TrafficGenerator.py revision 909a91c2
1# Copyright (c) 2019 Cisco and/or its affiliates.
2# Licensed under the Apache License, Version 2.0 (the "License");
3# you may not use this file except in compliance with the License.
4# You may obtain a copy of the License at:
5#
6#     http://www.apache.org/licenses/LICENSE-2.0
7#
8# Unless required by applicable law or agreed to in writing, software
9# distributed under the License is distributed on an "AS IS" BASIS,
10# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
11# See the License for the specific language governing permissions and
12# limitations under the License.
13
14"""Performance testing traffic generator library."""
15
16import time
17
18from robot.api import logger
19from robot.libraries.BuiltIn import BuiltIn
20
21from .DropRateSearch import DropRateSearch
22from .Constants import Constants
23from .ssh import exec_cmd_no_error, exec_cmd
24from .topology import NodeType
25from .topology import NodeSubTypeTG
26from .topology import Topology
27from .MLRsearch.AbstractMeasurer import AbstractMeasurer
28from .MLRsearch.MultipleLossRatioSearch import MultipleLossRatioSearch
29from .MLRsearch.ReceiveRateMeasurement import ReceiveRateMeasurement
30from .PLRsearch.PLRsearch import PLRsearch
31
32__all__ = ['TGDropRateSearchImpl', 'TrafficGenerator', 'OptimizedSearch']
33
34
35def check_subtype(node):
36    """Return supported subtype of given node, or raise an exception.
37
38    Currently only one subtype is supported,
39    but we want our code to be ready for other ones.
40
41    :param node: Topology node to check. Can be None.
42    :type node: dict or NoneType
43    :returns: Subtype detected.
44    :rtype: NodeSubTypeTG
45    :raises RuntimeError: If node is not supported, message explains how.
46    """
47    if node.get('type') is None:
48        raise RuntimeError('Node type is not defined')
49    elif node['type'] != NodeType.TG:
50        raise RuntimeError('Node type is {typ!r}, not a TG'.format(
51            typ=node['type']))
52    elif node.get('subtype') is None:
53        raise RuntimeError('TG subtype is not defined')
54    elif node['subtype'] == NodeSubTypeTG.TREX:
55        return NodeSubTypeTG.TREX
56    raise RuntimeError('TG subtype {sub!r} is not supported'.format(
57        sub=node['subtype']))
58
59
60class TGDropRateSearchImpl(DropRateSearch):
61    """Drop Rate Search implementation."""
62
63    def __init__(self):
64        super(TGDropRateSearchImpl, self).__init__()
65
66    def measure_loss(self, rate, frame_size, loss_acceptance,
67                     loss_acceptance_type, traffic_profile, skip_warmup=False):
68        """Runs the traffic and evaluate the measured results.
69
70        :param rate: Offered traffic load.
71        :param frame_size: Size of frame.
72        :param loss_acceptance: Permitted drop ratio or frames count.
73        :param loss_acceptance_type: Type of permitted loss.
74        :param traffic_profile: Module name as a traffic profile identifier.
75            See resources/traffic_profiles/trex for implemented modules.
76        :param skip_warmup: Start TRex without warmup traffic if true.
77        :type rate: float
78        :type frame_size: str
79        :type loss_acceptance: float
80        :type loss_acceptance_type: LossAcceptanceType
81        :type traffic_profile: str
82        :type skip_warmup: bool
83        :returns: Drop threshold exceeded? (True/False)
84        :rtype: bool
85        :raises NotImplementedError: If TG is not supported.
86        :raises RuntimeError: If TG is not specified.
87        """
88        # we need instance of TrafficGenerator instantiated by Robot Framework
89        # to be able to use trex_stl-*()
90        tg_instance = BuiltIn().get_library_instance(
91            'resources.libraries.python.TrafficGenerator')
92        subtype = check_subtype(tg_instance.node)
93        if subtype == NodeSubTypeTG.TREX:
94            unit_rate = str(rate) + self.get_rate_type_str()
95            if skip_warmup:
96                tg_instance.trex_stl_start_remote_exec(
97                    self.get_duration(), unit_rate, frame_size, traffic_profile,
98                    warmup_time=0.0)
99            else:
100                tg_instance.trex_stl_start_remote_exec(
101                    self.get_duration(), unit_rate, frame_size, traffic_profile)
102            loss = tg_instance.get_loss()
103            sent = tg_instance.get_sent()
104            if self.loss_acceptance_type_is_percentage():
105                loss = (float(loss) / float(sent)) * 100
106            logger.trace("comparing: {los} < {acc} {typ}".format(
107                los=loss, acc=loss_acceptance, typ=loss_acceptance_type))
108            return float(loss) <= float(loss_acceptance)
109        return False
110
111    def get_latency(self):
112        """Returns min/avg/max latency.
