From 6759cbc56a09c129f5902ddbbee7db665ca9c917 Mon Sep 17 00:00:00 2001
From: Jason Lowe <jlowe@apache.org>
Date: Mon, 11 Jul 2016 20:58:40 +0000
Subject: [PATCH] HADOOP-13362. DefaultMetricsSystem leaks the source name when
 a source unregisters. Contributed by Junping Du

---
 hadoop-common-project/hadoop-common/CHANGES.txt          | 3 +++
 .../apache/hadoop/metrics2/impl/MetricsSystemImpl.java   | 1 +
 .../apache/hadoop/metrics2/lib/DefaultMetricsSystem.java | 9 +++++++++
 .../containermanager/monitor/TestContainerMetrics.java   | 4 +++-
 4 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/hadoop-common-project/hadoop-common/CHANGES.txt b/hadoop-common-project/hadoop-common/CHANGES.txt
index 1abebf16c9b..4f6d2f92c71 100644
--- a/hadoop-common-project/hadoop-common/CHANGES.txt
+++ b/hadoop-common-project/hadoop-common/CHANGES.txt
@@ -12,6 +12,9 @@ Release 2.7.4 - UNRELEASED
 
   BUG FIXES
 
+    HADOOP-13362. DefaultMetricsSystem leaks the source name when a source
+    unregisters (Junping Du via jlowe)
+
 Release 2.7.3 - UNRELEASED
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics2/impl/MetricsSystemImpl.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics2/impl/MetricsSystemImpl.java
index 4f9289f8d95..a3a58550eb6 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics2/impl/MetricsSystemImpl.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics2/impl/MetricsSystemImpl.java
@@ -255,6 +255,7 @@ void unregisterSource(String name) {
     if (namedCallbacks.containsKey(name)) {
       namedCallbacks.remove(name);
     }
+    DefaultMetricsSystem.removeSourceName(name);
   }
 
   synchronized
diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics2/lib/DefaultMetricsSystem.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics2/lib/DefaultMetricsSystem.java
index d3a5508393e..3c4aa78e4d1 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics2/lib/DefaultMetricsSystem.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics2/lib/DefaultMetricsSystem.java
@@ -107,6 +107,11 @@ public static void removeMBeanName(ObjectName name) {
     INSTANCE.removeObjectName(name.toString());
   }
 
+  @InterfaceAudience.Private
+  public static void removeSourceName(String name) {
+    INSTANCE.removeSource(name);
+  }
+
   @InterfaceAudience.Private
   public static String sourceName(String name, boolean dupOK) {
     return INSTANCE.newSourceName(name, dupOK);
@@ -127,6 +132,10 @@ synchronized void removeObjectName(String name) {
     mBeanNames.map.remove(name);
   }
 
+  synchronized void removeSource(String name) {
+    sourceNames.map.remove(name);
+  }
+
   synchronized String newSourceName(String name, boolean dupOK) {
     if (sourceNames.map.containsKey(name)) {
       if (dupOK) {
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/monitor/TestContainerMetrics.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/monitor/TestContainerMetrics.java
index ec06856e878..87e6ed2ca66 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/monitor/TestContainerMetrics.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/monitor/TestContainerMetrics.java
@@ -136,7 +136,6 @@ public void testContainerMetricsFinished() throws InterruptedException {
     system.sampleMetrics();
     system.sampleMetrics();
     Thread.sleep(100);
-    system.stop();
     // verify metrics1 is unregistered
     assertTrue(metrics1 != ContainerMetrics.forContainer(
         system, containerId1, 1, 0));
@@ -146,6 +145,9 @@ public void testContainerMetricsFinished() throws InterruptedException {
     // verify metrics3 is still registered
     assertTrue(metrics3 == ContainerMetrics.forContainer(
         system, containerId3, 1, 0));
+    // move stop() to the end to verify registering containerId1 and
+    // containerId2 won't get MetricsException thrown.
+    system.stop();
     system.shutdown();
   }
 }