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>
20 from nepi.util import guid
21 from nepi.util.parallel import ParallelRun
22 from nepi.util.timefuncs import tnow, tdiffsec, stabsformat, tsformat
23 from nepi.execution.resource import ResourceFactory, ResourceAction, \
24 ResourceState, ResourceState2str
25 from nepi.execution.scheduler import HeapScheduler, Task, TaskStatus
26 from nepi.execution.trace import TraceAttr
28 # TODO: use multiprocessing instead of threading
29 # TODO: Allow to reconnect to a running experiment instance! (reconnect mode vs deploy mode)
40 class FailureLevel(object):
41 """ Describes the system failure state
47 class FailureManager(object):
48 """ The FailureManager is responsible for handling errors,
49 and deciding whether an experiment should be aborted
52 def __init__(self, ec):
53 self._ec = weakref.ref(ec)
54 self._failure_level = FailureLevel.OK
58 """ Returns the Experiment Controller """
63 if self._failure_level == FailureLevel.OK:
64 for guid in self.ec.resources:
65 state = self.ec.state(guid)
66 critical = self.ec.get(guid, "critical")
68 if state == ResourceState.FAILED and critical:
69 self._failure_level = FailureLevel.RM_FAILURE
70 self.ec.logger.debug("RM critical failure occurred on guid %d." \
71 " Setting EC FAILURE LEVEL to RM_FAILURE" % guid)
74 return self._failure_level != FailureLevel.OK
76 def set_ec_failure(self):
77 self._failure_level = FailureLevel.EC_FAILURE
80 class ECState(object):
81 """ State of the Experiment Controller
88 class ExperimentController(object):
90 .. class:: Class Args :
92 :param exp_id: Human readable identifier for the experiment scenario.
97 An experiment, or scenario, is defined by a concrete set of resources,
98 behavior, configuration and interconnection of those resources.
99 The Experiment Description (ED) is a detailed representation of a
100 single experiment. It contains all the necessary information to
101 allow repeating the experiment. NEPI allows to describe
102 experiments by registering components (resources), configuring them
103 and interconnecting them.
105 A same experiment (scenario) can be executed many times, generating
106 different results. We call an experiment execution (instance) a 'run'.
108 The ExperimentController (EC), is the entity responsible of
109 managing an experiment run. The same scenario can be
110 recreated (and re-run) by instantiating an EC and recreating
111 the same experiment description.
113 In NEPI, an experiment is represented as a graph of interconnected
114 resources. A resource is a generic concept in the sense that any
115 component taking part of an experiment, whether physical of
116 virtual, is considered a resource. A resources could be a host,
117 a virtual machine, an application, a simulator, a IP address.
119 A ResourceManager (RM), is the entity responsible for managing a
120 single resource. ResourceManagers are specific to a resource
121 type (i.e. An RM to control a Linux application will not be
122 the same as the RM used to control a ns-3 simulation).
123 To support a new type of resource in NEPI, a new RM must be
124 implemented. NEPI already provides a variety of
125 RMs to control basic resources, and new can be extended from
128 Through the EC interface the user can create ResourceManagers (RMs),
129 configure them and interconnect them, to describe an experiment.
130 Describing an experiment through the EC does not run the experiment.
131 Only when the 'deploy()' method is invoked on the EC, the EC will take
132 actions to transform the 'described' experiment into a 'running' experiment.
134 While the experiment is running, it is possible to continue to
135 create/configure/connect RMs, and to deploy them to involve new
136 resources in the experiment (this is known as 'interactive' deployment).
138 An experiments in NEPI is identified by a string id,
139 which is either given by the user, or automatically generated by NEPI.
140 The purpose of this identifier is to separate files and results that
141 belong to different experiment scenarios.
142 However, since a same 'experiment' can be run many times, the experiment
143 id is not enough to identify an experiment instance (run).
144 For this reason, the ExperimentController has two identifier, the
145 exp_id, which can be re-used in different ExperimentController,
146 and the run_id, which is unique to one ExperimentController instance, and
147 is automatically generated by NEPI.
