HADOOP-11257. Update "hadoop jar" documentation to warn against using it for launching yarn jars, addendum to print warning to stderr. Contributed by Masatake Iwasaki.

(cherry picked from commit 1fd350fa8ed83e7b99830ec7adf1b02a36c0c11e)

hadoop-common-project/hadoop-common/src/main/bin/hadoop

@@ -110,7 +110,7 @@ case $COMMAND in
     elif [ "$COMMAND" = "jar" ] ; then
       CLASS=org.apache.hadoop.util.RunJar
       if [[ -n "${YARN_OPTS}" ]] || [[ -n "${YARN_CLIENT_OPTS}" ]]; then
-        echo "WARNING: Use \"yarn jar\" to launch YARN applications."
+        echo "WARNING: Use \"yarn jar\" to launch YARN applications." 1>&2
       fi
     elif [ "$COMMAND" = "key" ] ; then
       CLASS=org.apache.hadoop.crypto.key.KeyShell

hadoop-common-project/hadoop-common/src/main/bin/hadoop.cmd

@@ -162,9 +162,9 @@ call :updatepath %HADOOP_BIN_PATH%
 
 :jar
   if defined YARN_OPTS (
-    @echo WARNING: Use "yarn jar" to launch YARN applications.
+    @echo WARNING: Use "yarn jar" to launch YARN applications. 1>&2
   ) else if defined YARN_CLIENT_OPTS (
-    @echo WARNING: Use "yarn jar" to launch YARN applications.
+    @echo WARNING: Use "yarn jar" to launch YARN applications. 1>&2
   )
   set CLASS=org.apache.hadoop.util.RunJar
   goto :eof