# Copyright 2009-present 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:: :doc:`/examples/high_availability` for examples of connecting to replica sets or sets of mongos servers. 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(host=['localhost:27017'], document_class=dict, tz_aware=False, connect=True), u'test_database') >>> c['test-database'] Database(MongoClient(host=['localhost:27017'], document_class=dict, tz_aware=False, connect=True), u'test-database') """ import contextlib import datetime import threading import warnings import weakref from collections import defaultdict from bson.codec_options import DEFAULT_CODEC_OPTIONS from bson.py3compat import (integer_types, string_type) from bson.son import SON from pymongo import (common, database, helpers, message, periodic_executor, uri_parser, client_session) from pymongo.change_stream import ClusterChangeStream from pymongo.client_options import ClientOptions from pymongo.command_cursor import CommandCursor from pymongo.cursor_manager import CursorManager from pymongo.errors import (AutoReconnect, BulkWriteError, ConfigurationError, ConnectionFailure, InvalidOperation, NetworkTimeout, NotMasterError, OperationFailure, PyMongoError, ServerSelectionTimeoutError) from pymongo.read_preferences import ReadPreference from pymongo.server_selectors import (writable_preferred_server_selector, writable_server_selector) from pymongo.server_type import SERVER_TYPE from pymongo.topology import Topology from pymongo.topology_description import TOPOLOGY_TYPE from pymongo.settings import TopologySettings from pymongo.write_concern import DEFAULT_WRITE_CONCERN class MongoClient(common.BaseObject): HOST = "localhost" PORT = 27017 # Define order to retrieve options from ClientOptions for __repr__. # No host/port; these are retrieved from TopologySettings. _constructor_args = ('document_class', 'tz_aware', 'connect') def __init__( self, host=None, port=None, document_class=dict, tz_aware=None, connect=None, **kwargs): """Client for a MongoDB instance, a replica set, or a set of mongoses. The client object is thread-safe and has connection-pooling built in. If an operation fails because of a network error, :class:`~pymongo.errors.ConnectionFailure` is raised and the client reconnects in the background. Application code should handle this exception (recognizing that the operation failed) and then continue to execute. The `host` parameter can be a full `mongodb URI `_, 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 percent encoded following RFC 2396:: try: # Python 3.x from urllib.parse import quote_plus except ImportError: # Python 2.x from urllib import quote_plus uri = "mongodb://%s:%s@%s" % ( quote_plus(user), quote_plus(password), host) client = MongoClient(uri) Unix domain sockets are also supported. The socket path must be percent encoded in the URI:: uri = "mongodb://%s:%s@%s" % ( quote_plus(user), quote_plus(password), quote_plus(socket_path)) client = MongoClient(uri) But not when passed as a simple hostname:: client = MongoClient('/tmp/mongodb-27017.sock') Starting with version 3.6, PyMongo supports mongodb+srv:// URIs. The URI must include one, and only one, hostname. The hostname will be resolved to one or more DNS `SRV records `_ which will be used as the seed list for connecting to the MongoDB deployment. When using SRV URIs, the `authSource` and `replicaSet` configuration options can be specified using `TXT records `_. See the `Initial DNS Seedlist Discovery spec `_ for more details. Note that the use of SRV URIs implicitly enables TLS support. Pass ssl=false in the URI to override. .. note:: MongoClient creation will block waiting for answers from DNS when mongodb+srv:// URIs are used. .. note:: Starting with version 3.0 the :class:`MongoClient` constructor no longer blocks while connecting to the server or servers, and it no longer raises :class:`~pymongo.errors.ConnectionFailure` if they are unavailable, nor :class:`~pymongo.errors.ConfigurationError` if the user's credentials are wrong. Instead, the constructor returns immediately and launches the connection process on background threads. You can check if the server is available like this:: from pymongo.errors import ConnectionFailure client = MongoClient() try: # The ismaster command is cheap and does not require auth. client.admin.command('ismaster') except ConnectionFailure: print("Server not available") .. warning:: When using PyMongo in a multiprocessing context, please read :ref:`multiprocessing` first. :Parameters: - `host` (optional): hostname or IP address or Unix domain socket path of a single mongod or mongos 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). Multihomed and round