def __init__(self, server_description, topology, pool, topology_settings):
"""Class to monitor a MongoDB server on a background thread.
Pass an initial ServerDescription, a Topology, a Pool, and
TopologySettings.
The Topology is weakly referenced. The Pool must be exclusive to this
Monitor.
"""
self._server_description = server_description
self._pool = pool
self._settings = topology_settings
self._avg_round_trip_time = MovingAverage()
# We strongly reference the executor and it weakly references us via
# this closure. When the monitor is freed, stop the executor soon.
def target():
monitor = self_ref()
if monitor is None:
return False # Stop the executor.
Monitor._run(monitor)
return True
executor = periodic_executor.PeriodicExecutor(
condition_class=self._settings.condition_class,
interval=common.HEARTBEAT_FREQUENCY,
min_interval=common.MIN_HEARTBEAT_INTERVAL,
target=target,
name="pymongo_server_monitor_thread")
self._executor = executor
# Avoid cycles. When self or topology is freed, stop executor soon.
self_ref = weakref.ref(self, executor.close)
self._topology = weakref.proxy(topology, executor.close)
class _RttMonitor(MonitorBase):
def __init__(self, topology, topology_settings, pool):
"""Maintain round trip times for a server.
The Topology is weakly referenced.
"""
super(_RttMonitor, self).__init__(
topology,
"pymongo_server_rtt_thread",
topology_settings.heartbeat_frequency,
common.MIN_HEARTBEAT_INTERVAL,
)
self._pool = pool
self._moving_average = MovingAverage()
self._lock = threading.Lock()
def close(self):
self.gc_safe_close()
# Increment the generation and maybe close the socket. If the executor
# thread has the socket checked out, it will be closed when checked in.
self._pool.reset()
def add_sample(self, sample):
"""Add a RTT sample."""
with self._lock:
self._moving_average.add_sample(sample)
def average(self):
"""Get the calculated average, or None if no samples yet."""
with self._lock:
return self._moving_average.get()
def reset(self):
"""Reset the average RTT."""
with self._lock:
return self._moving_average.reset()
def _run(self):
try:
# NOTE: This thread is only run when when using the streaming
# heartbeat protocol (MongoDB 4.4+).
# XXX: Skip check if the server is unknown?
rtt = self._ping()
self.add_sample(rtt)
except ReferenceError:
# Topology was garbage-collected.
self.close()
except Exception:
self._pool.reset()
def _ping(self):
"""Run a "hello" command and return the RTT."""
with self._pool.get_socket() as sock_info:
if self._executor._stopped:
raise Exception("_RttMonitor closed")
start = time.monotonic()
sock_info.hello()
return time.monotonic() - start
def __init__(self, topology, topology_settings, pool):
"""Maintain round trip times for a server.
The Topology is weakly referenced.
"""
super(_RttMonitor,
self).__init__(topology, "pymongo_server_rtt_thread",
topology_settings.heartbeat_frequency,
common.MIN_HEARTBEAT_INTERVAL)
self._pool = pool
self._moving_average = MovingAverage()
self._lock = threading.Lock()
def test_moving_average(self):
avg = MovingAverage([10])
self.assertEqual(10, avg.get())
avg2 = avg.clone_with(20)
self.assertEqual(15, avg2.get())
avg3 = avg2.clone_with(30)
self.assertEqual(20, avg3.get())
avg4 = avg3.clone_with(-100)
self.assertEqual((10 + 20 + 30 - 100) / 4., avg4.get())
avg5 = avg4.clone_with(17)
self.assertEqual((10 + 20 + 30 - 100 + 17) / 5., avg5.get())
avg6 = avg5.clone_with(43)
self.assertEqual((20 + 30 - 100 + 17 + 43) / 5., avg6.get())
avg7 = avg6.clone_with(-1111)
self.assertEqual((30 - 100 + 17 + 43 - 1111) / 5., avg7.get())
def test_moving_average(self):
avg = MovingAverage([10])
self.assertEqual(10, avg.get())
avg2 = avg.clone_with(20)
self.assertEqual(15, avg2.get())
avg3 = avg2.clone_with(30)
self.assertEqual(20, avg3.get())
avg4 = avg3.clone_with(-100)
self.assertEqual((10 + 20 + 30 - 100) / 4., avg4.get())
avg5 = avg4.clone_with(17)
self.assertEqual((10 + 20 + 30 - 100 + 17) / 5., avg5.get())
avg6 = avg5.clone_with(43)
self.assertEqual((20 + 30 - 100 + 17 + 43) / 5., avg6.get())
avg7 = avg6.clone_with(-1111)
self.assertEqual((30 - 100 + 17 + 43 - 1111) / 5., avg7.get())
def __init__(self, server_description, topology, pool,
topology_settings):
"""Have to copy entire constructor from Monitor so that we
can override _run and change the periodic executor's
interval."""
