Is no of block equal no of i p split no of container no of mapper

Question

Can someone tell me if the following statement is true?

 no of block  == no of i/p split ==  no of container == no of mapper

Answer 1

Split size is approximately equal to block size. InputSplit is user defined and the user can control split size based on the size of data in MapReduce program.

The number of map tasks is equal to the number of InputSplits. Initially ... InputFormat is used to define how these input files are split and read.

Container size depends on how much memory your program would require in general.