Major Description
Increases or decreases the number of threads from the starting value (fetcher.threads.fetch) up to a maximum (fetcher.threads.maximum) to achieve a target bandwidth (fetcher.threads.bandwidth).
It seems to be able to keep within 10% of the target bandwidth even when large numbers of errors are found or when a number of large pages is run across.
To achieve more accurate tracking Nutch should keep track of protocol overhead as well as the volume of pages downloaded.