hadoop3.1.4参数默认配置项

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<configuration>

<property>
  <name>hadoop.hdfs.configuration.version</name>
  <value>1</value>
  <description>version of this configuration file</description>
</property>

<property>
  <name>dfs.namenode.rpc-address</name>
  <value></value>
  <description>
    RPC address that handles all clients requests. In the case of HA/Federation where multiple namenodes exist,
    the name service id is added to the name e.g. dfs.namenode.rpc-address.ns1
    dfs.namenode.rpc-address.EXAMPLENAMESERVICE
    The value of this property will take the form of nn-host1:rpc-port. The NameNode's default RPC port is 8020.
  </description>
</property>

<property>
  <name>dfs.namenode.rpc-bind-host</name>
  <value></value>
  <description>
    The actual address the RPC server will bind to. If this optional address is
    set, it overrides only the hostname portion of dfs.namenode.rpc-address.
    It can also be specified per name node or name service for HA/Federation.
    This is useful for making the name node listen on all interfaces by
    setting it to 0.0.0.0.
  </description>
</property>

<property>
  <name>dfs.namenode.servicerpc-address</name>
  <value></value>
  <description>
    RPC address for HDFS Services communication. BackupNode, Datanodes and all other services should be
    connecting to this address if it is configured. In the case of HA/Federation where multiple namenodes exist,
    the name service id is added to the name e.g. dfs.namenode.servicerpc-address.ns1
    dfs.namenode.rpc-address.EXAMPLENAMESERVICE
    The value of this property will take the form of nn-host1:rpc-port.
    If the value of this property is unset the value of dfs.namenode.rpc-address will be used as the default.
  </description>
</property>

<property>
  <name>dfs.namenode.servicerpc-bind-host</name>
  <value></value>
  <description>
    The actual address the service RPC server will bind to. If this optional address is
    set, it overrides only the hostname portion of dfs.namenode.servicerpc-address.
    It can also be specified per name node or name service for HA/Federation.
    This is useful for making the name node listen on all interfaces by
    setting it to 0.0.0.0.
  </description>
</property>

<property>
  <name>dfs.namenode.lifeline.rpc-address</name>
  <value></value>
  <description>
    NameNode RPC lifeline address.  This is an optional separate RPC address
    that can be used to isolate health checks and liveness to protect against
    resource exhaustion in the main RPC handler pool.  In the case of
    HA/Federation where multiple NameNodes exist, the name service ID is added
    to the name e.g. dfs.namenode.lifeline.rpc-address.ns1.  The value of this
    property will take the form of nn-host1:rpc-port.  If this property is not
    defined, then the NameNode will not start a lifeline RPC server.  By
    default, the property is not defined.
  </description>
</property>

<property>
  <name>dfs.namenode.lifeline.rpc-bind-host</name>
  <value></value>
  <description>
    The actual address the lifeline RPC server will bind to.  If this optional
    address is set, it overrides only the hostname portion of
    dfs.namenode.lifeline.rpc-address.  It can also be specified per name node
    or name service for HA/Federation.  This is useful for making the name node
    listen on all interfaces by setting it to 0.0.0.0.
  </description>
</property>

<property>
  <name>dfs.namenode.secondary.http-address</name>
  <value>0.0.0.0:9868</value>
  <description>
    The secondary namenode http server address and port.
  </description>
</property>

<property>
  <name>dfs.namenode.secondary.https-address</name>
  <value>0.0.0.0:9869</value>
  <description>
    The secondary namenode HTTPS server address and port.
  </description>
</property>

<property>
  <name>dfs.datanode.address</name>
  <value>0.0.0.0:9866</value>
  <description>
    The datanode server address and port for data transfer.
  </description>
</property>

<property>
  <name>dfs.datanode.http.address</name>
  <value>0.0.0.0:9864</value>
  <description>
    The datanode http server address and port.
  </description>
</property>

<property>
  <name>dfs.datanode.ipc.address</name>
  <value>0.0.0.0:9867</value>
  <description>
    The datanode ipc server address and port.
  </description>
</property>

<property>
  <name>dfs.datanode.http.internal-proxy.port</name>
  <value>0</value>
  <description>
    The datanode's internal web proxy port.
    By default it selects a random port available in runtime.
  </description>
</property>

<property>
  <name>dfs.datanode.handler.count</name>
  <value>10</value>
  <description>The number of server threads for the datanode.</description>
</property>

<property>
  <name>dfs.namenode.http-address</name>
  <value>0.0.0.0:9870</value>
  <description>
    The address and the base port where the dfs namenode web ui will listen on.
  </description>
</property>

<property>
  <name>dfs.namenode.http-bind-host</name>
  <value></value>
  <description>
    The actual address the HTTP server will bind to. If this optional address
    is set, it overrides only the hostname portion of dfs.namenode.http-address.
    It can also be specified per name node or name service for HA/Federation.
    This is useful for making the name node HTTP server listen on all
    interfaces by setting it to 0.0.0.0.
  </description>
</property>

<property>
  <name>dfs.namenode.heartbeat.recheck-interval</name>
  <value>300000</value>
  <description>
    This time decides the interval to check for expired datanodes.
    With this value and dfs.heartbeat.interval, the interval of
    deciding the datanode is stale or not is also calculated.
    The unit of this configuration is millisecond.
  </description>
</property>

<property>
  <name>dfs.http.policy</name>
  <value>HTTP_ONLY</value>
  <description>Decide if HTTPS(SSL) is supported on HDFS
    This configures the HTTP endpoint for HDFS daemons:
      The following values are supported:
      - HTTP_ONLY : Service is provided only on http
      - HTTPS_ONLY : Service is provided only on https
      - HTTP_AND_HTTPS : Service is provided both on http and https
  </description>
</property>

<property>
  <name>dfs.client.https.need-auth</name>
  <value>false</value>
  <description>Whether SSL client certificate authentication is required
  </description>
</property>

<property>
  <name>dfs.client.cached.conn.retry</name>
  <value>3</value>
  <description>The number of times the HDFS client will pull a socket from the
   cache.  Once this number is exceeded, the client will try to create a new
   socket.
  </description>
</property>


<property>
  <name>dfs.https.server.keystore.resource</name>
  <value>ssl-server.xml</value>
  <description>Resource file from which ssl server keystore
  information will be extracted
  </description>
</property>

<property>
  <name>dfs