photos of Leon Trotsky

what is MapReduce Algorithm

MapReduce is a programming model and an associated implementation for processing and generating big data sets with a parallel, distributed algorithm on a cluster

• "Map" step: Each worker node applies the "map()" function to the local data, and writes the output to a temporary storage. A master node ensures that only one copy of redundant input data is processed.
• "Shuffle" step: Worker nodes redistribute data based on the output keys (produced by the "map()" function), such that all data belonging to one key is located on the same worker node.
• "Reduce" step: Worker nodes now process each group of output data, per key, in parallel.

• Implementations of MapReduce[edit]

  • Apache Hadoop
  • Couchdb
  • Infinispan
  • Riak
  • DiscoProject

credit goes to wikepedia

photos of George Washington - One Of the Founding Fathers Of the United States Of America

photos of Benjamin Franklin - One of the founding fathers of United States Of America

 Eat not to dullness 

Drink not to elevation

How do u parse Calendar in ShellScript

#!/bin/sh
cal 2 1997
output=$(cal 2 1997);

while read line;do
echo "Printing Each Line";
echo "$line";
word=$(echo $line | tr " " "\n");
set $word;
echo "Printing Each Day In Row";
echo $1
echo $2
echo $3
echo $4
echo $5
echo $6
echo $7
done<<<"$output";

what is /etc/passwd in unix?

whenever we create password for the user in unix ,unix stores password in a file in a location /etc/passwd

etc is the directory
passwd is the name of file

what is ulimit in unix?

ulimit contains a value which signifies the largest file that can be created by the user in the file system

default ulimit for ubuntu is unlimited