HADOOP-3408. Change FSNamesystem to send its metrics as integers to accommodate

collectors that don't support long values. Contributed by Lohit Vijayarenu.



git-svn-id: https://svn.apache.org/repos/asf/hadoop/core/trunk@658846 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -301,6 +301,10 @@ Trunk (unreleased changes)
     make sure they are in the range 0 to #reduces - 1 (cdouglas via
     omalley)
 
+    HADOOP-3408. Change FSNamesystem to send its metrics as integers to
+    accommodate collectors that don't support long values. (lohit vijayarenu
+    via cdouglas)
+
 Release 0.17.0 - 2008-05-18
 
   INCOMPATIBLE CHANGES

src/java/org/apache/hadoop/dfs/FSNamesystemMetrics.java

@@ -22,7 +22,6 @@ import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.metrics.*;
 import org.apache.hadoop.metrics.jvm.JvmMetrics;
-import org.apache.hadoop.metrics.util.MetricsLongValue;
 import org.apache.hadoop.metrics.util.MetricsIntValue;
 import org.apache.hadoop.metrics.util.MetricsTimeVaryingInt;
 import org.apache.hadoop.metrics.util.MetricsTimeVaryingRate;
@@ -44,15 +43,15 @@ public class FSNamesystemMetrics implements Updater {
   private final MetricsRecord metricsRecord;
   private FSNamesystem fsNameSystem;
    
-  public MetricsLongValue filesTotal = new MetricsLongValue("FilesTotal");
-  public MetricsLongValue blocksTotal = new MetricsLongValue("BlocksTotal");
-  public MetricsLongValue capacityTotal = new MetricsLongValue("CapacityTotal");
-  public MetricsLongValue capacityUsed = new MetricsLongValue("CapacityUsed");
-  public MetricsLongValue capacityRemaining = new MetricsLongValue("CapacityRemaining");
+  public MetricsIntValue filesTotal = new MetricsIntValue("FilesTotal");
+  public MetricsIntValue blocksTotal = new MetricsIntValue("BlocksTotal");
+  public MetricsIntValue capacityTotalGB = new MetricsIntValue("CapacityTotalGB");
+  public MetricsIntValue capacityUsedGB = new MetricsIntValue("CapacityUsedGB");
+  public MetricsIntValue capacityRemainingGB = new MetricsIntValue("CapacityRemainingGB");
   public MetricsIntValue totalLoad = new MetricsIntValue("TotalLoad");
-  public MetricsLongValue pendingReplicationBlocks = new MetricsLongValue("PendingReplicationBlocks");
-  public MetricsLongValue underReplicatedBlocks = new MetricsLongValue("UnderReplicatedBlocks");
-  public MetricsLongValue scheduledReplicationBlocks = new MetricsLongValue("ScheduledReplicationBlocks");
+  public MetricsIntValue pendingReplicationBlocks = new MetricsIntValue("PendingReplicationBlocks");
+  public MetricsIntValue underReplicatedBlocks = new MetricsIntValue("UnderReplicatedBlocks");
+  public MetricsIntValue scheduledReplicationBlocks = new MetricsIntValue("ScheduledReplicationBlocks");
   FSNamesystemMetrics(Configuration conf, FSNamesystem fsNameSystem) {
     String sessionId = conf.get("session.id");
     this.fsNameSystem = fsNameSystem;
@@ -69,6 +68,10 @@ public class FSNamesystemMetrics implements Updater {
     if (fsNameSystem != null) 
       fsNameSystem.shutdown();
   }
+
+  private int roundBytesToGBytes(long bytes) {
+    return Math.round(((float)bytes/(1024 * 1024 * 1024)));
+  }
       
   /**
    * Since this object is a registered updater, this method will be called
@@ -76,34 +79,42 @@ public class FSNamesystemMetrics implements Updater {
    * We set the metrics value within  this function before pushing it out. 
    * FSNamesystem updates its own local variables which are
    * light weight compared to Metrics counters. 
+   *
+   * Some of the metrics are explicity casted to int. Few metrics collectors
+   * do not handle long values. It is safe to cast to int for now as all these
+   * values fit in int value.
+   * Metrics related to DFS capacity are stored in bytes which do not fit in 
+   * int, so they are rounded to GB
    */
   public void doUpdates(MetricsContext unused) {
     synchronized (this) {
-      filesTotal.set(fsNameSystem.getFilesTotal());
+      filesTotal.set((int)fsNameSystem.getFilesTotal());
       filesTotal.pushMetric(metricsRecord);
 
-      blocksTotal.set(fsNameSystem.getBlocksTotal());
+      blocksTotal.set((int)fsNameSystem.getBlocksTotal());
       blocksTotal.pushMetric(metricsRecord);
       
-      capacityTotal.set(fsNameSystem.getCapacityTotal());
-      capacityTotal.pushMetric(metricsRecord);
+      capacityTotalGB.set(roundBytesToGBytes(fsNameSystem.getCapacityTotal()));
+      capacityTotalGB.pushMetric(metricsRecord);
       
-      capacityUsed.set(fsNameSystem.getCapacityUsed());
-      capacityUsed.pushMetric(metricsRecord);
+      capacityUsedGB.set(roundBytesToGBytes(fsNameSystem.getCapacityUsed()));
+      capacityUsedGB.pushMetric(metricsRecord);
       
-      capacityRemaining.set(fsNameSystem.getCapacityRemaining());
-      capacityRemaining.pushMetric(metricsRecord);
+      capacityRemainingGB.set(roundBytesToGBytes(fsNameSystem.
+                                               getCapacityRemaining()));
+      capacityRemainingGB.pushMetric(metricsRecord);
       
       totalLoad.set(fsNameSystem.getTotalLoad());
       totalLoad.pushMetric(metricsRecord);
       
-      pendingReplicationBlocks.set(fsNameSystem.getPendingReplicationBlocks());
+      pendingReplicationBlocks.set((int)fsNameSystem.
+                                   getPendingReplicationBlocks());
       pendingReplicationBlocks.pushMetric(metricsRecord);
 
-      underReplicatedBlocks.set(fsNameSystem.getUnderReplicatedBlocks());
+      underReplicatedBlocks.set((int)fsNameSystem.getUnderReplicatedBlocks());
       underReplicatedBlocks.pushMetric(metricsRecord);
 
-      scheduledReplicationBlocks.set(fsNameSystem.
+      scheduledReplicationBlocks.set((int)fsNameSystem.
                                       getScheduledReplicationBlocks());
       scheduledReplicationBlocks.pushMetric(metricsRecord);
     }