June 29, 2026
Bringing it together: How we rebuilt Elasticsearch as a columnar metrics engine; 6.6x less storage, 160x faster queries
Elasticsearch metrics in version 9.4 run on a fully columnar engine: 6.6x less storage, 160x faster queries, native PromQL and OTel support.
The hash() Elasticsearch won't name and the 12 bytes that prove it's Murmur3
Elasticsearch's routing formula uses MurmurHash3, but the docs never say so. This post names the function, walks through the full shard calculation, and shows you how to reproduce it externally.
June 12, 2026
How DocValuesSkippers in Lucene 10 make range queries faster without doubling your storage
DocValuesSkippers add block-level skipping to Lucene DocValues fields, speeding up range queries on sorted or insert-ordered indexes with less than 0.1% storage overhead.
January 28, 2026
Apache Lucene 2025 wrap-up
2025 was a stellar year for Apache Lucene; here are our highlights.
September 3, 2025
Vector search filtering: Keep it relevant
Performing vector search to find the most similar results to a query is not enough. Filtering is often needed to narrow down search results. This article explains how filtering works for vector search in Elasticsearch and Apache Lucene.
April 7, 2025
Speeding up merging of HNSW graphs
Explore the work we’ve been doing to reduce the overhead of building multiple HNSW graphs, particularly reducing the cost of merging graphs.
February 27, 2025
Filtered HNSW search, fast mode
Explore the improvements we have made for HNSW vector search in Apache Lucene through our ACORN-1 algorithm implementation.
February 7, 2025
Concurrency bugs in Lucene: How to fix optimistic concurrency failures
Thanks to Fray, a deterministic concurrency testing framework from CMU’s PASTA Lab, we tracked down a tricky Lucene bug and squashed it
January 7, 2025
Early termination in HNSW for faster approximate KNN search
Learn how HNSW can be made faster for KNN search, using smart early termination strategies.