Clients should be able to submit jobs (not only pipelines)

[turicas]

For some kinds of processing we don't need to submit complete pipelines to the cluster. Currently it's not possible unless we use a hack (create a pipeline with two jobs: the one you want to be executed and a dummy one).
We just need something like a JobManager class, like PipelineManager, but simpler.

[fccoelho]

Very important. Then it would be very nice to create a simple decorator people could use to submit jobs, as many distributed processing libraries have: People could decorate functions they want to offload to a pipelinin queue for distributed processing. I have something similar in my Liveplots package: https://github.com/fccoelho/liveplots/blob/master/src/liveplots/xmlrpcserver.py

def enqueue(f):
    """Decorator that places the call on a queue"""
    def queued(self,*args,**kw):
        Q.put((f,(self,)+args))
    queued.__doc__ = f.__doc__
    queued.__name__ = f.__name__
    return queued

where Q is a Queue object.

Also a customized map/reduce (this could be lifted from other python map/reduce libraries) framework would see great adoption.

[turicas]

The initial idea for this issue is just to implement something that I can submit a Job object instead of an entire Pipeline object (which is a group of Job objects). So, for the first implementation, the worker should exist on brokers to this approach work properly.
In a next release, maybe, we can think of remote code execution (we need to be more careful if implement this). I think it's needed but not for now -- @fccoelho, can you please create an issue describing this feature?

[fccoelho]

Done!