the write coordination mechanism for high-velocity streaming and CDC workloads on object storage. OCC forces constant retries under concurrent write contention, degrading throughput. NBCC assigns each writer an independent timeline, merging results asynchronously.
- Not the same as eventual consistency — writes are still serializable via timeline ordering and sequence number resolution.
- Does not eliminate the need for compaction — background merge of timelines is still required for read performance.
- Currently Hudi-specific; not available in Apache Iceberg or Delta Lake, which remain on OCC.
enablesApache Hudi — core concurrency model for Hudi 1.0 architectureenablesCDC into Lakehouse — allows high-frequency CDC ingestion without commit conflictssolvesRead / Write Amplification — eliminates retry-induced write duplication under contention
Definition
A concurrency model for lakehouse table formats that uses distributed timelines rather than locks or optimistic retries, allowing multiple writers to simultaneously mutate the same table and rows without blocking or failing commits.
Optimistic Concurrency Control (OCC) forces constant retries under high-velocity concurrent write workloads, degrading throughput and causing commit failures. Non-Blocking Concurrency Control assigns each writer an independent timeline, merging results asynchronously. Native to Apache Hudi 1.0, it enables high-frequency CDC ingestion without the commit contention that cripples OCC-based formats under streaming loads.
High-velocity CDC ingestion into lakehouse tables, concurrent multi-writer streaming pipelines, real-time lakehouse architectures requiring sub-minute data visibility.
Connections 5
Outbound 5
Resources 3
Deep technical comparison of streaming ingest mechanics across table formats, including analysis of NBCC in Hudi versus OCC in Iceberg and Delta.
Comprehensive guide covering concurrency models, write paths, and conflict resolution across all major open table formats.
Performance comparison of streaming concurrency models between Paimon LSM-trees and Hudi NBCC under CDC workloads.