ndn/experiments/multiple_failure_experiment.py

# -*- Mode:python; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
#
# Copyright (C) 2015 The University of Memphis,
#                    Arizona Board of Regents,
#                    Regents of the University of California.
#
# This file is part of Mini-NDN.
# See AUTHORS.md for a complete list of Mini-NDN authors and contributors.
#
# Mini-NDN is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Mini-NDN is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Mini-NDN, e.g., in COPYING.md file.
# If not, see <http://www.gnu.org/licenses/>.

from ndn.experiments.experiment import Experiment
from ndn.nlsr import Nlsr

import time

class MultipleFailureExperiment(Experiment):

    def __init__(self, args):

        self.PING_COLLECTION_TIME_BEFORE_FAILURE = 60

        self.FAILURE_INTERVAL = 60
        self.RECOVERY_INTERVAL = 60

        # This is the number of pings required to make it through the full experiment
        nInitialPings = self.PING_COLLECTION_TIME_BEFORE_FAILURE + len(args["net"].hosts)*(self.FAILURE_INTERVAL + self.RECOVERY_INTERVAL)
        print("Scheduling with %s initial pings" % nInitialPings)

        args["nPings"] = nInitialPings

        Experiment.__init__(self, args)

    def failNode(self, host):
        print("Bringing %s down" % host.name)
        host.nfd.stop()

    def recoverNode(self, host):
        print("Bringing %s up" % host.name)
        host.nfd.start()
        host.nlsr.start()
        host.nfd.setStrategy("/ndn/edu", self.strategy)
        host.cmd("ndnpingserver /ndn/edu/" + str(host) + " > ping-server &")

    def run(self):
        self.startPings()

        # After the pings are scheduled, collect pings for 1 minute
        time.sleep(self.PING_COLLECTION_TIME_BEFORE_FAILURE)

        nNodesRemainingToFail = len(self.net.hosts)

        # Fail and recover each node
        for host in self.net.hosts:
            # Fail the node
            self.failNode(host)

            # Stay in failure state for FAILURE_INTERVAL
            time.sleep(self.FAILURE_INTERVAL)

            # Bring the node back up
            self.recoverNode(host)

            # Number of pings required to reach the end of the test
            nPings = self.RECOVERY_INTERVAL + nNodesRemainingToFail*(self.FAILURE_INTERVAL + self.RECOVERY_INTERVAL)
            nNodesRemainingToFail = nNodesRemainingToFail - 1

            # Wait for NFD and NLSR to fully recover
            time.sleep(1)
            print("Scheduling with %s remaining pings" % nPings)

            # Restart pings
            for other in self.net.hosts:
                # Do not ping self
                if host.name != other.name:
                    self.ping(host, other, nPings)

            time.sleep(self.RECOVERY_INTERVAL)

Experiment.register("multiple-failure", MultipleFailureExperiment)