/
mongo_client.py
1510 lines (1239 loc) · 57.2 KB
/
mongo_client.py
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# Copyright 2009-2014 MongoDB, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you
# may not use this file except in compliance with the License. You
# may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
# implied. See the License for the specific language governing
# permissions and limitations under the License.
"""Tools for connecting to MongoDB.
.. seealso:: Module :mod:`~pymongo.master_slave_connection` for
connecting to master-slave clusters, and
:doc:`/examples/high_availability` for an example of how to connect
to a replica set, or specify a list of mongos instances for automatic
failover.
To get a :class:`~pymongo.database.Database` instance from a
:class:`MongoClient` use either dictionary-style or attribute-style
access:
.. doctest::
>>> from pymongo import MongoClient
>>> c = MongoClient()
>>> c.test_database
Database(MongoClient('localhost', 27017), u'test_database')
>>> c['test-database']
Database(MongoClient('localhost', 27017), u'test-database')
"""
import datetime
import random
import socket
import struct
import threading
import time
import warnings
from bson.py3compat import b
from pymongo import (auth,
common,
database,
helpers,
message,
pool,
thread_util,
uri_parser)
from pymongo.common import HAS_SSL
from pymongo.cursor_manager import CursorManager
from pymongo.errors import (AutoReconnect,
ConfigurationError,
ConnectionFailure,
DocumentTooLarge,
DuplicateKeyError,
InvalidURI,
OperationFailure)
from pymongo.member import Member
from pymongo.read_preferences import ReadPreference
EMPTY = b("")
def _partition_node(node):
"""Split a host:port string returned from mongod/s into
a (host, int(port)) pair needed for socket.connect().
"""
host = node
port = 27017
idx = node.rfind(':')
if idx != -1:
host, port = node[:idx], int(node[idx + 1:])
if host.startswith('['):
host = host[1:-1]
return host, port
class MongoClient(common.BaseObject):
"""Connection to MongoDB.
"""
HOST = "localhost"
PORT = 27017
def __init__(self, host=None, port=None, max_pool_size=100,
document_class=dict, tz_aware=False, _connect=True,
**kwargs):
"""Create a new connection to a single MongoDB instance at *host:port*.
The resultant client object has connection-pooling built
in. It also performs auto-reconnection when necessary. If an
operation fails because of a connection error,
:class:`~pymongo.errors.ConnectionFailure` is raised. If
auto-reconnection will be performed,
:class:`~pymongo.errors.AutoReconnect` will be
raised. Application code should handle this exception
(recognizing that the operation failed) and then continue to
execute.
Raises :class:`TypeError` if port is not an instance of
``int``. Raises :class:`~pymongo.errors.ConnectionFailure` if
the connection cannot be made.
The `host` parameter can be a full `mongodb URI
<http://dochub.mongodb.org/core/connections>`_, in addition to
a simple hostname. It can also be a list of hostnames or
URIs. Any port specified in the host string(s) will override
the `port` parameter. If multiple mongodb URIs containing
database or auth information are passed, the last database,
username, and password present will be used. For username and
passwords reserved characters like ':', '/', '+' and '@' must be
escaped following RFC 2396.
:Parameters:
- `host` (optional): hostname or IP address of the
instance to connect to, or a mongodb URI, or a list of
hostnames / mongodb URIs. If `host` is an IPv6 literal
it must be enclosed in '[' and ']' characters following
the RFC2732 URL syntax (e.g. '[::1]' for localhost)
- `port` (optional): port number on which to connect
- `max_pool_size` (optional): The maximum number of connections
that the pool will open simultaneously. If this is set, operations
will block if there are `max_pool_size` outstanding connections
from the pool. Defaults to 100.
- `document_class` (optional): default class to use for
documents returned from queries on this client
- `tz_aware` (optional): if ``True``,
:class:`~datetime.datetime` instances returned as values
in a document by this :class:`MongoClient` will be timezone
aware (otherwise they will be naive)
| **Other optional parameters can be passed as keyword arguments:**
- `socketTimeoutMS`: (integer) How long (in milliseconds) a send or
receive on a socket can take before timing out. Defaults to ``None``
(no timeout).
