hdfs

The default Hadoop ports are as follows: (HTTP ports, they have WEB UI): Daemon Default Port Configuration Parameter ———————– ———— ———————————- Namenode 50070 dfs.http.address Datanodes 50075 dfs.datanode.http.address Secondarynamenode 50090 dfs.secondary.http.address Backup/Checkpoint node? 50105 dfs.backup.http.address Jobracker 50030 mapred.job.tracker.http.address Tasktrackers 50060 mapred.task.tracker.http.address Internally, Hadoop mostly uses Hadoop IPC, which stands for Inter Process Communicator, to communicate amongst … Read more

I was facing the issue of namenode not starting. I found a solution using following: first delete all contents from temporary folder: rm -Rf <tmp dir> (my was /usr/local/hadoop/tmp) format the namenode: bin/hadoop namenode -format start all processes again:bin/start-all.sh You may consider rolling back as well using checkpoint (if you had it enabled).