How to trigger rsync after file changes?

[Peter]

Hi,

what is the best way to trigger rsync after a file upload? 

verbose: I want users to upload files to Server A. If all upload is
done, it should rsync itself to another server. 

The upload is done via ftp and users don´t want to use rsync
themselves, so what I am missing now ist something that triggers rsync
if something changed.

An alternative would be to use cron, but not a good one for similar
reasons. 

Maybe someone got this problem before?


Thank you very much!

Peter