113
114        :returns: Latency stats.
115        :rtype: list
116        """
117        tg_instance = BuiltIn().get_library_instance(
118            'resources.libraries.python.TrafficGenerator')
119        return tg_instance.get_latency_int()
120
121
122class TrafficGenerator(AbstractMeasurer):
123    """Traffic Generator.
124
125    FIXME: Describe API."""
126
127    # TODO: Decrease friction between various search and rate provider APIs.
128    # TODO: Remove "trex" from lines which could work with other TGs.
129
130    # Use one instance of TrafficGenerator for all tests in test suite
131    ROBOT_LIBRARY_SCOPE = 'TEST SUITE'
132
133    def __init__(self):
134        # TODO: Number of fields will be reduced with CSIT-1378.
135        self._node = None
136        # T-REX interface order mapping
137        self._ifaces_reordered = False
138        # Result holding fields, to be removed.
139        self._result = None
140        self._loss = None
141        self._sent = None
142        self._latency = None
143        self._received = None
144        # Measurement input fields, needed for async stop result.
145        self._start_time = None
146        self._rate = None
147        # Other input parameters, not knowable from measure() signature.
148        self.frame_size = None
149        self.traffic_profile = None
150        self.warmup_time = None
151        self.traffic_directions = None
152        # Transient data needed for async measurements.
153        self._xstats = (None, None)
154        # TODO: Rename "xstats" to something opaque, so TRex is not privileged?
155
156    @property
157    def node(self):
158        """Getter.
159
160        :returns: Traffic generator node.
161        :rtype: dict
162        """
163        return self._node
164
165    def get_loss(self):
166        """Return number of lost packets.
167
168        :returns: Number of lost packets.
169        :rtype: str
170        """
171        return self._loss
172
173    def get_sent(self):
174        """Return number of sent packets.
175
176        :returns: Number of sent packets.
177        :rtype: str
178        """
179        return self._sent
180
181    def get_received(self):
182        """Return number of received packets.
183
184        :returns: Number of received packets.
185        :rtype: str
186        """
187        return self._received
188
189    def get_latency_int(self):
190        """Return rounded min/avg/max latency.
191
192        :returns: Latency stats.
193        :rtype: list
194        """
195        return self._latency
196
197    def initialize_traffic_generator(
198            self, tg_node, tg_if1, tg_if2, tg_if1_adj_node, tg_if1_adj_if,
199            tg_if2_adj_node, tg_if2_adj_if, osi_layer, tg_if1_dst_mac=None,
200            tg_if2_dst_mac=None):
201        """TG initialization.
202
203        TODO: Document why do we need (and how do we use) _ifaces_reordered.
204
205        :param tg_node: Traffic generator node.
206        :param tg_if1: TG - name of first interface.
207        :param tg_if2: TG - name of second interface.
208        :param tg_if1_adj_node: TG if1 adjecent node.
209        :param tg_if1_adj_if: TG if1 adjecent interface.
210        :param tg_if2_adj_node: TG if2 adjecent node.
211        :param tg_if2_adj_if: TG if2 adjecent interface.
212        :param osi_layer: 'L2', 'L3' or 'L7' - OSI Layer testing type.
213        :param tg_if1_dst_mac: Interface 1 destination MAC address.
214        :param tg_if2_dst_mac: Interface 2 destination MAC address.
215        :type tg_node: dict
216        :type tg_if1: str
217        :type tg_if2: str
218        :type tg_if1_adj_node: dict
219        :type tg_if1_adj_if: str
220        :type tg_if2_adj_node: dict
221        :type tg_if2_adj_if: str
222        :type osi_layer: str
223        :type tg_if1_dst_mac: str
224        :type tg_if2_dst_mac: str
225        :returns: nothing
226        :raises RuntimeError: In case of issue during initialization.