self._server_description = server_description
self._pool = pool
self._settings = topology_settings
self._avg_round_trip_time = MovingAverage()
options = self._settings._pool_options
self._listeners = options.event_listeners
self._publish = self._listeners is not None
def target():
monitor = self_ref()
if monitor is None:
return False
MockMonitor._run(monitor) # Change target to subclass
return True
# Shorten interval
executor = periodic_executor.PeriodicExecutor(
interval=0.1,
min_interval=0.1,
target=target,
name="pymongo_server_monitor_thread")
self._executor = executor
self_ref = weakref.ref(self, executor.close)
self._topology = weakref.proxy(topology, executor.close)
def __init__(self, server_description, topology, pool, topology_settings):
"""Class to monitor a MongoDB server on a background thread.
Pass an initial ServerDescription, a Topology, a Pool, and
TopologySettings.
The Topology is weakly referenced. The Pool must be exclusive to this
Monitor.
"""
super(Monitor,
self).__init__(topology, "pymongo_server_monitor_thread",
topology_settings.heartbeat_frequency,
common.MIN_HEARTBEAT_INTERVAL)
self._server_description = server_description
self._pool = pool
self._settings = topology_settings
self._avg_round_trip_time = MovingAverage()
self._listeners = self._settings._pool_options.event_listeners
pub = self._listeners is not None
self._publish = pub and self._listeners.enabled_for_server_heartbeat
def run_scenario(self):
moving_average = MovingAverage()
if scenario_def['avg_rtt_ms'] != "NULL":
moving_average.add_sample(scenario_def['avg_rtt_ms'])
if scenario_def['new_rtt_ms'] != "NULL":
moving_average.add_sample(scenario_def['new_rtt_ms'])
self.assertAlmostEqual(moving_average.get(),
scenario_def['new_avg_rtt'])
def run_scenario(self):
moving_average = MovingAverage()
if scenario_def['avg_rtt_ms'] != "NULL":
moving_average.add_sample(scenario_def['avg_rtt_ms'])
if scenario_def['new_rtt_ms'] != "NULL":
moving_average.add_sample(scenario_def['new_rtt_ms'])
self.assertAlmostEqual(moving_average.get(),
scenario_def['new_avg_rtt'])
def __init__(
self,
server_description,
topology,
pool,
topology_settings):
"""Class to monitor a MongoDB server on a background thread.
Pass an initial ServerDescription, a Topology, a Pool, and
TopologySettings.
The Topology is weakly referenced. The Pool must be exclusive to this
Monitor.
"""
self._server_description = server_description
self._pool = pool
self._settings = topology_settings
self._avg_round_trip_time = MovingAverage()
self._listeners = self._settings._pool_options.event_listeners
pub = self._listeners is not None
self._publish = pub and self._listeners.enabled_for_server_heartbeat
# We strongly reference the executor and it weakly references us via
# this closure. When the monitor is freed, stop the executor soon.
def target():
monitor = self_ref()
if monitor is None:
return False # Stop the executor.
Monitor._run(monitor)
return True
executor = periodic_executor.PeriodicExecutor(
interval=self._settings.heartbeat_frequency,
min_interval=common.MIN_HEARTBEAT_INTERVAL,
target=target,
name="pymongo_server_monitor_thread")
self._executor = executor
# Avoid cycles. When self or topology is freed, stop executor soon.
self_ref = weakref.ref(self, executor.close)
self._topology = weakref.proxy(topology, executor.close)
def __init__(
self,
server_description,
topology,
pool,
topology_settings):
"""Class to monitor a MongoDB server on a background thread.
