perfSONAR User Q&A and Other Discussion

[Michael Reece <>]

Thank you for the responses, I've been off for a while. I sort of figured there was nothing I could do about the negative latency value itself because of the proximity of the nodes. I also understand that the latency isn't extremely accurate (perhaps not accurate at all?) and should be taken with grain of salt, but was told to have latency as one of metrics in the MaDDash. If the latency value is truly worthless at this range, maybe I will speak to my boss about removing it entirely.

I was more interested about the changing the color of the latency grid on MaDDash since the red makes it seem like there is major problem. Mark, I like your idea about changing the idea the result to an absolute value. Since the maddash.yaml doesn't contain the code where this occurs, where exactly do I make this change? Just not sure where the file would be located.

Thanks,

Mike Reece

On Thu, Mar 31, 2016 at 12:02 PM, Mark Feit <> wrote:

Gene Gerhiser writes:

Has the group looked at trying to implement PTP for these measurements.

We have, and the project’s statement on it is at the bottom of this page:  http://www.perfsonar.net/deploy/timekeeping-with-ntp

 We have 2 gps referenced PTP grand masters at our headquarters and one grandmaster at our LA facility.  Our switches have the ability to ask as transparent clocks. We do have some cheap (30 bucks or so) NIC cards that have PTP capability at the hardware layer and would be nice to use perfsonar to do these measurements as opposed to using something like ixcharriot.

Having the hardware support in place is great if you’ve got it.

I haven’t looked a great deal at what’s out there that can do these measurements on PTP-enabled systems.  Since the software that does the actual measurement work in perfSONAR is all other packages (iperf, OWAMP, etc.), is there anything open source that does those kinds of measurements?

—Mark