227        """
228        subtype = check_subtype(tg_node)
229        if subtype == NodeSubTypeTG.TREX:
230            self._node = tg_node
231
232            if1_pci = Topology().get_interface_pci_addr(self._node, tg_if1)
233            if2_pci = Topology().get_interface_pci_addr(self._node, tg_if2)
234            if1_addr = Topology().get_interface_mac(self._node, tg_if1)
235            if2_addr = Topology().get_interface_mac(self._node, tg_if2)
236
237            if osi_layer == 'L2':
238                if1_adj_addr = if2_addr
239                if2_adj_addr = if1_addr
240            elif osi_layer == 'L3':
241                if1_adj_addr = Topology().get_interface_mac(tg_if1_adj_node,
242                                                            tg_if1_adj_if)
243                if2_adj_addr = Topology().get_interface_mac(tg_if2_adj_node,
244                                                            tg_if2_adj_if)
245            elif osi_layer == 'L7':
246                if1_addr = Topology().get_interface_ip4(self._node, tg_if1)
247                if2_addr = Topology().get_interface_ip4(self._node, tg_if2)
248                if1_adj_addr = Topology().get_interface_ip4(tg_if1_adj_node,
249                                                            tg_if1_adj_if)
250                if2_adj_addr = Topology().get_interface_ip4(tg_if2_adj_node,
251                                                            tg_if2_adj_if)
252            else:
253                raise ValueError("Unknown Test Type")
254
255            # in case of switched environment we can override MAC addresses
256            if tg_if1_dst_mac is not None and tg_if2_dst_mac is not None:
257                if1_adj_addr = tg_if1_dst_mac
258                if2_adj_addr = tg_if2_dst_mac
259
260            if min(if1_pci, if2_pci) != if1_pci:
261                if1_pci, if2_pci = if2_pci, if1_pci
262                if1_addr, if2_addr = if2_addr, if1_addr
263                if1_adj_addr, if2_adj_addr = if2_adj_addr, if1_adj_addr
264                self._ifaces_reordered = True
265
266            if osi_layer == 'L2' or osi_layer == 'L3':
267                exec_cmd_no_error(
268                    self._node,
269                    "sh -c 'cat << EOF > /etc/trex_cfg.yaml\n"
270                    "- version: 2\n"
271                    "  interfaces: [\"{0}\",\"{1}\"]\n"
272                    "  port_info:\n"
273                    "      - dest_mac: [{2}]\n"
274                    "        src_mac: [{3}]\n"
275                    "      - dest_mac: [{4}]\n"
276                    "        src_mac: [{5}]\n"
277                    "EOF'"\
278                    .format(if1_pci, if2_pci,
279                            "0x"+if1_adj_addr.replace(":", ",0x"),
280                            "0x"+if1_addr.replace(":", ",0x"),
281                            "0x"+if2_adj_addr.replace(":", ",0x"),
282                            "0x"+if2_addr.replace(":", ",0x")),
283                    sudo=True, message='TRex config generation error')
284            elif osi_layer == 'L7':
285                exec_cmd_no_error(
286                    self._node,
287                    "sh -c 'cat << EOF > /etc/trex_cfg.yaml\n"
288                    "- version: 2\n"
289                    "  interfaces: [\"{0}\",\"{1}\"]\n"
290                    "  port_info:\n"
291                    "      - ip: [{2}]\n"
292                    "        default_gw: [{3}]\n"
293                    "      - ip: [{4}]\n"
294                    "        default_gw: [{5}]\n"
295                    "EOF'"\
296                    .format(if1_pci, if2_pci,
297                            if1_addr, if1_adj_addr,
298                            if2_addr, if2_adj_addr),
299                    sudo=True, message='TRex config generation error')
300            else:
301                raise ValueError("Unknown Test Type")
302
303            self._startup_trex(osi_layer)
304
305    def _startup_trex(self, osi_layer):
306        """Startup sequence for the TRex traffic generator.
307
308        :param osi_layer: 'L2', 'L3' or 'L7' - OSI Layer testing type.
309        :type osi_layer: str
310        :raises RuntimeError: If node subtype is not a TREX or startup failed.
311        """
312        # No need to check subtype, we know it is TREX.
313        for _ in range(0, 3):
314            # Kill TRex only if it is already running.
315            cmd = "sh -c 'pgrep t-rex && pkill t-rex && sleep 3 || true'"
316            exec_cmd_no_error(
317                self._node, cmd, sudo=True, message='Kill TRex failed!')
318
319            # Configure TRex.
