vmtp/perf_tool.py

290 lines
11 KiB
Python

# 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