Roman Safronov
72575889c8
This patch adds the ability to measure network downtime during live migration process. A fixture has been added to start and stop a background pinger process and also read status from it. The downtime measurement has 0.2 seconds granularity. In order to reduce overall traffic the ping payload size set to minimal value. Change-Id: I83c6a5d49f5d4da05deb677907e5048ecdd2242b
64 lines
2.3 KiB
Python
64 lines
2.3 KiB
Python
# Copyright 2022 OpenStack Foundation
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# All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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import signal
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import subprocess
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import fixtures
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from oslo_log import log
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LOG = log.getLogger(__name__)
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class NetDowntimeMeter(fixtures.Fixture):
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def __init__(self, dest_ip, interval='0.2'):
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self.dest_ip = dest_ip
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# Note: for intervals lower than 0.2 ping requires root privileges
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self.interval = interval
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self.ping_process = None
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def _setUp(self):
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self.start_background_pinger()
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def start_background_pinger(self):
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cmd = ['ping', '-q', '-s1']
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cmd.append('-i{}'.format(self.interval))
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cmd.append(self.dest_ip)
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LOG.debug("Starting background pinger to '{}' with interval {}".format(
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self.dest_ip, self.interval))
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self.ping_process = subprocess.Popen(
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cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
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self.addCleanup(self.cleanup)
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def cleanup(self):
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if self.ping_process and self.ping_process.poll() is None:
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LOG.debug('Terminating background pinger with pid {}'.format(
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self.ping_process.pid))
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self.ping_process.terminate()
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self.ping_process = None
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def get_downtime(self):
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self.ping_process.send_signal(signal.SIGQUIT)
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# Example of the expected output:
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# 264/274 packets, 3% loss
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output = self.ping_process.stderr.readline().strip().decode('utf-8')
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if output and len(output.split()[0].split('/')) == 2:
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succ, total = output.split()[0].split('/')
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return (int(total) - int(succ)) * float(self.interval)
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else:
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LOG.warning('Unexpected output obtained from the pinger: %s',
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output)
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