320            ports = ''
321            for port in self._node['interfaces'].values():
322                ports += ' {pci}'.format(pci=port.get('pci_address'))
323
324            cmd = ("sh -c 'cd {dir}/scripts/ && "
325                   "./dpdk_nic_bind.py -u {ports} || true'"
326                   .format(dir=Constants.TREX_INSTALL_DIR, ports=ports))
327            exec_cmd_no_error(
328                self._node, cmd, sudo=True,
329                message='Unbind PCI ports from driver failed!')
330
331            # Start TRex.
332            cmd = ("sh -c 'cd {dir}/scripts/ && "
333                   "nohup ./t-rex-64 --hdrh{mode} -i -c 7 > "
334                   "/tmp/trex.log 2>&1 &' > /dev/null"
335                   .format(dir=Constants.TREX_INSTALL_DIR,
336                           mode=' --astf' if osi_layer == 'L7' else ''))
337            try:
338                exec_cmd_no_error(self._node, cmd, sudo=True)
339            except RuntimeError:
340                cmd = "sh -c 'cat /tmp/trex.log'"
341                exec_cmd_no_error(
342                    self._node, cmd, sudo=True, message='Get TRex logs failed!')
343                raise RuntimeError('Start TRex failed!')
344
345            # Test if TRex starts successfuly.
346            cmd = ("sh -c '{dir}/resources/tools/trex/trex_server_info.py'"
347                   .format(dir=Constants.REMOTE_FW_DIR))
348            try:
349                exec_cmd_no_error(
350                    self._node, cmd, sudo=True, message='Test TRex failed!',
351                    retries=20)
352            except RuntimeError:
353                continue
354            return
355        # After max retries TRex is still not responding to API critical error
356        # occurred.
357        raise RuntimeError('Start TRex failed after multiple retries!')
358
359    @staticmethod
360    def is_trex_running(node):
361        """Check if TRex is running using pidof.
362
363        :param node: Traffic generator node.
364        :type node: dict
365        :returns: True if TRex is running otherwise False.
366        :rtype: bool
367        :raises RuntimeError: If node type is not a TG.
368        """
369        # No need to check subtype, we know it is TREX.
370
371        ret, _, _ = exec_cmd(node, "pidof t-rex", sudo=True)
372        return bool(int(ret) == 0)
373
374    @staticmethod
375    def teardown_traffic_generator(node):
376        """TG teardown.
377
378        :param node: Traffic generator node.
379        :type node: dict
380        :returns: nothing
381        :raises RuntimeError: If node type is not a TG,
382            or if TRex teardown fails.
383        """
384        subtype = check_subtype(node)
385        if subtype == NodeSubTypeTG.TREX:
386            exec_cmd_no_error(
387                node, "sh -c 'sudo pkill t-rex && sleep 3'",
388                sudo=False, message='pkill t-rex failed')
389
390    def _parse_traffic_results(self, stdout):
391        """Parse stdout of scripts into fields of self.
392
393        Block of code to reuse, by sync start, or stop after async.
394        TODO: Is the output TG subtype dependent?
395
396        :param stdout: Text containing the standard output.
397        :type stdout: str
398        """
399        # last line from console output
400        line = stdout.splitlines()[-1]
401        self._result = line
402        logger.info('TrafficGen result: {0}'.format(self._result))
403        self._received = self._result.split(', ')[1].split('=')[1]
404        self._sent = self._result.split(', ')[2].split('=')[1]
405        self._loss = self._result.split(', ')[3].split('=')[1]
406        self._latency = []
407        self._latency.append(self._result.split(', ')[4].split('=')[1])
408        self._latency.append(self._result.split(', ')[5].split('=')[1])
409
410    def trex_stl_stop_remote_exec(self, node):
411        """Execute script on remote node over ssh to stop running traffic.
412
413        Internal state is updated with measurement results.
414
415        :param node: TRex generator node.
416        :type node: dict
417        :raises RuntimeError: If stop traffic script fails.
418        """
419        # No need to check subtype, we know it is TREX.
420        x_args = ""
421        for index, value in enumerate(self._xstats):
422            if value is not None:
423                # Nested quoting is fun.
424                value = value.replace("'", "\"")
425                x_args += " --xstat{i}='\"'\"'{v}'\"'\"'".format(
426                    i=index, v=value)
427        stdout, _ = exec_cmd_no_error(
428            node, "sh -c '{d}/resources/tools/trex/trex_stateless_stop.py{a}'"\
429            .format(d=Constants.REMOTE_FW_DIR, a=x_args),
430            message='TRex stateless runtime error')
431        self._parse_traffic_results(stdout)
432
433    def trex_stl_start_remote_exec(
434            self, duration, rate, frame_size, traffic_profile, async_call=False,
435            latency=True, warmup_time=5.0, traffic_directions=2, tx_port=0,
436            rx_port=1):
437        """Execute script on remote node over ssh to start traffic.
