Let us explore details about how to list the commands and get the help or usage for given command. Even though we can run commands from almost all the nodes in the clusters, we should only use Gateway to run HDFS Commands. First we need to make sure designated Gateway server is Gateway for HDFS …
As part of this topic, we will build the jar file and run as the jar file For building the jar file we typically use a tool called SBT SBT stands for a simple build tool Scala applications can be compiled in many other ways but SBT is the most popular one Set up SBT Go …
Development Cycle – Compile source code to jar using SBT Read More »
As part of this section we will get into all important HDFS commands. Getting list of commands and help Creating directories and changing ownership Managing files and file permissions Controlling access using ACLs Overriding Properties HDFS usage and Metadata Commands Creating Snapshots Using CLI for administration We are deliberately not sharing command snippets here for …
Let us see tuples in detail A tuple is another data structure in Scala It can hold heterogeneous elements Syntax for tuple val t = (1, “Hello World”) Another syntax for tuple val t: (Int, String) = (1, “Hello World”) Tuple has a handful of methods Elements of tuples can be accessed using _ notation (t._1 will return 1 and t._2 return Hello …
As part of this topic, we will explore Basic I/O operations Read data from files Convert into collection Perform collection operation to preview the data Run map-reduce operations Reading data from files To read files from a file system in scala there is a package called scala.io In scala.io we have a package named Source which …
Basic I/O Operations and using Scala Collections APIs Read More »
As highlighted earlier replication will cover all system failures and redundant networking will cover cable and network card failures. But it will not cover the rack maintenance or network switch failures. Rack is nothing but container where we place multiple servers in it. Also replication can only cover n-1 nodes in a m node cluster …
