Re: [ns] trace file for target flow

[Lloyd Wood <l.wood@eim.surrey.ac.uk>]

On Wed, 12 Jul 2000, Chengzhi Li wrote:

> I run a simulation for 45Mpbs links and more than 4000 VoIP
> flows in a 6 nodes topology over 60 min.  I only need to know 
> the performance about target flows (only 80 flows).  Although 
> I use trace-queue {n1 n2 file} to minimize the trace file, it 
> is still huge.  Is it possible to only store the entries related
> to target flows?

pipe your output through a pattern matcher that only matches lines
relating to target flows. This trick for compressing tracefiles is
well-known:

set f [open "|gzip -c > outputtrace.tr.gz" w]

you could instead write e.g. an awk script that only writes out lines
if e.g. $8, $9 and $10 match your requirements for a flow, or do that
with a perl WHILE (<OUTFILE>) loop and regexp of some sort...

set f [open "|awk -f strip.awk |gzip -c > outputtrace.tr.gz" w]

or

set f [open "|perl strip.pl |gzip -c > outputtrace.tr.gz" w]

L.

<L.Wood@surrey.ac.uk>PGP<http://www.ee.surrey.ac.uk/Personal/L.Wood/>