151 def __init__(self, exp_id = None):
152 super(ExperimentController, self).__init__()
154 self._logger = logging.getLogger("ExperimentController")
156 # Run identifier. It identifies a concrete execution instance (run)
158 # Since a same experiment (same configuration) can be executed many
159 # times, this run_id permits to separate result files generated on
160 # different experiment executions
161 self._run_id = tsformat()
163 # Experiment identifier. Usually assigned by the user
164 # Identifies the experiment scenario (i.e. configuration,
165 # resources used, etc)
166 self._exp_id = exp_id or "exp-%s" % os.urandom(8).encode('hex')
168 # generator of globally unique ids
169 self._guid_generator = guid.GuidGenerator()
172 self._resources = dict()
174 # Scheduler. It a queue that holds tasks scheduled for
175 # execution, and yields the next task to be executed
176 # ordered by execution and arrival time
177 self._scheduler = HeapScheduler()
182 # RM groups (for deployment)
183 self._groups = dict()
185 # generator of globally unique id for groups
186 self._group_id_generator = guid.GuidGenerator()
188 # Flag to stop processing thread
191 # Entity in charge of managing system failures
192 self._fm = FailureManager(self)
195 self._state = ECState.RUNNING
197 # The runner is a pool of threads used to parallelize
199 nthreads = int(os.environ.get("NEPI_NTHREADS", "50"))
200 self._runner = ParallelRun(maxthreads = nthreads)
202 # Event processing thread
203 self._cond = threading.Condition()
204 self._thread = threading.Thread(target = self._process)
205 self._thread.setDaemon(True)
210 """ Return the logger of the Experiment Controller
217 """ Return the state of the Experiment Controller
224 """ Return the experiment id assigned by the user
231 """ Return the experiment instance (run) identifier
238 return self._fm.abort
240 def wait_finished(self, guids):
241 """ Blocking method that wait until all RMs in the 'guid' list
242 reach a state >= STOPPED (i.e. FINISHED, STOPPED, FAILED or
243 RELEASED ) or until a System Failure occurs (e.g. Task Failure)
245 :param guids: List of guids
253 return self.wait(guids, state = ResourceState.STOPPED,
256 def wait_started(self, guids):
257 """ Blocking method that wait until all RMs in the 'guid' list
258 reach a state >= STARTED or until a System Failure occurs
261 :param guids: List of guids
268 return self.wait(guids, state = ResourceState.STARTED,
271 def wait_released(self, guids):
272 """ Blocking method that wait until all RMs in the 'guid' list
273 reach a state = RELEASED or until the EC fails
275 :param guids: List of guids
280 return self._state == ECState.FAILED
282 return self.wait(guids, state = ResourceState.RELEASED,
285 def wait_deployed(self, guids):
286 """ Blocking method that wait until all RMs in the 'guid' list
287 reach a state >= READY or until a System Failure occurs
290 :param guids: List of guids
297 return self.wait(guids, state = ResourceState.READY,
300 def wait(self, guids, state, quit):
301 """ Blocking method that wait until all RMs in the 'guid' list
302 reach a state >= 'state' or until quit yileds True
304 :param guids: List of guids
307 if isinstance(guids, int):
310 # Make a copy to avoid modifying the original guids list
314 # If there are no more guids to wait for
315 # or the quit function returns True, exit the loop
316 if len(guids) == 0 or quit():
319 # If a guid reached one of the target states, remove it from list
321 rstate = self.state(guid)
323 hrrstate = ResourceState2str.get(rstate)
324 hrstate = ResourceState2str.get(state)
328 self.logger.debug(" guid %d DONE - state is %s, required is >= %s " % (
329 guid, hrrstate, hrstate))
332 self.logger.debug(" WAITING FOR guid %d - state is %s, required is >= %s " % (
333 guid, hrrstate, hrstate))
336 def get_task(self, tid):
337 """ Get a specific task
339 :param tid: Id of the task
343 return self._tasks.get(tid)
345 def get_resource(self, guid):
346 """ Get a specific Resource Manager
348 :param guid: Id of the task
350 :rtype: ResourceManager
352 return self._resources.get(guid)
356 """ Returns the list of all the Resource Manager Id
361 return self._resources.keys()
363 def register_resource(self, rtype, guid = None):
364 """ Register a Resource Manager. It creates a new 'guid', if it is not specified,
365 for the RM of type 'rtype' and add it to the list of Resources.
