HDFS-9626. TestBlockReplacement#testBlockReplacement fails occasionally. Contributed by Xiao Chen.

Change-Id: I5cee398dfc361121d8b666ffd1203cc14a4ace24

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

@@ -1687,6 +1687,9 @@ Release 2.8.0 - UNRELEASED
     HDFS-9619. SimulatedFSDataset sometimes can not find blockpool for the
     correct namenode (Wei-Chiu Chuang via vinayakumarb)
 
+    HDFS-9626. TestBlockReplacement#testBlockReplacement fails occasionally.
+    (Xiao Chen via zhz)
+
 Release 2.7.3 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestBlockReplacement.java

@@ -198,9 +198,10 @@ public class TestBlockReplacement {
       LOG.info("Testcase 4: invalid del hint " + proxies.get(0) );
       assertTrue(replaceBlock(b, proxies.get(0), proxies.get(1), source));
       // after cluster has time to resolve the over-replication,
-      // block locations should contain two proxies,
-      // and either source or newNode, but not both.
-      checkBlocks(proxies.toArray(new DatanodeInfo[proxies.size()]), 
+      // block locations should contain any 3 of the blocks, since after the
+      // deletion the number of racks is still >=2 for sure.
+      // See HDFS-9314 for details, espacially the comment on 18/Nov/15 14:09.
+      checkBlocks(new DatanodeInfo[]{},
           fileName.toString(), 
           DEFAULT_BLOCK_SIZE, REPLICATION_FACTOR, client);
     } finally {