Hadoop NoHostToRoute

If you get NoHostToRoute error message then chances are that reason could be one of the those which are mentioned here.

http://wiki.apache.org/hadoop/NoRouteToHost

Hadoop works on IP4 networks so if you have IP6 network then you have to disable it by following command

sudo sed -i 's/net.ipv6.bindv6only\ =\ 1/net.ipv6.bindv6only\ =\ 0/' \
/etc/sysctl.d/bindv6only.conf && sudo invoke-rc.d procps restart

 

Inside Hadoop 0.23 IP6 check is made inside , libexec/hadoop-config.sh file by following code.

 

# check if net.ipv6.bindv6only is set to 1
bindv6only=$(/sbin/sysctl -n net.ipv6.bindv6only 2> /dev/null)
if [ -n "$bindv6only" ] && [ "$bindv6only" -eq "1" ] && [ "$HADOOP_ALLOW_IPV6" != "yes" ]
then
  echo "Error: \"net.ipv6.bindv6only\" is set to 1 - Java networking could be broken"
  echo "For more info: http://wiki.apache.org/hadoop/HadoopIPv6"
  exit 1
fi

 

The following article in Hadoop wiki explains the Hadoop and IP6

http://wiki.apache.org/hadoop/HadoopIPv6