2 # NEPI, a framework to manage network experiments
3 # Copyright (C) 2013 INRIA
5 # This program is free software: you can redistribute it and/or modify
6 # it under the terms of the GNU General Public License as published by
7 # the Free Software Foundation, either version 3 of the License, or
8 # (at your option) any later version.
10 # This program is distributed in the hope that it will be useful,
11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 # GNU General Public License for more details.
15 # You should have received a copy of the GNU General Public License
16 # along with this program. If not, see <http://www.gnu.org/licenses/>.
18 # Author: Alina Quereilhac <alina.quereilhac@inria.fr>
28 from nepi.util import guid
29 from nepi.util.parallel import ParallelRun
30 from nepi.util.timefuncs import tnow, tdiffsec, stabsformat, tsformat
31 from nepi.execution.resource import ResourceFactory, ResourceAction, \
32 ResourceState, ResourceState2str
33 from nepi.execution.scheduler import HeapScheduler, Task, TaskStatus
34 from nepi.execution.trace import TraceAttr
36 # TODO: use multiprocessing instead of threading
37 # TODO: When a failure occurs during deployment, scp and ssh processes are left running behind!!
38 # TODO: Allow to reconnect to a running experiment instance! (reconnect mode vs deploy mode)
40 class ECState(object):
41 """ State of the Experiment Controller
48 class ExperimentController(object):
50 .. class:: Class Args :
52 :param exp_id: Human readable identifier for the experiment scenario.
53 It will be used in the name of the directory
54 where experiment related information is stored
59 An experiment, or scenario, is defined by a concrete use, behavior,
60 configuration and interconnection of resources that describe a single
61 experiment case (We call this the experiment description).
62 A same experiment (scenario) can be run many times.
64 The ExperimentController (EC), is the entity responsible for
65 managing an experiment instance (run). The same scenario can be
66 recreated (and re-run) by instantiating an EC and recreating
67 the same experiment description.
69 In NEPI, an experiment is represented as a graph of interconnected
70 resources. A resource is a generic concept in the sense that any
71 component taking part of an experiment, whether physical of
72 virtual, is considered a resource. A resources could be a host,
73 a virtual machine, an application, a simulator, a IP address.
75 A ResourceManager (RM), is the entity responsible for managing a
76 single resource. ResourceManagers are specific to a resource
77 type (i.e. An RM to control a Linux application will not be
78 the same as the RM used to control a ns-3 simulation).
79 In order for a new type of resource to be supported in NEPI
80 a new RM must be implemented. NEPI already provides different
81 RMs to control basic resources, and new can be extended from
84 Through the EC interface the user can create ResourceManagers (RMs),
85 configure them and interconnect them, in order to describe an experiment.
86 Describing an experiment through the EC does not run the experiment.
87 Only when the 'deploy()' method is invoked on the EC, will the EC take
88 actions to transform the 'described' experiment into a 'running' experiment.
90 While the experiment is running, it is possible to continue to
91 create/configure/connect RMs, and to deploy them to involve new
92 resources in the experiment (this is known as 'interactive' deployment).
94 An experiments in NEPI is identified by a string id,
95 which is either given by the user, or automatically generated by NEPI.
96 The purpose of this identifier is to separate files and results that
97 belong to different experiment scenarios.
98 However, since a same 'experiment' can be run many times, the experiment
99 id is not enough to identify an experiment instance (run).
100 For this reason, the ExperimentController has two identifier, the
101 exp_id, which can be re-used by different ExperimentController instances,
102 and the run_id, which unique to a ExperimentController instance, and
103 is automatically generated by NEPI.
107 def __init__(self, exp_id = None):
108 super(ExperimentController, self).__init__()
109 # root directory to store files
111 # Run identifier. It identifies a concrete instance (run) of an experiment.
