HADOOP-10496. Metrics system FileSink can leak file descriptor. Contributed by Chris Nauroth.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1587141 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -383,6 +383,8 @@ Release 2.5.0 - UNRELEASED
     HADOOP-10495. TestFileUtil fails on Windows due to bad permission
     assertions. (cnauroth)
 
+    HADOOP-10496. Metrics system FileSink can leak file descriptor. (cnauroth)
+
 Release 2.4.1 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics2/MetricsSink.java

@@ -18,6 +18,8 @@
 
 package org.apache.hadoop.metrics2;
 
+import java.io.Closeable;
+
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
 
@@ -26,7 +28,9 @@ import org.apache.hadoop.classification.InterfaceStability;
  * Implementations of this interface consume the {@link MetricsRecord} generated
  * from {@link MetricsSource}. It registers with {@link MetricsSystem} which
  * periodically pushes the {@link MetricsRecord} to the sink using
- * {@link #putMetrics(MetricsRecord)} method.
+ * {@link #putMetrics(MetricsRecord)} method.  If the implementing class also
+ * implements {@link Closeable}, then the MetricsSystem will close the sink when
+ * it is stopped.
  */
 @InterfaceAudience.Public
 @InterfaceStability.Evolving

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics2/impl/MetricsSinkAdapter.java

@@ -18,6 +18,7 @@
 
 package org.apache.hadoop.metrics2.impl;
 
+import java.io.Closeable;
 import java.util.Random;
 import java.util.concurrent.*;
 
@@ -25,6 +26,7 @@ import static com.google.common.base.Preconditions.*;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.io.IOUtils;
 import org.apache.hadoop.metrics2.lib.MutableGaugeInt;
 import org.apache.hadoop.metrics2.lib.MetricsRegistry;
 import org.apache.hadoop.metrics2.lib.MutableCounterInt;
@@ -198,6 +200,9 @@ class MetricsSinkAdapter implements SinkQueue.Consumer<MetricsBuffer> {
     } catch (InterruptedException e) {
       LOG.warn("Stop interrupted", e);
     }
+    if (sink instanceof Closeable) {
+      IOUtils.cleanup(LOG, (Closeable)sink);
+    }
   }
 
   String name() {

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics2/sink/FileSink.java

@@ -18,8 +18,10 @@
 
 package org.apache.hadoop.metrics2.sink;
 
+import java.io.Closeable;
 import java.io.File;
 import java.io.FileWriter;
+import java.io.IOException;
 import java.io.PrintWriter;
 
 import org.apache.commons.configuration.SubsetConfiguration;
@@ -36,7 +38,7 @@ import org.apache.hadoop.metrics2.MetricsTag;
  */
 @InterfaceAudience.Public
 @InterfaceStability.Evolving
-public class FileSink implements MetricsSink {
+public class FileSink implements MetricsSink, Closeable {
   private static final String FILENAME_KEY = "filename";
   private PrintWriter writer;
 
@@ -81,4 +83,9 @@ public class FileSink implements MetricsSink {
   public void flush() {
     writer.flush();
   }
+
+  @Override
+  public void close() throws IOException {
+    writer.close();
+  }
 }

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/metrics2/sink/TestFileSink.java

@@ -105,11 +105,18 @@ public class TestFileSink {
     ms.publishMetricsNow(); // publish the metrics
     ms.stop();
     ms.shutdown();
-    
-    InputStream is = new FileInputStream(outFile);
-    ByteArrayOutputStream baos = new ByteArrayOutputStream((int)outFile.length());
-    IOUtils.copyBytes(is, baos, 1024, true);
-    String outFileContent = new String(baos.toByteArray(), "UTF-8");
+
+    InputStream is = null;
+    ByteArrayOutputStream baos = null;
+    String outFileContent = null;
+    try {
+      is = new FileInputStream(outFile);
+      baos = new ByteArrayOutputStream((int)outFile.length());
+      IOUtils.copyBytes(is, baos, 1024, true);
+      outFileContent = new String(baos.toByteArray(), "UTF-8");
+    } finally {
+      IOUtils.cleanup(null, baos, is);
+    }
 
     // Check the out file content. Should be something like the following:
     //1360244820087 test1.testRecord1: Context=test1, testTag1=testTagValue1, testTag2=testTagValue2, Hostname=myhost, testMetric1=1, testMetric2=2