"HADOOP"FS.DEFAULTFS 9000 ports are not even on the outside.

"Problem phenomenon"

Three virtual machines, respectively, master,slave1,slave2, according to the online step configuration start Hadoop, is no datanode, from the Slave1 log, is due to the request was refuse dropped.

"Problem Solving"

In Master's host file IP mapping, master is mapped to 127.0.0.1 by default and needs to be commented out. (Host file location/etc/hosts)

127.0.0.1 localhost
#127.0.1.1 Master
10.0.10.229 slave1
10.0.10.228 Slave2

Note: This detail problem is easy to toss new people.

"HADOOP"FS.DEFAULTFS 9000 ports are not even on the outside.