cdh4.3，Exception from the logs ,after ./start-dfs.sh ,datanode and namenode start fail

Question

here is the logs from hadoop-datanode-...log:

FATAL org.apache.hadoop.hdfs.server.datanode.DataNode: Initialization failed for block pool Block pool BP-1421227885-192.168.2.14-1371135284949 (storage id DS-30209445-192.168.2.41-50010-1371109358645) service to /192.168.2.8:8020 org.apache.hadoop.ipc.RemoteException(org.apache.hadoop.hdfs.server.protocol.DisallowedDatanodeException): Datanode denied communication with namenode: DatanodeRegistration(0.0.0.0, storageID=DS-30209445-192.168.2.41-50010-1371109358645, infoPort=50075, ipcPort=50020, storageInfo=lv=-40;cid=CID-f16e4a3e-4776-4893-9f43-b04d8dc651c9;nsid=1710848135;c=0) at org.apache.hadoop.hdfs.server.blockmanagement.DatanodeManager.registerDatanode(DatanodeManager.java:648) at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.registerDatanode(FSNamesystem.java:3498)

my mistake:namenode can start,datanode can't start

Answer 1

I saw this once too, the namenode server needs to do a reverse lookup request , so an nslookup 192.168.2.41 should return a name, it doesn't so 0.0.0.0 is also recorded

You don't need to hardcode address into /etc/hosts if you have dns working correctly (i.e. the in-addr.arpa file matches the entries in domain file) But if you don't have dns then you need to help hadoop out.