We've done that as a workaround for old legacy web apps where nobody had originally thought about failover (and had spread data updates all over the filesystem, intermingled with code... It was not fun to untangle).It works, but we've always supplemented it with regular full filesystem rsync's.

Our cases have also had very limited semantics (uploads that adds new files or modify files, but no deletions ever) that made things easier.

This seems a lot cleaner...

Though these days we mostly use glusterfs and most of those old apps have thankfully been retired or cleaned up.