438
439        In sync mode, measurement results are stored internally.
440        In async mode, initial data including xstats are stored internally.
441
442        :param duration: Time expresed in seconds for how long to send traffic.
443        :param rate: Traffic rate expressed with units (pps, %)
444        :param frame_size: L2 frame size to send (without padding and IPG).
445        :param traffic_profile: Module name as a traffic profile identifier.
446            See resources/traffic_profiles/trex for implemented modules.
447        :param async_call: If enabled then don't wait for all incomming trafic.
448        :param latency: With latency measurement.
449        :param warmup_time: Warmup time period.
450        :param traffic_directions: Traffic is bi- (2) or uni- (1) directional.
451            Default: 2
452        :param tx_port: Traffic generator transmit port for first flow.
453            Default: 0
454        :param rx_port: Traffic generator receive port for first flow.
455            Default: 1
456        :type duration: float
457        :type rate: str
458        :type frame_size: str
459        :type traffic_profile: str
460        :type async_call: bool
461        :type latency: bool
462        :type warmup_time: float
463        :type traffic_directions: int
464        :type tx_port: int
465        :type rx_port: int
466        :raises RuntimeError: In case of TG driver issue.
467        """
468        # No need to check subtype, we know it is TREX.
469        reorder = self._ifaces_reordered  # Just to make the next line fit.
470        p_0, p_1 = (rx_port, tx_port) if reorder else (tx_port, rx_port)
471        # Values from Robot can introduce type unicode,
472        # we need to encode them, so that repr() does not lead with 'u'.
473        if isinstance(rate, unicode):
474            rate = rate.encode("utf-8")
475        if not isinstance(duration, (float, int)):
476            duration = float(duration)
477        if not isinstance(warmup_time, (float, int)):
478            warmup_time = float(warmup_time)
479        command = (
480            "sh -c '{tool}/resources/tools/trex/trex_stateless_profile.py"
481            " --profile {prof}/resources/traffic_profiles/trex/{traffic}.py"
482            " --duration {duration!r} --frame_size {frame_size} --rate {rate!r}"
483            " --warmup_time {warmup!r} --port_0 {p_0} --port_1 {p_1}"
484            " --traffic_directions {dirs}").format(
485                tool=Constants.REMOTE_FW_DIR, prof=Constants.REMOTE_FW_DIR,
486                traffic=traffic_profile, duration=duration,
487                frame_size=frame_size, rate=rate, warmup=warmup_time, p_0=p_0,
488                p_1=p_1, dirs=traffic_directions)
489        if async_call:
490            command += " --async_start"
491        if latency:
492            command += " --latency"
493        command += "'"
494
495        stdout, _ = exec_cmd_no_error(
496            self._node, command, timeout=float(duration) + 60,
497            message='TRex stateless runtime error')
498
499        self.traffic_directions = traffic_directions
500        if async_call:
501            #no result
502            self._start_time = time.time()
503            self._rate = float(rate[:-3]) if "pps" in rate else float(rate)
504            self._received = None
505            self._sent = None
506            self._loss = None
507            self._latency = None
508            xstats = [None, None]
509            index = 0
510            for line in stdout.splitlines():
511                if "Xstats snapshot {i}: ".format(i=index) in line:
512                    xstats[index] = line[19:]
513                    index += 1
514                if index == 2:
515                    break
516            self._xstats = tuple(xstats)
517        else:
518            self._parse_traffic_results(stdout)
519            self._start_time = None
520            self._rate = None
521
522    def stop_traffic_on_tg(self):
523        """Stop all traffic on TG.
524
525        :returns: Structure containing the result of the measurement.
526        :rtype: ReceiveRateMeasurement
527        :raises RuntimeError: If TG is not set.
528        """
529        subtype = check_subtype(self._node)
530        if subtype == NodeSubTypeTG.TREX:
531            self.trex_stl_stop_remote_exec(self._node)
532        return self.get_measurement_result()
533
534    def send_traffic_on_tg(
535            self, duration, rate, frame_size, traffic_profile, warmup_time=5,
536            async_call=False, latency=True, traffic_directions=2, tx_port=0,
537            rx_port=1):
538        """Send traffic from all configured interfaces on TG.
