distributed tsung: {post request: read contents from file} whether file needs to be present on all clients?

I have 4 systems on which i have erlang and tsung installed.
am trying to load-test with post requests where contents are read from file.
on the controller i had file /home/tsung/files/testfile.txt (sized about 50MB) but not on all clients.
test still passed, the file is never copied to client.

Not sure if controller passes around the contents (50 MB) around for each client, consuming much of bandwidth.

Would it help me to save some bandwidth for actual test if i copy all files on all nodes?
Can controller also be used as client to generate load along with rest of clients?

Solution

No, data files are not need to be present on all nodes, the file is only on the controller. You can't save bandwith by put the files on nodes. Yes the controller can be used as client too with use_controller_vm="true" in scenario as describe in the doc https://tsung.readthedocs.org/en/latest/conf-client-server.html?highlight=use_controller_vm