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Liang Xie commented on HDFS-6591: --------------------------------- [~andrew.purt...@gmail.com], good idea! [~cnauroth], will dive into it definitely, nice finding! so that memory copy optimization is immature ? :) i will rethink it later. (I assumed even two threads mutate the buffer in a face condition, the final result should be same due to that two threads have read out a same source result.) > while loop is executed tens of thousands of times in Hedged Read > ------------------------------------------------------------------ > > Key: HDFS-6591 > URL: https://issues.apache.org/jira/browse/HDFS-6591 > Project: Hadoop HDFS > Issue Type: Bug > Components: hdfs-client > Affects Versions: 2.4.0 > Reporter: LiuLei > Assignee: Liang Xie > Attachments: HDFS-6591-v2.txt, HDFS-6591-v3.txt, HDFS-6591.txt, > LoopTooManyTimesTestCase.patch > > > I download hadoop-2.4.1-rc1 code from > http://people.apache.org/~acmurthy/hadoop-2.4.1-rc1/, I test the Hedged > Read. I find the while loop in hedgedFetchBlockByteRange method is executed > tens of thousands of times. -- This message was sent by Atlassian JIRA (v6.2#6252)