HDFS-9744. TestDirectoryScanner#testThrottling occasionally time out after 300 seconds. Contributed by Lin Yiqun.

(cherry picked from commit 90d1af141666ba12f18d44464cb6169c445d0902)

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestDirectoryScanner.java

@@ -556,7 +556,7 @@ public class TestDirectoryScanner {
    *
    * @throws Exception thrown on unexpected failure
    */
-  @Test (timeout=300000)
+  @Test (timeout=600000)
   public void testThrottling() throws Exception {
     Configuration conf = new Configuration(CONF);