- `connectTimeoutMS`: (integer) How long (in milliseconds) a
connection can take to be opened before timing out. Defaults to
``20000``.
- `waitQueueTimeoutMS`: (integer) How long (in milliseconds) a
thread will wait for a socket from the pool if the pool has no
free sockets. Defaults to ``None`` (no timeout).
- `waitQueueMultiple`: (integer) Multiplied by max_pool_size to give
the number of threads allowed to wait for a socket at one time.
Defaults to ``None`` (no waiters).
- `auto_start_request`: If ``True``, each thread that accesses
this :class:`MongoClient` has a socket allocated to it for the
thread's lifetime. This ensures consistent reads, even if you
read after an unacknowledged write. Defaults to ``False``
- `use_greenlets`: If ``True``, :meth:`start_request()` will ensure
that the current greenlet uses the same socket for all
operations until :meth:`end_request()`
| **Write Concern options:**
- `w`: (integer or string) If this is a replica set, write operations
will block until they have been replicated to the specified number
or tagged set of servers. `w=<int>` always includes the replica set
primary (e.g. w=3 means write to the primary and wait until
replicated to **two** secondaries). Passing w=0 **disables write
acknowledgement** and all other write concern options.
- `wtimeout`: (integer) Used in conjunction with `w`. Specify a value
in milliseconds to control how long to wait for write propagation
to complete. If replication does not complete in the given
timeframe, a timeout exception is raised.
- `j`: If ``True`` block until write operations have been committed
to the journal. Cannot be used in combination with `fsync`. Prior
to MongoDB 2.6 this option was ignored if the server was running
without journaling. Starting with MongoDB 2.6 write operations will
fail with an exception if this option is used when the server is
running without journaling.
- `fsync`: If ``True`` and the server is running without journaling,
blocks until the server has synced all data files to disk. If the
server is running with journaling, this acts the same as the `j`
option, blocking until write operations have been committed to the
journal. Cannot be used in combination with `j`.
| **Replica set keyword arguments for connecting with a replica set
- either directly or via a mongos:**
| (ignored by standalone mongod instances)
- `replicaSet`: (string) The name of the replica set to connect to.
The driver will verify that the replica set it connects to matches
this name. Implies that the hosts specified are a seed list and the
driver should attempt to find all members of the set. *Ignored by
mongos*.
- `read_preference`: The read preference for this client. If
connecting to a secondary then a read preference mode *other* than
PRIMARY is required - otherwise all queries will throw
:class:`~pymongo.errors.AutoReconnect` "not master".
See :class:`~pymongo.read_preferences.ReadPreference` for all
available read preference options.
- `tag_sets`: Ignored unless connecting to a replica set via mongos.
Specify a priority-order for tag sets, provide a list of
tag sets: ``[{'dc': 'ny'}, {'dc': 'la'}, {}]``. A final, empty tag
set, ``{}``, means "read from any member that matches the mode,
ignoring tags.
| **SSL configuration:**
- `ssl`: If ``True``, create the connection to the server using SSL.
- `ssl_keyfile`: The private keyfile used to identify the local
connection against mongod. If included with the ``certfile`` then
only the ``ssl_certfile`` is needed. Implies ``ssl=True``.
- `ssl_certfile`: The certificate file used to identify the local
connection against mongod. Implies ``ssl=True``.
- `ssl_cert_reqs`: Specifies whether a certificate is required from
the other side of the connection, and whether it will be validated
if provided. It must be one of the three values ``ssl.CERT_NONE``
(certificates ignored), ``ssl.CERT_OPTIONAL``
(not required, but validated if provided), or ``ssl.CERT_REQUIRED``
(required and validated). If the value of this parameter is not
``ssl.CERT_NONE``, then the ``ssl_ca_certs`` parameter must point
to a file of CA certificates. Implies ``ssl=True``.
- `ssl_ca_certs`: The ca_certs file contains a set of concatenated
"certification authority" certificates, which are used to validate
certificates passed from the other end of the connection.
Implies ``ssl=True``.
