HDFS-6934: Use a unique ClientContext in each test.
HDFS-6934: Add comment.
HDFS-6934: minor cleanup.
HDFS-7165. Separate block metrics for files with replication count 1. (Zhe Zhang via wang)
HDFS-7222. Expose DataNode network errors as a metric. (Charles Lamb via wang)
HDFS-7227. Fix findbugs warning about NP_DEREFERENCE_OF_READLINE_VALUE in SpanReceiverHost (cmccabe)
HDFS-7232. Populate hostname in httpfs audit log (Zoran Dimitrijevic via aw)
HDFS-7257. Add the time of last HA state transition to NN's /jmx page. Contributed by Charles Lamb.
HADOOP-11170. ZKDelegationTokenSecretManager fails to renewToken created by a peer. (Arun Suresh and Gregory Chanan via kasha)
HDFS-7223. Tracing span description of IPC client is too long (iwasakims via cmccabe)
HDFS-7243. HDFS concat operation should not be allowed in Encryption Zone. (clamb via yliu)
YARN-2209. Replaced AM resync/shutdown command with corresponding exceptions and made related MR changes. Contributed by Jian He.
Updated CHANGES.txt to move YARN-2682 to branch-2.6
HDFS-7258. CacheReplicationMonitor rescan schedule log should use DEBUG level instead of INFO level. Contributed by Xiaoyu Yao.
HDFS-6934: Fix file descriptor leak in BlockSender.
Merge branch 'apache-trunk' into HDFS-6934
HDFS-6934: When calculating checksum, use share-delete file input stream on block file and buffering on output meta file.