HDFS-16458. [SPS]: Fix bug for unit test of reconfiguring SPS mode (#4041)

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestNameNodeReconfigure.java

@@ -307,6 +307,8 @@ public class TestNameNodeReconfigure {
         StoragePolicySatisfierMode.EXTERNAL.toString(),
         nameNode.getConf().get(DFS_STORAGE_POLICY_SATISFIER_MODE_KEY,
             DFS_STORAGE_POLICY_SATISFIER_MODE_DEFAULT));
+    assertNotNull("SPS Manager should be created",
+        nameNode.getNamesystem().getBlockManager().getSPSManager());
   }
 
   /**
@@ -322,6 +324,8 @@ public class TestNameNodeReconfigure {
         StoragePolicySatisfierMode.NONE.toString());
     verifySPSEnabled(nameNode, DFS_STORAGE_POLICY_SATISFIER_MODE_KEY,
         StoragePolicySatisfierMode.NONE, false);
+    assertNull("SPS Manager should be null",
+        nameNode.getNamesystem().getBlockManager().getSPSManager());
 
     Path filePath = new Path("/testSPS");
     DistributedFileSystem fileSystem = cluster.getFileSystem();
@@ -345,7 +349,7 @@ public class TestNameNodeReconfigure {
             .getNamesystem().getBlockManager().getSPSManager();
     boolean isSPSRunning = spsMgr != null ? spsMgr.isSatisfierRunning()
         : false;
-    assertEquals(property + " has wrong value", isSPSRunning, isSPSRunning);
+    assertEquals(property + " has wrong value", isSatisfierRunning, isSPSRunning);
     String actual = nameNode.getConf().get(property,
         DFS_STORAGE_POLICY_SATISFIER_MODE_DEFAULT);
     assertEquals(property + " has wrong value", expected,