While I was trying to poke around in hadoop environment I noticed that namenode wouldn’t start up. After doing some research I found that its the IPv6 issue. So I summarized steps I took to resolve the issue
We are starting the hadoop stack
we can see the name node seems like it did not start as we can see in jps list
first step is make sure you can ssh local machine (127.0.0.1)
I tried tee see port activity looks like entire hadoop stack is using Ip6. we can change this behavior by changing hadoop-env.sh file in conf directory
export HADOOP_OPTS=-Djava.net.preferIPv4Stack=true
stop all hadoop services and start hadoop stak