from __future__ import absolute_import, division import copy import functools import heapq import itertools import logging import random import threading # selectors in stdlib as of py3.4 try: import selectors # pylint: disable=import-error except ImportError: # vendored backport module from .vendor import selectors34 as selectors import socket import time from kafka.vendor import six from .cluster import ClusterMetadata from .conn import BrokerConnection, ConnectionStates, collect_hosts, get_ip_port_afi from . import errors as Errors from .future import Future from .metrics import AnonMeasurable from .metrics.stats import Avg, Count, Rate from .metrics.stats.rate import TimeUnit from .protocol.metadata import MetadataRequest from .protocol.produce import ProduceRequest from .vendor import socketpair from .version import __version__ if six.PY2: ConnectionError = None log = logging.getLogger('kafka.client') class KafkaClient(object): """ A network client for asynchronous request/response network I/O. This is an internal class used to implement the user-facing producer and consumer clients. This class is not thread-safe! Attributes: cluster (:any:`ClusterMetadata`): Local cache of cluster metadata, retrived via MetadataRequests during :meth:`.poll`. Keyword Arguments: bootstrap_servers: 'host[:port]' string (or list of 'host[:port]' strings) that the consumer should contact to bootstrap initial cluster metadata. This does not have to be the full node list. It just needs to have at least one broker that will respond to a Metadata API Request. Default port is 9092. If no servers are specified, will default to localhost:9092. client_id (str): a name for this client. This string is passed in each request to servers and can be used to identify specific server-side log entries that correspond to this client. Also submitted to GroupCoordinator for logging with respect to consumer group administration. Default: 'kafka-python-{version}' reconnect_backoff_ms (int): The amount of time in milliseconds to wait before attempting to reconnect to a given host. Default: 50. request_timeout_ms (int): Client request timeout in milliseconds. Default: 40000. retry_backoff_ms (int): Milliseconds to backoff when retrying on errors. Default: 100. max_in_flight_requests_per_connection (int): Requests are pipelined to kafka brokers up to this number of maximum requests per broker connection. Default: 5. receive_buffer_bytes (int): The size of the TCP receive buffer (SO_RCVBUF) to use when reading data. Default: None (relies on system defaults). Java client defaults to 32768. send_buffer_bytes (int): The size of the TCP send buffer (SO_SNDBUF) to use when sending data. Default: None (relies on system defaults). Java client defaults to 131072. socket_options (list): List of tuple-arguments to socket.setsockopt to apply to broker connection sockets. Default: [(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)] metadata_max_age_ms (int): The period of time in milliseconds after which we force a refresh of metadata even if we haven't seen any partition leadership changes to proactively discover any new brokers or partitions. Default: 300000 security_protocol (str): Protocol used to communicate with brokers. Valid values are: PLAINTEXT, SSL. Default: PLAINTEXT. ssl_context (ssl.SSLContext): pre-configured SSLContext for wrapping socket connections. If provided, all other ssl_* configurations will be ignored. Default: None. ssl_check_hostname (bool): flag to configure whether ssl handshake should verify that the certificate matches the brokers hostname. default: true. ssl_cafile (str): optional filename of ca file to use in certificate veriication. default: none. ssl_certfile (str): optional filename of file in pem format containing the client certificate, as well as any ca certificates needed to establish the certificate's authenticity. default: none. ssl_keyfile (str): optional filename containing the client private key. default: none. ssl_password (str): optional password to be used when loading the certificate chain. default: none. ssl_crlfile (str): optional filename containing the CRL to check for certificate expiration. By default, no CRL check is done. When providing a file, only the leaf certificate will be checked against this CRL. The CRL can only be checked with Python 3.4+ or 2.7.9+. default: none. api_version (tuple): Specify which Kafka API version to use. If set to None, KafkaClient will attempt to infer the broker version by probing various APIs. For the full list of supported versions, see KafkaClient.API_VERSIONS. Default: None api_version_auto_timeout_ms (int): number of milliseconds to throw a timeout exception from the constructor when checking the broker api version. Only applies if api_version is None selector (selectors.BaseSelector): Provide a specific selector implementation to use for I/O multiplexing. Default: selectors.DefaultSelector metrics (kafka.metrics.Metrics): Optionally provide a metrics instance for capturing network IO stats. Default: None. metric_group_prefix (str): Prefix for metric names. Default: '' sasl_mechanism (str): string picking sasl mechanism when security_protocol is SASL_PLAINTEXT or SASL_SSL. Currently only PLAIN is supported. Default: None sasl_plain_username (str): username for sasl PLAIN authentication. Default: None sasl_plain_password (str): password for sasl PLAIN authentication. Default: None """ DEFAULT_CONFIG = { 'bootstrap_servers': 'localhost', 'client_id': 'kafka-python-' + __version__, 'request_timeout_ms': 40000, 'reconnect_backoff_ms': 50, 'max_in_flight_requests_per_connection': 5, 'receive_buffer_bytes': None, 'send_buffer_bytes': None, 'socket_options': [(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)], 'retry_backoff_ms': 100, 'metadata_max_age_ms': 300000, 'security_protocol': 'PLAINTEXT', 'ssl_context': None, 'ssl_check_hostname': True, 'ssl_cafile': None, 'ssl_certfile': None, 'ssl_keyfile': None, 'ssl_password': None, 'ssl_crlfile': None, 'api_version': None, 'api_version_auto_timeout_ms': 2000, 'selector': selectors.DefaultSelector, 'metrics': None, 'metric_group_prefix': '', 'sasl_mechanism': None, 'sasl_plain_username': None, 'sasl_plain_password': None, } API_VERSIONS = [ (0, 10, 1), (0, 10, 0), (0, 10), (0, 9), (0, 8, 2), (0, 8, 1), (0, 8, 0) ] def __init__(self, **configs): self.config = copy.copy(self.DEFAULT_CONFIG) for key in self.config: if key in configs: self.config[key] = configs[key] if self.config['api_version'] is not None: assert self.config['api_version'] in self.API_VERSIONS, ( 'api_version [{0}] must be one of: {1}'.format( self.config['api_version'], str(self.API_VERSIONS))) self.cluster = ClusterMetadata(**self.config) self._topics = set() # empty set will fetch all topic metadata self._metadata_refresh_in_progress = False self._last_no_node_available_ms = 0 self._selector = self.config['selector']() self._conns = {} self._connecting = set() self._refresh_on_disconnects = True self._delayed_tasks = DelayedTaskQueue() self._last_bootstrap = 0 self._bootstrap_fails = 0 self._wake_r, self._wake_w = socket.socketpair() self._wake_r.setblocking(False) self._wake_lock = threading.Lock() self._selector.register(self._wake_r, selectors.EVENT_READ) self._closed = False self._sensors = None if self.config['metrics']: self._sensors = KafkaClientMetrics(self.config['metrics'], self.config['metric_group_prefix'], self._conns) self._bootstrap(collect_hosts(self.config['bootstrap_servers'])) # Check Broker Version if not set explicitly if self.config['api_version'] is None: check_timeout = self.config['api_version_auto_timeout_ms'] / 1000 self.config['api_version'] = self.check_version(timeout=check_timeout) def _bootstrap(self, hosts): log.info('Bootstrapping cluster metadata from %s', hosts) # Exponential backoff if bootstrap fails backoff_ms = self.config['reconnect_backoff_ms'] * 2 ** self._bootstrap_fails next_at = self._last_bootstrap + backoff_ms / 1000.0 self._refresh_on_disconnects = False now = time.time() if next_at > now: log.debug("Sleeping %0.4f before bootstrapping again", next_at - now) time.sleep(next_at - now) self._last_bootstrap = time.time() if self.config['api_version'] is None or self.config['api_version'] < (0, 10): metadata_request = MetadataRequest[0]([]) else: metadata_request = MetadataRequest[1](None) for host, port, afi in hosts: log.debug("Attempting to bootstrap via node at %s:%s", host, port) cb = functools.partial(self._conn_state_change, 'bootstrap') bootstrap = BrokerConnection(host, port, afi, state_change_callback=cb, node_id='bootstrap', **self.config) bootstrap.connect() while bootstrap.connecting(): bootstrap.connect() if not bootstrap.connected(): bootstrap.close() continue