Re: [Testbed-admins] Event system questions

["Manuel Requena" <mrequena@cttc.es>]

> > When I swap in or modify an experiment, the events are not
> > scheduled. I know it because I launch some "tcpdump" in the
> > nodes. Are there some log files to see when the events are
> > scheduled? I don't see my UDP packets (every 5ms during 20 secs with
> > a length of 500 bytes). But in the first 2 secs and every 10ms, I
> > see some UDP packets (not mine ones) of 62 bytes (ethernet length)
> > between the 2 nodes. What are these packets?
> 
> Hi. The notion of when an experiment has officially started might not
> be obvious; it is when the experiment state changes to active (you can
> see that in the web interface). This is also when the email that says
> the experiment has swapped, is sent.
> 

I receive the email, the experiment is active in the web interface and even
I wait long minutes, much more minutes that the experiment should be
running... but events are not scheduled (i.e. my UDP packets are not sent).

> > - How the nodes are synchronized? What precision you can get?
> >   "Emulab nodes are kept in sync with NTP", but where the NTP server
> >   is? boss? ops? When nodes boot I get the following:
> 
> The ntp server is typically ops.
> 
> In fact, what testbed are we talking about?
> 

All my doubts are related to our "Emulab" testbed. Currently, I'm testing
your Emulab software (Version 5.0) in our testbed in order to use it as the
management and control software.

In our EXTREME Testbed
(http://www.cttc.es/en/projects/testbeds/project/EXTREME.jsp), I have
installed ops and boss and I have added 4 nodes to our new "Emulab" Testbed.
For these nodes, I use the FC6+FBSD62 image from your website.
 
> > "Starting ntpd.
> >
> > Oct  1 07:29:09 tbsdelay0 ntpdate[1021]: no server suitable for
> > synchronization found
> >
> > WARNING: ntpdate failed!"
> >
> > So I guess my nodes are not synchronized. What I have to modify?
> > Nodes configuration? Some tables? Emulab software installation?
> 
> There is supposed to be a CNAME in the local named file that directs
> ntp.xxx.yyy to the local ops node. Do you have that CNAME?

Yes, I have the CNAME. But there is no NTP server in ops. 

I have added ntpd_enable="YES" to /etc/rc.conf in ops. I have also created a
configuration file (/etc/ntp.conf) for the NTP server in ops. Should it be
created by the Emulab soft? How? 

> > - In the "at" command, how the "0.0 time" is specified? When I "Replay
> > events", I guess that the "0.0 time" is more or less when I select the
> > option in the web interface. Could I specify the "0.0 time" at
> > 13:15, for
> > example, and the rest of the "+XX" events are scheduled accordingly?
> 
> No, there is no way to do this. It is probably not a difficult change
> to the parser though, if you wanted to give it a try and send us
> patches.
> 

I'll give a try and if I get something interesting I'll send you. 

Manuel