.. seealso:: :meth:`end_request`
.. mongodoc:: connections
.. versionchanged:: 2.5
Added additional ssl options
.. versionadded:: 2.4
"""
if host is None:
host = self.HOST
if isinstance(host, basestring):
host = [host]
if port is None:
port = self.PORT
if not isinstance(port, int):
raise TypeError("port must be an instance of int")
seeds = set()
username = None
password = None
self.__default_database_name = None
opts = {}
for entity in host:
if "://" in entity:
if entity.startswith("mongodb://"):
res = uri_parser.parse_uri(entity, port)
seeds.update(res["nodelist"])
username = res["username"] or username
password = res["password"] or password
self.__default_database_name = (
res["database"] or self.__default_database_name)
opts = res["options"]
else:
idx = entity.find("://")
raise InvalidURI("Invalid URI scheme: "
"%s" % (entity[:idx],))
else:
seeds.update(uri_parser.split_hosts(entity, port))
if not seeds:
raise ConfigurationError("need to specify at least one host")
# Seeds are only used before first connection attempt; nodes are then
# used for any reconnects. Nodes are set to all replica set members
# if connecting to a replica set (besides arbiters), or to all
# available mongoses from the seed list, or to the one standalone
# mongod.
self.__seeds = frozenset(seeds)
self.__nodes = frozenset()
self.__member = None # TODO: Rename to __server.
# _pool_class and _event_class are for deep customization of PyMongo,
# e.g. Motor. SHOULD NOT BE USED BY THIRD-PARTY DEVELOPERS.
pool_class = kwargs.pop('_pool_class', pool.Pool)
event_class = kwargs.pop('_event_class', None)
options = {}
for option, value in kwargs.iteritems():
option, value = common.validate(option, value)
options[option] = value
options.update(opts)
self.__max_pool_size = common.validate_positive_integer_or_none(
'max_pool_size', max_pool_size)
self.__cursor_manager = CursorManager(self)
self.__repl = options.get('replicaset')
self.__direct = len(seeds) == 1 and not self.__repl
self.__net_timeout = options.get('sockettimeoutms')
self.__conn_timeout = options.get('connecttimeoutms')
self.__wait_queue_timeout = options.get('waitqueuetimeoutms')
self.__wait_queue_multiple = options.get('waitqueuemultiple')
self.__use_ssl = options.get('ssl', None)
self.__ssl_keyfile = options.get('ssl_keyfile', None)
self.__ssl_certfile = options.get('ssl_certfile', None)
self.__ssl_cert_reqs = options.get('ssl_cert_reqs', None)
self.__ssl_ca_certs = options.get('ssl_ca_certs', None)
ssl_kwarg_keys = [k for k in kwargs.keys() if k.startswith('ssl_')]
if self.__use_ssl == False and ssl_kwarg_keys:
raise ConfigurationError("ssl has not been enabled but the "
"following ssl parameters have been set: "
"%s. Please set `ssl=True` or remove."
% ', '.join(ssl_kwarg_keys))
if self.__ssl_cert_reqs and not self.__ssl_ca_certs:
raise ConfigurationError("If `ssl_cert_reqs` is not "
"`ssl.CERT_NONE` then you must "
"include `ssl_ca_certs` to be able "
"to validate the server.")
if ssl_kwarg_keys and self.__use_ssl is None:
# ssl options imply ssl = True
self.__use_ssl = True
if self.__use_ssl and not HAS_SSL:
raise ConfigurationError("The ssl module is not available. If you "
"are using a python version previous to "
"2.6 you must install the ssl package "
"from PyPI.")
self.__use_greenlets = options.get('use_greenlets', False)
self.__pool_class = pool_class
self.__connecting = False
if self.__use_greenlets:
# Greenlets don't need to lock around access to the Member;
# they're only interrupted when they do I/O.
self.__connecting_lock = thread_util.DummyLock()
else:
self.__connecting_lock = threading.Lock()
if event_class:
self.__event_class = event_class
else:
