I have a cluster set up rsync'ing large directory structures from a
master machine to child machines across a network. The directory gets
synchronized to all the child machines every 15 minutes very well.

However there is an application we would like to support that needs
much more immediate file replication.

This application touches certain files in the large directory structure
on the master machine. When those files are touched they need to be
copied to the other child machines as fast as possible.

Our engineers are working to add functionality to copy files to the
child machines using scp across the network.

I am wondering if rsync provides a facility whereby I can instruct it
that a certain file has changed and needs to be replicated immediately.

Because it would be a lot easier to tell rsync to replicate the file
rather than deal w/ scp

Please let me know if rsync or any other utilities I may consider have
any capabilities in this manner