Data Analysis Hadoop Configuration
Question :
What are the Data Analysis Hadoop Configuration? How Can We Check Whether Namenode Is Working? and how to restart?
Answer :
Core-site.xml and hdfs-site.xml are the two important Hadoop core configuration files. Core-site.xml file helps in informing Hadoop daemon where NameNode runs in the cluster. It has the configuration settings Hadoop core such as the I/O setting. Hdfs-site.xml file contains the configuration settings for HDFS daemon, the Secondary NameNode, the NameNode, as well as the DataNodes.
In order to check whether NameNode is working or not, the user should use the jps command. With the help of this, all running Hadoop daemon can be seen, and hence the user can easily identify whether NameNode daemon is running or not.
A password-less SSH in a fully distributed environment is needed because the cluster in a fully distributed environment is live as well as running, the communication is too frequent. The NodeManager as well as the DataNode should be capable of sending messages quickly to the master server.
SSH is commonly known as a secure socket shell or secure shell. It is a network protocol that gives users a secure way in order to access a computer over an unsecured network. It is a password-less secure communication where data pockets are sent throughout the slave. It is not only between slaves and masters. It is also between two hosts.
In order to move the current task to another node, the user should stop all the task trackers while decommissioning the nodes is in a Hadoop cluster.
References
Shah, A., & Padole, M. (2019). Apache Hadoop: A Guide for Cluster Configuration & Testing.