robin DNS addresses are **not** supported. - `port` (optional): port number on which to connect - `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) - `connect` (optional): if ``True`` (the default), immediately begin connecting to MongoDB in the background. Otherwise connect on the first operation. | **Other optional parameters can be passed as keyword arguments:** - `maxPoolSize` (optional): The maximum allowable number of concurrent connections to each connected server. Requests to a server will block if there are `maxPoolSize` outstanding connections to the requested server. Defaults to 100. Cannot be 0. - `minPoolSize` (optional): The minimum required number of concurrent connections that the pool will maintain to each connected server. Default is 0. - `maxIdleTimeMS` (optional): The maximum number of milliseconds that a connection can remain idle in the pool before being removed and replaced. Defaults to `None` (no limit). - `socketTimeoutMS`: (integer or None) Controls how long (in milliseconds) the driver will wait for a response after sending an ordinary (non-monitoring) database operation before concluding that a network error has occurred. Defaults to ``None`` (no timeout). - `connectTimeoutMS`: (integer or None) Controls how long (in milliseconds) the driver will wait during server monitoring when connecting a new socket to a server before concluding the server is unavailable. Defaults to ``20000`` (20 seconds). - `serverSelectionTimeoutMS`: (integer) Controls how long (in milliseconds) the driver will wait to find an available, appropriate server to carry out a database operation; while it is waiting, multiple server monitoring operations may be carried out, each controlled by `connectTimeoutMS`. Defaults to ``30000`` (30 seconds). - `waitQueueTimeoutMS`: (integer or None) 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 or None) Multiplied by maxPoolSize to give the number of threads allowed to wait for a socket at one time. Defaults to ``None`` (no limit). - `heartbeatFrequencyMS`: (optional) The number of milliseconds between periodic server checks, or None to accept the default frequency of 10 seconds. - `appname`: (string or None) The name of the application that created this MongoClient instance. MongoDB 3.4 and newer will print this value in the server log upon establishing each connection. It is also recorded in the slow query log and profile collections. - `driver`: (pair or None) A driver implemented on top of PyMongo can pass a :class:`~pymongo.driver_info.DriverInfo` to add its name, version, and platform to the message printed in the server log when establishing a connection. - `event_listeners`: a list or tuple of event listeners. See :mod:`~pymongo.monitoring` for details. - `retryWrites`: (boolean) Whether supported write operations executed within this MongoClient will be retried once after a network error on MongoDB 3.6+. Defaults to ``False``. The supported write operations are: - :meth:`~pymongo.collection.Collection.bulk_write`, as long as :class:`~pymongo.operations.UpdateMany` or :class:`~pymongo.operations.DeleteMany` are not included. - :meth:`~pymongo.collection.Collection.delete_one` - :meth:`~pymongo.collection.Collection.insert_one` - :meth:`~pymongo.collection.Collection.insert_many` - :meth:`~pymongo.collection.Collection.replace_one` - :meth:`~pymongo.collection.Collection.update_one` - :meth:`~pymongo.collection.Collection.find_one_and_delete` - :meth:`~pymongo.collection.Collection.find_one_and_replace` - :meth:`~pymongo.collection.Collection.find_one_and_update` Unsupported write operations include, but are not limited to, :meth:`~pymongo.collection.Collection.aggregate` using the ``$out`` pipeline operator and any operation with an unacknowledged write concern (e.g. {w: 0})). See https://github.com/mongodb/specifications/blob/master/source/retryable-writes/retryable-writes.rst - `socketKeepAlive`: (boolean) **DEPRECATED** Whether to send periodic keep-alive packets on connected sockets. Defaults to ``True``. Disabling it is not recommended, see https://docs.mongodb.com/manual/faq/diagnostics/#does-tcp-keepalive-time-affect-mongodb-deployments", - `compressors`: Comma separated list of compressors for wire protocol compression. The list is used to negotiate a compressor with the server. Currently supported options are "snappy" and "zlib". Support for snappy requires the `python-snappy `_ package. zlib support requires the Python standard library zlib module. By default no compression is used. Compression support must also be enabled on the server. MongoDB 3.4+ supports snappy compression. MongoDB 3.6+ supports snappy and zlib. - `zlibCompressionLevel`: (int) The zlib compression level to use when zlib is used as the wire protocol compressor. Supported values are -1 through 9. -1 tells the zlib library to use its default compression level (usually 6). 