distcp.map.bandwidth.mb exists in distcp-defaults.xml config file, but it is not honored even when it is . Current code always overwrites it with either default value (java const) or with -bandwidth command line option.
The expected behavior (at least how I would expect it) is to honor the value set in distcp-defaults.xml unless user explicitly specify -bandwidth command line flag. If there is no value set in .xml file or as a command line flag, then the constant from java code should be used.
Additionally, I would expect that we also try to get values from distcp-site.xml, similar to other hadoop systems.