Pass an initial ServerDescription, a Topology, a Pool, and
TopologySettings.
The Topology is weakly referenced. The Pool must be exclusive to this
Monitor.
"""
self._server_description = server_description
# A weakref callback, takes ref to the freed topology as its parameter.
def close(dummy):
self.close()
self._topology = weakref.proxy(topology, close)
self._pool = pool
self._settings = topology_settings
self._avg_round_trip_time = MovingAverage()
# We strongly reference the executor and it weakly references us via
# this closure. When the monitor is freed, stop the executor soon.
self_ref = weakref.ref(self, close)
def target():
monitor = self_ref()
if monitor is None:
return False # Stop the executor.
Monitor._run(monitor)
return True
self._executor = periodic_executor.PeriodicExecutor(
condition_class=self._settings.condition_class,
interval=common.HEARTBEAT_FREQUENCY,
min_interval=common.MIN_HEARTBEAT_INTERVAL,
target=target)
def test_2_sample_moving_average(self):
avg = MovingAverage(2)
self.assertEqual(None, avg.get())
avg.update(10)
self.assertEqual(10, avg.get())
avg.update(20)
self.assertEqual(15, avg.get())
avg.update(30)
self.assertEqual(25, avg.get())
avg.update(-100)
self.assertEqual(-35, avg.get())
def test_trivial_moving_average(self):
avg = MovingAverage(1)
self.assertEqual(None, avg.get())
avg.update(10)
self.assertEqual(10, avg.get())
avg.update(20)
self.assertEqual(20, avg.get())
avg.update(0)
self.assertEqual(0, avg.get())
def test_empty_moving_average(self):
avg = MovingAverage(0)
self.assertEqual(None, avg.get())
avg.update(10)
self.assertEqual(None, avg.get())
def test_moving_average(self):
avg = MovingAverage()
self.assertIsNone(avg.get())
avg.add_sample(10)
self.assertAlmostEqual(10, avg.get())
avg.add_sample(20)
self.assertAlmostEqual(12, avg.get())
avg.add_sample(30)
self.assertAlmostEqual(15.6, avg.get())
class Monitor(object):
def __init__(self, server_description, topology, pool, topology_settings):
"""Class to monitor a MongoDB server on a background thread.
Pass an initial ServerDescription, a Topology, a Pool, and
TopologySettings.
The Topology is weakly referenced. The Pool must be exclusive to this
Monitor.
"""
self._server_description = server_description
self._pool = pool
self._settings = topology_settings
self._avg_round_trip_time = MovingAverage()
# We strongly reference the executor and it weakly references us via
# this closure. When the monitor is freed, stop the executor soon.
def target():
monitor = self_ref()
if monitor is None:
return False # Stop the executor.
Monitor._run(monitor)
return True
executor = periodic_executor.PeriodicExecutor(
condition_class=self._settings.condition_class,
interval=common.HEARTBEAT_FREQUENCY,
min_interval=common.MIN_HEARTBEAT_INTERVAL,
target=target,
name="pymongo_server_monitor_thread")
self._executor = executor
# Avoid cycles. When self or topology is freed, stop executor soon.
self_ref = weakref.ref(self, executor.close)
self._topology = weakref.proxy(topology, executor.close)
def open(self):
"""Start monitoring, or restart after a fork.
Multiple calls have no effect.
"""
self._executor.open()
def close(self):
"""Close and stop monitoring.
open() restarts the monitor after closing.
"""
self._executor.close()
# Increment the pool_id and maybe close the socket. If the executor
# thread has the socket checked out, it will be closed when checked in.
self._pool.reset()
def join(self, timeout=None):
self._executor.join(timeout)
def request_check(self):
"""If the monitor is sleeping, wake and check the server soon."""
self._executor.wake()
def _run(self):
try:
self._server_description = self._check_with_retry()
self._topology.on_change(self._server_description)
except ReferenceError:
# Topology was garbage-collected.
self.close()
def _check_with_retry(self):
"""Call ismaster once or twice. Reset server's pool on error.
Returns a ServerDescription.
