HDFS-17064. Document the usage of the new Balancer "sortTopNodes" and "hotBlockTimeInterval" parameter (#5794). Contributed by Haiyang Hu.

Reviewed-by: Shuyan Zhang <zqingchai@gmail.com>
Reviewed-by: He Xiaoqiao <hexiaoqiao@apache.org>
Signed-off-by: Ayush Saxena <ayushsaxena@apache.org>

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/balancer/Balancer.java

@@ -206,9 +206,9 @@ public class Balancer {
       + "on over-utilized machines."
       + "\n\t[-asService]\tRun as a long running service."
       + "\n\t[-sortTopNodes]"
-      + "\n\t[-hotBlockTimeInterval]\tprefer to move cold blocks."
       + "\tSort datanodes based on the utilization so "
-      + "that highly utilized datanodes get scheduled first.";
+      + "that highly utilized datanodes get scheduled first."
+      + "\n\t[-hotBlockTimeInterval]\tprefer to move cold blocks.";
 
   @VisibleForTesting
   private static volatile boolean serviceRunning = false;

hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/HDFSCommands.md

@@ -292,6 +292,8 @@ Usage:
               [-idleiterations <idleiterations>]
               [-runDuringUpgrade]
               [-asService]
+              [-sortTopNodes]
+              [-hotBlockTimeInterval <specified time interval>]
 
 | COMMAND\_OPTION | Description |
 |:---- |:---- |
@@ -304,6 +306,7 @@ Usage:
 | `-idleiterations` \<iterations\> | Maximum number of idle iterations before exit. This overwrites the default idleiterations(5). |
 | `-runDuringUpgrade` | Whether to run the balancer during an ongoing HDFS upgrade. This is usually not desired since it will not affect used space on over-utilized machines. |
 | `-asService` | Run Balancer as a long running service. |
+| `-sortTopNodes` | Sort datanodes based on the utilization so that highly utilized datanodes get scheduled first. |
 | `-hotBlockTimeInterval` | Prefer moving cold blocks i.e blocks associated with files accessed or modified before the specified time interval. |
 | `-h`\|`--help` | Display the tool usage and help information and exit. |