In hadoop if we increase our data nodes means we want invest some money to purchase new hard ware is it right

[#1]

@Raviteja Bhagam

In short, yes, but remember the popularity of hadoop is the ability to work with low-end servers especially for the data nodes. you as well re-cycle you old hardware too :-)

What really matters is the disk JBOD and memory but YARN calculates by aggregating the cluster memory and uses that during allocation of tasks.

HTH