539
540        In async mode, xstats is stored internally,
541        to enable getting correct result when stopping the traffic.
542        In both modes, stdout is returned,
543        but _parse_traffic_results only works in sync output.
544
545        Note that bidirectional traffic also contains flows
546        transmitted from rx_port and received in tx_port.
547        But some tests use asymmetric traffic, so those arguments are relevant.
548
549        Also note that traffic generator uses DPDK driver which might
550        reorder port numbers based on wiring and PCI numbering.
551        This method handles that, so argument values are invariant,
552        but you can see swapped valued in debug logs.
553
554        TODO: Is it better to have less descriptive argument names
555        just to make them less probable to be viewed as misleading or confusing?
556        See https://gerrit.fd.io/r/#/c/17625/11/resources/libraries/python\
557        /TrafficGenerator.py@406
558
559        :param duration: Duration of test traffic generation in seconds.
560        :param rate: Offered load per interface (e.g. 1%, 3gbps, 4mpps, ...).
561        :param frame_size: Frame size (L2) in Bytes.
562        :param traffic_profile: Module name as a traffic profile identifier.
563            See resources/traffic_profiles/trex for implemented modules.
564        :param warmup_time: Warmup phase in seconds.
565        :param async_call: Async mode.
566        :param latency: With latency measurement.
567        :param traffic_directions: Traffic is bi- (2) or uni- (1) directional.
568            Default: 2
569        :param tx_port: Traffic generator transmit port for first flow.
570            Default: 0
571        :param rx_port: Traffic generator receive port for first flow.
572            Default: 1
573        :type duration: str
574        :type rate: str
575        :type frame_size: str
576        :type traffic_profile: str
577        :type warmup_time: float
578        :type async_call: bool
579        :type latency: bool
580        :type traffic_directions: int
581        :type tx_port: int
582        :type rx_port: int
583        :returns: TG output.
584        :rtype: str
585        :raises RuntimeError: If TG is not set, or if node is not TG,
586            or if subtype is not specified.
587        :raises NotImplementedError: If TG is not supported.
588        """
589        subtype = check_subtype(self._node)
590        if subtype == NodeSubTypeTG.TREX:
591            self.trex_stl_start_remote_exec(
592                duration, rate, frame_size, traffic_profile, async_call,
593                latency, warmup_time, traffic_directions, tx_port, rx_port)
594
595        return self._result
596
597    def no_traffic_loss_occurred(self):
598        """Fail if loss occurred in traffic run.
599
600        :returns: nothing
601        :raises Exception: If loss occured.
602        """
603        if self._loss is None:
604            raise RuntimeError('The traffic generation has not been issued')
605        if self._loss != '0':
606            raise RuntimeError('Traffic loss occurred: {0}'.format(self._loss))
607
608    def fail_if_no_traffic_forwarded(self):
609        """Fail if no traffic forwarded.
610
611        :returns: nothing
612        :raises Exception: If no traffic forwarded.
613        """
614        if self._received is None:
615            raise RuntimeError('The traffic generation has not been issued')
616        if self._received == '0':
617            raise RuntimeError('No traffic forwarded')
618
619    def partial_traffic_loss_accepted(self, loss_acceptance,
620                                      loss_acceptance_type):
621        """Fail if loss is higher then accepted in traffic run.
622
623        :param loss_acceptance: Permitted drop ratio or frames count.
624        :param loss_acceptance_type: Type of permitted loss.
625        :type loss_acceptance: float
626        :type loss_acceptance_type: LossAcceptanceType
627        :returns: nothing
628        :raises Exception: If loss is above acceptance criteria.
629        """
630        if self._loss is None:
631            raise Exception('The traffic generation has not been issued')
632
633        if loss_acceptance_type == 'percentage':
634            loss = (float(self._loss) / float(self._sent)) * 100
635        elif loss_acceptance_type == 'frames':
636            loss = float(self._loss)
637        else:
638            raise Exception('Loss acceptance type not supported')
639
640        if loss > float(loss_acceptance):
641            raise Exception("Traffic loss {} above loss acceptance: {}".format(
642                loss, loss_acceptance))
643
644    def set_rate_provider_defaults(self, frame_size, traffic_profile,
645                                   warmup_time=0.0, traffic_directions=2):
646        """Store values accessed by measure().
647
648        :param frame_size: Frame size identifier or value [B].
