From ac37ca0b67b2776b9f972dc69077f41935ee5812 Mon Sep 17 00:00:00 2001
From: Jonathan Hung <jhung@linkedin.com>
Date: Thu, 25 Feb 2021 15:08:43 -0800
Subject: [PATCH] YARN-10651. CapacityScheduler crashed with NPE in
 AbstractYarnScheduler.updateNodeResource(). Contributed by Haibo Chen

---
 .../resourcemanager/scheduler/AbstractYarnScheduler.java     | 5 +++++
 1 file changed, 5 insertions(+)

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/AbstractYarnScheduler.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/AbstractYarnScheduler.java
index f95b30b1e5..97e25d5caf 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/AbstractYarnScheduler.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/AbstractYarnScheduler.java
@@ -848,6 +848,11 @@ public abstract class AbstractYarnScheduler
     writeLock.lock();
     try {
       SchedulerNode node = getSchedulerNode(nm.getNodeID());
+      if (node == null) {
+        LOG.info("Node: " + nm.getNodeID() + " has already been taken out of " +
+            "scheduling. Skip updating its resource");
+        return;
+      }
       Resource newResource = resourceOption.getResource();
       final int timeout = resourceOption.getOverCommitTimeout();
       Resource oldResource = node.getTotalResource();