"""
# According to the spec, if an ismaster call fails we reset the
# server's pool. If a server was once connected, change its type
# to Unknown only after retrying once.
address = self._server_description.address
retry = self._server_description.server_type != SERVER_TYPE.Unknown
try:
return self._check_once()
except ReferenceError:
raise
except Exception as error:
self._topology.reset_pool(address)
default = ServerDescription(address, error=error)
if not retry:
self._avg_round_trip_time.reset()
# Server type defaults to Unknown.
return default
# Try a second and final time. If it fails return original error.
try:
return self._check_once()
except ReferenceError:
raise
except Exception:
self._avg_round_trip_time.reset()
return default
def _check_once(self):
"""A single attempt to call ismaster.
Returns a ServerDescription, or raises an exception.
"""
with self._pool.get_socket({}) as sock_info:
response, round_trip_time = self._check_with_socket(sock_info)
self._avg_round_trip_time.add_sample(round_trip_time)
sd = ServerDescription(
address=self._server_description.address,
ismaster=response,
round_trip_time=self._avg_round_trip_time.get())
return sd
def _check_with_socket(self, sock_info):
"""Return (IsMaster, round_trip_time).
Can raise ConnectionFailure or OperationFailure.
"""
start = _time()
request_id, msg, max_doc_size = message.query(0, 'admin.$cmd', 0, -1,
{'ismaster': 1}, None,
DEFAULT_CODEC_OPTIONS)
# TODO: use sock_info.command()
sock_info.send_message(msg, max_doc_size)
raw_response = sock_info.receive_message(1, request_id)
result = helpers._unpack_response(raw_response)
return IsMaster(result['data'][0]), _time() - start
class Monitor(object):
def __init__(
self,
server_description,
topology,
pool,
topology_settings):
"""Class to monitor a MongoDB server on a background thread.
Pass an initial ServerDescription, a Topology, a Pool, and
TopologySettings.
The Topology is weakly referenced. The Pool must be exclusive to this
Monitor.
"""
self._server_description = server_description
self._pool = pool
self._settings = topology_settings
self._avg_round_trip_time = MovingAverage()
self._listeners = self._settings._pool_options.event_listeners
pub = self._listeners is not None
self._publish = pub and self._listeners.enabled_for_server_heartbeat
# We strongly reference the executor and it weakly references us via
# this closure. When the monitor is freed, stop the executor soon.
def target():
monitor = self_ref()
if monitor is None:
return False # Stop the executor.
Monitor._run(monitor)
return True
executor = periodic_executor.PeriodicExecutor(
interval=self._settings.heartbeat_frequency,
min_interval=common.MIN_HEARTBEAT_INTERVAL,
target=target,
name="pymongo_server_monitor_thread")
self._executor = executor
# Avoid cycles. When self or topology is freed, stop executor soon.
self_ref = weakref.ref(self, executor.close)
self._topology = weakref.proxy(topology, executor.close)
def open(self):
"""Start monitoring, or restart after a fork.
Multiple calls have no effect.
"""
self._executor.open()
def close(self):
"""Close and stop monitoring.
open() restarts the monitor after closing.
"""
self._executor.close()
# Increment the pool_id and maybe close the socket. If the executor
# thread has the socket checked out, it will be closed when checked in.
self._pool.reset()
def join(self, timeout=None):
self._executor.join(timeout)
def request_check(self):
"""If the monitor is sleeping, wake and check the server soon."""
self._executor.wake()
def _run(self):
try:
self._server_description = self._check_with_retry()
self._topology.on_change(self._server_description)
except ReferenceError:
# Topology was garbage-collected.
self.close()
def _check_with_retry(self):
"""Call ismaster once or twice. Reset server's pool on error.
Returns a ServerDescription.
