HDFS-3325. When configuring 'dfs.namenode.safemode.threshold-pct' to a value greater or equal to 1 there is mismatch in the UI report (Contributed by J.Andreina)

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

@@ -338,6 +338,10 @@ Release 2.8.0 - UNRELEASED
     HDFS-7867. Update action param from "start" to "prepare" in rolling upgrade
     javadoc (J.Andreina via vinayakumarb)
 
+    HDFS-3325. When configuring "dfs.namenode.safemode.threshold-pct" to a value
+    greater or equal to 1 there is mismatch in the UI report
+    (J.Andreina via vinayakumarb)
+
 Release 2.7.0 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java

@@ -5417,7 +5417,7 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
         msg += String.format(
           "The reported blocks %d needs additional %d"
           + " blocks to reach the threshold %.4f of total blocks %d.%n",
-          blockSafe, (blockThreshold - blockSafe) + 1, threshold, blockTotal);
+                blockSafe, (blockThreshold - blockSafe), threshold, blockTotal);
         thresholdsMet = false;
       } else {
         msg += String.format("The reported blocks %d has reached the threshold"

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestSafeMode.java

@@ -198,7 +198,7 @@ public class TestSafeMode {
     
     String status = nn.getNamesystem().getSafemode();
     assertEquals("Safe mode is ON. The reported blocks 0 needs additional " +
-        "15 blocks to reach the threshold 0.9990 of total blocks 15." + NEWLINE +
+        "14 blocks to reach the threshold 0.9990 of total blocks 15." + NEWLINE +
         "The number of live datanodes 0 has reached the minimum number 0. " +
         "Safe mode will be turned off automatically once the thresholds " +
         "have been reached.", status);

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

@@ -498,7 +498,7 @@ public class TestHASafeMode {
             + nodeThresh + ". In safe mode extension. "
             + "Safe mode will be turned off automatically"));
     } else {
-      int additional = total - safe;
+      int additional = (int) (total * 0.9990) - safe;
       assertTrue("Bad safemode status: '" + status + "'",
           status.startsWith(
               "Safe mode is ON. " +