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Imran Rashid commented on SPARK-24938: -------------------------------------- This should be an easy change to make, its just a question of running a test. I keep meaning to do it, but have too many other things in flight, so anybody is welcome to do it. You could use SPARK-24918 and https://github.com/squito/spark-memory to check the memory usage before and after. > Understand usage of netty's onheap memory use, even with offheap pools > ---------------------------------------------------------------------- > > Key: SPARK-24938 > URL: https://issues.apache.org/jira/browse/SPARK-24938 > Project: Spark > Issue Type: Improvement > Components: Spark Core > Affects Versions: 2.4.0 > Reporter: Imran Rashid > Priority: Major > Labels: memory-analysis > > We've observed that netty uses large amount of onheap memory in its pools, in > addition to the expected offheap memory when I added some instrumentation > (using SPARK-24918 and https://github.com/squito/spark-memory). We should > figure out why its using that memory, and whether its really necessary. > It might be just this one line: > https://github.com/apache/spark/blob/master/common/network-common/src/main/java/org/apache/spark/network/protocol/MessageEncoder.java#L82 > which means that even with a small burst of messages, each arena will grow by > 16MB which could lead to a 128 MB spike of an almost entirely unused pool. > Switching to requesting a buffer from the default pool would probably fix > this. -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org