"""
# According to the spec, if an ismaster call fails we reset the
# server's pool. If a server was once connected, change its type
# to Unknown only after retrying once.
address = self._server_description.address
retry = True
metadata = None
if self._server_description.server_type == SERVER_TYPE.Unknown:
retry = False
metadata = self._pool.opts.metadata
start = _time()
try:
# If the server type is unknown, send metadata with first check.
return self._check_once(metadata=metadata)
except ReferenceError:
raise
except Exception as error:
error_time = _time() - start
if self._publish:
self._listeners.publish_server_heartbeat_failed(
address, error_time, error)
self._topology.reset_pool(address)
default = ServerDescription(address, error=error)
if not retry:
self._avg_round_trip_time.reset()
# Server type defaults to Unknown.
return default
# Try a second and final time. If it fails return original error.
# Always send metadata: this is a new connection.
start = _time()
try:
return self._check_once(metadata=self._pool.opts.metadata)
except ReferenceError:
raise
except Exception as error:
error_time = _time() - start
if self._publish:
self._listeners.publish_server_heartbeat_failed(
address, error_time, error)
self._avg_round_trip_time.reset()
return default
def _check_once(self, metadata=None):
"""A single attempt to call ismaster.
Returns a ServerDescription, or raises an exception.
"""
address = self._server_description.address
if self._publish:
self._listeners.publish_server_heartbeat_started(address)
with self._pool.get_socket({}) as sock_info:
response, round_trip_time = self._check_with_socket(
sock_info, metadata=metadata)
self._avg_round_trip_time.add_sample(round_trip_time)
sd = ServerDescription(
address=address,
ismaster=response,
round_trip_time=self._avg_round_trip_time.get())
if self._publish:
self._listeners.publish_server_heartbeat_succeeded(
address, round_trip_time, response)
return sd
def _check_with_socket(self, sock_info, metadata=None):
"""Return (IsMaster, round_trip_time).
Can raise ConnectionFailure or OperationFailure.
"""
cmd = SON([('ismaster', 1)])
if metadata is not None:
cmd['client'] = metadata
if self._server_description.max_wire_version >= 6:
cluster_time = self._topology.max_cluster_time()
if cluster_time is not None:
cmd['$clusterTime'] = cluster_time
start = _time()
request_id, msg, max_doc_size = message.query(
0, 'admin.$cmd', 0, -1, cmd,
None, DEFAULT_CODEC_OPTIONS)
# TODO: use sock_info.command()
sock_info.send_message(msg, max_doc_size)
reply = sock_info.receive_message(request_id)
return IsMaster(reply.command_response()), _time() - start
def test_empty_moving_average(self):
avg = MovingAverage(0)
self.assertEqual(None, avg.get())
avg.update(10)
self.assertEqual(None, avg.get())
def test_moving_average(self):
avg = MovingAverage()
self.assertIsNone(avg.get())
avg.add_sample(10)
self.assertAlmostEqual(10, avg.get())
avg.add_sample(20)
self.assertAlmostEqual(12, avg.get())
avg.add_sample(30)
self.assertAlmostEqual(15.6, avg.get())
def test_trivial_moving_average(self):
avg = MovingAverage(1)
self.assertEqual(None, avg.get())
avg.update(10)
self.assertEqual(10, avg.get())
avg.update(20)
self.assertEqual(20, avg.get())
avg.update(0)
self.assertEqual(0, avg.get())
def test_2_sample_moving_average(self):
avg = MovingAverage(2)
self.assertEqual(None, avg.get())
avg.update(10)
self.assertEqual(10, avg.get())
avg.update(20)
self.assertEqual(15, avg.get())
avg.update(30)
self.assertEqual(25, avg.get())
avg.update(-100)
self.assertEqual(-35, avg.get())
def test_5_sample_moving_average(self):
avg = MovingAverage(5)
self.assertEqual(None, avg.get())
avg.update(10)
self.assertEqual(10, avg.get())
avg.update(20)
self.assertEqual(15, avg.get())
avg.update(30)
self.assertEqual(20, avg.get())
avg.update(-100)
self.assertEqual((10 + 20 + 30 - 100) / 4, avg.get())
avg.update(17)
self.assertEqual((10 + 20 + 30 - 100 + 17) / 5., avg.get())
avg.update(43)
self.assertEqual((20 + 30 - 100 + 17 + 43) / 5., avg.get())
avg.update(-1111)
self.assertEqual((30 - 100 + 17 + 43 - 1111) / 5., avg.get())
class Monitor(MonitorBase):
def __init__(self, server_description, topology, pool, topology_settings):
"""Class to monitor a MongoDB server on a background thread.
Pass an initial ServerDescription, a Topology, a Pool, and
TopologySettings.