future = bootstrap.send(metadata_request) while not future.is_done: bootstrap.recv() if future.failed(): bootstrap.close() continue self.cluster.update_metadata(future.value) log.info('Bootstrap succeeded: found %d brokers and %d topics.', len(self.cluster.brokers()), len(self.cluster.topics())) # A cluster with no topics can return no broker metadata # in that case, we should keep the bootstrap connection if not len(self.cluster.brokers()): self._conns['bootstrap'] = bootstrap else: bootstrap.close() self._bootstrap_fails = 0 break # No bootstrap found... else: log.error('Unable to bootstrap from %s', hosts) # Max exponential backoff is 2^12, x4000 (50ms -> 200s) self._bootstrap_fails = min(self._bootstrap_fails + 1, 12) self._refresh_on_disconnects = True def _can_connect(self, node_id): if node_id not in self._conns: if self.cluster.broker_metadata(node_id): return True return False conn = self._conns[node_id] return conn.disconnected() and not conn.blacked_out() def _conn_state_change(self, node_id, conn): if conn.connecting(): # SSL connections can enter this state 2x (second during Handshake) if node_id not in self._connecting: self._connecting.add(node_id) self._selector.register(conn._sock, selectors.EVENT_WRITE) elif conn.connected(): log.debug("Node %s connected", node_id) if node_id in self._connecting: self._connecting.remove(node_id) try: self._selector.unregister(conn._sock) except KeyError: pass self._selector.register(conn._sock, selectors.EVENT_READ, conn) if self._sensors: self._sensors.connection_created.record() if 'bootstrap' in self._conns and node_id != 'bootstrap': bootstrap = self._conns.pop('bootstrap') # XXX: make conn.close() require error to cause refresh self._refresh_on_disconnects = False bootstrap.close() self._refresh_on_disconnects = True # Connection failures imply that our metadata is stale, so let's refresh elif conn.state is ConnectionStates.DISCONNECTING: if node_id in self._connecting: self._connecting.remove(node_id) try: self._selector.unregister(conn._sock) except KeyError: pass if self._sensors: self._sensors.connection_closed.record() if self._refresh_on_disconnects and not self._closed: log.warning("Node %s connection failed -- refreshing metadata", node_id) self.cluster.request_update() def _maybe_connect(self, node_id): """Idempotent non-blocking connection attempt to the given node id.""" if node_id not in self._conns: broker = self.cluster.broker_metadata(node_id) assert broker, 'Broker id %s not in current metadata' % node_id log.debug("Initiating connection to node %s at %s:%s", node_id, broker.host, broker.port) host, port, afi = get_ip_port_afi(broker.host) cb = functools.partial(self._conn_state_change, node_id) self._conns[node_id] = BrokerConnection(host, broker.port, afi, state_change_callback=cb, node_id=node_id, **self.config) conn = self._conns[node_id] if conn.connected(): return True conn.connect() return conn.connected() def ready(self, node_id, metadata_priority=True): """Check whether a node is connected and ok to send more requests. Arguments: node_id (int): the id of the node to check metadata_priority (bool): Mark node as not-ready if a metadata refresh is required. Default: True Returns: bool: True if we are ready to send to the given node """ self._maybe_connect(node_id) return self.is_ready(node_id, metadata_priority=metadata_priority) def connected(self, node_id): """Return True iff the node_id is connected.""" if node_id not in self._conns: return False return self._conns[node_id].connected() def close(self, node_id=None): """Close one or all broker connections. Arguments: node_id (int, optional): the id of the node to close """ if node_id is None: self._closed = True for conn in self._conns.values(): conn.close() self._wake_r.close() self._wake_w.close() self._selector.close() elif node_id in self._conns: self._conns[node_id].close() else: log.warning("Node %s not found in current connection list; skipping", node_id) return def is_disconnected(self, node_id): """Check whether the node connection has been disconnected or failed. A disconnected node has either been closed or has failed. Connection failures are usually transient and can be resumed in the next ready() call, but there are cases where transient failures need to be caught and re-acted upon. Arguments: node_id (int): the id of the node to check Returns: bool: