perfSONAR User Q&A and Other Discussion

[Brian Candler <>]

I have a number of existing hosts in a network and I want to be able to 
run performance tests between those hosts. Those hosts are performing 
other functions and I don't want to reinstall them with the perfsonar 
toolkit, nor dedicate them to that function.

As far as I understand, the underlying tests (iperf, iperf3, nuttcp) are 
managed by bwctld.

So my questions are:

Q1: is it possible/reasonable/recommended to set up one central 
management node running perfsonar toolkit, and then install just 
bwctl-server and iperf and/or owamp on the other nodes?

(I am even thinking of things like remote OSX workstations)

I am testing toolkit 3.4.1 inside a VM, with two other hosts just 
running bwctl-server and iperf, and it appears to work; but I wonder if 
there are pitfalls I should be aware of.

Q2: is it possible to get perfsonar to schedule tests between pairs of 
remote hosts?

bwctl allows third-party testing, i.e. you can specify a remote client 
and a remote server.

In the GUI under "Configure Tests" you can select the local interface 
and add "test members" hosts. It's not entirely clear, but I presume the 
tests all run between your host and the members, not between the members 
(which would be an N^2 explosion). Is that correct?

In my test with two other hosts, the results page shows only

src = <remote host>  dst = <perfsonar host>

i.e. no graphs between <remote1> and <remote2>

In the FAQ, I see a mention in passing of a "mesh configuration", but 
googling for that term turns up a google-code project which seems to be 
between a mesh of perfsonar hosts.

Q3: In the main results page, I see a throughput figure src-dst, but 
dst-src is "n/a". Is it only measuring incoming traffic then? Is it 
possible to get measurement in the opposite direction as well?

I don't see how to configure this when I edit the configuration of a 
throughput test.

Q4: Probably a silly question, but when I view a throughput graph, I see 
a large graph at the top and a small graph at the bottom (with no 
vertical axis legend). What's the bottom graph showing?

Q5: I have scheduled ping tests, but I can't see the results anywhere. 
The main page shows n/a for packet loss and latency. Is there anything 
which the remote hosts need for this to work?

I haven't installed owamp on the remote hosts because it's not in the 
Ubuntu repositories; does the ping test make use of owamp? (Even though 
"one-way delay test" is a separate type of test)

Q6: Final supplementary question.

Is it possible to prevent a perfsonar instance registering itself in the 
global 'directory of services'? Is not joining any communities enough to 
stop this happening?

Also, If you have a private collection of perfsonar instances, can you 
run your own lookup service and have them join that instead?

That's enough questions for now... thanks in advance for your attention!

Regards,

Brian Candler.