Q:

Does Datanode read configuration file from Namenode?

I am trying to find a quick and dirty answer for the following question:
Does datanode read configuration file from namenode?

A:

No, it does not. 
Only in the case where the namenode is on the same server and uses the configuration files from the same directory. This is usually the case when using the pseudo-distributed configuration. In a distributed fashion, the datanode is usually on a different machine and thus uses its own configuration files. No synchronization is happening on the Hadoop application level.

