[tg] TG

[Fernando Lemos (QRA)]

Hello... thanks for the help.

The problem of creating the log file is solved now. I make the server wait for a fixed time now, and when it stops, I can see the log file.

Now, the problem is how to synchronize the two machines.

I don't have access to the NTP servers on my testbed, so I could only have the NTP daemon installed, but it would not synchronize the machines for me. 

If they are, let's say, about 1 sec. different time from each other, then, when I compare the log on the client side, with the log on the server side, the values I will find for average delay are going to be wrong. So, is there a way to solve this problem? Is it possible, if you have a closed environment (testbed), and you need simple to synchronize the clocks of generator and sink so that when you examine the log files you get really the delay from the network?

Thanks,

Fernando.



-----Original Message-----
From: Barbara Denny [mailto:denny@isi.edu]
Sent: den 28 februari 2002 00:21
To: Fernando Lemos (QRA)
Cc: 'tg@postel.org'
Subject: Re: [tg] TG


NTP does require access to time keeping devices.  If you don't plan to be
install them, and aren't connected to the net  to access the other servers, then you
can't use NTP.

I am not sure I believe that you had no log files.  As long as the client exited, a log
file would have been created  Since your server script used the wait command, the
log file might not have been "created" yet.  It all depends on the buffering on unix
regarding what you see. Since you did not tell TG to end on the server side, it is still
waiting.  You can use "kill -TERM " with the TGrocessid to cause TG to be killed,
and the buffers to be flushed and the log file to be closed.  If you want the buffers
to be flushed while TG is running then you need to use the -f option (see
the manual).  If you are still trying to run server and client scripts on the same
machine, make sure you give different log file names.

barbara

> I have got the libraries of TG for linux. Now I am trying to make my first test.
> There are two problems.
>
> First, I wasn't able to run NTP, cause from what I have read, NTP will synchronize my computer with some server, but my testbed has no Internet access! What I would like is simple synchronize this two Linux boxes with each other, but I think I can't do it with NTP, can I?
>
> the second is that when I tried to run TG I did:
>
> tg -f -i spec1 -o out
>
> where spec1 is the specification file for client / server in accordance with the documentation, or the examples.
>
> I expected it to create out file for me (log file) but after the client finishes its work, the server is still on wait state, and no log files were generated at all! What am I doing wrong?
>
> Thanks, Fernando.
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