# Prevent a cycle; this lambda shouldn't refer to self.
g = self.__use_greenlets
event_class = lambda: thread_util.create_event(g)
self.__event_class = event_class
self.__future_member = None
self.__document_class = document_class
self.__tz_aware = common.validate_boolean('tz_aware', tz_aware)
self.__auto_start_request = options.get('auto_start_request', False)
# cache of existing indexes used by ensure_index ops
self.__index_cache = {}
self.__auth_credentials = {}
super(MongoClient, self).__init__(**options)
if self.slave_okay:
warnings.warn("slave_okay is deprecated. Please "
"use read_preference instead.", DeprecationWarning,
stacklevel=2)
if _connect:
try:
self._ensure_connected(True)
except AutoReconnect, e:
# ConnectionFailure makes more sense here than AutoReconnect
raise ConnectionFailure(str(e))
if username:
mechanism = options.get('authmechanism', 'MONGODB-CR')
source = (
options.get('authsource')
or self.__default_database_name
or 'admin')
credentials = auth._build_credentials_tuple(mechanism,
source,
unicode(username),
unicode(password),
options)
try:
self._cache_credentials(source, credentials, _connect)
except OperationFailure, exc:
raise ConfigurationError(str(exc))
def _cached(self, dbname, coll, index):
"""Test if `index` is cached.
"""
cache = self.__index_cache
now = datetime.datetime.utcnow()
return (dbname in cache and
coll in cache[dbname] and
index in cache[dbname][coll] and
now < cache[dbname][coll][index])
def _cache_index(self, database, collection, index, cache_for):
"""Add an index to the index cache for ensure_index operations.
"""
now = datetime.datetime.utcnow()
expire = datetime.timedelta(seconds=cache_for) + now
if database not in self.__index_cache:
self.__index_cache[database] = {}
self.__index_cache[database][collection] = {}
self.__index_cache[database][collection][index] = expire
elif collection not in self.__index_cache[database]:
self.__index_cache[database][collection] = {}
self.__index_cache[database][collection][index] = expire
else:
self.__index_cache[database][collection][index] = expire
def _purge_index(self, database_name,
collection_name=None, index_name=None):
"""Purge an index from the index cache.
If `index_name` is None purge an entire collection.
If `collection_name` is None purge an entire database.
"""
if not database_name in self.__index_cache:
return
if collection_name is None:
del self.__index_cache[database_name]
return
if not collection_name in self.__index_cache[database_name]:
return
if index_name is None:
del self.__index_cache[database_name][collection_name]
return
if index_name in self.__index_cache[database_name][collection_name]:
del self.__index_cache[database_name][collection_name][index_name]
def _cache_credentials(self, source, credentials, connect=True):
"""Add credentials to the database authentication cache
for automatic login when a socket is created. If `connect` is True,
verify the credentials on the server first.
"""
if source in self.__auth_credentials:
# Nothing to do if we already have these credentials.
if credentials == self.__auth_credentials[source]:
return
raise OperationFailure('Another user is already authenticated '
'to this database. You must logout first.')
if connect:
member = self.__ensure_member()
sock_info = self.__socket(member)
try:
# Since __check_auth was called in __socket
# there is no need to call it here.
auth.authenticate(credentials, sock_info, self.__simple_command)
sock_info.authset.add(credentials)
finally:
member.pool.maybe_return_socket(sock_info)
self.__auth_credentials[source] = credentials
def _purge_credentials(self, source):
"""Purge credentials from the database authentication cache.
"""
if source in self.__auth_credentials:
del self.__auth_credentials[source]
def __create_pool(self, pair):
return self.__pool_class(
pair,
self.__max_pool_size,
self.__net_timeout,
self.__conn_timeout,
self.__use_ssl,
use_greenlets=self.__use_greenlets,
ssl_keyfile=self.__ssl_keyfile,
ssl_certfile=self.__ssl_certfile,
ssl_cert_reqs=self.__ssl_cert_reqs,
ssl_ca_certs=self.__ssl_ca_certs,
wait_queue_timeout=self.__wait_queue_timeout,
wait_queue_multiple=self.__wait_queue_multiple)
def __check_auth(self, sock_info):
"""Authenticate using cached database credentials.
"""
if self.__auth_credentials or sock_info.authset:
cached = set(self.__auth_credentials.itervalues())
authset = sock_info.authset.copy()
# Logout any credentials that no longer exist in the cache.
for credentials in authset - cached:
self.__simple_command(sock_info, credentials[1], {'logout': 1})
sock_info.authset.discard(credentials)
for credentials in cached - authset:
auth.authenticate(credentials,
sock_info, self.__simple_command)
sock_info.authset.add(credentials)
def __member_property(self, attr_name, default=None):
member = self.__member
if member:
return getattr(member, attr_name)
return default
@property
def host(self):
"""Current connected host.
