time variable throttling rsync traffic

[Andrew Gideon]

On Tue, 15 Sep 2009 12:11:03 -0400, Eric S. Johansson wrote:

> run rsync till a given time deadline, killing off the original program
> instance and then restart with a new bandwidth limit.  I would probably
> use a small program invoking rsync and then sending a signal when "it's
> Time" then starting a new rsync run.

I'd recommend that you use what someone else has suggested: the --rsh 
option to invoke some utility which uses SSH but which adds throttling.  
This would give you much more flexibility in testing, including the 
ability (for example) to reread a configuration file upon receipt of a 
USR1 signal.

No restarts of rsync necessary, therefore, to change the bw consumption.

It can also potentially be extended in other directions.  For one crazy 
example, the utility (or some other utility that modifies the first 
utilities configuration) could listen on a port for messages from - 
presumably - the receiving server.  That would be a way for the receiving 
server to tell the sender what bandwidth to consume.

I'm not clear that this is an improvement over withholding ACKs, mind 
you, but at least it is a possibility with which you can experiment.

	- Andrew