[GitHub] [incubator-druid] shivtools commented on a change in pull request #7174: Change reservoir sampling of segments to spliterator approach

[GitBox <gi...@apache.org>]

shivtools commented on a change in pull request #7174: Change reservoir sampling of segments to spliterator approach
URL: https://github.com/apache/incubator-druid/pull/7174#discussion_r261899405
 
 

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 File path: server/src/main/java/org/apache/druid/server/coordinator/ReservoirSegmentSampler.java
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 @@ -21,36 +21,57 @@
 
 import org.apache.druid.timeline.DataSegment;
 
+import java.util.Collection;
 import java.util.List;
+import java.util.Spliterator;
 import java.util.concurrent.ThreadLocalRandom;
+import java.util.stream.Collectors;
+import java.util.stream.StreamSupport;
 
 final class ReservoirSegmentSampler
 {
+  final static int SPLITERATOR_SIZE_THRESHOLD = 10;
 
 Review comment:
   I ran some benchmarks by hand and observed that `25` resulted in the most uniform selection of segments. See results in this [Gist](https://gist.github.com/shivtools/7e8af2038e155e2cd8131a10f53035a5).
   
   

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