From 233ca3e2a5145f006316f899e61a02bf97c38e75 Mon Sep 17 00:00:00 2001
From: Karthik Kambatla <kasha@apache.org>
Date: Sat, 7 Jun 2014 00:51:50 +0000
Subject: [PATCH] YARN-2122. In AllocationFileLoaderService, the reloadThread
 should be created in init() and started in start(). (Robert Kanter via kasha)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1601046 13f79535-47bb-0310-9956-ffa450edef68
---
 hadoop-yarn-project/CHANGES.txt               |  4 +
 .../dev-support/findbugs-exclude.xml          |  5 ++
 .../fair/AllocationFileLoaderService.java     | 82 ++++++++++---------
 3 files changed, 52 insertions(+), 39 deletions(-)

diff --git a/hadoop-yarn-project/CHANGES.txt b/hadoop-yarn-project/CHANGES.txt
index ac1dcb7193d..236208215a0 100644
--- a/hadoop-yarn-project/CHANGES.txt
+++ b/hadoop-yarn-project/CHANGES.txt
@@ -124,6 +124,9 @@ Release 2.5.0 - UNRELEASED
 
     YARN-1977. Add tests on getApplicationRequest with filtering start time range. (junping_du)
 
+    YARN-2122. In AllocationFileLoaderService, the reloadThread should be created
+    in init() and started in start(). (Robert Kanter via kasha)
+
   OPTIMIZATIONS
 
   BUG FIXES 
@@ -150,6 +153,7 @@ Release 2.5.0 - UNRELEASED
 
     YARN-2011. Fix typo and warning in TestLeafQueue (Chen He via junping_du)
 
+
     YARN-2042. String shouldn't be compared using == in
     QueuePlacementRule#NestedUserQueue#getQueueForApp (Chen He via Sandy Ryza)
 
diff --git a/hadoop-yarn-project/hadoop-yarn/dev-support/findbugs-exclude.xml b/hadoop-yarn-project/hadoop-yarn/dev-support/findbugs-exclude.xml
index 79ce7460c21..2da958a08bf 100644
--- a/hadoop-yarn-project/hadoop-yarn/dev-support/findbugs-exclude.xml
+++ b/hadoop-yarn-project/hadoop-yarn/dev-support/findbugs-exclude.xml
@@ -142,6 +142,11 @@
     <Class name="org.apache.hadoop.yarn.server.nodemanager.containermanager.logaggregation.LogAggregationService" />
     <Bug pattern="IS2_INCONSISTENT_SYNC" />
   </Match>
+  <Match>
+    <Class name="org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.AllocationFileLoaderService" />
+    <Field name="allocFile" />
+    <Bug pattern="IS2_INCONSISTENT_SYNC" />
+  </Match>
   <!-- Inconsistent sync warning - minimumAllocation is only initialized once and never changed -->
   <Match>
     <Class name="org.apache.hadoop.yarn.server.resourcemanager.scheduler.AbstractYarnScheduler" />
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/AllocationFileLoaderService.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/AllocationFileLoaderService.java
index 3a962a8ce52..064bdfc817f 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/AllocationFileLoaderService.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/AllocationFileLoaderService.java
@@ -98,55 +98,59 @@ public AllocationFileLoaderService(Clock clock) {
   }
   
   @Override
-  public void init(Configuration conf) {
+  public void serviceInit(Configuration conf) throws Exception {
     this.allocFile = getAllocationFile(conf);
-    super.init(conf);
-  }
-  
-  @Override
-  public void start() {
-    if (allocFile == null) {
-      return;
-    }
-    reloadThread = new Thread() {
-      public void run() {
-        while (running) {
-          long time = clock.getTime();
-          long lastModified = allocFile.lastModified();
-          if (lastModified > lastSuccessfulReload &&
-              time > lastModified + ALLOC_RELOAD_WAIT_MS) {
-            try {
-              reloadAllocations();
-            } catch (Exception ex) {
+    if (allocFile != null) {
+      reloadThread = new Thread() {
+        @Override
+        public void run() {
+          while (running) {
+            long time = clock.getTime();
+            long lastModified = allocFile.lastModified();
+            if (lastModified > lastSuccessfulReload &&
+                time > lastModified + ALLOC_RELOAD_WAIT_MS) {
+              try {
+                reloadAllocations();
+              } catch (Exception ex) {
+                if (!lastReloadAttemptFailed) {
+                  LOG.error("Failed to reload fair scheduler config file - " +
+                      "will use existing allocations.", ex);
+                }
+                lastReloadAttemptFailed = true;
+              }
+            } else if (lastModified == 0l) {
               if (!lastReloadAttemptFailed) {
-                LOG.error("Failed to reload fair scheduler config file - " +
-                    "will use existing allocations.", ex);
+                LOG.warn("Failed to reload fair scheduler config file because" +
+                    " last modified returned 0. File exists: "
+                    + allocFile.exists());
               }
               lastReloadAttemptFailed = true;
             }
-          } else if (lastModified == 0l) {
-            if (!lastReloadAttemptFailed) {
-              LOG.warn("Failed to reload fair scheduler config file because" +
-                  " last modified returned 0. File exists: " + allocFile.exists());
+            try {
+              Thread.sleep(reloadIntervalMs);
+            } catch (InterruptedException ex) {
+              LOG.info(
+                  "Interrupted while waiting to reload alloc configuration");
             }
-            lastReloadAttemptFailed = true;
-          }
-          try {
-            Thread.sleep(reloadIntervalMs);
-          } catch (InterruptedException ex) {
-            LOG.info("Interrupted while waiting to reload alloc configuration");
           }
         }
-      }
-    };
-    reloadThread.setName("AllocationFileReloader");
-    reloadThread.setDaemon(true);
-    reloadThread.start();
-    super.start();
+      };
+      reloadThread.setName("AllocationFileReloader");
+      reloadThread.setDaemon(true);
+    }
+    super.serviceInit(conf);
   }
   
   @Override
-  public void stop() {
+  public void serviceStart() throws Exception {
+    if (reloadThread != null) {
+      reloadThread.start();
+    }
+    super.serviceStart();
+  }
+  
+  @Override
+  public void serviceStop() throws Exception {
     running = false;
     if (reloadThread != null) {
       reloadThread.interrupt();
@@ -156,7 +160,7 @@ public void stop() {
         LOG.warn("reloadThread fails to join.");
       }
     }
-    super.stop();
+    super.serviceStop();
   }
   
   /**