MAPREDUCE-4844. Counters / AbstractCounters have constant references not declared final. (Brahma Reddy Battula via gera)

(cherry picked from commit a0795c1e81685b812288cf2f4df6f8d23da30ab8)

hadoop-mapreduce-project/CHANGES.txt

@@ -76,6 +76,9 @@ Release 2.8.0 - UNRELEASED
     causes counter limits are not reset correctly.
     (Zhihai Xu via harsh)
 
+    MAPREDUCE-4844. Counters / AbstractCounters have constant references not
+    declared final. (Brahma Reddy Battula via gera)
+
 Release 2.7.0 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/Counters.java

@@ -62,9 +62,9 @@ import com.google.common.collect.Iterators;
 public class Counters
     extends AbstractCounters<Counters.Counter, Counters.Group> {
   
-  public static int MAX_COUNTER_LIMIT = Limits.getCountersMax();
-  public static int MAX_GROUP_LIMIT = Limits.getGroupsMax();
-  private static HashMap<String, String> depricatedCounterMap =
+  public static final int MAX_COUNTER_LIMIT = Limits.getCountersMax();
+  public static final int MAX_GROUP_LIMIT = Limits.getGroupsMax();
+  private static final HashMap<String, String> depricatedCounterMap =
       new HashMap<String, String>();
   
   static {

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/counters/AbstractCounters.java

@@ -64,11 +64,11 @@ public abstract class AbstractCounters<C extends Counter,
   /**
    * A cache from enum values to the associated counter.
    */
-  private Map<Enum<?>, C> cache = Maps.newIdentityHashMap();
+  private final Map<Enum<?>, C> cache = Maps.newIdentityHashMap();
   //framework & fs groups
-  private Map<String, G> fgroups = new ConcurrentSkipListMap<String, G>();
+  private final Map<String, G> fgroups = new ConcurrentSkipListMap<String, G>();
   // other groups
-  private Map<String, G> groups = new ConcurrentSkipListMap<String, G>();
+  private final Map<String, G> groups = new ConcurrentSkipListMap<String, G>();
   private final CounterGroupFactory<C, G> groupFactory;
 
   // For framework counter serialization without strings