367 :param rtype: Type of the RM
369 :return: Id of the RM
372 # Get next available guid
373 guid = self._guid_generator.next(guid)
376 rm = ResourceFactory.create(rtype, self, guid)
379 self._resources[guid] = rm
383 def get_attributes(self, guid):
384 """ Return all the attibutes of a specific RM
386 :param guid: Guid of the RM
388 :return: List of attributes
391 rm = self.get_resource(guid)
392 return rm.get_attributes()
394 def register_connection(self, guid1, guid2):
395 """ Registers a guid1 with a guid2.
396 The declaration order is not important
398 :param guid1: First guid to connect
399 :type guid1: ResourceManager
401 :param guid2: Second guid to connect
402 :type guid: ResourceManager
404 rm1 = self.get_resource(guid1)
405 rm2 = self.get_resource(guid2)
407 rm1.register_connection(guid2)
408 rm2.register_connection(guid1)
410 def register_condition(self, guids1, action, guids2, state,
412 """ Registers an action START or STOP for all RM on guids1 to occur
413 time 'time' after all elements in guids2 reached state 'state'.
415 :param guids1: List of guids of RMs subjected to action
418 :param action: Action to register (either START or STOP)
419 :type action: ResourceAction
421 :param guids2: List of guids of RMs to we waited for
424 :param state: State to wait for on RMs (STARTED, STOPPED, etc)
425 :type state: ResourceState
427 :param time: Time to wait after guids2 has reached status
431 if isinstance(guids1, int):
433 if isinstance(guids2, int):
437 rm = self.get_resource(guid1)
438 rm.register_condition(action, guids2, state, time)
440 def enable_trace(self, guid, name):
443 :param name: Name of the trace
446 rm = self.get_resource(guid)
447 rm.enable_trace(name)
449 def trace_enabled(self, guid, name):
450 """ Returns True if trace is enabled
452 :param name: Name of the trace
455 rm = self.get_resource(guid)
456 return rm.trace_enabled(name)
458 def trace(self, guid, name, attr = TraceAttr.ALL, block = 512, offset = 0):
459 """ Get information on collected trace
461 :param name: Name of the trace
464 :param attr: Can be one of:
465 - TraceAttr.ALL (complete trace content),
466 - TraceAttr.STREAM (block in bytes to read starting at offset),
467 - TraceAttr.PATH (full path to the trace file),
468 - TraceAttr.SIZE (size of trace file).
471 :param block: Number of bytes to retrieve from trace, when attr is TraceAttr.STREAM
474 :param offset: Number of 'blocks' to skip, when attr is TraceAttr.STREAM
479 rm = self.get_resource(guid)
480 return rm.trace(name, attr, block, offset)
482 def discover(self, guid):
483 """ Discover a specific RM defined by its 'guid'
485 :param guid: Guid of the RM
489 rm = self.get_resource(guid)
492 def provision(self, guid):
493 """ Provision a specific RM defined by its 'guid'
495 :param guid: Guid of the RM
499 rm = self.get_resource(guid)
500 return rm.provision()
502 def get(self, guid, name):
503 """ Get a specific attribute 'name' from the RM 'guid'
505 :param guid: Guid of the RM
508 :param name: attribute's name
512 rm = self.get_resource(guid)
515 def set(self, guid, name, value):
516 """ Set a specific attribute 'name' from the RM 'guid'
517 with the value 'value'
519 :param guid: Guid of the RM
522 :param name: attribute's name
525 :param value: attribute's value
528 rm = self.get_resource(guid)
529 return rm.set(name, value)
531 def state(self, guid, hr = False):
532 """ Returns the state of a resource
534 :param guid: Resource guid
537 :param hr: Human readable. Forces return of a
538 status string instead of a number
542 rm = self.get_resource(guid)
546 return ResourceState2str.get(state)
550 def stop(self, guid):
551 """ Stop a specific RM defined by its 'guid'
553 :param guid: Guid of the RM
557 rm = self.get_resource(guid)
560 def start(self, guid):
561 """ Start a specific RM defined by its 'guid'
563 :param guid: Guid of the RM
567 rm = self.get_resource(guid)
570 def set_with_conditions(self, name, value, guids1, guids2, state,
572 """ Set value 'value' on attribute with name 'name' on all RMs of
573 guids1 when 'time' has elapsed since all elements in guids2
574 have reached state 'state'.
