perfSONAR User Q&A and Other Discussion

[Pete Siemsen <>]

We have a perfSONAR server that is directly connected to a router. The router reports that the "Output drops" counter is going up on the interface that connects to the perfSONAR server. We graph output drops on all interfaces, so I have a nice graph that shows that the drops occur in regular spurts. So, some test that runs regularly causes the drops. Like, every ~20 minutes, there's a spurt of 2000 output drops.

There are 18 tests defined on the server. I want to identify the one that is causing the drops.

I can monitor the interface on the router, and see the "output drops" counter bump up once in a while. I could wait for a spurt, then identify the test that is running "right now". To identify the test running right now, I could do a "top" command and see the "iperf3" or "java" process that is consuming the most CPU. I also see several bwctl processes, each of which shows the remote site name/IP.

This is almost enough, but I feel like I don't have my mind right :-) What's the clueful way to approach this problem?

-- Pete