Hadoop3.x DataNode工作机制-尚硅谷资料

DN 向 NN 汇报当前解读信息的时间间隔，默认 6 小时；

<property>

    <name>dfs.blockreport.intervalMsec</name>

    <value>21600000</value>

    <description>Determines block reporting interval in 

milliseconds.</description>

</property>

DN 扫描自己节点块信息列表的时间，默认 6 小时

<property>

    <name>dfs.datanode.directoryscan.interval</name>

    <value>21600s</value>

    <description>Interval in seconds for Datanode to scan data

directories and reconcile the difference between blocks in memory and on 

the disk.

    Support multiple time unit suffix(case insensitive), as described

    in dfs.heartbeat.interval.

</description>

</property>

<property>

 <name>dfs.namenode.heartbeat.recheck-interval</name>

 <value>300000</value>

</property>

<property>

 <name>dfs.heartbeat.interval</name>

 <value>3</value>

</property>