I'm not sure if this is related, but I'm seeing some errors in hadoop-hadoop-namenode-hadoop-master.log
2015-09-23 19:56:27,798 WARN org.apache.hadoop.hdfs.server.blockmanagement.DatanodeManager: Unresolved datanode registration: hostname cannot be resolved (ip=192.168.51.1, hostname=192.168.51.1) 2015-09-23 19:56:27,800 INFO org.apache.hadoop.ipc.Server: IPC Server handler 6 on 54310, call org.apache.hadoop.hdfs.server.protocol.DatanodeProtocol.registerDatanode from 192.168.51.1:54554 Call#373 Retry#0 org.apache.hadoop.hdfs.server.protocol.DisallowedDatanodeException: Datanode denied communication with namenode because hostname cannot be resolved (ip=192.168.51.1, hostname=192.168.51.1): DatanodeRegistration(0.0.0.0:50010, datanodeUuid=8a5d90c8-b909-46d3-80ec-2a3a8f1fe904, infoPort=50075, infoSecurePort=0, ipcPort=50020, storageInfo=lv=-56;cid=CID-bc60d031-11b0-4eb5-8f9b-da0f8a069ea6;nsid=1223814533;c=0) at org.apache.hadoop.hdfs.server.blockmanagement.DatanodeManager.registerDatanode(DatanodeManager.java:863) at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.registerDatanode(FSNamesystem.java:4529) at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.registerDatanode(NameNodeRpcServer.java:1279) at org.apache.hadoop.hdfs.protocolPB.DatanodeProtocolServerSideTranslatorPB.registerDatanode(DatanodeProtocolServerSideTranslatorPB.java:95) at org.apache.hadoop.hdfs.protocol.proto.DatanodeProtocolProtos$DatanodeProtocolService$2.callBlockingMethod(DatanodeProtocolProtos.java:28539) at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:616) at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:969) at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2049) at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2045) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAs(Subject.java:422) at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1657) at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2043) I don't have a server with the IP 192.168.51.1 and I don't think I'm referencing that anywhere. Is there some reason that it's trying to add that host as a namenode? On Wed, Sep 23, 2015 at 1:58 PM, Daniel Watrous <dwmaill...@gmail.com> wrote: > Hi, > > I have deployed a multi-node cluster with one master and two data nodes. > Here's what jps shows: > > hadoop@hadoop-master:~$ jps > 24641 SecondaryNameNode > 24435 DataNode > 24261 NameNode > 24791 ResourceManager > 25483 Jps > 24940 NodeManager > > hadoop@hadoop-data1:~$ jps > 15556 DataNode > 16198 NodeManager > 16399 Jps > > hadoop@hadoop-data2:~$ jps > 16418 Jps > 15575 DataNode > 16216 NodeManager > > When I open the web console, I only see one node running: > http://screencast.com/t/E6yehRvUbt > > Where are the other two nodes? Why don't they show up? > > Next I run one of the example scripts > > hadoop@hadoop-master:~$ hadoop jar > /usr/local/hadoop/share/hadoop/mapreduce/hadoop-mapreduce-examples-2.7.1.jar > pi 10 30 > Number of Maps = 10 > Samples per Map = 30 > Wrote input for Map #0 > Wrote input for Map #1 > ... > Job Finished in 2.956 seconds > Estimated value of Pi is 3.14146666666666666667 > > I can't see this anywhere in the web interface. I thought it might show in > the Applications sub-menu. Should I be able to see this? It appears to run > successfully. > > Daniel >