An unfortunate side effect of switching from print to output() is
that all output() goes to stderr. We should probably carefully
consider whether this is the right thing to do.
Although the walkthrough doesn't specify waiting, it is a race
condition that we occasionally hit in tests. Adding a 2 second
delay seems realistic (for when a human is doing the walkthrough)
and should reduce the likelihood of hitting the race condition.
than CPU-limited, which should expose the feature we are trying
to demonstrate (TCP data rate slowing down as latency increases
due to congestion control.)
Without waiting for mn to exit, OVS keeps listening on the
static listening port, which prevents UserSwitch from listening
on it (and starting up) in the next test.
For some time, UserSwitch has suffered from abysmal performance due
to rx and tx offload settings. In the latest Ubuntu 16.04/Linux 4.4
kernel, it simply doesn't work with the default settings, since
packets with bad TCP checksums are generated at one end, passed through
the user switch, and dropped at the other. It doesn't seem to be
something we can fix in UserSwitch itself although it may be possible
to do something in the C code of the Stanford reference switch and
CPqD switch.
Previously the standard OpenFlow poort (6653) that Controller()
may be listening at would conflict with the default listenPort
for switch 20 (usually UserSwitch 20), breaking waitConnected()
and disconnecting that switch from the network in general.
Fixes#668
It's very useful to be able to pass parameters to tests.
Unfortunately, our previous --test argument syntax didn't
permit it, because , was used as a delimiter for multiple
tests. With this change, we change , to become a delimiter
for arguments, as it is with other options to mn. For now,
we introduce + as a separator, as it is legal in filenames
and therefore shouldn't conflict with special characters
used by Unix shells.
We also reorganize mn a bit to make it hopefully slightly
clearer.
Unfortunately pexpect() seems to be timing out with a 30 second
timeout rather than the 600 seconds we are passing in. How
could this even be working normally? It is puzzling. We are
going to try specifying the timeout in the spawn() call.
Also if the test fails, we use %e format for readability.
Bob Lantz
Brian O'Connor
Brian O'Connor
Niels van Adrichem
Felix Konstantin Maurer
Nirmoy Das
vik_y