HDFS-2002. Incorrect computation of needed blocks in getTurnOffTip(). Contributed by Plamen Jeliazkov.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23@1196229 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -1760,6 +1760,9 @@ Release 0.22.0 - Unreleased
     HDFS-2452. OutOfMemoryError in DataXceiverServer takes down the DataNode
     (Uma Maheswara Rao via cos)
 
+    HDFS-2002. Incorrect computation of needed blocks in getTurnOffTip().
+    (Plamen Jeliazkov via shv)
+
 Release 0.21.1 - Unreleased
 
     HDFS-1466. TestFcHdfsSymlink relies on /tmp/test not existing. (eli)

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

@@ -2833,6 +2833,9 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
     private SafeModeInfo(Configuration conf) {
       this.threshold = conf.getFloat(DFS_NAMENODE_SAFEMODE_THRESHOLD_PCT_KEY,
           DFS_NAMENODE_SAFEMODE_THRESHOLD_PCT_DEFAULT);
+      if(threshold > 1.0) {
+        LOG.warn("The threshold value should't be greater than 1, threshold: " + threshold);
+      }
       this.datanodeThreshold = conf.getInt(
         DFS_NAMENODE_SAFEMODE_MIN_DATANODES_KEY,
         DFS_NAMENODE_SAFEMODE_MIN_DATANODES_DEFAULT);
@@ -3120,7 +3123,7 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
           msg += String.format(
             "The reported blocks %d needs additional %d"
             + " blocks to reach the threshold %.4f of total blocks %d.",
-            blockSafe, (blockThreshold - blockSafe), threshold, blockTotal);
+            blockSafe, (blockThreshold - blockSafe) + 1, threshold, blockTotal);
         }
         if (numLive < datanodeThreshold) {
           if (!"".equals(msg)) {
@@ -3129,7 +3132,7 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
           msg += String.format(
             "The number of live datanodes %d needs an additional %d live "
             + "datanodes to reach the minimum number %d.",
-            numLive, datanodeThreshold - numLive, datanodeThreshold);
+            numLive, (datanodeThreshold - numLive) + 1 , datanodeThreshold);
         }
         msg += " " + leaveMsg;
       } else {

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

@@ -58,8 +58,9 @@ public class TestSafeMode {
 
       String tipMsg = cluster.getNamesystem().getSafeModeTip();
       assertTrue("Safemode tip message looks right",
-                 tipMsg.contains("The number of live datanodes 0 needs an " +
-                                 "additional 1 live"));
+                 tipMsg.contains("The number of live datanodes 0 needs an additional " +
+                                 "2 live datanodes to reach the minimum number 1. " +
+                                 "Safe mode will be turned off automatically."));
 
       // Start a datanode
       cluster.startDataNodes(conf, 1, true, null, null);