Cannot assign requested address

Question

cat /etc/hosts

127.0.0.1 localhost.localdomain localhost
#192.168.0.105 UG-BLR-L030.example.com UG-BLR-L030 localhost 

192.168.0.105 UG-BLR-L030 localhost.localdomain localhost

# The following lines are desirable for IPv6 capable hosts
::1     ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters

core-site.xml

<configuration>
  <property>
    <name>hadoop.tmp.dir</name>
    <value>/usr/local/hadoop/hadoop-data</value>
    <description>A base for other temporary directories.</description>
  </property>

  <property>
    <name>fs.default.name</name>
    <value>hdfs://UG-BLR-L030:54310</value>
    <description>The name of the default file system.  A URI whose
    scheme and authority determine the FileSystem implementation.  The
    uri's scheme determines the config property (fs.SCHEME.impl) naming
    the FileSystem implementation class.  The uri's authority is used to
    determine the host, port, etc. for a filesystem.</description>
  </property>
</configuration>

Whenever I try to start hadoop with this command start-dfs.sh I get the following error :

2015-05-03 15:59:45,189 INFO org.apache.hadoop.hdfs.server.namenode.DecommissionManager: Interrupted Monitor
java.lang.InterruptedException: sleep interrupted
    at java.lang.Thread.sleep(Native Method)
    at org.apache.hadoop.hdfs.server.namenode.DecommissionManager$Monitor.run(DecommissionManager.java:65)
    at java.lang.Thread.run(Thread.java:745)
2015-05-03 15:59:45,195 ERROR org.apache.hadoop.hdfs.server.namenode.NameNode: java.net.BindException: Problem binding to UG-BLR-L030/192.168.0.105:54310 : Cannot assign requested address
    at org.apache.hadoop.ipc.Server.bind(Server.java:227)
    at org.apache.hadoop.ipc.Server$Listener.<init>(Server.java:301)
    at org.apache.hadoop.ipc.Server.<init>(Server.java:1483)
    at org.apache.hadoop.ipc.RPC$Server.<init>(RPC.java:545)
    at org.apache.hadoop.ipc.RPC.getServer(RPC.java:506)
    at org.apache.hadoop.hdfs.server.namenode.NameNode.initialize(NameNode.java:294)
    at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:496)
    at org.apache.hadoop.hdfs.server.namenode.NameNode.createNameNode(NameNode.java:1279)
    at org.apache.hadoop.hdfs.server.namenode.NameNode.main(NameNode.java:1288)
Caused by: java.net.BindException: Cannot assign requested address
    at sun.nio.ch.Net.bind0(Native Method)
    at sun.nio.ch.Net.bind(Net.java:463)
    at sun.nio.ch.Net.bind(Net.java:455)
    at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223)
    at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74)
    at org.apache.hadoop.ipc.Server.bind(Server.java:225)
    ... 8 more

2015-05-03 15:59:45,196 INFO org.apache.hadoop.hdfs.server.namenode.NameNode: SHUTDOWN_MSG: 
/************************************************************
SHUTDOWN_MSG: Shutting down NameNode at UG-BLR-L030/192.168.0.105
************************************************************/

ifconfig

eth0      Link encap:Ethernet  HWaddr f0:1f:af:4a:6b:fa  
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:340842 errors:0 dropped:0 overruns:0 frame:0
          TX packets:197054 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:410705701 (410.7 MB)  TX bytes:18456910 (18.4 MB)
          Interrupt:20 Memory:f7e00000-f7e20000 

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:1085723 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1085723 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:136152053 (136.1 MB)  TX bytes:136152053 (136.1 MB)

wlan0     Link encap:Ethernet  HWaddr 0c:8b:fd:1d:14:ba  
          inet addr:192.168.0.105  Bcast:192.168.0.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:873934 errors:0 dropped:0 overruns:0 frame:0
          TX packets:630943 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:919721448 (919.7 MB)  TX bytes:92919940 (92.9 MB)

Error:

ERROR org.apache.hadoop.hdfs.server.namenode.NameNode: java.net.BindException: Problem binding to UG-BLR-L030/192.168.0.105:54310 : Cannot assign requested address

Why does hadoop try to connect to UG-BLR-L030/192.168.0.105:54310 instead of UG-BLR-L030:54310 or 192.168.0.105:54310

Answer 1

I managed to get this to work by editing my hosts file to look like this :

127.0.0.1 UG-BLR-L030.example.com UG-BLR-L030 localhost
192.168.0.105 UG-BLR-L030.example.com UG-BLR-L030