.. versionchanged:: 1.3
``host`` is now a property rather than a method.
"""
member = self.__member
if member:
return member.host[0]
return None
@property
def port(self):
"""Current connected port.
.. versionchanged:: 1.3
``port`` is now a property rather than a method.
"""
member = self.__member
if member:
return member.host[1]
return None
@property
def is_primary(self):
"""If this instance is connected to a standalone, a replica set
primary, or the master of a master-slave set.
.. versionadded:: 2.3
"""
return self.__member_property('is_primary', False)
@property
def is_mongos(self):
"""If this instance is connected to mongos.
.. versionadded:: 2.3
"""
return self.__member_property('is_mongos', False)
@property
def max_pool_size(self):
"""The maximum number of sockets the pool will open concurrently.
When the pool has reached `max_pool_size`, operations block waiting for
a socket to be returned to the pool. If ``waitQueueTimeoutMS`` is set,
a blocked operation will raise :exc:`~pymongo.errors.ConnectionFailure`
after a timeout. By default ``waitQueueTimeoutMS`` is not set.
.. warning:: SIGNIFICANT BEHAVIOR CHANGE in 2.6. Previously, this
parameter would limit only the idle sockets the pool would hold
onto, not the number of open sockets. The default has also changed
to 100.
.. versionchanged:: 2.6
.. versionadded:: 1.11
"""
return self.__max_pool_size
@property
def use_greenlets(self):
"""Whether calling :meth:`start_request` assigns greenlet-local,
rather than thread-local, sockets.
.. versionadded:: 2.4.2
"""
return self.__use_greenlets
@property
def nodes(self):
"""List of all known nodes.
Nodes are either specified when this instance was created,
or discovered through the replica set discovery mechanism.
.. versionadded:: 1.8
"""
return self.__nodes
@property
def auto_start_request(self):
"""Is auto_start_request enabled?
"""
return self.__auto_start_request
def get_document_class(self):
return self.__document_class
def set_document_class(self, klass):
self.__document_class = klass
document_class = property(get_document_class, set_document_class,
doc="""Default class to use for documents
returned from this client.
.. versionadded:: 1.7
""")
@property
def tz_aware(self):
"""Does this client return timezone-aware datetimes?
.. versionadded:: 1.8
"""
return self.__tz_aware
@property
def max_bson_size(self):
"""Return the maximum size BSON object the connected server
accepts in bytes. Defaults to 16MB if not connected to a
server.
.. versionadded:: 1.10
"""
return self.__member_property('max_bson_size', common.MAX_BSON_SIZE)
@property
def max_message_size(self):
"""Return the maximum message size the connected server
accepts in bytes. Defaults to 32MB if not connected to a
server.
.. versionadded:: 2.6
"""
return self.__member_property(
'max_message_size', common.MAX_MESSAGE_SIZE)
@property
def min_wire_version(self):
"""The minWireVersion reported by the server.
Returns ``0`` when connected to server versions prior to MongoDB 2.6.
.. versionadded:: 2.7
"""
return self.__member_property(
'min_wire_version', common.MIN_WIRE_VERSION)
@property
def max_wire_version(self):
"""The maxWireVersion reported by the server.
Returns ``0`` when connected to server versions prior to MongoDB 2.6.
.. versionadded:: 2.7
"""
return self.__member_property(
'max_wire_version', common.MAX_WIRE_VERSION)
@property
def max_write_batch_size(self):
"""The maxWriteBatchSize reported by the server.
Returns a default value when connected to server versions prior to
MongoDB 2.6.
.. versionadded:: 2.7
"""
return self.__member_property(
'max_write_batch_size', common.MAX_WRITE_BATCH_SIZE)
def __simple_command(self, sock_info, dbname, spec):
"""Send a command to the server. May raise AutoReconnect.
