This message was deleted.

The java stack btw:

Caused by: java.lang.OutOfMemoryError: Direct buffer memory
	at java.nio.Bits.reserveMemory(Bits.java:175) ~[?:?]
	at java.nio.DirectByteBuffer.<init>(DirectByteBuffer.java:118) ~[?:?]
	at java.nio.ByteBuffer.allocateDirect(ByteBuffer.java:317) ~[?:?]
	at org.apache.druid.segment.CompressedPools$4.get(CompressedPools.java:102) ~[druid-processing-25.0.0.jar:25.0.0]
	at org.apache.druid.segment.CompressedPools$4.get(CompressedPools.java:95) ~[druid-processing-25.0.0.jar:25.0.0]
	at org.apache.druid.collections.StupidPool.makeObjectWithHandler(StupidPool.java:171) ~[druid-core-25.0.0.jar:25.0.0]
	at org.apache.druid.collections.StupidPool.take(StupidPool.java:154) ~[druid-core-25.0.0.jar:25.0.0]
	at org.apache.druid.segment.CompressedPools.getByteBuf(CompressedPools.java:110) ~[druid-processing-25.0.0.jar:25.0.0]
	at org.apache.druid.segment.data.DecompressingByteBufferObjectStrategy.fromByteBuffer(DecompressingByteBufferObjectStrategy.java:49) ~[druid-processing-25.0.0.jar:25.0.0]
	at org.apache.druid.segment.data.DecompressingByteBufferObjectStrategy.fromByteBuffer(DecompressingByteBufferObjectStrategy.java:28) ~[druid-processing-25.0.0.jar:25.0.0]

IIRC, the sketch’s internal hash table can be up to 2x nominalEntries, so 256kiB since each entry is 64 bits, plus something like 32 extra bytes for extra internal use (storing configured nominal entries, current size, etc)