HDFS-12347. TestBalancerRPCDelay#testBalancerRPCDelay fails very frequently. Contributed by Bharat Viswanadham

(cherry picked from commit c7499f2d242c64bee8f822a22161d956525f7153)

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -15,6 +15,9 @@ Release 2.7.6 - UNRELEASED
     HDFS-12881. Output streams closed with IOUtils suppressing write errors.
     (Ajay Kumar via jlowe)
 
+    HDFS-12347. TestBalancerRPCDelay#testBalancerRPCDelay fails very frequently.
+    (Bharat Viswanadham via Tsz-Wo Nicholas Sze)
+
 Release 2.7.5 - 2017-12-14
 
   INCOMPATIBLE CHANGES

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/balancer/TestBalancer.java

@@ -1679,7 +1679,7 @@ public class TestBalancer {
     initConf(conf);
     conf.setInt(DFSConfigKeys.DFS_BALANCER_DISPATCHERTHREADS_KEY, 30);
 
-    int numDNs = 40;
+    int numDNs = 20;
     long[] capacities = new long[numDNs];
     String[] racks = new String[numDNs];
     for(int i = 0; i < numDNs; i++) {