"""
rqst_id, msg, _ = message.query(0, dbname + '.$cmd', 0, -1, spec)
start = time.time()
try:
sock_info.sock.sendall(msg)
response = self.__receive_message_on_socket(1, rqst_id, sock_info)
except socket.error, e:
sock_info.close()
raise AutoReconnect(e)
except:
sock_info.close()
raise
end = time.time()
response = helpers._unpack_response(response)['data'][0]
msg = "command %r failed: %%s" % spec
helpers._check_command_response(response, None, msg)
return response, end - start
def __try_node(self, node):
"""Try to connect to this node and see if it works for our connection
type. Returns a Member and set of hosts (including this one). Doesn't
modify state.
:Parameters:
- `node`: The (host, port) pair to try.
"""
# Call 'ismaster' directly so we can get a response time.
connection_pool = self.__create_pool(node)
sock_info = connection_pool.get_socket()
try:
response, res_time = self.__simple_command(sock_info,
'admin',
{'ismaster': 1})
finally:
connection_pool.maybe_return_socket(sock_info)
member = Member(
node,
connection_pool,
response,
res_time)
nodes = frozenset([node])
# Replica Set?
if not self.__direct:
# Check that this host is part of the given replica set.
if self.__repl and member.set_name != self.__repl:
raise ConfigurationError("%s:%d is not a member of "
"replica set %s"
% (node[0], node[1], self.__repl))
if "hosts" in response:
nodes = frozenset([
_partition_node(h) for h in response["hosts"]])
if member.is_primary:
return member, nodes
elif "primary" in response:
# Shortcut: a secondary usually tells us who the primary is.
candidate = _partition_node(response["primary"])
return self.__try_node(candidate)
# Explain why we aren't using this connection.
raise AutoReconnect('%s:%d is not primary or master' % node)
# Direct connection
if member.is_arbiter and not self.__direct:
raise ConfigurationError("%s:%d is an arbiter" % node)
return member, nodes
def __pick_nearest(self, candidates):
"""Return the 'nearest' Member instance based on response time.
Doesn't modify state.
"""
latency = self.secondary_acceptable_latency_ms
# Only used for mongos high availability, ping_time is in seconds.
fastest = min([
member.ping_time for member in candidates])
near_candidates = [
member for member in candidates
if member.ping_time - fastest < latency / 1000.0]
return random.choice(near_candidates)
def __ensure_member(self):
"""Connect and return a Member instance, or raise AutoReconnect."""
# If `connecting` is False, no thread is in __find_node(),
# and `future_member` is resolved. `member` may be None if the
# last __find_node() attempt failed, otherwise it is in `nodes`.
#
# If `connecting` is True, a thread is in __find_node(),
# `member` is None, and `future_member` is pending.
#
# To violate these invariants temporarily, acquire the lock.
# Note that disconnect() interacts with this method.
self.__connecting_lock.acquire()
if self.__member:
member = self.__member
self.__connecting_lock.release()
return member
elif self.__connecting:
# A thread is in __find_node(). Wait.
future = self.__future_member
self.__connecting_lock.release()
return future.result()
else:
self.__connecting = True
future = self.__future_member = thread_util.Future(
self.__event_class)
self.__connecting_lock.release()
member = None
nodes = None
exc = None
try:
try:
member, nodes = self.__find_node()
return member
except Exception, e:
exc = e
raise
finally:
# We're either returning a Member or raising an error.
# Propagate either outcome to waiting threads.
self.__connecting_lock.acquire()
self.__member = member
self.__connecting = False
# If we discovered a set of nodes, use them from now on;
# otherwise we're raising an error. Stick with the last
# known good set of nodes.
if nodes:
self.__nodes = nodes
if member:
# Unblock waiting threads.
future.set_result(member)
else:
# Raise exception in waiting threads.
future.set_exception(exc)
self.__connecting_lock.release()
def __find_node(self):
"""Find a server suitable for our connection type.
Returns a Member and a set of nodes. Doesn't modify state.
If only one host was supplied to __init__ see if we can connect
to it. Don't check if the host is a master/primary so we can make
a direct connection to read from a secondary or send commands to
an arbiter.
If more than one host was supplied treat them as a seed list for
connecting to a replica set or to support high availability for
mongos. If connecting to a replica set try to find the primary,
and set `nodes` to list of all members.
If a mongos seed list was provided find the "nearest" mongos and
return it, setting `nodes` to all mongoses in the seed list that
are up.
