HDFS-7283. Bump DataNode OOM log from WARN to ERROR. Contributed by Stephen Chu.

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -303,6 +303,9 @@ Release 2.7.0 - UNRELEASED
     HDFS-7223. Tracing span description of IPC client is too long (iwasakims
     via cmccabe)
 
+    HDFS-7283. Bump DataNode OOM log from WARN to ERROR.
+    (Stephen Chu via wheat9)
+
   OPTIMIZATIONS
 
   BUG FIXES

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataXceiverServer.java

@@ -161,7 +161,7 @@ class DataXceiverServer implements Runnable {
         // DataNode can run out of memory if there is too many transfers.
         // Log the event, Sleep for 30 seconds, other transfers may complete by
         // then.
-        LOG.warn("DataNode is out of memory. Will retry in 30 seconds.", ie);
+        LOG.error("DataNode is out of memory. Will retry in 30 seconds.", ie);
         try {
           Thread.sleep(30 * 1000);
         } catch (InterruptedException e) {