576 :param name: Name of attribute to set in RM
579 :param value: Value of attribute to set in RM
582 :param guids1: List of guids of RMs subjected to action
585 :param action: Action to register (either START or STOP)
586 :type action: ResourceAction
588 :param guids2: List of guids of RMs to we waited for
591 :param state: State to wait for on RMs (STARTED, STOPPED, etc)
592 :type state: ResourceState
594 :param time: Time to wait after guids2 has reached status
598 if isinstance(guids1, int):
600 if isinstance(guids2, int):
604 rm = self.get_resource(guid)
605 rm.set_with_conditions(name, value, guids2, state, time)
607 def deploy(self, guids = None, wait_all_ready = True, group = None):
608 """ Deploy all resource manager in guids list
610 :param guids: List of guids of RMs to deploy
613 :param wait_all_ready: Wait until all RMs are ready in
614 order to start the RMs
617 :param group: Id of deployment group in which to deploy RMs
621 self.logger.debug(" ------- DEPLOY START ------ ")
624 # If no guids list was passed, all 'NEW' RMs will be deployed
626 for guid in self.resources:
627 if self.state(guid) == ResourceState.NEW:
630 if isinstance(guids, int):
633 # Create deployment group
634 # New guids can be added to a same deployment group later on
638 group = self._group_id_generator.next()
640 if group not in self._groups:
641 self._groups[group] = []
643 self._groups[group].extend(guids)
645 def wait_all_and_start(group):
646 # Function that checks if all resources are READY
647 # before scheduling a start_with_conditions for each RM
650 # Get all guids in group
651 guids = self._groups[group]
654 if self.state(guid) < ResourceState.READY:
659 callback = functools.partial(wait_all_and_start, group)
660 self.schedule("1s", callback)
662 # If all resources are ready, we schedule the start
664 rm = self.get_resource(guid)
665 self.schedule("0s", rm.start_with_conditions)
667 if wait_all_ready and new_group:
668 # Schedule a function to check that all resources are
669 # READY, and only then schedule the start.
670 # This aims at reducing the number of tasks looping in the
672 # Instead of having many start tasks, we will have only one for
674 callback = functools.partial(wait_all_and_start, group)
675 self.schedule("0s", callback)
678 rm = self.get_resource(guid)
679 rm.deployment_group = group
680 self.schedule("0s", rm.deploy_with_conditions)
682 if not wait_all_ready:
683 self.schedule("0s", rm.start_with_conditions)
685 if rm.conditions.get(ResourceAction.STOP):
686 # Only if the RM has STOP conditions we
687 # schedule a stop. Otherwise the RM will stop immediately
688 self.schedule("0s", rm.stop_with_conditions)
690 def release(self, guids = None):
691 """ Release al RMs on the guids list or
692 all the resources if no list is specified
694 :param guids: List of RM guids
699 guids = self.resources
701 # Remove all pending tasks from the scheduler queue
702 for tid in list(self._scheduler.pending):
703 self._scheduler.remove(tid)
708 rm = self.get_resource(guid)
709 self.schedule("0s", rm.release)
711 self.wait_released(guids)
714 """ Shutdown the Experiment Controller.