112 # Since a same experiment (same configuration) can be run many times,
113 # this id permits to identify concrete exoeriment run
114 self._run_id = tsformat()
116 # Experiment identifier. Usually assigned by the user
117 self._exp_id = exp_id or "exp-%s" % os.urandom(8).encode('hex')
119 # generator of globally unique ids
120 self._guid_generator = guid.GuidGenerator()
123 self._resources = dict()
126 self._scheduler = HeapScheduler()
131 # Event processing thread
132 self._cond = threading.Condition()
133 self._thread = threading.Thread(target = self._process)
134 self._thread.setDaemon(True)
138 self._state = ECState.RUNNING
141 self._logger = logging.getLogger("ExperimentController")
145 """ Return the logger of the Experiment Controller
152 """ Return the state of the Experiment Controller
159 """ Return the experiment id assigned by the user
166 """ Return the experiment instance (run) identifier
173 """ Put the state of the Experiment Controller into a final state :
174 Either TERMINATED or FAILED
177 return self.ecstate in [ECState.FAILED, ECState.TERMINATED]
179 def wait_finished(self, guids):
180 """ Blocking method that wait until all the RM from the 'guid' list
181 reached the state FINISHED
183 :param guids: List of guids
186 return self.wait(guids)
188 def wait_started(self, guids):
189 """ Blocking method that wait until all the RM from the 'guid' list
190 reached the state STARTED
192 :param guids: List of guids
195 return self.wait(guids, states = [ResourceState.STARTED,
196 ResourceState.STOPPED,
197 ResourceState.FAILED,
198 ResourceState.FINISHED])
200 def wait(self, guids, states = [ResourceState.FINISHED,
201 ResourceState.FAILED,
202 ResourceState.STOPPED]):
203 """ Blocking method that waits until all the RM from the 'guid' list
204 reached state 'state' or until a failure occurs
206 :param guids: List of guids
209 if isinstance(guids, int):
212 # we randomly alter the order of the guids to avoid ordering
213 # dependencies (e.g. LinuxApplication RMs runing on the same
214 # linux host will be synchronized by the LinuxNode SSH lock)
215 random.shuffle(guids)
218 # If no more guids to wait for or an error occured, then exit
219 if len(guids) == 0 or self.finished:
222 # If a guid reached one of the target states, remove it from list
224 state = self.state(guid)
230 self.logger.debug(" WAITING FOR %g - state %s " % (guid,
231 self.state(guid, hr = True)))
233 # Take the opportunity to 'refresh' the states of the RMs.
234 # Query only the first up to N guids (not to overwhelm
237 lim = n if len(guids) > n else ( len(guids) -1 )
238 nguids = guids[0: lim]
240 # schedule state request for all guids (take advantage of
241 # scheduler multi threading).
243 callback = functools.partial(self.state, guid)
244 self.schedule("0s", callback)
246 # If the guid is not in one of the target states, wait and
247 # continue quering. We keep the sleep big to decrease the
248 # number of RM state queries
251 def get_task(self, tid):
252 """ Get a specific task
254 :param tid: Id of the task
258 return self._tasks.get(tid)
260 def get_resource(self, guid):
261 """ Get a specific Resource Manager
263 :param guid: Id of the task
265 :rtype: ResourceManager
267 return self._resources.get(guid)
271 """ Returns the list of all the Resource Manager Id
276 return self._resources.keys()
278 def register_resource(self, rtype, guid = None):
279 """ Register a Resource Manager. It creates a new 'guid', if it is not specified,
280 for the RM of type 'rtype' and add it to the list of Resources.
282 :param rtype: Type of the RM
284 :return: Id of the RM
287 # Get next available guid
288 guid = self._guid_generator.next(guid)
291 rm = ResourceFactory.create(rtype, self, guid)
294 self._resources[guid] = rm
298 def get_attributes(self, guid):
299 """ Return all the attibutes of a specific RM
301 :param guid: Guid of the RM
303 :return: List of attributes
306 rm = self.get_resource(guid)
307 return rm.get_attributes()
309 def register_connection(self, guid1, guid2):
310 """ Registers a guid1 with a guid2.
