From c6914b1cb6e4cab8263cd3ae5cc00bc7a8de25de Mon Sep 17 00:00:00 2001
From: Viraj Jasani <vjasani@apache.org>
Date: Thu, 25 Nov 2021 07:53:04 +0530
Subject: [PATCH] HDFS-16350. Datanode start time should be set after RPC
 server starts successfully (#3711)

(cherry picked from commit cdc13e91b619159dc4bf185ad53b950bdf5de52a)
---
 .../java/org/apache/hadoop/hdfs/server/datanode/DataNode.java  | 3 ++-
 .../apache/hadoop/hdfs/server/datanode/TestDataNodeMXBean.java | 1 +
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java
index bd57f402966..f35534cc703 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java
@@ -416,7 +416,7 @@ public class DataNode extends ReconfigurableBase
 
   private ScheduledThreadPoolExecutor metricsLoggerTimer;
 
-  private final long startTime = now();
+  private long startTime = 0;
 
   /**
    * Creates a dummy DataNode for testing purpose.
@@ -2681,6 +2681,7 @@ public class DataNode extends ReconfigurableBase
     }
     ipcServer.setTracer(tracer);
     ipcServer.start();
+    startTime = now();
     startPlugins(getConf());
   }
 
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestDataNodeMXBean.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestDataNodeMXBean.java
index f72f1bce130..ea43cccbb18 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestDataNodeMXBean.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestDataNodeMXBean.java
@@ -77,6 +77,7 @@ public class TestDataNodeMXBean extends SaslDataTransferTestCase {
       Assert.assertEquals(datanode.getVersion(),version);
       // get attribute "DNStartedTimeInMillis"
       long startTime = (long) mbs.getAttribute(mxbeanName, "DNStartedTimeInMillis");
+      Assert.assertTrue("Datanode start time should not be 0", startTime > 0);
       Assert.assertEquals(datanode.getDNStartedTimeInMillis(), startTime);
       // get attribute "SotfwareVersion"
       String softwareVersion =