# Copyright 2014 Cisco Systems, Inc. All rights reserved. # # Licensed under the Apache License, Version 2.0 (the "License"); you may # not use this file except in compliance with the License. You may obtain # a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the # License for the specific language governing permissions and limitations # under the License. # import abc import os import re # where to copy the tool on the target, must end with slash SCP_DEST_DIR = '/tmp/' # # A base class for all tools that can be associated to an instance # class PerfTool(object): __metaclass__ = abc.ABCMeta def __init__(self, name, perf_tool_path, instance): self.name = name self.instance = instance self.dest_path = SCP_DEST_DIR + name self.pid = None self.perf_tool_path = perf_tool_path # install the tool to the instance # returns False if fail, True if success def install(self): if self.perf_tool_path: local_path = os.path.join(self.perf_tool_path, self.name) return self.instance.scp(self.name, local_path, self.dest_path) # no install needed return True @abc.abstractmethod def get_server_launch_cmd(self): '''To be implemented by sub-classes.''' return None def start_server(self): '''Launch the server side of this tool :return: True if success, False if error ''' # check if server is already started if not self.pid: self.pid = self.instance.ssh.pidof(self.name) if not self.pid: cmd_list = self.get_server_launch_cmd() # Start the tool server self.instance.buginf('Starting %s server...' % (self.name)) for launch_cmd in cmd_list: launch_out = self.instance.exec_command(launch_cmd) self.pid = self.instance.ssh.pidof(self.name) else: self.instance.buginf('%s server already started pid=%s' % (self.name, self.pid)) if self.pid: return True else: self.instance.display('Cannot launch server %s: %s' % (self.name, launch_out)) return False # Terminate pid if started def dispose(self): if self.pid: # Terminate the iperf server self.instance.buginf('Terminating %s', self.name) self.instance.ssh.kill_proc(self.pid) self.pid = None def parse_error(self, msg): return {'error': msg, 'tool': self.name} def parse_results(self, protocol, throughput, lossrate=None, retrans=None, rtt_ms=None, reverse_dir=False, msg_size=None, cpu_load=None): res = {'throughput_kbps': throughput, 'protocol': protocol, 'tool': self.name} if self.instance.config.vm_bandwidth: res['bandwidth_limit_kbps'] = self.instance.config.vm_bandwidth if lossrate is not None: res['loss_rate'] = lossrate if retrans: res['retrans'] = retrans if rtt_ms: res['rtt_ms'] = rtt_ms if reverse_dir: res['direction'] = 'reverse' if msg_size: res['pkt_size'] = msg_size if cpu_load: res['cpu_load'] = cpu_load return res @abc.abstractmethod def run_client_dir(self, target_ip, mss, reverse_dir=False, bandwidth_kbps=0, udp=False, length=0, no_cpu_timed=0): # must be implemented by sub classes return None def find_udp_bdw(self, pkt_size, target_ip): '''Find highest UDP bandwidth within max loss rate for given packet size :return: a dictionary describing the optimal bandwidth (see parse_results()) ''' # we use a binary search to converge to the optimal throughput # start with 5Gbps - mid-range between 1 and 10Gbps # Convergence can be *very* tricky because UDP throughput behavior # can vary dramatically between host runs and guest runs. # The packet rate limitation is going to dictate the effective # send rate, meaning that small packet sizes will yield the worst # throughput. # The measured throughput can be vastly smaller than the requested # throughput even when the loss rate is zero when the sender cannot # send fast enough to fill the network, in that case increasing the # requested rate will not make it any better # Examples: # 1. too much difference between requested/measured bw - regardless of loss rate # => retry with bw mid-way between the requested bw and the measured bw # /tmp/nuttcp-7.3.2 -T2 -u -l128 -R5000000K -p5001 -P5002 -fparse 192.168.1.2 # megabytes=36.9785 real_seconds=2.00 rate_Mbps=154.8474 tx_cpu=23 rx_cpu=32 # drop=78149 pkt=381077 data_loss=20.50746 # /tmp/nuttcp-7.3.2 -T2 -u -l128 -R2500001K -p5001 -P5002 -fparse 192.168.1.2 # megabytes=47.8063 real_seconds=2.00 rate_Mbps=200.2801 tx_cpu=24 rx_cpu=34 # drop=0 pkt=391629 data_loss=0.00000 # 2. measured and requested bw are