HDFS-4739. NN can miscalculate the number of extra edit log segments to retain. Contributed by Aaron T. Myers.


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Update CHANGES.txt for HDFS-4739.


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Merge -c 1471796 from trunk to branch-2 to fix MAPREDUCE-5166. Fix ConcurrentModificationException due to insufficient synchronization on updates to task Counters. Contributed by Sandy Ryza.

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Merge remote branch 'origin/branch-2' into branch-2-gd