Null Pointer Exception on DIH with MySQL

[Aleksey Vorona]

We have Solr 3.6.1 running on Jetty (7.x) and using DIH to get data from 
the MySQL database. On one of the environment the import always fails 
with an exception: http://pastebin.com/tG28cHPe

It is a null pointer exception on connection being null. I've tested 
that I can connect from the Solr server to Mysql server via command line 
mysql client.

Does anybody knows anything about this exception and how to fix it?

I am not able to reproduce it on any other environment.

-- Aleksey