HDFS-10302. BlockPlacementPolicyDefault should use default replication considerload value. Contributed by Lin Yiqun.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockPlacementPolicyDefault.java

@@ -79,7 +79,8 @@ public class BlockPlacementPolicyDefault extends BlockPlacementPolicy {
                          NetworkTopology clusterMap, 
                          Host2NodesMap host2datanodeMap) {
     this.considerLoad = conf.getBoolean(
-        DFSConfigKeys.DFS_NAMENODE_REPLICATION_CONSIDERLOAD_KEY, true);
+        DFSConfigKeys.DFS_NAMENODE_REPLICATION_CONSIDERLOAD_KEY,
+        DFSConfigKeys.DFS_NAMENODE_REPLICATION_CONSIDERLOAD_DEFAULT);
     this.considerLoadFactor = conf.getDouble(
         DFSConfigKeys.DFS_NAMENODE_REPLICATION_CONSIDERLOAD_FACTOR,
         DFSConfigKeys.DFS_NAMENODE_REPLICATION_CONSIDERLOAD_FACTOR_DEFAULT);