def _run_iperf3(self, results_buffer, iperf):
''' Runs the given iperf3 and writes the results into the given list
buffer by appending the result to it
Note: this driver function is specifically tailored to the purposes of
traffic testing. Key differences from calling IPerf3.run():
- only uses the IPerf3 objects as containers
- uses subprocess to run iperf3 with the given arguments
- as a result, only picks some arguments that are expected to exist
and ignores others
This is done to enable multiple instances to run concurrently in
threads without worrying about race conditions on stdout, as the iperf3
module's run() will reroute stdout to a private pipe. To avoid this, we
use subprocess to give each iperf run its own private pipe. The only
other option is to fork each child iperf into its own subprocess, which
is not too different from this implementation.
Args:
results_buffer (list): the results buffer to which the
iperf3.TestResult object to should be appended
iperf (iperf3.IPerf3): the iperf3 object to run
'''
# Constructing the subprocess call
params = ('-B', iperf.bind_address, '-p', str(iperf.port), '-J')
if ipaddress.ip_address(iperf.bind_address).version == 6:
params += ('-6', )
if 'c' == iperf.role:
params = ('-c', iperf.server_hostname) + params
params += ('-b', str(iperf.bandwidth), '-t', str(iperf.duration))
# For ipv6 there is delay in configuring ipv6 address on eth3
# interface of test vm, so sleep for 5 secs
if ipaddress.ip_address(iperf.bind_address).version == 6:
time.sleep(5)
if 'udp' == iperf.protocol:
params += ('-u', )
else:
params = ('-s', ) + params
params += ('-1', )
params = ('iperf3', ) + params
# Make the iperf3 call and spin off the subprocess
self._server.log.debug('Running iperf3 command: %s', ' '.join(params))
with subprocess.Popen(params, stdout=subprocess.PIPE) as proc:
result_str = proc.stdout.read().decode('utf-8')
results_buffer += [iperf3.TestResult(result_str)]
self._barrier.wait()
def test_result(self):
dirname = os.path.dirname(os.path.abspath(__file__))
with open(os.path.join(dirname, 'results.json')) as f:
json = f.read()
result = iperf3.TestResult(json)
assert result.sent_bps == 935992000
assert result.sent_kbps == 935992
assert result.sent_Mbps == 935.992
assert isclose(result.sent_kB_s, 114256.836, rel_tol=0.01)
assert isclose(result.sent_MB_s, 111.579, rel_tol=0.01)
assert result.received_bps == 934268000
assert result.received_kbps == 934268
assert result.received_Mbps == 934.268
assert isclose(result.received_kB_s, 114046.387, rel_tol=0.01)
assert isclose(result.received_MB_s, 111.373, rel_tol=0.01)