From c2a17659d1d48407edf437131783b653dbc87bc1 Mon Sep 17 00:00:00 2001
From: Ayush Saxena <ayushsaxena@apache.org>
Date: Sat, 8 Aug 2020 14:33:53 +0530
Subject: [PATCH] HDFS-15443. Setting dfs.datanode.max.transfer.threads to a
 very small value can cause strange failure. Contributed by AMC-team.

---
 .../apache/hadoop/hdfs/server/datanode/DataXceiverServer.java  | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataXceiverServer.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataXceiverServer.java
index 7faf2108bd4..43d292c1b55 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataXceiverServer.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataXceiverServer.java
@@ -188,6 +188,9 @@ class DataXceiverServer implements Runnable {
     this.maxXceiverCount =
       conf.getInt(DFSConfigKeys.DFS_DATANODE_MAX_RECEIVER_THREADS_KEY,
                   DFSConfigKeys.DFS_DATANODE_MAX_RECEIVER_THREADS_DEFAULT);
+    Preconditions.checkArgument(this.maxXceiverCount >= 1,
+        DFSConfigKeys.DFS_DATANODE_MAX_RECEIVER_THREADS_KEY +
+        " should not be less than 1.");
 
     this.estimateBlockSize = conf.getLongBytes(DFSConfigKeys.DFS_BLOCK_SIZE_KEY,
         DFSConfigKeys.DFS_BLOCK_SIZE_DEFAULT);