The Topology is weakly referenced. The Pool must be exclusive to this
Monitor.
"""
self._server_description = server_description
self._pool = pool
self._settings = topology_settings
self._avg_round_trip_time = MovingAverage()
self._listeners = self._settings._pool_options.event_listeners
pub = self._listeners is not None
self._publish = pub and self._listeners.enabled_for_server_heartbeat
# We strongly reference the executor and it weakly references us via
# this closure. When the monitor is freed, stop the executor soon.
def target():
monitor = self_ref()
if monitor is None:
return False # Stop the executor.
Monitor._run(monitor)
return True
executor = periodic_executor.PeriodicExecutor(
interval=self._settings.heartbeat_frequency,
min_interval=common.MIN_HEARTBEAT_INTERVAL,
target=target,
name="pymongo_server_monitor_thread")
self._executor = executor
# Avoid cycles. When self or topology is freed, stop executor soon.
self_ref = weakref.ref(self, executor.close)
self._topology = weakref.proxy(topology, executor.close)
def close(self):
super(Monitor, self).close()
# Increment the pool_id and maybe close the socket. If the executor
# thread has the socket checked out, it will be closed when checked in.
self._pool.reset()
def _run(self):
try:
self._server_description = self._check_with_retry()
self._topology.on_change(self._server_description)
except ReferenceError:
# Topology was garbage-collected.
self.close()
def _check_with_retry(self):
"""Call ismaster once or twice. Reset server's pool on error.
Returns a ServerDescription.
"""
# According to the spec, if an ismaster call fails we reset the
# server's pool. If a server was once connected, change its type
# to Unknown only after retrying once.
address = self._server_description.address
retry = True
if self._server_description.server_type == SERVER_TYPE.Unknown:
retry = False
start = _time()
try:
return self._check_once()
except ReferenceError:
raise
except Exception as error:
error_time = _time() - start
if self._publish:
self._listeners.publish_server_heartbeat_failed(
address, error_time, error)
self._topology.reset_pool(address)
default = ServerDescription(address, error=error)
if not retry:
self._avg_round_trip_time.reset()
# Server type defaults to Unknown.
return default
# Try a second and final time. If it fails return original error.
# Always send metadata: this is a new connection.
start = _time()
try:
return self._check_once()
except ReferenceError:
raise
except Exception as error:
error_time = _time() - start
if self._publish:
self._listeners.publish_server_heartbeat_failed(
address, error_time, error)
self._avg_round_trip_time.reset()
return default
def _check_once(self):
"""A single attempt to call ismaster.
Returns a ServerDescription, or raises an exception.
"""
address = self._server_description.address
if self._publish:
self._listeners.publish_server_heartbeat_started(address)
with self._pool.get_socket({}) as sock_info:
response, round_trip_time = self._check_with_socket(sock_info)
self._avg_round_trip_time.add_sample(round_trip_time)
sd = ServerDescription(
address=address,
ismaster=response,
round_trip_time=self._avg_round_trip_time.get())
if self._publish:
self._listeners.publish_server_heartbeat_succeeded(
address, round_trip_time, response)
return sd
def _check_with_socket(self, sock_info):
"""Return (IsMaster, round_trip_time).
Can raise ConnectionFailure or OperationFailure.
"""
start = _time()
try:
return (sock_info.ismaster(self._pool.opts.metadata,
self._topology.max_cluster_time()),
_time() - start)
except OperationFailure as exc:
# Update max cluster time even when isMaster fails.
self._topology.receive_cluster_time(
exc.details.get('$clusterTime'))
raise
def test_5_sample_moving_average(self):
avg = MovingAverage(5)
self.assertEqual(None, avg.get())
avg.update(10)
self.assertEqual(10, avg.get())
avg.update(20)
self.assertEqual(15, avg.get())
avg.update(30)
self.assertEqual(20, avg.get())
avg.update(-100)
self.assertEqual((10 + 20 + 30 - 100) / 4, avg.get())
avg.update(17)
self.assertEqual((10 + 20 + 30 - 100 + 17) / 5., avg.get())
avg.update(43)
self.assertEqual((20 + 30 - 100 + 17 + 43) / 5., avg.get())
avg.update(-1111)
self.assertEqual((30 - 100 + 17 + 43 - 1111) / 5., avg.get())
class Monitor(object):
def __init__(
self,
server_description,
topology,
pool,
topology_settings):
"""Class to monitor a MongoDB server on a background thread.
