diff options
Diffstat (limited to 'research/experiments/020-lossy-paths/run.py')
| -rw-r--r-- | research/experiments/020-lossy-paths/run.py | 41 |
1 files changed, 26 insertions, 15 deletions
diff --git a/research/experiments/020-lossy-paths/run.py b/research/experiments/020-lossy-paths/run.py index 4b98d6b..b2bdd35 100644 --- a/research/experiments/020-lossy-paths/run.py +++ b/research/experiments/020-lossy-paths/run.py @@ -3,11 +3,13 @@ reordering and a bottleneck, against quinn, and beside TCP CUBIC. Each case runs in `unshare -rn` (an unprivileged network namespace) whose -loopback is the path, both ways: MTU 1500, and TCP's segments no larger -(gso_max_size), so each is a packet; a 50 Mbit/s bottleneck (tbf) whose -queue holds about a round trip of it; under it netem's delay (half the -RTT), jitter (packets reorder) and random loss. Pure and quinn send without -UDP GSO: a qdisc takes a GSO burst as one packet. +loopback is the path: MTU 1500, and TCP's segments no larger +(gso_max_size), so each is a packet. Each way netem gives delay (half the +RTT), jitter (packets reorder) and random loss; the way to the receivers +(ports 40000-40007) then goes through a 50 Mbit/s bottleneck (tbf) whose +queue holds a round trip of it, and the way back (answers, TCP's +acknowledgments) does not queue behind it. Pure and quinn send without UDP +GSO: a qdisc takes a GSO burst as one packet. bulk a backlog of 1 KiB records for --seconds (Pure: a link and a listener, transport.c; quinn: one stream); the goodput from the @@ -38,6 +40,7 @@ QUINN = ROOT / 'research/experiments/019-idle-links/quic/target/release/idle-qui TC = shutil.which('tc') or '/usr/sbin/tc' IP = shutil.which('ip') or '/usr/sbin/ip' RATE_MBIT, SIZE = 50, 1000 +PURE_PORT, QUINN_PORT, TCP_PORT, OTHER_TCP_PORT = 40001, 40002, 40003, 40004 # the receivers, beyond the bottleneck sys.path.insert(0, str(ROOT / 'tests')) @@ -66,15 +69,21 @@ def build(work): def path(rtt_ms, loss, jitter_ms): - """The loopback as the path.""" + """The loopback as the path: back (band 1:1) and forth (1:2, to the + receivers' ports, with the bottleneck after its netem).""" subprocess.run([IP, 'link', 'set', 'lo', 'up', 'mtu', '1500', 'gso_max_size', '1500', 'gso_max_segs', '1'], check=True) queue = max(30000, RATE_MBIT * 1000000 // 8 * rtt_ms // 1000) # a round trip of the bottleneck, in bytes - subprocess.run([TC, 'qdisc', 'add', 'dev', 'lo', 'root', 'handle', '1:', 'tbf', 'rate', f'{RATE_MBIT}mbit', - 'burst', '15000', 'limit', str(queue)], check=True) netem = ['delay', f'{rtt_ms / 2}ms'] + ([f'{jitter_ms}ms'] if jitter_ms else []) + \ (['loss', f'{loss}%'] if loss else []) + ['limit', '100000'] - subprocess.run([TC, 'qdisc', 'add', 'dev', 'lo', 'parent', '1:1', 'handle', '10:', 'netem'] + netem, check=True) + for rule in (['qdisc', 'add', 'dev', 'lo', 'root', 'handle', '1:', 'prio', 'bands', '2', 'priomap'] + ['0'] * 16, + ['qdisc', 'add', 'dev', 'lo', 'parent', '1:1', 'handle', '10:', 'netem'] + netem, + ['qdisc', 'add', 'dev', 'lo', 'parent', '1:2', 'handle', '20:', 'netem'] + netem, + ['qdisc', 'add', 'dev', 'lo', 'parent', '20:1', 'handle', '21:', 'tbf', 'rate', f'{RATE_MBIT}mbit', + 'burst', '15000', 'limit', str(queue)], + ['filter', 'add', 'dev', 'lo', 'protocol', 'ip', 'parent', '1:0', 'prio', '1', 'u32', 'match', 'ip', + 'dport', '40000', '0xfff8', 'flowid', '1:2']): + subprocess.run([TC] + rule, check=True) def goodput(timeline, record_bytes, skip_s=2.0, until_s=None): @@ -88,13 +97,14 @@ def goodput(timeline, record_bytes, skip_s=2.0, until_s=None): def pure(work, seconds, rate=0, count=2000000): done = subprocess.run([str(ROOT / 'build/link-transport'), str(work / 'sender.pmod'), str(work / 'receiver.pmod'), str(count), str(SIZE), '20000', str(rate), str(seconds)], capture_output=True, text=True, - env={**os.environ, 'TRANSPORT_GSO': '0'}, timeout=seconds + 120) + env={**os.environ, 'TRANSPORT_GSO': '0', 'TRANSPORT_PORT': str(PURE_PORT)}, + timeout=seconds + 120) assert done.returncode == 0, done.stderr[-2000:] return json.loads(done.stdout) def quinn_server(work): - server = subprocess.Popen([str(QUINN), 'serve', str(work / 'cert.der'), str(work / 'key.der')], + server = subprocess.Popen([str(QUINN), 'serve', str(work / 'cert.der'), str(work / 'key.der'), str(QUINN_PORT)], stdout=subprocess.PIPE, text=True, env={**os.environ, 'QUIC_GSO': '0'}) port = json.loads(server.stdout.readline())['port'] return server, port @@ -119,10 +129,11 @@ class Tcp: """A TCP CUBIC flow: a sender writing as fast as it may for seconds, a receiver counting bytes in each 100 ms from when it starts.""" - def __init__(self, seconds): + def __init__(self, seconds, port): self.seconds = seconds self.listener = socket.socket() - self.listener.bind(('127.0.0.1', 0)) + self.listener.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) + self.listener.bind(('127.0.0.1', port)) self.listener.listen(1) self.timeline = [] self.began = None @@ -178,10 +189,10 @@ def inner(case): if key in result: row[key] = result[key] else: # share: who beside a TCP CUBIC flow - tcp = Tcp(seconds) + tcp = Tcp(seconds, TCP_PORT) tcp.start() if who == 'tcp': - other = Tcp(seconds) + other = Tcp(seconds, OTHER_TCP_PORT) other.start() theirs = [b / (SIZE + 13) for b in other.join()] else: |