649        :param traffic_profile: Module name as a traffic profile identifier.
650            See resources/traffic_profiles/trex for implemented modules.
651        :param warmup_time: Traffic duration before measurement starts [s].
652        :param traffic_directions: Traffic is bi- (2) or uni- (1) directional.
653            Default: 2
654        :type frame_size: str or int
655        :type traffic_profile: str
656        :type warmup_time: float
657        :type traffic_directions: int
658        """
659        self.frame_size = frame_size
660        self.traffic_profile = str(traffic_profile)
661        self.warmup_time = float(warmup_time)
662        self.traffic_directions = traffic_directions
663
664    def get_measurement_result(self, duration=None, transmit_rate=None):
665        """Return the result of last measurement as ReceiveRateMeasurement.
666
667        Separate function, as measurements can end either by time
668        or by explicit call, this is the common block at the end.
669
670        TODO: Fail on running or already reported measurement.
671
672        :param duration: Measurement duration [s] if known beforehand.
673            For explicitly stopped measurement it is estimated.
674        :param transmit_rate: Target aggregate transmit rate [pps].
675            If not given, computed assuming it was bidirectional.
676        :type duration: float or NoneType
677        :type transmit_rate: float or NoneType
678        :returns: Structure containing the result of the measurement.
679        :rtype: ReceiveRateMeasurement
680        """
681        if duration is None:
682            duration = time.time() - self._start_time
683            self._start_time = None
684        if transmit_rate is None:
685            transmit_rate = self._rate * self.traffic_directions
686        transmit_count = int(self.get_sent())
687        loss_count = int(self.get_loss())
688        measurement = ReceiveRateMeasurement(
689            duration, transmit_rate, transmit_count, loss_count)
690        measurement.latency = self.get_latency_int()
691        return measurement
692
693    def measure(self, duration, transmit_rate):
694        """Run trial measurement, parse and return aggregate results.
695
696        Aggregate means sum over traffic directions.
697
698        :param duration: Trial duration [s].
699        :param transmit_rate: Target aggregate transmit rate [pps].
700        :type duration: float
701        :type transmit_rate: float
702        :returns: Structure containing the result of the measurement.
703        :rtype: ReceiveRateMeasurement
704        :raises RuntimeError: If TG is not set, or if node is not TG,
705            or if subtype is not specified.
706        :raises NotImplementedError: If TG is not supported.
707        """
708        duration = float(duration)
709        transmit_rate = float(transmit_rate)
710        # TG needs target Tr per stream, but reports aggregate Tx and Dx.
711        unit_rate_int = transmit_rate / float(self.traffic_directions)
712        unit_rate_str = str(unit_rate_int) + "pps"
713        self.send_traffic_on_tg(
714            duration, unit_rate_str, self.frame_size, self.traffic_profile,
715            warmup_time=self.warmup_time, latency=True,
716            traffic_directions=self.traffic_directions)
717        return self.get_measurement_result(duration, transmit_rate)
718
719
720class OptimizedSearch(object):
721    """Class to be imported as Robot Library, containing search keywords.
722
723    Aside of setting up measurer and forwarding arguments,
724    the main business is to translate min/max rate from unidir to aggregate.
725    """
726
727    @staticmethod
728    def perform_optimized_ndrpdr_search(
729            frame_size, traffic_profile, minimum_transmit_rate,
730            maximum_transmit_rate, packet_loss_ratio=0.005,
731            final_relative_width=0.005, final_trial_duration=30.0,
732            initial_trial_duration=1.0, number_of_intermediate_phases=2,
733            timeout=720.0, doublings=1, traffic_directions=2):
734        """Setup initialized TG, perform optimized search, return intervals.
735
736        :param frame_size: Frame size identifier or value [B].
737        :param traffic_profile: Module name as a traffic profile identifier.
738            See resources/traffic_profiles/trex for implemented modules.
739        :param minimum_transmit_rate: Minimal uni-directional
740            target transmit rate [pps].
741        :param maximum_transmit_rate: Maximal uni-directional
742            target transmit rate [pps].
743        :param packet_loss_ratio: Fraction of packets lost, for PDR [1].
744        :param final_relative_width: Final lower bound transmit rate
745            cannot be more distant that this multiple of upper bound [1].
746        :param final_trial_duration: Trial duration for the final phase [s].
747        :param initial_trial_duration: Trial duration for the initial phase
748            and also for the first intermediate phase [s].
