mapreduce over hbase table

[Rajeshkumar J]

Hi,

   I am running a mapreduce job over hbase table. I went through some blogs
and in that it is mentioned that data locality will be achieved for this
job other than some cases like region reassignment and others. When I run
mapreduce job over hbase table it takes each region as input for each
mapper. My question is how this job knows which region exists where? can
anyone explain this flow

Thanks