311 The declaration order is not important
313 :param guid1: First guid to connect
314 :type guid1: ResourceManager
316 :param guid2: Second guid to connect
317 :type guid: ResourceManager
319 rm1 = self.get_resource(guid1)
320 rm2 = self.get_resource(guid2)
322 rm1.register_connection(guid2)
323 rm2.register_connection(guid1)
325 def register_condition(self, group1, action, group2, state,
327 """ Registers an action START or STOP for all RM on group1 to occur
328 time 'time' after all elements in group2 reached state 'state'.
330 :param group1: List of guids of RMs subjected to action
333 :param action: Action to register (either START or STOP)
334 :type action: ResourceAction
336 :param group2: List of guids of RMs to we waited for
339 :param state: State to wait for on RMs (STARTED, STOPPED, etc)
340 :type state: ResourceState
342 :param time: Time to wait after group2 has reached status
346 if isinstance(group1, int):
348 if isinstance(group2, int):
352 rm = self.get_resource(guid1)
353 rm.register_condition(action, group2, state, time)
355 def enable_trace(self, guid, name):
358 :param name: Name of the trace
361 rm = self.get_resource(guid)
362 rm.enable_trace(name)
364 def trace_enabled(self, guid, name):
365 """ Returns True if trace is enabled
367 :param name: Name of the trace
370 rm = self.get_resource(guid)
371 return rm.trace_enabled(name)
373 def trace(self, guid, name, attr = TraceAttr.ALL, block = 512, offset = 0):
374 """ Get information on collected trace
376 :param name: Name of the trace
379 :param attr: Can be one of:
380 - TraceAttr.ALL (complete trace content),
381 - TraceAttr.STREAM (block in bytes to read starting at offset),
382 - TraceAttr.PATH (full path to the trace file),
383 - TraceAttr.SIZE (size of trace file).
386 :param block: Number of bytes to retrieve from trace, when attr is TraceAttr.STREAM
389 :param offset: Number of 'blocks' to skip, when attr is TraceAttr.STREAM
394 rm = self.get_resource(guid)
395 return rm.trace(name, attr, block, offset)
397 def discover(self, guid):
398 """ Discover a specific RM defined by its 'guid'
400 :param guid: Guid of the RM
404 rm = self.get_resource(guid)
407 def provision(self, guid):
408 """ Provision a specific RM defined by its 'guid'
410 :param guid: Guid of the RM
414 rm = self.get_resource(guid)
415 return rm.provision()
417 def get(self, guid, name):
418 """ Get a specific attribute 'name' from the RM 'guid'
420 :param guid: Guid of the RM
423 :param name: attribute's name
427 rm = self.get_resource(guid)
430 def set(self, guid, name, value):
431 """ Set a specific attribute 'name' from the RM 'guid'
432 with the value 'value'
434 :param guid: Guid of the RM
437 :param name: attribute's name
440 :param value: attribute's value
443 rm = self.get_resource(guid)
444 return rm.set(name, value)
446 def state(self, guid, hr = False):
447 """ Returns the state of a resource
449 :param guid: Resource guid
452 :param hr: Human readable. Forces return of a
453 status string instead of a number
457 rm = self.get_resource(guid)
461 return ResourceState2str.get(state)
465 def stop(self, guid):
466 """ Stop a specific RM defined by its 'guid'
468 :param guid: Guid of the RM
472 rm = self.get_resource(guid)
475 def start(self, guid):
476 """ Start a specific RM defined by its 'guid'
478 :param guid: Guid of the RM
482 rm = self.get_resource(guid)
485 def set_with_conditions(self, name, value, group1, group2, state,
487 """ Set value 'value' on attribute with name 'name' on all RMs of
488 group1 when 'time' has elapsed since all elements in group2
489 have reached state 'state'.
