From ba43233451128118e999f51f7c52f2d50993b56e Mon Sep 17 00:00:00 2001
From: avijayanhwx <14299376+avijayanhwx@users.noreply.github.com>
Date: Thu, 25 Jul 2019 07:54:46 -0700
Subject: [PATCH] HDDS-1749 : Ozone Client should randomize the list of nodes
 in pipeline for reads. (#1124)

---
 .../java/org/apache/hadoop/hdds/scm/XceiverClientGrpc.java    | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/hadoop-hdds/client/src/main/java/org/apache/hadoop/hdds/scm/XceiverClientGrpc.java b/hadoop-hdds/client/src/main/java/org/apache/hadoop/hdds/scm/XceiverClientGrpc.java
index eee813fd75b..9f99ab58ea7 100644
--- a/hadoop-hdds/client/src/main/java/org/apache/hadoop/hdds/scm/XceiverClientGrpc.java
+++ b/hadoop-hdds/client/src/main/java/org/apache/hadoop/hdds/scm/XceiverClientGrpc.java
@@ -54,6 +54,7 @@
 
 import java.io.File;
 import java.io.IOException;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -269,6 +270,9 @@ private XceiverClientReply sendCommandWithRetry(
       datanodeList = pipeline.getNodesInOrder();
     } else {
       datanodeList = pipeline.getNodes();
+      // Shuffle datanode list so that clients do not read in the same order
+      // every time.
+      Collections.shuffle(datanodeList);
     }
     for (DatanodeDetails dn : datanodeList) {
       try {