Added simple all-to-all UDP bandwidth test.

examples/udpbwtest.py

@@ -0,0 +1,101 @@
+#!/usr/bin/python
+
+"""
+Create a tree network and run udpbwtest.c on it, attempting to
+saturate global bandwidth by sending constant all-to-all
+udp traffic. This should be something of a stress test.
+
+We should also make a tcp version. :D
+"""
+
+import select, sys, time, re
+from mininet import init, TreeNet, Cli, flush, quietRun
+
+# Some useful stuff: buffered readline and host monitoring
+
+def readline( host, buffer ):
+   "Read a line from a host, buffering with buffer."
+   buffer += host.read( 1024 )
+   if '\n' not in buffer: return None, buffer
+   pos = buffer.find( '\n' )
+   line = buffer[ 0 : pos ]
+   rest = buffer[ pos + 1 :]
+   return line, rest
+
+def monitor( hosts, seconds ):
+   "Monitor a set of hosts and yield their output."
+   poller = select.poll()
+   Node = hosts[ 0 ] # so we can call class method
+   buffers = {}
+   for host in hosts:
+      poller.register( host.stdout )
+      buffers[ host ] = ''
+   quitTime = time.time() + seconds
+   while time.time() < quitTime:
+      ready = poller.poll()
+      for fd, event in ready: 
+         host = Node.fdToNode( fd )
+         line, buffers[ host ] = readline( host, buffers[ host ] )
+         if line: yield host, line
+   yield None, ''
+
+# bwtest support
+
+def parsebwtest( line,
+   r=re.compile( r'(\d+) s: in ([\d\.]+) Mbps, out ([\d\.]+) Mbps' ) ):
+   match = r.match( line )
+   return match.group( 1, 2, 3 ) if match else ( None, None, None )
+   
+def printTotalHeader():
+   print
+   print "time(s)\thosts\ttotal in/out (Mbps)\tavg in/out (Mbps)"
+
+def printTotal( time=None, result=None ):
+   intotal = outtotal = 0.0
+   count = len( result )
+   for host, inbw, outbw in result:
+      intotal += inbw
+      outtotal += outbw
+   inavg = intotal / count if count > 0 else 0
+   outavg = outtotal / count if count > 0 else 0   
+   print '%d\t%d\t%.2f/%.2f\t\t%.2f/%.2f' % ( time, count, intotal, outtotal,
+      inavg, outavg )
+   
+def udpbwtest( controllers, switches, hosts, seconds ):
+   "Start up and monitor udpbwtest on each of our hosts."
+   hostCount = len( hosts )
+   print "*** Starting udpbwtest on hosts"
+   for host in hosts: 
+      ips = [ h.IP() for h in hosts if h != host ]
+      print host.name, ; flush()
+      host.cmd( './udpbwtest ' + ' '.join( ips ) + ' &' )
+   print
+   results = {}
+   print "*** Monitoring hosts"
+   output = monitor( hosts, seconds )
+   while True:
+      host, line = output.next()
+      if host is None: break
+      time, inbw, outbw = parsebwtest( line )
+      if time is not None:
+         time, inbw, outbw = int( time ), float( inbw ), float( outbw )
+         result = results.get( time, [] ) + [ ( host, inbw, outbw ) ]
+         if len( result ) == hostCount: printTotal( time, result )
+         results[ time ] = result
+   print "*** Stopping udpbwtest processes"
+   # We *really* don't want these things hanging around!
+   quietRun( 'killall -9 udpbwtest' )
+   print 
+   print "*** Results:"
+   printTotalHeader()
+   times = sorted( results.keys() )
+   for time in times:
+      printTotal( time - times[ 0 ] , results[ time ] )
+   print 
+     
+if __name__ == '__main__':
+   init()
+   network = TreeNet( depth=2, fanout=8, kernel=True )
+   def test( c, s, h ): return udpbwtest( c, s, h, seconds=10 )
+   network.run( test )
+