I'm getting

USAGE LIMIT EXCEEDED

on a suitelet I wrote that does batch invoice processing. I was able to avert the error for a print button project that prints one invoice, but for many, many invoices, there's just no way a suitelet will work. I'm assuming there's no onRequest entry point for a map reduce script. Should I initiate the MR script with a task.MapReduceScriptTask object within the suitelet?