Creating MapFile.Reader instance in reducer setup

[Ondřej Klimpera]

Hello, I'm tring to use MapFile (stored on HDFS) in my reduce task, 
which processes some text data.

When I try to initialize MapFile.Reader in reducer configure() method, 
app throws NullPointerException, when the same approach is used for each 
reduce() method call with the same parameters, everything goes all right.

But creating instance of Reader for each reduce() call creates big slow 
down.

Do you have any idea what am I doing wrong.

Thanks
Ondrej Klimpera