Posts in "Hadoop"

Hadoop Architecture

Apache Hadoop is a java based open source software. Basically, it’s a framework which is used to execute batch processing jobs on huge clusters. It is designed so that it can be scaled from a single server to hundreds of thousands of nodes in the cluster, with a high extent of fault-tolerance. Rather than relying… Continue reading

Format aborted in /app/hadoop/tmp/dfs/name

While startng the Hadoop i was just trying to format the filesystem. For that i have executed below command. bin/hadoop namenode -format But i am getting below error while doing this. Could you please let me know what could be the reason behind this. Warning: $HADOOP_HOME is deprecated. 13/08/10 13:52:56 INFO namenode.NameNode: STARTUP_MSG: /************************************************************ STARTUP_MSG:… Continue reading

Hadoop Interview Question

What is the difference between and in Hadoop   There are different scripts in bin dir in Hadoop which is used to launch Hadoop DFS and Hadoop Map/Reduce Daemons. – Starts the Hadoop DFS daemons (Namenode and Datanodes) – Stops the Hadoop DFS daemons (Namenode and Datanodes) – Starts all Hadoop daemons (Namenode, datanodes,… Continue reading