From 8641a2c08b0ce0f1f23cf2d508baccc4f627a385 Mon Sep 17 00:00:00 2001
From: Anu Engineer <aengineer@apache.org>
Date: Tue, 27 Jun 2017 00:39:47 -0700
Subject: [PATCH] HDFS-12045. Add log when Diskbalancer volume is transient
 storage type. Contributed by steven-wugang.

---
 .../hadoop/hdfs/server/datanode/DiskBalancer.java    | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DiskBalancer.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DiskBalancer.java
index 0c75001e5f..6b2cd52f91 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DiskBalancer.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DiskBalancer.java
@@ -1011,15 +1011,19 @@ public void copyBlocks(VolumePair pair, DiskBalancerWorkItem item) {
         return;
       }
 
+      if (source.isTransientStorage() || dest.isTransientStorage()) {
+        final String errMsg = "Disk Balancer - Unable to support " +
+                "transient storage type.";
+        LOG.error(errMsg);
+        item.setErrMsg(errMsg);
+        return;
+      }
+
       List<FsVolumeSpi.BlockIterator> poolIters = new LinkedList<>();
       startTime = Time.now();
       item.setStartTime(startTime);
       secondsElapsed = 0;
 
-      if (source.isTransientStorage() || dest.isTransientStorage()) {
-        return;
-      }
-
       try {
         openPoolIters(source, poolIters);
         if (poolIters.size() == 0) {