items() vs. iteritems() and decode() bytes in monitorFiles
Probably not strictly correct if bytes are split - we still
need to deal with this properly.
Networkx moved graphviz_layout, so we look for it in two different
places.
Also plot() should be fixed for regular Mininet(), which doesn't have
a .servers list.
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.)
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.
With a 1 ms delay, the performance tests periodically fails
under nested virtualization, which is how we are testing it.
Increasing the delay should make the effect (lower TCP
data rates as latency increases, due to TCP's congestion
control algorithm) more pronounced and robust.
If we want to observe a monotonic affect, we should
make sure that we are in fact CPU limited where it
matters. In this case, we are CPU limiting the hosts,
and the iperf client uses a lot of CPU. We need to
reduce the CPU allocation so that iperf is in fact
CPU bound.
We also correct the CPU allocation so that the client
and server each receive 50% of the total. Previously
we were specifying the per-host CPU allocation, so
45% meant we were allocating 90% of the overall CPU,
which seems a bit confusing. On the other hand, now
at 40% each host gets 20% of the CPU, which could also
be considered slightly confusing!
Although the client transmit rate is going to be the
limiting factor, we still measure the received data
rate at the server, because that is more interesting
than the initial burst of buffering at the client.
Measuring at the server becomes more important as
we reduce the iperf time.
The output is also changed slightly, and the test has
been updated appropriately.
Although we could use print() from __future__, this messes
up scripts which use examples as modules.
The simple, if not nicest for 2.7, solution is to use
info(), output() and other mininet.log functions. The disadvantage
is that we may have to adjust things if we change info() to
add automatic newlines, but we can burn that bridge in Mininet
3.x.
Previously we were using both ip link and ifconfig - not only is
this inconsistent and redundant, but it also broke when newer
ip link changed the reported names of certain interfacs to
"h1-eth0@36:".
Fixes#592
Bob Lantz
Brian O'Connor
Niels van Adrichem
vik_y
Xiaozhou Li
Xiaozhou Li
Brad Walker
Roan Huang