def stop_network(self):
if not self.net_stopped:
self.net_stopped = True
log.info("Removing interfaces and restoring all network state.")
if self.tcp_policy == "dctcp":
dc_utils.exec_process("sysctl -w net.ipv4.tcp_ecn=0")
# reset the active host congestion control to the previous value
cmd = "sysctl -w net.ipv4.tcp_congestion_control=%s" % self.prev_cc
dc_utils.exec_process(cmd)
log.info("Deleting the virtual network")
self.net.stop()
log.info("Successfully deleted the virtual network")
def load_congestion_control(tcp_policy):
if tcp_policy == "dctcp":
dc_utils.exec_process("modprobe tcp_dctcp")
dc_utils.exec_process("sysctl -w net.ipv4.tcp_ecn=1")
elif tcp_policy == "tcp_nv":
dc_utils.exec_process("modprobe tcp_nv")
elif tcp_policy == "pcc":
if (os.popen("lsmod | grep pcc").read() == ""):
dc_utils.exec_process("insmod %s/tcp_pcc.ko" % FILE_DIR)
def record_rate(in_rate, ctrl_rate, sleep, out_dir):
# Convert to human readable format
ctrl_rate = ctrl_rate * (in_rate / 1e3)
in_rate = in_rate / 1e6
log.info(f"Input: {in_rate} Mbps Expected: {ctrl_rate} kbps")
log.info(f"Waiting for {sleep} seconds...")
out_dir = "control_test"
out_file = f"{out_dir}/{in_rate}mbps_in_{ctrl_rate}kbps_expected"
dc_utils.check_dir(out_dir)
ifstat_cmd = "ifstat -b "
ifstat_cmd += "-i s1-eth1 " # interface to listen on
ifstat_cmd += "-q 1 " # measurement interval
ifstat_cmd += "%d " % sleep # measure how long
return dc_utils.exec_process(ifstat_cmd, out_file=out_file)
def _install_proactive(self):
"""
Install proactive flow entries for the switch.
"""
protocols = ["ip", "arp"]
# West Switch
ovs_flow_cmd = "ovs-ofctl add-flow %s " % self.core_switch
ovs_flow_cmd += "-O OpenFlow13 "
for prot in protocols:
i = 1
j = 1
for k in range(1, self.conf["num_hosts"] + 1):
cmd = ovs_flow_cmd
cmd += "table=0,idle_timeout=0,"
cmd += "hard_timeout=0,priority=10,"
cmd += "nw_dst=10.%d.0.%d," % (i, j)
cmd += "%s," % prot
cmd += "actions=output:%d" % k
dc_utils.exec_process(cmd)
j += 1
if j == 3:
j = 1
i += 1
def _start_pkt_capture_tshark(self, out_dir):
# start a tshark capture process
dmp_file = "%s/pkt_snapshot.pcap" % (out_dir)
dmp_cmd = "tshark "
for host_iface in self.net_man.host_ctrl_map:
dmp_cmd += "-i %s " % host_iface
dmp_cmd += "-w %s " % dmp_file
dmp_cmd += "-f %s " % self.transport # filter transport protocol
dmp_cmd += "-b duration:300 " # reset pcap file after 300s
dmp_cmd += "-b filesize:%d " % 10e5 # reset pcap file after 1GB
dmp_cmd += "-b files:1 " # only write one capture file
dmp_cmd += "-B 500 " # mb size of the packet buffer
dmp_cmd += "-q " # do not log.info to stdout
dmp_cmd += "-n " # do not resolve hosts
dmp_cmd += "-F pcapng " # format of the capture file
dmp_proc = dc_utils.exec_process(dmp_cmd, out_file=dmp_file)
self.service_procs.append(dmp_proc)
def _install_proactive(self):
"""
Install proactive flow entries for the switch.
"""
protocols = ["ip", "arp"]
for prot in protocols:
# West Switch
ovs_flow_cmd = "ovs-ofctl add-flow %s " % self.switch_w
ovs_flow_cmd += "-O OpenFlow13 "
for index, host in enumerate(self.hosts_w):
port = index + 2
host_ip = self.host_ips[host]
cmd = ovs_flow_cmd
cmd += "table=0,idle_timeout=0,"
cmd += "hard_timeout=0,priority=10,"
cmd += "%s," % prot
cmd += "nw_dst=%s," % host_ip
cmd += "actions=output:%d" % port
dc_utils.exec_process(cmd)
cmd = ovs_flow_cmd
cmd += "table=0,idle_timeout=0,hard_timeout=0,priority=10,"
cmd += "%s," % prot
cmd += "nw_dst=10.2.0.0/16,actions=output:1"
dc_utils.exec_process(cmd)
# East Switch
ovs_flow_cmd = "ovs-ofctl add-flow %s " % self.switch_e
ovs_flow_cmd += "-O OpenFlow13 "
for index, host in enumerate(self.hosts_e):
port = index + 2
host_ip = self.host_ips[host]
cmd = ovs_flow_cmd
cmd += "table=0,idle_timeout=0,"
cmd += "hard_timeout=0,priority=10,"
cmd += "%s," % prot
cmd += "nw_dst=%s," % host_ip
cmd += "actions=output:%d" % port
dc_utils.exec_process(cmd)
cmd = ovs_flow_cmd
cmd += "table=0,idle_timeout=0,hard_timeout=0,priority=10,"
cmd += "%s," % prot
cmd += "nw_dst=10.1.0.0/16,actions=output:1"
dc_utils.exec_process(cmd)
def _install_proactive(self):
"""
Install proactive flow entries for switches.
