perfsonar development work

[Jochen Reinwand <>]

On Friday 10 August 2007 15:19, Nicolas Simar wrote:
> Seems that the current solution suggested to LHC is the one of an
> applicance. (Hades for the time being).
> But the T1 want the possibility to communicate with the T2-T3 and get
> themselves organised. So in a second phase, we need to ensure the
> capability to interface in a way or another with the T2s for OWD
> measurements. I hope this does help a little bit. You can talk wiht
> Loukik if you wish to get more info, he was at the meeting.
> They need mostly regular scheduled and a bit of on-demand.
>
> It seems that for the time being the appliance is the solution to work
> on, with some hooks to allow regular tests on other measurements points
> hosted by T2-T3. (but more in a second phase). I'll be able to know more
> when I'll be back as HAns and Marian who attended the meeting were on
> holiday (So didn't get much feedback)

This information is far than enough for planning the next steps!! This more 
or 
less means that we're going for solution 1. (see below), then over to 2., 
enabling on-demand. In the end we will reach something similar to 3., but not 
as "problematic" as I stated for solution 3.
I assume that the second phase will not happen in the next 4 months ;-)
This means we should have enough time to make some sort of release for T2-T3. 
As long as there will not be too much measurement points in T2 and T3 it will 
be possible to handle them. Since there are only a few on-demand 
measurements, there should also be no problem with running owampd in parallel 
to Hades. Nevertheless we will work on OWAMP Hades integration to implement 
on-demand measurements in the best way possible, because it is really worth 
the effort.

To sum up: Everything that is required will be possible using the Hades 
system 
(including OWAMP standard for on-demand measurements). From our side this 
means we know exactly what to do and how to do it. We can now start 
developing ;-)
The only thing missing is the exact time scheduling. But since all time 
consuming aspects are not to be done in the near future, no difficulties 
should arise here.

Find in the following the three points mentioned above for reference with 
some 
note:

> > 1. Only Hades is used in a fully managed service. No problem! Everythings
> > ready. You can have it tomorrow.
> >
> > 2. As before only full managed Hades service, but on-demand measurements
> > should be possible. For on-demand measurements we are planing to use the
> > OWAMP protocol. We are really sure, that this is the best solution since
> > OWAMP is an accepted standard and being compatible to it is much better
> > than developing something completely different. This can be achieved in
> > many different ways, but I don't want to bore you with technical details.
> > Would not be too much development work for us. A simple but perhaps even
> > sufficient workaround is to just start an OWAMP daemon on the Hades
> > machines and ignore the interference issues.
> >
> > 3. In the previous scenario Hades will not be installed on machines that
> > are not managed by us. Only we install and configure the machines. For
> > other (unmanaged) machines only on-demand is possible via OWAMP. If we
> > want to enable Hades for other machines (additionally to the machines
> > from the managed service) a lot of issues arise. For Example we have to
> > build some sort of installable software release. That's a lot of work!
> > Also Hades needs one(!) central server for managing all machines and for
> > the data collection. Access is necessary via SSH. If the machine does not
> > provide this, it cannot take part in the measurement network.

Point 3. is, of course, no problem, if the number of machines is not too 
high, 
the admins of the machines are cooperative (at least SSH access), and we have 
more time for working on this release. 

regards,
Jochen

-- 
Jochen Reinwand, DFN-Labor
Friedrich-Alexander-Universität Erlangen-Nürnberg
Regionales RechenZentrum Erlangen (RRZE)
Martensstraße 1, 91058 Erlangen, Germany
Tel. +49 9131 85-28689, -28800, Fax +49 9131 302941

www.win-labor.dfn.de