HADOOP-11586. Update use of Iterator to Iterable in AbstractMetricsContext.java. Contributed by Ray Chiang.

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -594,6 +594,9 @@ Release 2.7.0 - UNRELEASED
     HADOOP-11543. Improve help message for hadoop/yarn command. (Brahma 
     Reddy Battula via ozawa).
 
+    HADOOP-11586. Update use of Iterator to Iterable in
+    AbstractMetricsContext.java. (Ray Chiang via aajisaka)
+
   OPTIMIZATIONS
 
     HADOOP-11323. WritableComparator#compare keeps reference to byte array.

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics/spi/AbstractMetricsContext.java

@@ -318,13 +318,13 @@ public abstract class AbstractMetricsContext implements MetricsContext {
    *  Emits the records.
    */
   private synchronized void emitRecords() throws IOException {
-    for (String recordName : bufferedData.keySet()) {
-      RecordMap recordMap = bufferedData.get(recordName);
+    for (Map.Entry<String,RecordMap> recordEntry : bufferedData.entrySet()) {
+      RecordMap recordMap = recordEntry.getValue();
       synchronized (recordMap) {
         Set<Entry<TagMap, MetricMap>> entrySet = recordMap.entrySet ();
         for (Entry<TagMap, MetricMap> entry : entrySet) {
           OutputRecord outRec = new OutputRecord(entry.getKey(), entry.getValue());
-          emitRecord(contextName, recordName, outRec);
+          emitRecord(contextName, recordEntry.getKey(), outRec);
         }
       }
     }
@@ -339,8 +339,8 @@ public abstract class AbstractMetricsContext implements MetricsContext {
   @Override
   public synchronized Map<String, Collection<OutputRecord>> getAllRecords() {
     Map<String, Collection<OutputRecord>> out = new TreeMap<String, Collection<OutputRecord>>();
-    for (String recordName : bufferedData.keySet()) {
-      RecordMap recordMap = bufferedData.get(recordName);
+    for (Map.Entry<String,RecordMap> recordEntry : bufferedData.entrySet()) {
+      RecordMap recordMap = recordEntry.getValue();
       synchronized (recordMap) {
         List<OutputRecord> records = new ArrayList<OutputRecord>();
         Set<Entry<TagMap, MetricMap>> entrySet = recordMap.entrySet();
@@ -348,7 +348,7 @@ public abstract class AbstractMetricsContext implements MetricsContext {
           OutputRecord outRec = new OutputRecord(entry.getKey(), entry.getValue());
           records.add(outRec);
         }
-        out.put(recordName, records);
+        out.put(recordEntry.getKey(), records);
       }
     }
     return out;