True iff the node exists and is disconnected """ if node_id not in self._conns: return False return self._conns[node_id].disconnected() def connection_delay(self, node_id): """ Return the number of milliseconds to wait, based on the connection state, before attempting to send data. When disconnected, this respects the reconnect backoff time. When connecting, returns 0 to allow non-blocking connect to finish. When connected, returns a very large number to handle slow/stalled connections. Arguments: node_id (int): The id of the node to check Returns: int: The number of milliseconds to wait. """ if node_id not in self._conns: return 0 conn = self._conns[node_id] time_waited_ms = time.time() - (conn.last_attempt or 0) if conn.disconnected(): return max(self.config['reconnect_backoff_ms'] - time_waited_ms, 0) elif conn.connecting(): return 0 else: return 999999999 def is_ready(self, node_id, metadata_priority=True): """Check whether a node is ready to send more requests. In addition to connection-level checks, this method also is used to block additional requests from being sent during a metadata refresh. Arguments: node_id (int): id of the node to check metadata_priority (bool): Mark node as not-ready if a metadata refresh is required. Default: True Returns: bool: True if the node is ready and metadata is not refreshing """ if not self._can_send_request(node_id): return False # if we need to update our metadata now declare all requests unready to # make metadata requests first priority if metadata_priority: if self._metadata_refresh_in_progress: return False if self.cluster.ttl() == 0: return False return True def _can_send_request(self, node_id): if node_id not in self._conns: return False conn = self._conns[node_id] return conn.connected() and conn.can_send_more() def send(self, node_id, request): """Send a request to a specific node. Arguments: node_id (int): destination node request (Struct): request object (not-encoded) Raises: AssertionError: if node_id is not in current cluster metadata Returns: Future: resolves to Response struct or Error """ if not self._maybe_connect(node_id): return Future().failure(Errors.NodeNotReadyError(node_id)) return self._conns[node_id].send(request) def poll(self, timeout_ms=None, future=None, sleep=True, delayed_tasks=True): """Try to read and write to sockets. This method will also attempt to complete node connections, refresh stale metadata, and run previously-scheduled tasks. Arguments: timeout_ms (int, optional): maximum amount of time to wait (in ms) for at least one response. Must be non-negative. The actual timeout will be the minimum of timeout, request timeout and metadata timeout. Default: request_timeout_ms future (Future, optional): if provided, blocks until future.is_done sleep (bool): if True and there is nothing to do (no connections or requests in flight), will sleep for duration timeout before returning empty results. Default: False. Returns: list: responses received (can be empty) """ if timeout_ms is None: timeout_ms = self.config['request_timeout_ms'] responses = [] # Loop for futures, break after first loop if None while True: # Attempt to complete pending connections for node_id in list(self._connecting): self._maybe_connect(node_id) # Send a metadata request if needed metadata_timeout_ms = self._maybe_refresh_metadata() # Send scheduled tasks if delayed_tasks: for task, task_future in self._delayed_tasks.pop_ready(): try: result = task() except Exception as e: log.error("Task %s failed: %s", task, e) task_future.failure(e) else: task_future.success(result) # If we got a future that is already done, don't block in _poll if future and future.is_done: timeout = 0 else: timeout = min( timeout_ms, metadata_timeout_ms, self._delayed_tasks.next_at() * 1000, self.config['request_timeout_ms']) timeout = max(0, timeout / 1000.0) # avoid negative timeouts responses.extend(self._poll(timeout, sleep=sleep)) # If all we had was a timeout (future is None) - only do one poll # If we do have a future, we keep looping until it is done if not future or future.is_done: break return responses def _poll(self, timeout, sleep=True): # select on reads across all connected sockets, blocking up to timeout assert self.in_flight_request_count() > 0 or self._connecting or sleep responses = [] processed = set() start_select = time.time() ready = self._selector.select(timeout) end_select = time.time() if self._sensors: self._sensors.select_time.record((end_select - start_select) * 1000000000) for key, events in ready: if key.fileobj is self._wake_r: self._clear_wake_fd() continue elif not (events & selectors.EVENT_READ): continue conn = key.data processed.add(conn) if not conn.in_flight_requests: # if we got an EVENT_READ but there were no in-flight requests, one of # two things has happened: # # 1. The remote end closed the connection (because it died, or because # a firewall timed out, or whatever) # 2. The protocol is out of sync. # # either way, we can no longer safely use this connection # # Do a 1-byte read to check protocol didnt get out of sync, and then close the conn try: unexpected_data = key.fileobj.recv(1) if unexpected_data: # anything other than a 0-byte read means protocol issues log.warning('Protocol out of sync on %r, closing', conn) except socket.error: pass conn.close(Errors.ConnectionError('Socket EVENT_READ without in-flight-requests')) continue # Accumulate as many responses as the connection has pending while conn.in_flight_requests: response = conn.recv() # Note: conn.recv runs callbacks / errbacks # Incomplete responses are buffered internally # while conn.in_flight_requests retains the request if not response: break responses.append(response) # Check for additional pending SSL bytes if self.config['security_protocol'] in ('SSL', 'SASL_SSL'): # TODO: optimize for conn in self._conns.values(): if conn not in processed and conn.connected() and conn._sock.pending(): response = conn.recv() if response: responses.append(response) for conn in six.itervalues(self._conns): if conn.requests_timed_out(): log.warning('%s timed out after %s ms. Closing connection.', conn, conn.config['request_timeout_ms']) conn.close(error=Errors.RequestTimedOutError( 'Request timed out after %s ms' % conn.config['request_timeout_ms'])) if self._sensors: self._sensors.io_time.record((time.time() - end_select) * 1000000000) return responses def in_flight_request_count(self, node_id=None): """Get the number of in-flight requests for a node or all nodes. Arguments: node_id (int, optional): a specific node to check. If unspecified, return the total for all nodes Returns: int: pending in-flight requests for the node, or all nodes if None """ if node_id is not None: if node_id not in self._conns: return 0 return len(self._conns[node_id].in_flight_requests) else: return sum([len(conn.in_flight_requests) for conn in self._conns.values()]) def least_loaded_node(self): """Choose the node with fewest outstanding requests, with fallbacks. This method will prefer a node with an existing connection, but will potentially choose a node for which we don't yet have a connection if all existing connections are in use. This method will never choose a node that was disconnected within the reconnect backoff period. If all else fails, the method will attempt to bootstrap again using the bootstrap_servers list. Returns: node_id or None if no suitable node was found """ nodes = [broker.nodeId for broker in self.cluster.brokers()] random.shuffle(nodes) inflight = float('inf') found = None for node_id in nodes: conn = self._conns.get(node_id) connected = conn is not None and conn.connected() blacked_out = conn is not None and conn.blacked_out() curr_inflight = len(conn.in_flight_requests) if conn else 0 if connected and curr_inflight == 0: # if we find an established connection # with no in-flight requests, we can stop right away return node_id elif not blacked_out and curr_inflight < inflight: # otherwise if this is the best we have found so far, record that inflight = curr_inflight found = node_id if found is not None: return found # some broker versions return an empty list of broker metadata # if there are no topics created yet. the bootstrap process # should detect this and keep a 'bootstrap' node alive until # a non-bootstrap node is connected and non-empty broker # metadata is available elif 'bootstrap' in self._conns: return 'bootstrap' # Last option: try to bootstrap again # this should only happen if no prior bootstrap has been successful log.error('No nodes found in metadata -- retrying bootstrap') self._bootstrap(collect_hosts(self.config['bootstrap_servers'])) return None def set_topics(self, topics): """Set specific topics to track for metadata. Arguments: topics (list of