Pass an initial ServerDescription, a Topology, a Pool, and
TopologySettings.
The Topology is weakly referenced. The Pool must be exclusive to this
Monitor.
"""
self._server_description = server_description
self._pool = pool
self._settings = topology_settings
self._avg_round_trip_time = MovingAverage()
self._listeners = self._settings._pool_options.event_listeners
pub = self._listeners is not None
self._publish = pub and self._listeners.enabled_for_server_heartbeat
# We strongly reference the executor and it weakly references us via
# this closure. When the monitor is freed, stop the executor soon.
def target():
monitor = self_ref()
if monitor is None:
return False # Stop the executor.
Monitor._run(monitor)
return True
executor = periodic_executor.PeriodicExecutor(
interval=self._settings.heartbeat_frequency,
min_interval=common.MIN_HEARTBEAT_INTERVAL,
target=target,
name="pymongo_server_monitor_thread")
self._executor = executor
# Avoid cycles. When self or topology is freed, stop executor soon.
self_ref = weakref.ref(self, executor.close)
self._topology = weakref.proxy(topology, executor.close)
def open(self):
"""Start monitoring, or restart after a fork.
Multiple calls have no effect.
"""
self._executor.open()
def close(self):
"""Close and stop monitoring.
open() restarts the monitor after closing.
"""
self._executor.close()
# Increment the pool_id and maybe close the socket. If the executor
# thread has the socket checked out, it will be closed when checked in.
self._pool.reset()
def join(self, timeout=None):
self._executor.join(timeout)
def request_check(self):
"""If the monitor is sleeping, wake and check the server soon."""
self._executor.wake()
def _run(self):
try:
self._server_description = self._check_with_retry()
self._topology.on_change(self._server_description)
except ReferenceError:
# Topology was garbage-collected.
self.close()
def _check_with_retry(self):
"""Call ismaster once or twice. Reset server's pool on error.
Returns a ServerDescription.
"""
# According to the spec, if an ismaster call fails we reset the
# server's pool. If a server was once connected, change its type
# to Unknown only after retrying once.
address = self._server_description.address
retry = True
metadata = None
if self._server_description.server_type == SERVER_TYPE.Unknown:
retry = False
metadata = self._pool.opts.metadata
start = _time()
try:
# If the server type is unknown, send metadata with first check.
return self._check_once(metadata=metadata)
except ReferenceError:
raise
except Exception as error:
error_time = _time() - start
if self._publish:
self._listeners.publish_server_heartbeat_failed(
address, error_time, error)
self._topology.reset_pool(address)
default = ServerDescription(address, error=error)
if not retry:
self._avg_round_trip_time.reset()
# Server type defaults to Unknown.
return default
# Try a second and final time. If it fails return original error.
# Always send metadata: this is a new connection.
start = _time()
try:
return self._check_once(metadata=self._pool.opts.metadata)
except ReferenceError:
raise
except Exception as error:
error_time = _time() - start
if self._publish:
self._listeners.publish_server_heartbeat_failed(
address, error_time, error)
self._avg_round_trip_time.reset()
return default
def _check_once(self, metadata=None):
"""A single attempt to call ismaster.
Returns a ServerDescription, or raises an exception.
"""
address = self._server_description.address
if self._publish:
self._listeners.publish_server_heartbeat_started(address)
with self._pool.get_socket({}) as sock_info:
response, round_trip_time = self._check_with_socket(
sock_info, metadata=metadata)
self._avg_round_trip_time.add_sample(round_trip_time)
sd = ServerDescription(
address=address,
ismaster=response,
round_trip_time=self._avg_round_trip_time.get())
if self._publish:
self._listeners.publish_server_heartbeat_succeeded(
address, round_trip_time, response)
return sd
def _check_with_socket(self, sock_info, metadata=None):
"""Return (IsMaster, round_trip_time).
Can raise ConnectionFailure or OperationFailure.