"""
protocols = ["ip", "arp"]
switches = self.edge_switches + self.agg_switches + self.core_switches
for sw in switches:
num = int(sw[-1:])
ovs_flow_cmd = "ovs-ofctl add-flow %s -O OpenFlow13 " % sw
ovs_grp_cmd = "ovs-ofctl add-group %s -O OpenFlow13 " % sw
# Set upstream links of lower level switches
if sw in self.edge_switches or sw in self.agg_switches:
cmd = ovs_grp_cmd
cmd += "group_id=1,type=select,"
cmd += "bucket=output:1,bucket=output:2"
if self.fanout == 8:
cmd += ",bucket=output:3,bucket=output:4"
dc_utils.exec_process(cmd)
# Configure entries per protocol
for prot in protocols:
cmd = ovs_flow_cmd
cmd += "table=0,priority=10,%s,actions=group:1" % prot
dc_utils.exec_process(cmd)
# Configure entries per protocol
for prot in protocols:
# Edge Switches
if sw in self.edge_switches:
# Set downstream links
for i in range(1, self.density + 1):
cmd = ovs_flow_cmd
cmd += "table=0,idle_timeout=0,"
cmd += "hard_timeout=0,priority=40,"
cmd += "%s," % prot
cmd += "nw_dst=10.%d.0.%d," % (num, i)
cmd += "actions=output:%d" % (self.fanout / 2 + i)
dc_utils.exec_process(cmd)
# Aggregation Switches
if sw in self.agg_switches:
# Set downstream links
subnetList = self.create_subnet_list(num)
k = 1
for i in subnetList:
cmd = ovs_flow_cmd
cmd += "table=0,idle_timeout=0,"
cmd += "hard_timeout=0,priority=40,"
cmd += "%s," % prot
cmd += "nw_dst=10.%d.0.0/16," % i
cmd += "actions=output:%d" % (self.fanout / 2 + k)
dc_utils.exec_process(cmd)
k += 1
# Core Switches
if sw in self.core_switches:
# Set downstream links
j = 1
k = 1
for i in range(1, len(self.edge_switches) + 1):
cmd = ovs_flow_cmd
cmd += "table=0,idle_timeout=0,"
cmd += "hard_timeout=0,priority=10,"
cmd += "%s," % prot
cmd += "nw_dst=10.%d.0.0/16," % i
cmd += "actions=output:%d" % j
dc_utils.exec_process(cmd)
k += 1
if k == self.fanout / 2 + 1:
j += 1
k = 1
def _apply_qdisc(self, port):
""" Here be dragons... """
# tc_cmd = "tc qdisc add dev %s " % (port)
# cmd = "root handle 1: hfsc default 10"
# log.info(tc_cmd + cmd)
# dc_utils.exec_process(tc_cmd + cmd)
# tc_cmd = "tc class add dev %s " % (port)
# cmd = "parent 1: classid 1:10 hfsc sc rate %dbit ul rate %dbit" % (
# self.topo.max_bps, self.topo.max_bps)
# log.info(tc_cmd + cmd)
# dc_utils.exec_process(tc_cmd + cmd)
limit = int(self.topo.max_queue)
avg_pkt_size = 1500 # MTU packet size
tc_cmd = "tc qdisc add dev %s " % (port)
cmd = "root handle 1: htb default 10 "
# cmd = "root handle 1: estimator 250msec 1sec htb default 10 "
cmd += " direct_qlen %d " % (limit / avg_pkt_size)
log.debug(tc_cmd + cmd)
dc_utils.exec_process(tc_cmd + cmd)
tc_cmd = "tc class add dev %s " % (port)
cmd = "parent 1: classid 1:10 htb rate %dbit burst %d" % (
self.topo.max_bps, self.topo.max_bps)
log.debug(tc_cmd + cmd)
dc_utils.exec_process(tc_cmd + cmd)
if self.tcp_policy == "dctcp":
marking_threshold = calc_ecn(self.topo.max_bps, avg_pkt_size)
# Apply aggressive RED to mark excess packets in the queue
max_q = limit / 4
min_q = int(marking_threshold)
tc_cmd = "tc qdisc add dev %s " % (port)
cmd = "parent 1:10 handle 20:1 red "
cmd += "limit %d " % (limit)