str): topics to check for metadata Returns: Future: resolves after metadata request/response """ if set(topics).difference(self._topics): future = self.cluster.request_update() else: future = Future().success(set(topics)) self._topics = set(topics) return future def add_topic(self, topic): """Add a topic to the list of topics tracked via metadata. Arguments: topic (str): topic to track Returns: Future: resolves after metadata request/response """ if topic in self._topics: return Future().success(set(self._topics)) self._topics.add(topic) return self.cluster.request_update() # request metadata update on disconnect and timedout def _maybe_refresh_metadata(self): """Send a metadata request if needed. Returns: int: milliseconds until next refresh """ ttl = self.cluster.ttl() next_reconnect_ms = self._last_no_node_available_ms + self.cluster.refresh_backoff() next_reconnect_ms = max(next_reconnect_ms - time.time() * 1000, 0) wait_for_in_progress_ms = 9999999999 if self._metadata_refresh_in_progress else 0 timeout = max(ttl, next_reconnect_ms, wait_for_in_progress_ms) if timeout == 0: node_id = self.least_loaded_node() if node_id is None: log.debug("Give up sending metadata request since no node is available") # mark the timestamp for no node available to connect self._last_no_node_available_ms = time.time() * 1000 return timeout if self._can_send_request(node_id): topics = list(self._topics) if self.cluster.need_all_topic_metadata or not topics: topics = [] if self.config['api_version'] < (0, 10) else None api_version = 0 if self.config['api_version'] < (0, 10) else 1 request = MetadataRequest[api_version](topics) log.debug("Sending metadata request %s to node %s", request, node_id) future = self.send(node_id, request) future.add_callback(self.cluster.update_metadata) future.add_errback(self.cluster.failed_update) self._metadata_refresh_in_progress = True def refresh_done(val_or_error): self._metadata_refresh_in_progress = False future.add_callback(refresh_done) future.add_errback(refresh_done) elif self._can_connect(node_id): log.debug("Initializing connection to node %s for metadata request", node_id) self._maybe_connect(node_id) # If _maybe_connect failed immediately, this node will be put into blackout and we # should allow immediately retrying in case there is another candidate node. If it # is still connecting, the worst case is that we end up setting a longer timeout # on the next round and then wait for the response. else: # connected, but can't send more OR connecting # In either case, we just need to wait for a network event to let us know the selected # connection might be usable again. self._last_no_node_available_ms = time.time() * 1000 return timeout def schedule(self, task, at): """Schedule a new task to be executed at the given time. This is "best-effort" scheduling and should only be used for coarse synchronization. A task cannot be scheduled for multiple times simultaneously; any previously scheduled instance of the same task will be cancelled. Arguments: task (callable): task to be scheduled at (float or int): epoch seconds when task should run Returns: Future: resolves to result of task call, or exception if raised """ return self._delayed_tasks.add(task, at) def unschedule(self, task): """Unschedule a task. This will remove all instances of the task from the task queue. This is a no-op if the task is not scheduled. Arguments: task (callable): task to be unscheduled """ self._delayed_tasks.remove(task) def check_version(self, node_id=None, timeout=2, strict=False): """Attempt to guess the version of a Kafka broker. Note: It is possible that this method blocks longer than the specified timeout. This can happen if the entire cluster is down and the client enters a bootstrap backoff sleep. This is only possible if node_id is None. Returns: version tuple, i.e. (0, 10), (0, 9), (0, 8, 2), ... Raises: NodeNotReadyError (if node_id is provided) NoBrokersAvailable (if node_id is None) UnrecognizedBrokerVersion: please file bug if seen! AssertionError (if strict=True): please file bug if seen! """ end = time.time() + timeout while time.time() < end: # It is possible that least_loaded_node falls back to bootstrap, # which can block for an increasing backoff period try_node = node_id or self.least_loaded_node() if try_node is None: raise Errors.NoBrokersAvailable() self._maybe_connect(try_node) conn = self._conns[try_node] # We will intentionally cause socket failures # These should not trigger metadata refresh self._refresh_on_disconnects = False try: remaining = end - time.time() version = conn.check_version(timeout=remaining, strict=strict) return version except Errors.NodeNotReadyError: # Only raise to user if this is a node-specific request if node_id is not None: raise finally: self._refresh_on_disconnects = True # Timeout else: raise Errors.NoBrokersAvailable() def wakeup(self): with self._wake_lock: if self._wake_w.send(b'x') != 1: log.warning('Unable to send to wakeup socket!') def _clear_wake_fd(self): # reading from wake socket should only happen in a single thread while True: try: self._wake_r.recv(1024) except: break class DelayedTaskQueue(object): # see https://docs.python.org/2/library/heapq.html def __init__(self): self._tasks = [] # list of entries arranged in a heap self._task_map = {} # mapping of tasks to entries self._counter = itertools.count() # unique sequence count def add(self, task, at): """Add a task to run at a later time. Arguments: task: can be anything, but generally a callable at (float or int): epoch seconds to schedule task Returns: Future: a future that will be returned with the task when ready """ if task in self._task_map: self.remove(task) count = next(self._counter) future = Future() entry = [at, count, (task, future)] self._task_map[task] = entry heapq.heappush(self._tasks, entry) return future def remove(self, task): """Remove a previously scheduled task. Raises: KeyError: if task is not found """ entry = self._task_map.pop(task) task, future = entry[-1] future.failure(Errors.Cancelled) entry[-1] = 'REMOVED' def _drop_removed(self): while self._tasks and self._tasks[0][-1] is 'REMOVED': at, count, task = heapq.heappop(self._tasks) def _pop_next(self): self._drop_removed() if not self._tasks: raise KeyError('pop from an empty DelayedTaskQueue') _, _, maybe_task = heapq.heappop(self._tasks) if maybe_task is 'REMOVED': raise ValueError('popped a removed tasks from queue - bug') else: task, future = maybe_task del self._task_map[task] return (task, future) def next_at(self): """Number of seconds until next task is ready.""" self._drop_removed() if not self._tasks: return 9999999999 else: return max(self._tasks[0][0] - time.time(), 0) def pop_ready(self): """Pop and return a list of all ready (task, future) tuples""" ready_tasks = [] while self._tasks and self._tasks[0][0] < time.time(): try: task = self._pop_next() except KeyError: break ready_tasks.append(task) return ready_tasks class KafkaClientMetrics(object): def __init__(self, metrics, metric_group_prefix, conns): self.metrics = metrics self.metric_group_name = metric_group_prefix + '-metrics' self.connection_closed = metrics.sensor('connections-closed') self.connection_closed.add(metrics.metric_name( 'connection-close-rate', self.metric_group_name, 'Connections closed per second in the window.'), Rate()) self.connection_created = metrics.sensor('connections-created') self.connection_created.add(metrics.metric_name( 'connection-creation-rate', self.metric_group_name, 'New connections established per second in the window.'), Rate()) self.select_time = metrics.sensor('select-time') self.select_time.add(metrics.metric_name( 'select-rate', self.metric_group_name, 'Number of times the I/O layer checked for new I/O to perform per' ' second'), Rate(sampled_stat=Count())) self.select_time.add(metrics.metric_name( 'io-wait-time-ns-avg', self.metric_group_name, 'The average length of time the I/O thread spent waiting for a' ' socket ready for reads or writes in nanoseconds.'), Avg()) self.select_time.add(metrics.metric_name( 'io-wait-ratio', self.metric_group_name, 'The fraction of time the I/O thread spent waiting.'), Rate(time_unit=TimeUnit.NANOSECONDS)) self.io_time = metrics.sensor('io-time') self.io_time.add(metrics.metric_name( 'io-time-ns-avg', self.metric_group_name, 'The average length of time for I/O per select call in nanoseconds.'), Avg()) self.io_time.add(metrics.metric_name( 'io-ratio', self.metric_group_name, 'The fraction of time the I/O thread spent doing I/O'), Rate(time_unit=TimeUnit.NANOSECONDS)) metrics.add_metric(metrics.metric_name( 'connection-count', self.metric_group_name, 'The current number of active connections.'), AnonMeasurable( lambda config, now: len(conns)))