Fix TaskTracker blacklisting to work correctly in one- and two-node clusters. Contributed by Arun.

git-svn-id: https://svn.apache.org/repos/asf/lucene/hadoop/trunk@534973 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -322,6 +322,9 @@ Trunk (unreleased changes)
 95. HADOOP-485.  Allow a different comparator for grouping keys in
     calls to reduce.  (Tahir Hashmi via cutting)
 
+96. HADOOP-1322.  Fix TaskTracker blacklisting to work correctly in
+    one- and two-node clusters.  (Arun C Murthy via cutting)
+
 
 Release 0.12.3 - 2007-04-06
 

src/java/org/apache/hadoop/mapred/JobInProgress.java

@@ -594,7 +594,8 @@ class JobInProgress {
     // tasktracker prior to assigning it a new one.
     //
     int taskTrackerFailedTasks = getTrackerTaskFailures(taskTracker);
-    if (taskTrackerFailedTasks >= conf.getMaxTaskFailuresPerTracker()) {
+    if ((flakyTaskTrackers < (clusterSize * CLUSTER_BLACKLIST_PERCENT)) && 
+        taskTrackerFailedTasks >= conf.getMaxTaskFailuresPerTracker()) {
       if (LOG.isDebugEnabled()) {
         String flakyTracker = convertTrackerNameToHostName(taskTracker); 
         LOG.debug("Ignoring the black-listed tasktracker: '" + flakyTracker