cmd += "bandwidth %dbit " % self.topo.max_bps
cmd += "avpkt %d " % avg_pkt_size
cmd += "min %d " % min_q
cmd += "max %d " % max_q
# Ballpark burst hard limit...
burst = (min_q + min_q + max_q) / (3 * avg_pkt_size)
cmd += "burst %d " % burst
cmd += "probability 0.1"
cmd += " ecn "
log.debug(tc_cmd + cmd)
dc_utils.exec_process(tc_cmd + cmd)
else:
tc_cmd = "tc qdisc add dev %s " % (port)
cmd = "parent 1:10 handle 20:1 bfifo "
cmd += " limit %d" % limit
dc_utils.exec_process(tc_cmd + cmd)
# tc_cmd = "tc qdisc add dev %s " % (port)
# cmd = "root handle 1 netem limit %d rate 10mbit" % (
# limit / avg_pkt_size)
# log.info(tc_cmd + cmd)
# dc_utils.exec_process(tc_cmd + cmd)
# limit = int(self.topo.max_queue)
# tc_cmd = "tc qdisc add dev %s " % (port)
# cmd = "parent 1:10 handle 20: codel "
# cmd += " limit %d" % (limit)
# dc_utils.exec_process(tc_cmd + cmd)
# limit = int(self.topo.max_queue)
# max_q = self.topo.max_queue / 4
# min_q = max_q / 3
# tc_cmd = "tc qdisc add dev %s " % (port)
# cmd = "parent 1:10 handle 20:1 sfq limit %d" % (
# self.topo.max_queue)
# if self.dctcp:
# dc_utils.exec_process("sysctl -w net.ipv4.tcp_ecn=1")
# cmd += "ecn "
# # cmd += "redflowlimit "
# # cmd += "min %d " % (min_q)
# # cmd += "max %d " % (max_q)
# # cmd += "probability 1"
# log.info(tc_cmd + cmd)
# dc_utils.exec_process(tc_cmd + cmd)
# Apply tc choke to mark excess packets in the queue with ecn
# limit = int(self.topo.max_queue)
# max_q = self.topo.max_queue
# min_q = 400
# tc_cmd = "tc qdisc add dev %s " % (port)
# cmd = "parent 1:10 handle 10:1 choke limit %d " % limit
# cmd += "bandwidth %dbit " % self.topo.max_bps
# cmd += "min %d " % (min_q)
# cmd += "max %d " % (max_q)
# cmd += "probability 0.001"
# # if self.dctcp:
# cmd += " ecn "
# log.info(tc_cmd + cmd)
# dc_utils.exec_process(tc_cmd + cmd)
# tc_cmd = "tc qdisc add dev %s " % (port)
# cmd = "parent 1:10 handle 30:1 fq_codel limit %d " % (
# self.topo.max_queue)
# if ("dctcp" in self.conf) and self.conf["dctcp"]:
# dc_utils.exec_process("sysctl -w net.ipv4.tcp_ecn=1")
# cmd += "ecn "
# log.info(tc_cmd + cmd)
# dc_utils.exec_process(tc_cmd + cmd)
dc_utils.exec_process("ip link set %s txqueuelen %d" %
(port, limit / avg_pkt_size))
dc_utils.exec_process("ip link set %s mtu 1500" % port)
def _config_hosts(self, net):
for host in net.hosts:
# Increase the maximum total buffer-space allocatable
# This is measured in units of pages (4096 bytes)
dc_utils.exec_process("sysctl -w net.ipv4.tcp_window_scaling=1",
host)
dc_utils.exec_process("sysctl -w net.ipv4.tcp_timestamps=1", host)
dc_utils.exec_process("sysctl -w net.ipv4.tcp_sack=1", host)
dc_utils.exec_process("sysctl -w net.ipv4.tcp_syn_retries=10",
host)
# dc_utils.exec_process(
# "sysctl -w net.core.default_qdisc=pfifo_fast", host)
# dc_utils.exec_process("sysctl -w net.ipv4.tcp_recovery=0")
if self.tcp_policy == "dctcp":
dc_utils.exec_process(
"sysctl -w net.ipv4.tcp_congestion_control=dctcp", host)
dc_utils.exec_process("sysctl -w net.ipv4.tcp_ecn=1", host)
dc_utils.exec_process("sysctl -w net.ipv4.tcp_ecn_fallback=0",
host)
elif self.tcp_policy == "tcp_nv":
dc_utils.exec_process(
"sysctl -w net.ipv4.tcp_congestion_control=nv", host)
elif self.tcp_policy == "pcc":
dc_utils.exec_process(
"sysctl -w net.ipv4.tcp_congestion_control=pcc", host)