Is it possible for the JobTracker to schedule using a virtual TaskTracker?

[Todd Hoff <to...@gmail.com>]

What I'd like to do is schedule part of a job using another job system
to service mapper or reducer requests. It would be possible to this, I
think, using a TestTracker as an intermediary, but that would be a of
waste of resources. It would be better if the JobTracker could just
schedule onto the other system directly. After poking around looking
for how this might be done, I didn't find anything. Any ideas? Thanks.