[jira] [Created] (LUCENE-10142) use a better RNG for Hnsw vectors

["Robert Muir (Jira)" <ji...@apache.org>]

Robert Muir created LUCENE-10142:
------------------------------------

             Summary: use a better RNG for Hnsw vectors
                 Key: LUCENE-10142
                 URL: https://issues.apache.org/jira/browse/LUCENE-10142
             Project: Lucene - Core
          Issue Type: Task
            Reporter: Robert Muir


When profiling indexing with vectors at http://people.apache.org/~mikemccand/lucenebench/, I see a fair amount of time spent in java.util.Random.

{noformat}
PERCENT       CPU SAMPLES   STACK
...
7.30%         305461        java.util.Random#nextInt()
{noformat}

We don't need its thread-safety guarantees (CAS loop etc). 
We can use SplittableRandom as a drop-in replacement.




--
This message was sent by Atlassian Jira
(v8.3.4#803005)

---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscribe@lucene.apache.org
For additional commands, e-mail: issues-help@lucene.apache.org