749        :param number_of_intermediate_phases: Number of intermediate phases
750            to perform before the final phase [1].
751        :param timeout: The search will fail itself when not finished
752            before this overall time [s].
753        :param doublings: How many doublings to do in external search step.
754            Default 1 is suitable for fairly stable tests,
755            less stable tests might get better overal duration with 2 or more.
756        :param traffic_directions: Traffic is bi- (2) or uni- (1) directional.
757            Default: 2
758        :type frame_size: str or int
759        :type traffic_profile: str
760        :type minimum_transmit_rate: float
761        :type maximum_transmit_rate: float
762        :type packet_loss_ratio: float
763        :type final_relative_width: float
764        :type final_trial_duration: float
765        :type initial_trial_duration: float
766        :type number_of_intermediate_phases: int
767        :type timeout: float
768        :type doublings: int
769        :type traffic_directions: int
770        :returns: Structure containing narrowed down NDR and PDR intervals
771            and their measurements.
772        :rtype: NdrPdrResult
773        :raises RuntimeError: If total duration is larger than timeout.
774        """
775        minimum_transmit_rate *= traffic_directions
776        maximum_transmit_rate *= traffic_directions
777        # we need instance of TrafficGenerator instantiated by Robot Framework
778        # to be able to use trex_stl-*()
779        tg_instance = BuiltIn().get_library_instance(
780            'resources.libraries.python.TrafficGenerator')
781        tg_instance.set_rate_provider_defaults(
782            frame_size, traffic_profile, traffic_directions=traffic_directions)
783        algorithm = MultipleLossRatioSearch(
784            measurer=tg_instance, final_trial_duration=final_trial_duration,
785            final_relative_width=final_relative_width,
786            number_of_intermediate_phases=number_of_intermediate_phases,
787            initial_trial_duration=initial_trial_duration, timeout=timeout,
788            doublings=doublings)
789        result = algorithm.narrow_down_ndr_and_pdr(
790            minimum_transmit_rate, maximum_transmit_rate, packet_loss_ratio)
791        return result
792
793    @staticmethod
794    def perform_soak_search(
795            frame_size, traffic_profile, minimum_transmit_rate,
796            maximum_transmit_rate, plr_target=1e-7, tdpt=0.1,
797            initial_count=50, timeout=1800.0, trace_enabled=False,
798            traffic_directions=2):
799        """Setup initialized TG, perform soak search, return avg and stdev.
800
801        :param frame_size: Frame size identifier or value [B].
802        :param traffic_profile: Module name as a traffic profile identifier.
803            See resources/traffic_profiles/trex for implemented modules.
804        :param minimum_transmit_rate: Minimal uni-directional
805            target transmit rate [pps].
806        :param maximum_transmit_rate: Maximal uni-directional
807            target transmit rate [pps].
808        :param plr_target: Fraction of packets lost to achieve [1].
809        :param tdpt: Trial duration per trial.
810            The algorithm linearly increases trial duration with trial number,
811            this is the increment between succesive trials, in seconds.
812        :param initial_count: Offset to apply before the first trial.
813            For example initial_count=50 makes first trial to be 51*tdpt long.
814            This is needed because initial "search" phase of integrator
815            takes significant time even without any trial results.
816        :param timeout: The search will stop after this overall time [s].
817        :param traffic_directions: Traffic is bi- (2) or uni- (1) directional.
818            Default: 2
819        :type frame_size: str or int
820        :type traffic_profile: str
821        :type minimum_transmit_rate: float
822        :type maximum_transmit_rate: float
823        :type plr_target: float
824        :type initial_count: int
825        :type timeout: float
826        :type traffic_directions: int
827        :returns: Average and stdev of estimated aggregate rate giving PLR.
828        :rtype: 2-tuple of float
829        """
830        minimum_transmit_rate *= traffic_directions
831        maximum_transmit_rate *= traffic_directions
832        tg_instance = BuiltIn().get_library_instance(
833            'resources.libraries.python.TrafficGenerator')
834        tg_instance.set_rate_provider_defaults(
835            frame_size, traffic_profile, traffic_directions=traffic_directions)
836        algorithm = PLRsearch(
837            measurer=tg_instance, trial_duration_per_trial=tdpt,
838            packet_loss_ratio_target=plr_target,
839            trial_number_offset=initial_count, timeout=timeout,
840            trace_enabled=trace_enabled)
841        result = algorithm.search(minimum_transmit_rate, maximum_transmit_rate)
842        return result
843