From 4d211d5fde5a4f17f7bf2cc62636167b49a79cbd Mon Sep 17 00:00:00 2001
From: Karthik Kambatla <kasha@apache.org>
Date: Sat, 12 Jul 2014 15:10:19 +0000
Subject: [PATCH] YARN-2274. FairScheduler: Add debug information about cluster
 capacity, availability and reservations. (kasha)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1609942 13f79535-47bb-0310-9956-ffa450edef68
---
 hadoop-yarn-project/CHANGES.txt               |  3 +++
 .../scheduler/fair/FairScheduler.java         | 20 ++++++++++++++++---
 2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/hadoop-yarn-project/CHANGES.txt b/hadoop-yarn-project/CHANGES.txt
index 2461cf2f6c..bfe257558f 100644
--- a/hadoop-yarn-project/CHANGES.txt
+++ b/hadoop-yarn-project/CHANGES.txt
@@ -40,6 +40,9 @@ Release 2.6.0 - UNRELEASED
     YARN-2242. Improve exception information on AM launch crashes. (Li Lu 
     via junping_du)
 
+    YARN-2274. FairScheduler: Add debug information about cluster capacity, 
+    availability and reservations. (kasha)
+
   OPTIMIZATIONS
 
   BUG FIXES
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/FairScheduler.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/FairScheduler.java
index 7a4e79c36a..6f9b76f010 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/FairScheduler.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/FairScheduler.java
@@ -136,6 +136,8 @@ public class FairScheduler extends
 
   // How often fair shares are re-calculated (ms)
   protected long UPDATE_INTERVAL = 500;
+  private final int UPDATE_DEBUG_FREQUENCY = 5;
+  private int updatesToSkipForDebug = UPDATE_DEBUG_FREQUENCY;
 
   private Thread updateThread;
   private Thread schedulingThread;
@@ -275,6 +277,18 @@ public class FairScheduler extends
     // Recursively compute fair shares for all queues
     // and update metrics
     rootQueue.recomputeShares();
+
+    if (LOG.isDebugEnabled()) {
+      if (--updatesToSkipForDebug < 0) {
+        updatesToSkipForDebug = UPDATE_DEBUG_FREQUENCY;
+        LOG.debug("Cluster Capacity: " + clusterResource +
+            "  Allocations: " + rootMetrics.getAllocatedResources() +
+            "  Availability: " + Resource.newInstance(
+            rootMetrics.getAvailableMB(),
+            rootMetrics.getAvailableVirtualCores()) +
+            "  Demand: " + rootQueue.getDemand());
+      }
+    }
   }
 
   /**
@@ -879,14 +893,14 @@ public class FairScheduler extends
         // Update application requests
         application.updateResourceRequests(ask);
 
-        LOG.debug("allocate: post-update");
         application.showRequests();
       }
 
       if (LOG.isDebugEnabled()) {
-        LOG.debug("allocate:" +
+        LOG.debug("allocate: post-update" +
             " applicationAttemptId=" + appAttemptId +
-            " #ask=" + ask.size());
+            " #ask=" + ask.size() +
+            " reservation= " + application.getCurrentReservation());
 
         LOG.debug("Preempting " + application.getPreemptionContainers().size()
             + " container(s)");