HDFS-17846. Enhance the stability of the unit test TestDirectoryScanner. (#8022) Contributed by Zhaobo Huang

* HDFS-17846. Enhance the stability of the unit test TestDirectoryScanner.

Signed-off-by: Shilun Fan <[email protected]>

Author: huangzhaobo99

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

@@ -831,7 +831,7 @@ public void testThrottling() throws Exception {
 
     // We need lots of blocks so the report compiler threads have enough to
     // keep them busy while we watch them.
-    int blocks = 20000;
+    int blocks = 40000;
     int maxRetries = 3;
 
     cluster = new MiniDFSCluster.Builder(conf).build();