"""
cmd = SON([('ismaster', 1)])
if metadata is not None:
cmd['client'] = metadata
if self._server_description.max_wire_version >= 6:
cluster_time = self._topology.max_cluster_time()
if cluster_time is not None:
cmd['$clusterTime'] = cluster_time
start = _time()
request_id, msg, max_doc_size = message.query(
0, 'admin.$cmd', 0, -1, cmd,
None, DEFAULT_CODEC_OPTIONS)
# TODO: use sock_info.command()
sock_info.send_message(msg, max_doc_size)
reply = sock_info.receive_message(request_id)
return IsMaster(reply.command_response()), _time() - start
class Monitor(object):
def __init__(
self,
server_description,
topology,
pool,
topology_settings):
"""Class to monitor a MongoDB server on a background thread.
Pass an initial ServerDescription, a Topology, a Pool, and
TopologySettings.
The Topology is weakly referenced. The Pool must be exclusive to this
Monitor.
"""
self._server_description = server_description
self._pool = pool
self._settings = topology_settings
self._avg_round_trip_time = MovingAverage()
# We strongly reference the executor and it weakly references us via
# this closure. When the monitor is freed, stop the executor soon.
def target():
monitor = self_ref()
if monitor is None:
return False # Stop the executor.
Monitor._run(monitor)
return True
executor = periodic_executor.PeriodicExecutor(
interval=common.HEARTBEAT_FREQUENCY,
min_interval=common.MIN_HEARTBEAT_INTERVAL,
target=target,
name="pymongo_server_monitor_thread")
self._executor = executor
# Avoid cycles. When self or topology is freed, stop executor soon.
self_ref = weakref.ref(self, executor.close)
self._topology = weakref.proxy(topology, executor.close)
def open(self):
"""Start monitoring, or restart after a fork.
Multiple calls have no effect.
"""
self._executor.open()
def close(self):
"""Close and stop monitoring.
open() restarts the monitor after closing.
"""
self._executor.close()
# Increment the pool_id and maybe close the socket. If the executor
# thread has the socket checked out, it will be closed when checked in.
self._pool.reset()
def join(self, timeout=None):
self._executor.join(timeout)
def request_check(self):
"""If the monitor is sleeping, wake and check the server soon."""
self._executor.wake()
def _run(self):
try:
self._server_description = self._check_with_retry()
self._topology.on_change(self._server_description)
except ReferenceError:
# Topology was garbage-collected.
self.close()
def _check_with_retry(self):
"""Call ismaster once or twice. Reset server's pool on error.
Returns a ServerDescription.
"""
# According to the spec, if an ismaster call fails we reset the
# server's pool. If a server was once connected, change its type
# to Unknown only after retrying once.
address = self._server_description.address
retry = self._server_description.server_type != SERVER_TYPE.Unknown
try:
return self._check_once()
except ReferenceError:
raise
except Exception as error:
self._topology.reset_pool(address)
default = ServerDescription(address, error=error)
if not retry:
self._avg_round_trip_time.reset()
# Server type defaults to Unknown.
return default
# Try a second and final time. If it fails return original error.
try:
return self._check_once()
except ReferenceError:
raise
except Exception:
self._avg_round_trip_time.reset()
return default
def _check_once(self):
"""A single attempt to call ismaster.
Returns a ServerDescription, or raises an exception.
"""
with self._pool.get_socket({}) as sock_info:
response, round_trip_time = self._check_with_socket(sock_info)
self._avg_round_trip_time.add_sample(round_trip_time)
sd = ServerDescription(
address=self._server_description.address,
ismaster=response,
round_trip_time=self._avg_round_trip_time.get())
return sd
def _check_with_socket(self, sock_info):
"""Return (IsMaster, round_trip_time).
Can raise ConnectionFailure or OperationFailure.
"""
start = _time()
request_id, msg, max_doc_size = message.query(
0, 'admin.$cmd', 0, -1, {'ismaster': 1},
None, DEFAULT_CODEC_OPTIONS)
# TODO: use sock_info.command()
sock_info.send_message(msg, max_doc_size)
raw_response = sock_info.receive_message(1, request_id)
result = helpers._unpack_response(raw_response)
return IsMaster(result['data'][0]), _time() - start
