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Colin Patrick McCabe commented on HDFS-7325: -------------------------------------------- bq. The < above should be <=. One tricky thing here is that the patch moves this block after the {{numAllocated--}}. So I believe this should be correct... bq. How about simply including the change in HDFS-7358 and resolving this? OK. > Prevent thundering herd problem in ByteArrayManager by using notify not > notifyAll > --------------------------------------------------------------------------------- > > Key: HDFS-7325 > URL: https://issues.apache.org/jira/browse/HDFS-7325 > Project: Hadoop HDFS > Issue Type: Bug > Affects Versions: 2.6.0 > Reporter: Colin Patrick McCabe > Assignee: Colin Patrick McCabe > Attachments: HDFS-7325.001.patch > > > Currently ByteArrayManager wakes all waiting threads whenever a byte array is > released and count == limit. However, only one thread can proceed. With a > large number of waiters, this will cause a thundering herd problem. (See > http://en.wikipedia.org/wiki/Thundering_herd_problem.) We should avoid this > by only waking a single thread. -- This message was sent by Atlassian JIRA (v6.3.4#6332)