HDFS-9436. Make NNThroughputBenchmark$BlockReportStats run with 10 datanodes by default. Contributed by Mingliang.

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

@@ -1766,6 +1766,9 @@ Release 2.8.0 - UNRELEASED
     HDFS-8335. FSNamesystem should construct FSPermissionChecker only if
     permission is enabled. (Gabor Liptak via wheat9)
 
+    HDFS-9436. Make NNThroughputBenchmark$BlockReportStats run with 10
+    datanodes by default. (Mingliang Liu via shv)
+
   BUG FIXES
 
     HDFS-7501. TransactionsSinceLastCheckpoint can be negative on SBNs.

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/NNThroughputBenchmark.java

@@ -1098,6 +1098,8 @@ public class NNThroughputBenchmark implements Tool {
 
     BlockReportStats(List<String> args) {
       super();
+      numThreads = 10;
+      numOpsRequired = 30;
       this.blocksPerReport = 100;
       this.blocksPerFile = 10;
       // set heartbeat interval to 3 min, so that expiration were 40 min
@@ -1258,7 +1260,7 @@ public class NNThroughputBenchmark implements Tool {
     ReplicationStats(List<String> args) {
       super();
       numThreads = 1;
-      numDatanodes = 3;
+      numDatanodes = 10;
       nodesToDecommission = 1;
       nodeReplicationLimit = 100;
       totalBlocks = 100;