491 :param name: Name of attribute to set in RM
494 :param value: Value of attribute to set in RM
497 :param group1: List of guids of RMs subjected to action
500 :param action: Action to register (either START or STOP)
501 :type action: ResourceAction
503 :param group2: List of guids of RMs to we waited for
506 :param state: State to wait for on RMs (STARTED, STOPPED, etc)
507 :type state: ResourceState
509 :param time: Time to wait after group2 has reached status
513 if isinstance(group1, int):
515 if isinstance(group2, int):
519 rm = self.get_resource(guid)
520 rm.set_with_conditions(name, value, group2, state, time)
522 def stop_with_conditions(self, guid):
523 """ Stop a specific RM defined by its 'guid' only if all the conditions are true
525 :param guid: Guid of the RM
529 rm = self.get_resource(guid)
530 return rm.stop_with_conditions()
532 def start_with_conditions(self, guid):
533 """ Start a specific RM defined by its 'guid' only if all the conditions are true
535 :param guid: Guid of the RM
539 rm = self.get_resource(guid)
540 return rm.start_with_condition()
542 def deploy(self, group = None, wait_all_ready = True):
543 """ Deploy all resource manager in group
545 :param group: List of guids of RMs to deploy
548 :param wait_all_ready: Wait until all RMs are ready in
549 order to start the RMs
553 self.logger.debug(" ------- DEPLOY START ------ ")
556 # By default, if not deployment group is indicated,
557 # all RMs that are undeployed will be deployed
559 for guid in self.resources:
560 if self.state(guid) == ResourceState.NEW:
563 if isinstance(group, int):
566 # Before starting deployment we disorder the group list with the
567 # purpose of speeding up the whole deployment process.
568 # It is likely that the user inserted in the 'group' list closely
569 # resources one after another (e.g. all applications
570 # connected to the same node can likely appear one after another).
571 # This can originate a slow down in the deployment since the N
572 # threads the parallel runner uses to processes tasks may all
573 # be taken up by the same family of resources waiting for the
574 # same conditions (e.g. LinuxApplications running on a same
575 # node share a single lock, so they will tend to be serialized).
576 # If we disorder the group list, this problem can be mitigated.
577 random.shuffle(group)
579 def wait_all_and_start(group):
582 if self.state(guid) < ResourceState.READY:
587 callback = functools.partial(wait_all_and_start, group)
588 self.schedule("1s", callback)
590 # If all resources are read, we schedule the start
592 rm = self.get_resource(guid)
593 self.schedule("0s", rm.start_with_conditions)
596 # Schedule the function that will check all resources are
597 # READY, and only then it will schedule the start.
598 # This is aimed to reduce the number of tasks looping in the scheduler.
599 # Intead of having N start tasks, we will have only one
600 callback = functools.partial(wait_all_and_start, group)
601 self.schedule("1s", callback)
604 rm = self.get_resource(guid)
605 self.schedule("0s", rm.deploy)
607 if not wait_all_ready:
608 self.schedule("1s", rm.start_with_conditions)
610 if rm.conditions.get(ResourceAction.STOP):
611 # Only if the RM has STOP conditions we
612 # schedule a stop. Otherwise the RM will stop immediately
613 self.schedule("2s", rm.stop_with_conditions)
615 def release(self, group = None):
616 """ Release the elements of the list 'group' or
617 all the resources if any group is specified
619 :param group: List of RM
624 group = self.resources
628 rm = self.get_resource(guid)
629 thread = threading.Thread(target=rm.release)
630 threads.append(thread)
631 thread.setDaemon(True)
634 while list(threads) and not self.finished:
636 # Time out after 5 seconds to check EC not terminated
638 if not thread.is_alive():
639 threads.remove(thread)
642 """ Shutdown the Experiment Controller.