Otherwise we iterate through the list trying to find a host we can
send write operations to.
"""
assert not self.__member, \
"__find_node unexpectedly running with a non-null Member"
errors = []
mongos_candidates = []
candidates = self.__nodes or self.__seeds
chosen_member = None
discovered_nodes = None
for candidate in candidates:
try:
member, nodes = self.__try_node(candidate)
if member.is_mongos and not self.__direct:
mongos_candidates.append(member)
# We intend to find all the mongoses; keep trying nodes.
continue
elif len(mongos_candidates):
raise ConfigurationError("Seed list cannot contain a mix "
"of mongod and mongos instances.")
# We've found a suitable node.
chosen_member = member
discovered_nodes = nodes
break
except (OperationFailure, ConfigurationError, ValueError):
# The server is available but something failed, e.g. auth,
# wrong replica set name, or incompatible wire protocol.
raise
except Exception, why:
errors.append(str(why))
if len(mongos_candidates):
# If we have a mongos seed list, pick the "nearest" member.
chosen_member = self.__pick_nearest(mongos_candidates)
mongoses = frozenset(m.host for m in mongos_candidates)
# The first time, __nodes is empty and mongoses becomes nodes.
return chosen_member, self.__nodes or mongoses
if not chosen_member:
# Couldn't find a suitable host.
raise AutoReconnect(', '.join(errors))
return chosen_member, discovered_nodes
def __socket(self, member):
"""Get a SocketInfo.
Calls disconnect() on error.
"""
connection_pool = member.pool
try:
if self.auto_start_request and not connection_pool.in_request():
connection_pool.start_request()
sock_info = connection_pool.get_socket()
except socket.error, why:
self.disconnect()
# Check if a unix domain socket
host, port = member.host
if host.endswith('.sock'):
host_details = "%s:" % host
else:
host_details = "%s:%d:" % (host, port)
raise AutoReconnect("could not connect to "
"%s %s" % (host_details, str(why)))
try:
self.__check_auth(sock_info)
except:
connection_pool.maybe_return_socket(sock_info)
raise
return sock_info
def _ensure_connected(self, sync=False):
"""Ensure this client instance is connected to a mongod/s.
"""
self.__ensure_member()
def disconnect(self):
"""Disconnect from MongoDB.
Disconnecting will close all underlying sockets in the connection
pool. If this instance is used again it will be automatically
re-opened. Care should be taken to make sure that :meth:`disconnect`
is not called in the middle of a sequence of operations in which
ordering is important. This could lead to unexpected results.
.. seealso:: :meth:`end_request`
.. versionadded:: 1.3
"""
self.__connecting_lock.acquire()
member, self.__member = self.__member, None
self.__connecting_lock.release()
# Close sockets promptly.
if member:
member.pool.reset()
def close(self):
"""Alias for :meth:`disconnect`
Disconnecting will close all underlying sockets in the connection
pool. If this instance is used again it will be automatically
re-opened. Care should be taken to make sure that :meth:`disconnect`
is not called in the middle of a sequence of operations in which
ordering is important. This could lead to unexpected results.
.. seealso:: :meth:`end_request`
.. versionadded:: 2.1
"""
self.disconnect()
def alive(self):
"""Return ``False`` if there has been an error communicating with the
server, else ``True``.
This method attempts to check the status of the server with minimal I/O.
The current thread / greenlet retrieves a socket from the pool (its
request socket if it's in a request, or a random idle socket if it's not
in a request) and checks whether calling `select`_ on it raises an
error. If there are currently no idle sockets, :meth:`alive` will
attempt to actually connect to the server.
A more certain way to determine server availability is::
client.admin.command('ping')
.. _select: http://docs.python.org/2/library/select.html#select.select
"""
# In the common case, a socket is available and was used recently, so
# calling select() on it is a reasonable attempt to see if the OS has
# reported an error.
self.__connecting_lock.acquire()
member = self.__member
self.__connecting_lock.release()
if not member:
return False
else:
sock_info = None
try:
try:
sock_info = member.pool.get_socket()
return not pool._closed(sock_info.sock)
except (socket.error, ConnectionFailure):
return False
finally:
member.pool.maybe_return_socket(sock_info)