HDFS-11408. The config name of balance bandwidth is out of date. Contributed by Yiqun Lin.

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DFSClient.java

@@ -2233,7 +2233,7 @@ public class DFSClient implements java.io.Closeable, RemotePeerFactory,
 
   /**
    * Requests the namenode to tell all datanodes to use a new, non-persistent
-   * bandwidth value for dfs.balance.bandwidthPerSec.
+   * bandwidth value for dfs.datanode.balance.bandwidthPerSec.
    * See {@link ClientProtocol#setBalancerBandwidth(long)}
    * for more details.
    *

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DistributedFileSystem.java

@@ -1599,7 +1599,7 @@ public class DistributedFileSystem extends FileSystem {
 
   /**
    * Requests the namenode to tell all datanodes to use a new, non-persistent
-   * bandwidth value for dfs.balance.bandwidthPerSec.
+   * bandwidth value for dfs.datanode.balance.bandwidthPerSec.
    * The bandwidth parameter is the max number of bytes per second of network
    * bandwidth to be used by a datanode during balancing.
    *

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/ClientProtocol.java

@@ -938,7 +938,7 @@ public interface ClientProtocol {
 
   /**
    * Tell all datanodes to use a new, non-persistent bandwidth value for
-   * dfs.balance.bandwidthPerSec.
+   * dfs.datanode.balance.bandwidthPerSec.
    *
    * @param bandwidth Blanacer bandwidth in bytes per second for this datanode.
    * @throws IOException

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

@@ -114,7 +114,7 @@ import com.google.common.base.Preconditions;
  * defined in the default configuration file:
  * <pre>
  * <property>
- *   <name>dfs.balance.bandwidthPerSec</name>
+ *   <name>dfs.datanode.balance.bandwidthPerSec</name>
  *   <value>1048576</value>
  * <description>  Specifies the maximum bandwidth that each datanode 
  * can utilize for the balancing purpose in term of the number of bytes 

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

@@ -184,7 +184,7 @@ public class DatanodeDescriptor extends DatanodeInfo {
   private boolean forceRegistration = false;
 
   // A system administrator can tune the balancer bandwidth parameter
-  // (dfs.balance.bandwidthPerSec) dynamically by calling
+  // (dfs.datanode.balance.bandwidthPerSec) dynamically by calling
   // "dfsadmin -setBalanacerBandwidth <newbandwidth>", at which point the
   // following 'bandwidth' variable gets updated with the new value for each
   // node. Once the heartbeat command is issued to update the value on the

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

@@ -1738,7 +1738,7 @@ public class DatanodeManager {
 
   /**
    * Tell all datanodes to use a new, non-persistent bandwidth value for
-   * dfs.balance.bandwidthPerSec.
+   * dfs.datanode.balance.bandwidthPerSec.
    *
    * A system administrator can tune the balancer bandwidth parameter
    * (dfs.datanode.balance.bandwidthPerSec) dynamically by calling

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/protocol/BalancerBandwidthCommand.java

@@ -19,7 +19,7 @@ package org.apache.hadoop.hdfs.server.protocol;
 
 /*
  * A system administrator can tune the balancer bandwidth parameter
- * (dfs.balance.bandwidthPerSec) dynamically by calling
+ * (dfs.datanode.balance.bandwidthPerSec) dynamically by calling
  * "dfsadmin -setBalanacerBandwidth newbandwidth".
  * This class is to define the command which sends the new bandwidth value to
  * each datanode.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/DFSAdmin.java

@@ -1078,7 +1078,7 @@ public class DFSAdmin extends FsShell {
       "\tHDFS block balancing.\n\n" +
       "\t\t<bandwidth> is the maximum number of bytes per second\n" +
       "\t\tthat will be used by each datanode. This value overrides\n" +
-      "\t\tthe dfs.balance.bandwidthPerSec parameter.\n\n" +
+      "\t\tthe dfs.datanode.balance.bandwidthPerSec parameter.\n\n" +
       "\t\t--- NOTE: The new value is not persistent on the DataNode.---\n";
 
     String getBalancerBandwidth = "-getBalancerBandwidth <datanode_host:ipc_port>:\n" +

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

@@ -394,7 +394,7 @@ Usage:
 | `-printTopology` | Print a tree of the racks and their nodes as reported by the Namenode |
 | `-refreshNamenodes` datanodehost:port | For the given datanode, reloads the configuration files, stops serving the removed block-pools and starts serving new block-pools. |
 | `-deleteBlockPool` datanode-host:port blockpoolId [force] | If force is passed, block pool directory for the given blockpool id on the given datanode is deleted along with its contents, otherwise the directory is deleted only if it is empty. The command will fail if datanode is still serving the block pool. Refer to refreshNamenodes to shutdown a block pool service on a datanode. |
-| `-setBalancerBandwidth` \<bandwidth in bytes per second\> | Changes the network bandwidth used by each datanode during HDFS block balancing. \<bandwidth\> is the maximum number of bytes per second that will be used by each datanode. This value overrides the dfs.balance.bandwidthPerSec parameter. NOTE: The new value is not persistent on the DataNode. |
+| `-setBalancerBandwidth` \<bandwidth in bytes per second\> | Changes the network bandwidth used by each datanode during HDFS block balancing. \<bandwidth\> is the maximum number of bytes per second that will be used by each datanode. This value overrides the dfs.datanode.balance.bandwidthPerSec parameter. NOTE: The new value is not persistent on the DataNode. |
 | `-getBalancerBandwidth` \<datanode\_host:ipc\_port\> | Get the network bandwidth(in bytes per second) for the given datanode. This is the maximum network bandwidth used by the datanode during HDFS block balancing.|
 | `-fetchImage` \<local directory\> | Downloads the most recent fsimage from the NameNode and saves it in the specified local directory. |
 | `-allowSnapshot` \<snapshotDir\> | Allowing snapshots of a directory to be created. If the operation completes successfully, the directory becomes snapshottable. See the [HDFS Snapshot Documentation](./HdfsSnapshots.html) for more information. |