715 Releases all the resources and stops task processing thread
718 # If there was a major failure we can't exit gracefully
719 if self._state == ECState.FAILED:
720 raise RuntimeError("EC failure. Can not exit gracefully")
724 # Mark the EC state as TERMINATED
725 self._state = ECState.TERMINATED
727 # Stop processing thread
730 # Notify condition to wake up the processing thread
733 if self._thread.is_alive():
736 def schedule(self, date, callback, track = False):
737 """ Schedule a callback to be executed at time date.
739 :param date: string containing execution time for the task.
740 It can be expressed as an absolute time, using
741 timestamp format, or as a relative time matching
742 ^\d+.\d+(h|m|s|ms|us)$
744 :param callback: code to be executed for the task. Must be a
745 Python function, and receives args and kwargs
748 :param track: if set to True, the task will be retrivable with
749 the get_task() method
751 :return : The Id of the task
753 timestamp = stabsformat(date)
754 task = Task(timestamp, callback)
755 task = self._scheduler.schedule(task)
758 self._tasks[task.id] = task
760 # Notify condition to wake up the processing thread
766 """ Process scheduled tasks.
770 The _process method is executed in an independent thread held by the
771 ExperimentController for as long as the experiment is running.
773 Tasks are scheduled by invoking the schedule method with a target callback.
774 The schedule method is given a execution time which controls the
775 order in which tasks are processed.
777 Tasks are processed in parallel using multithreading.
778 The environmental variable NEPI_NTHREADS can be used to control
779 the number of threads used to process tasks. The default value is 50.
783 To execute tasks in parallel, an ParallelRunner (PR) object, holding
784 a pool of threads (workers), is used.
785 For each available thread in the PR, the next task popped from
786 the scheduler queue is 'put' in the PR.
787 Upon receiving a task to execute, each PR worker (thread) invokes the
788 _execute method of the EC, passing the task as argument.
789 This method, calls task.callback inside a try/except block. If an
790 exception is raised by the tasks.callback, it will be trapped by the
791 try block, logged to standard error (usually the console), and the EC
792 state will be set to ECState.FAILED.
793 The invocation of _notify immediately after, forces the processing
794 loop in the _process method, to wake up if it was blocked waiting for new
795 tasks to arrived, and to check the EC state.
796 As the EC is in FAILED state, the processing loop exits and the
797 'finally' block is invoked. In the 'finally' block, the 'sync' method
798 of the PR is invoked, which forces the PR to raise any unchecked errors
799 that might have been raised by the workers.
805 while not self._stop:
809 task = self._scheduler.next()
812 # No task to execute. Wait for a new task to be scheduled.
815 # The task timestamp is in the future. Wait for timeout
816 # or until another task is scheduled.
818 if now < task.timestamp:
819 # Calculate timeout in seconds
820 timeout = tdiffsec(task.timestamp, now)
822 # Re-schedule task with the same timestamp
823 self._scheduler.schedule(task)
827 # Wait timeout or until a new task awakes the condition
828 self._cond.wait(timeout)
833 # Process tasks in parallel
834 self._runner.put(self._execute, task)
837 err = traceback.format_exc()
838 self.logger.error("Error while processing tasks in the EC: %s" % err)
840 # Set the EC to FAILED state
841 self._state = ECState.FAILED
843 # Set the FailureManager failure level to EC failure
844 self._fm.set_ec_failure()
846 self.logger.debug("Exiting the task processing loop ... ")
849 self._runner.destroy()
851 def _execute(self, task):
852 """ Executes a single task.
854 :param task: Object containing the callback to execute
859 If the invokation of the task callback raises an
860 exception, the processing thread of the ExperimentController
861 will be stopped and the experiment will be aborted.
865 task.status = TaskStatus.DONE
868 task.result = task.callback()
871 err = traceback.format_exc()
873 task.status = TaskStatus.ERROR
875 self.logger.error("Error occurred while executing task: %s" % err)
878 """ Awakes the processing thread in case it is blocked waiting
879 for a new task to be scheduled.