How to disable the requirement of ssh

Dear colleagues,

As we know, hadoop uses ssh to connect other nodes. It is a little
inconvenient, because it requires me type the password for each nodes.

I find ssh can disable the password requirement for localhost in
"Hadoop quick start", is there a way to disable the password
requirement of ssh for other nodes?

Thanks!

Best wishes,
Bin YANG



--
Bin YANG
Department of Computer Science and Engineering
Fudan University
Shanghai, P. R. China
EMail: yangbinisme82@...