import contextlib import logging import os import socket import time from tornado import iostream LOGGER = logging.getLogger(__name__) SETTINGS_KEY = 'sprockets.mixins.metrics.statsd' """``self.settings`` key that configures this mix-in.""" class StatsdMixin(object): """Mix this class in to record metrics to a Statsd server.""" def initialize(self): super(StatsdMixin, self).initialize() def set_metric_tag(self, tag, value): """Ignored for statsd since it does not support tagging. :param str tag: name of the tag to set :param str value: value to assign """ pass def record_timing(self, duration, *path): """Record a timing. This method records a timing to the application's namespace followed by a calculated path. Each element of `path` is converted to a string and normalized before joining the elements by periods. The normalization process is little more than replacing periods with dashes. :param float duration: timing to record in seconds :param path: elements of the metric path to record """ self.application.statsd.send(path, duration * 1000.0, 'ms') def increase_counter(self, *path, **kwargs): """Increase a counter. This method increases a counter within the application's namespace. Each element of `path` is converted to a string and normalized before joining the elements by periods. The normalization process is little more than replacing periods with dashes. :param path: elements of the metric path to incr :keyword int amount: amount to increase the counter by. If omitted, the counter is increased by one. """ self.application.statsd.send(path, kwargs.get('amount', '1'), 'c') @contextlib.contextmanager def execution_timer(self, *path): """ Record the time it takes to perform an arbitrary code block. :param path: elements of the metric path to record This method returns a context manager that records the amount of time spent inside of the context and submits a timing metric to the specified `path` using (:meth:`record_timing`). """ start = time.time() try: yield finally: self.record_timing(max(start, time.time()) - start, *path) def on_finish(self): """ Records the time taken to process the request. This method records the amount of time taken to process the request (as reported by :meth:`~tornado.httputil.HTTPServerRequest.request_time`) under the path defined by the class's module, it's name, the request method, and the status code. The :meth:`.record_timing` method is used to send the metric, so the configured namespace is used as well. """ super(StatsdMixin, self).on_finish() self.record_timing(self.request.request_time(), self.__class__.__name__, self.request.method, self.get_status()) class StatsDCollector(object): """Collects and submits stats to StatsD. This class should be constructed using the :meth:`~sprockets.mixins.statsd.install` method. When installed, it is attached to the :class:`~tornado.web.Application` instance for your web application. :param str host: The StatsD host :param str port: The StatsD port :param str protocol: The StatsD protocol. May be either ``udp`` or ``tcp``. :param str namespace: The StatsD bucket to write metrics into. :param bool prepend_metric_type: Optional flag to prepend bucket path with the StatsD metric type """ METRIC_TYPES = {'c': 'counters', 'ms': 'timers'} def __init__(self, host, port, protocol='udp', namespace='sprockets', prepend_metric_type=True): self._host = host self._port = int(port) self._address = (self._host, self._port) self._namespace = namespace self._prepend_metric_type = prepend_metric_type if protocol == 'tcp': self._tcp = True self._sock = self._tcp_socket() elif protocol == 'udp': self._tcp = False self._sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, 0) else: raise ValueError('Invalid protocol: {}'.format(protocol)) def _tcp_socket(self): """Connect to statsd via TCP and return the IOStream handle. :rtype: iostream.IOStream """ sock = iostream.IOStream(socket.socket( socket.AF_INET, socket.SOCK_STREAM, socket.IPPROTO_TCP)) try: sock.connect(self._address, self._tcp_on_connected) except (OSError, socket.error) as error: LOGGER.error('Failed to connect via TCP: %s', error) sock.set_close_callback(self._tcp_on_closed) return sock def _tcp_on_closed(self): """Invoked when the socket is closed.""" LOGGER.warning('Disconnected from statsd, reconnecting') self._sock = self._tcp_socket() def _tcp_on_connected(self): """Invoked when the IOStream is connected""" LOGGER.debug('Connected to statsd at %s via TCP', self._address) def send(self, path, value, metric_type): """Send a metric to Statsd. :param list path: The metric path to record :param mixed value: The value to record :param str metric_type: The metric type """ msg = '{0}:{1}|{2}'.format( self._build_path(path, metric_type), value, metric_type) msg = self._build_udp_or_tcp_message(msg) LOGGER.debug('Sending %s to %s:%s', msg.encode('ascii'), self._host, self._port) try: if self._tcp: return self._sock.write(msg.encode('ascii')) self._sock.sendto(msg.encode('ascii'), (self._host, self._port)) except (OSError, socket.error) as error: # pragma: nocover LOGGER.exception('Error sending statsd metric: %s', error) def _build_udp_or_tcp_message(self, msg): if self._tcp is False: return msg return msg + "\n" def _build_path(self, path, metric_type): """Return a normalized path. :param list path: elements of the metric path to record :param str metric_type: The metric type :rtype: str """ path = self._get_prefixes(metric_type) + list(path) return '{}.{}'.format(self._namespace, '.'.join(str(p).replace('.', '-') for p in path)) def _get_prefixes(self, metric_type): """Get prefixes where applicable Add metric prefix counters, timers respectively if :attr:`prepend_metric_type` flag is True. :param str metric_type: The metric type :rtype: list """ prefixes = [] if self._prepend_metric_type: prefixes.append(self.METRIC_TYPES[metric_type]) return prefixes def install(application, **kwargs): """Call this to install StatsD for the Tornado application. :param tornado.web.Application application: the application to install the collector into. :param kwargs: keyword parameters to pass to the :class:`StatsDCollector` initializer. :returns: :data:`True` if the client was installed successfully, or :data:`False` otherwise. - **host** The StatsD host. If host is not specified, the ``STATSD_HOST`` environment variable, or default `127.0.0.1`, will be pass into the :class:`StatsDCollector`. - **port** The StatsD port. If port is not specified, the ``STATSD_PORT`` environment variable, or default `8125`, will be pass into the :class:`StatsDCollector`. - **namespace** The StatsD bucket to write metrics into. """ if getattr(application, 'statsd', None) is not None: LOGGER.warning('Statsd collector is already installed') return False if 'host' not in kwargs: kwargs['host'] = os.environ.get('STATSD_HOST', '127.0.0.1') if 'port' not in kwargs: kwargs['port'] = os.environ.get('STATSD_PORT', '8125') if 'protocol' not in kwargs: kwargs['protocol'] = os.environ.get('STATSD_PROTOCOL', 'udp') setattr(application, 'statsd', StatsDCollector(**kwargs)) return True