If you run your business out of multiple data centers and have a large volume of data collected, you may want to consider setting up a Hadoop cluster in each data center rather than sending all your collected data back to a single data center. There may be regulatory implications regarding data crossing certain geographic boundaries. Chances are there is somebody in your company who knows much more about compliance than you or I, so seek them out before you start copying data across borders. Of course, not collating your data will make it more difficult to analyze it, as you can't just run one MapReduce job against all the data. Instead, you would have to run parallel jobs and then combine the results in a second pass. Adjusting your data processing procedures is better than potentially breaking the law. Be sure to do your homework.

Pulling all your data into a single cluster may also be more than your networking can handle. Depending on how your data...