Can we configure more than one active name node to serve a different portion of name space?

What does mean it.
This is what written on Hortonworks site.
there are multiple NameNodes working independently. Each NameNode serves a unique portion of the namespace (namespaceID) and manages a unique set of blocks (blockpoolID). The clusterID ties the whole cluster together as a single logical unit. It’s the same across all nodes in the cluster.

Yes, there is concept of HDFS Federation where you can have multiple active namenodes managing different namespaces. But it is used only in very large cluster.

Hi ,
Thanks for the information. Could you give me some link or any doc where the main configuration changes is written.

nn1,nn2 generally we write here active and standby name node so what can we change here in the case of HDFS federation? we have write here all namenode id like nn1,nn2,nn3,nn4

i just want to know that main configuration changes in core-site.xml and hdfs-site.xml