very close : # if loss_rate is too low # increase bw mid-way between requested and last max bw # if loss rate is too high # decrease bw mid-way between the measured bw and the last min bw # else stop iteration (converged) # /tmp/nuttcp-7.3.2 -T2 -u -l8192 -R859376K -p5001 -P5002 -fparse 192.168.1.2 # megabytes=204.8906 real_seconds=2.00 rate_Mbps=859.2992 tx_cpu=99 rx_cpu=10 # drop=0 pkt=26226 data_loss=0.00000 min_kbps = 1 max_kbps = 10000000 kbps = 5000000 min_loss_rate = self.instance.config.udp_loss_rate_range[0] max_loss_rate = self.instance.config.udp_loss_rate_range[1] # stop if the remaining range to cover is less than 5% while (min_kbps * 100 / max_kbps) < 95: res_list = self.run_client_dir(target_ip, 0, bandwidth_kbps=kbps, udp=True, length=pkt_size, no_cpu_timed=1) # always pick the first element in the returned list of dict(s) # should normally only have 1 element res = res_list[0] if 'error' in res: return res loss_rate = res['loss_rate'] measured_kbps = res['throughput_kbps'] self.instance.buginf('pkt-size=%d throughput=%d<%d/%d<%d Kbps loss-rate=%d' % (pkt_size, min_kbps, measured_kbps, kbps, max_kbps, loss_rate)) # expected rate must be at least 80% of the requested rate if (measured_kbps * 100 / kbps) < 80: # the measured bw is too far away from the requested bw # take half the distance or 3x the measured bw whichever is lowest kbps = min(measured_kbps + (kbps - measured_kbps) / 2, measured_kbps * 3) max_kbps = kbps continue # The measured bw is within striking distance from the requested bw # increase bw if loss rate is too small if loss_rate < min_loss_rate: # undershot if measured_kbps > min_kbps: min_kbps = measured_kbps else: # to make forward progress we need to increase min_kbps # and try a higher bw since the loss rate is too low min_kbps = int((max_kbps + min_kbps) / 2) kbps = int((max_kbps + min_kbps) / 2) # print ' undershot, min=%d kbps=%d max=%d' % (min_kbps, kbps, max_kbps) elif loss_rate > max_loss_rate: # overshot max_kbps = kbps if measured_kbps < kbps: kbps = measured_kbps else: kbps = int((max_kbps + min_kbps) / 2) # print ' overshot, min=%d kbps=%d max=%d' % (min_kbps, kbps, max_kbps) else: # converged within loss rate bracket break return res def get_proto_profile(self): '''Return a tuple containing the list of protocols (tcp/udp) and list of packet sizes (udp only) ''' # start with TCP (udp=False) then UDP proto_list = [] proto_pkt_sizes = [] if 'T' in self.instance.config.protocols: proto_list.append(False) proto_pkt_sizes.append(self.instance.config.tcp_pkt_sizes) if 'U' in self.instance.config.protocols: proto_list.append(True) proto_pkt_sizes.append(self.instance.config.udp_pkt_sizes) return (proto_list, proto_pkt_sizes) class PingTool(PerfTool): ''' A class to run ping and get loss rate and round trip time ''' def __init__(self, instance): PerfTool.__init__(self, 'ping', None, instance) def run_client(self, target_ip, ping_count=5): '''Perform the ping operation :return: a dict containing the results stats Example of output: 10 packets transmitted, 10 packets received, 0.0% packet loss round-trip min/avg/max/stddev = 55.855/66.074/103.915/13.407 ms or 5 packets transmitted, 5 received, 0% packet loss, time 3998ms rtt min/avg/max/mdev = 0.455/0.528/0.596/0.057 ms ''' cmd = "ping -c " + str(ping_count) + " " + str(target_ip) cmd_out = self.instance.exec_command(cmd) if not cmd_out: res = {'protocol': 'ICMP', 'tool': 'ping', 'error': 'failed'} return res match = re.search(r'(\d*) packets transmitted, (\d*) ', cmd_out) if match: tx_packets = match.group(1) rx_packets = match.group(2) else: tx_packets = 0 rx_packets = 0 match = re.search(r'min/avg/max/[a-z]* = ([\d\.]*)/([\d\.]*)/([\d\.]*)/([\d\.]*)', cmd_out) if match: rtt_min = match.group(1) rtt_avg = match.group(2) rtt_max = match.group(3) rtt_stddev = match.group(4) else: rtt_min = 0 rtt_max = 0 rtt_avg = 0 rtt_stddev = 0 res = {'protocol': 'ICMP', 'tool': 'ping', 'tx_packets': tx_packets, 'rx_packets': rx_packets, 'rtt_min_ms': rtt_min, 'rtt_max_ms': rtt_max, 'rtt_avg_ms': rtt_avg, 'rtt_stddev': rtt_stddev} return res def get_server_launch_cmd(self): # not applicable return None def run_client_dir(self, target_ip, mss, reverse_dir=False, bandwidth_kbps=0, udp=False, length=0, no_cpu_timed=0): # not applicable return None