643 Releases all the resources and stops task processing thread
648 # Mark the EC state as TERMINATED
649 self._state = ECState.TERMINATED
651 # Notify condition to wake up the processing thread
654 if self._thread.is_alive():
657 def schedule(self, date, callback, track = False):
658 """ Schedule a callback to be executed at time date.
660 :param date: string containing execution time for the task.
661 It can be expressed as an absolute time, using
662 timestamp format, or as a relative time matching
663 ^\d+.\d+(h|m|s|ms|us)$
665 :param callback: code to be executed for the task. Must be a
666 Python function, and receives args and kwargs
669 :param track: if set to True, the task will be retrivable with
670 the get_task() method
672 :return : The Id of the task
674 timestamp = stabsformat(date)
675 task = Task(timestamp, callback)
676 task = self._scheduler.schedule(task)
679 self._tasks[task.id] = task
681 # Notify condition to wake up the processing thread
687 """ Process scheduled tasks.
691 The _process method is executed in an independent thread held by the
692 ExperimentController for as long as the experiment is running.
694 Tasks are scheduled by invoking the schedule method with a target callback.
695 The schedule method is given a execution time which controls the
696 order in which tasks are processed.
698 Tasks are processed in parallel using multithreading.
699 The environmental variable NEPI_NTHREADS can be used to control
700 the number of threads used to process tasks. The default value is 50.
704 To execute tasks in parallel, an ParallelRunner (PR) object, holding
705 a pool of threads (workers), is used.
706 For each available thread in the PR, the next task popped from
707 the scheduler queue is 'put' in the PR.
708 Upon receiving a task to execute, each PR worker (thread) invokes the
709 _execute method of the EC, passing the task as argument.
710 This method, calls task.callback inside a try/except block. If an
711 exception is raised by the tasks.callback, it will be trapped by the
712 try block, logged to standard error (usually the console), and the EC
713 state will be set to ECState.FAILED.
714 The invocation of _notify immediately after, forces the processing
715 loop in the _process method, to wake up if it was blocked waiting for new
716 tasks to arrived, and to check the EC state.
717 As the EC is in FAILED state, the processing loop exits and the
718 'finally' block is invoked. In the 'finally' block, the 'sync' method
719 of the PR is invoked, which forces the PR to raise any unchecked errors
720 that might have been raised by the workers.
723 nthreads = int(os.environ.get("NEPI_NTHREADS", "50"))
725 runner = ParallelRun(maxthreads = nthreads)
729 while not self.finished:
732 task = self._scheduler.next()
735 # No task to execute. Wait for a new task to be scheduled.
738 # The task timestamp is in the future. Wait for timeout
739 # or until another task is scheduled.
741 if now < task.timestamp:
742 # Calculate timeout in seconds
743 timeout = tdiffsec(task.timestamp, now)
745 # Re-schedule task with the same timestamp
746 self._scheduler.schedule(task)
750 # Wait timeout or until a new task awakes the condition
751 self._cond.wait(timeout)
756 # Process tasks in parallel
757 runner.put(self._execute, task)
760 err = traceback.format_exc()
761 self.logger.error("Error while processing tasks in the EC: %s" % err)
763 self._state = ECState.FAILED
765 self.logger.debug("Exiting the task processing loop ... ")
768 def _execute(self, task):
769 """ Executes a single task.
771 :param task: Object containing the callback to execute
776 If the invokation of the task callback raises an
777 exception, the processing thread of the ExperimentController
778 will be stopped and the experiment will be aborted.
782 task.status = TaskStatus.DONE
785 task.result = task.callback()
788 err = traceback.format_exc()
790 task.status = TaskStatus.ERROR
792 self.logger.error("Error occurred while executing task: %s" % err)
794 # Set the EC to FAILED state (this will force to exit the task
796 self._state = ECState.FAILED
798 # Notify condition to wake up the processing thread
801 # Propage error to the ParallelRunner
805 """ Awakes the processing thread in case it is blocked waiting
806 for a new task to be scheduled.