#!/usr/bin/env python """ A multi-heart Heartbeat system using PUB and XREP sockets. pings are sent out on the PUB, and hearts are tracked based on their XREQ identities. Authors: * Min RK """ #----------------------------------------------------------------------------- # Copyright (C) 2010-2011 The IPython Development Team # # Distributed under the terms of the BSD License. The full license is in # the file COPYING, distributed as part of this software. #----------------------------------------------------------------------------- from __future__ import print_function import time import uuid import zmq from zmq.devices import ThreadDevice from zmq.eventloop import ioloop, zmqstream from IPython.config.configurable import LoggingConfigurable from IPython.utils.traitlets import Set, Instance, CFloat, Integer from IPython.parallel.util import asbytes, log_errors class Heart(object): """A basic heart object for responding to a HeartMonitor. This is a simple wrapper with defaults for the most common Device model for responding to heartbeats. It simply builds a threadsafe zmq.FORWARDER Device, defaulting to using SUB/XREQ for in/out. You can specify the XREQ's IDENTITY via the optional heart_id argument.""" device=None id=None def __init__(self, in_addr, out_addr, in_type=zmq.SUB, out_type=zmq.DEALER, heart_id=None): self.device = ThreadDevice(zmq.FORWARDER, in_type, out_type) # do not allow the device to share global Context.instance, # which is the default behavior in pyzmq > 2.1.10 self.device.context_factory = zmq.Context self.device.daemon=True self.device.connect_in(in_addr) self.device.connect_out(out_addr) if in_type == zmq.SUB: self.device.setsockopt_in(zmq.SUBSCRIBE, b"") if heart_id is None: heart_id = uuid.uuid4().bytes self.device.setsockopt_out(zmq.IDENTITY, heart_id) self.id = heart_id def start(self): return self.device.start() class HeartMonitor(LoggingConfigurable): """A basic HeartMonitor class pingstream: a PUB stream pongstream: an XREP stream period: the period of the heartbeat in milliseconds""" period = Integer(3000, config=True, help='The frequency at which the Hub pings the engines for heartbeats ' '(in ms)', ) pingstream=Instance('zmq.eventloop.zmqstream.ZMQStream') pongstream=Instance('zmq.eventloop.zmqstream.ZMQStream') loop = Instance('zmq.eventloop.ioloop.IOLoop') def _loop_default(self): return ioloop.IOLoop.instance() # not settable: hearts=Set() responses=Set() on_probation=Set() last_ping=CFloat(0) _new_handlers = Set() _failure_handlers = Set() lifetime = CFloat(0) tic = CFloat(0) def __init__(self, **kwargs): super(HeartMonitor, self).__init__(**kwargs) self.pongstream.on_recv(self.handle_pong) def start(self): self.tic = time.time() self.caller = ioloop.PeriodicCallback(self.beat, self.period, self.loop) self.caller.start() def add_new_heart_handler(self, handler): """add a new handler for new hearts""" self.log.debug("heartbeat::new_heart_handler: %s", handler) self._new_handlers.add(handler) def add_heart_failure_handler(self, handler): """add a new handler for heart failure""" self.log.debug("heartbeat::new heart failure handler: %s", handler) self._failure_handlers.add(handler) def beat(self): self.pongstream.flush() self.last_ping = self.lifetime toc = time.time() self.lifetime += toc-self.tic self.tic = toc self.log.debug("heartbeat::sending %s", self.lifetime) goodhearts = self.hearts.intersection(self.responses) missed_beats = self.hearts.difference(goodhearts) heartfailures = self.on_probation.intersection(missed_beats) newhearts = self.responses.difference(goodhearts) map(self.handle_new_heart, newhearts) map(self.handle_heart_failure, heartfailures) self.on_probation = missed_beats.intersection(self.hearts) self.responses = set() # print self.on_probation, self.hearts # self.log.debug("heartbeat::beat %.3f, %i beating hearts", self.lifetime, len(self.hearts)) self.pingstream.send(asbytes(str(self.lifetime))) # flush stream to force immediate socket send self.pingstream.flush() def handle_new_heart(self, heart): if self._new_handlers: for handler in self._new_handlers: handler(heart) else: self.log.info("heartbeat::yay, got new heart %s!", heart) self.hearts.add(heart) def handle_heart_failure(self, heart): if self._failure_handlers: for handler in self._failure_handlers: try: handler(heart) except Exception as e: self.log.error("heartbeat::Bad Handler! %s", handler, exc_info=True) pass else: self.log.info("heartbeat::Heart %s failed :(", heart) self.hearts.remove(heart) @log_errors def handle_pong(self, msg): "a heart just beat" current = asbytes(str(self.lifetime)) last = asbytes(str(self.last_ping)) if msg[1] == current: delta = time.time()-self.tic # self.log.debug("heartbeat::heart %r took %.2f ms to respond"%(msg[0], 1000*delta)) self.responses.add(msg[0]) elif msg[1] == last: delta = time.time()-self.tic + (self.lifetime-self.last_ping) self.log.warn("heartbeat::heart %r missed a beat, and took %.2f ms to respond", msg[0], 1000*delta) self.responses.add(msg[0]) else: self.log.warn("heartbeat::got bad heartbeat (possibly old?): %s (current=%.3f)", msg[1], self.lifetime) if __name__ == '__main__': loop = ioloop.IOLoop.instance() context = zmq.Context() pub = context.socket(zmq.PUB) pub.bind('tcp://127.0.0.1:5555') xrep = context.socket(zmq.ROUTER) xrep.bind('tcp://127.0.0.1:5556') outstream = zmqstream.ZMQStream(pub, loop) instream = zmqstream.ZMQStream(xrep, loop) hb = HeartMonitor(loop, outstream, instream) loop.start()