0 means no compression. 1 is best speed. 9 is best compression. Defaults to -1. | **Write Concern options:** | (Only set if passed. No default values.) - `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=` 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:** - `replicaSet`: (string or None) The name of the replica set to connect to. The driver will verify that all servers it connects to match this name. Implies that the hosts specified are a seed list and the driver should attempt to find all members of the set. Defaults to ``None``. | **Read Preference:** - `readPreference`: The replica set read preference for this client. One of ``primary``, ``primaryPreferred``, ``secondary``, ``secondaryPreferred``, or ``nearest``. Defaults to ``primary``. - `readPreferenceTags`: Specifies a tag set as a comma-separated list of colon-separated key-value pairs. For example ``dc:ny,rack:1``. Defaults to ``None``. - `maxStalenessSeconds`: (integer) The maximum estimated length of time a replica set secondary can fall behind the primary in replication before it will no longer be selected for operations. Defaults to ``-1``, meaning no maximum. If maxStalenessSeconds is set, it must be a positive integer greater than or equal to 90 seconds. | **Authentication:** - `username`: A string. - `password`: A string. Although username and password must be percent-escaped in a MongoDB URI, they must not be percent-escaped when passed as parameters. In this example, both the space and slash special characters are passed as-is:: MongoClient(username="user name", password="pass/word") - `authSource`: The database to authenticate on. Defaults to the database specified in the URI, if provided, or to "admin". - `authMechanism`: See :data:`~pymongo.auth.MECHANISMS` for options. If no mechanism is specified, PyMongo automatically uses MONGODB-CR when connected to a pre-3.0 version of MongoDB, SCRAM-SHA-1 when connected to MongoDB 3.0 through 3.6, and negotiates the mechanism to use (SCRAM-SHA-1 or SCRAM-SHA-256) when connected to MongoDB 4.0+. - `authMechanismProperties`: Used to specify authentication mechanism specific options. To specify the service name for GSSAPI authentication pass authMechanismProperties='SERVICE_NAME:' .. seealso:: :doc:`/examples/authentication` | **SSL configuration:** - `ssl`: If ``True``, create the connection to the server using SSL. Defaults to ``False``. - `ssl_certfile`: The certificate file used to identify the local connection against mongod. Implies ``ssl=True``. Defaults to ``None``. - `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``. Defaults to ``None``. - `ssl_pem_passphrase`: The password or passphrase for decrypting the private key in ``ssl_certfile`` or ``ssl_keyfile``. Only necessary if the private key is encrypted. Only supported by python 2.7.9+ (pypy 2.5.1+) and 3.3+. Defaults to ``None``. - `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_REQUIRED`` (certificates required and validated), or ``ssl.CERT_OPTIONAL`` (the same as CERT_REQUIRED, unless the server was configured to use anonymous ciphers). If the value of this parameter is not ``ssl.CERT_NONE`` and a value is not provided for ``ssl_ca_certs`` PyMongo will attempt to load system provided CA certificates. If the python version in use does not support loading system CA certificates then the ``ssl_ca_certs`` parameter must point to a file of CA certificates. Implies ``ssl=True``. Defaults to ``ssl.CERT_REQUIRED`` if not provided and ``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``. Defaults to ``None``. - `ssl_crlfile`: The path to a PEM or DER formatted certificate revocation list. Only supported by python 2.7.9+ (pypy 2.5.1+) and 3.4+. Defaults to ``None``. - `ssl_match_hostname`: If ``True`` (the default), and `ssl_cert_reqs` is not ``ssl.CERT_NONE``, enables hostname verification using the :func:`~ssl.match_hostname` function from python's :mod:`~ssl` module. Think very carefully before setting this to ``False`` as that could make your application vulnerable to man-in-the-middle attacks. | **Read Concern options:** | (If not set explicitly, this will use the server default) - `readConcernLevel`: (string) The read concern level specifies the level of isolation for read operations. For example, a read operation using a read concern level of ``majority`` will only return data that has been written to a majority of nodes. If the level is left unspecified, the server default will be used. .. mongodoc:: connections .. versionchanged:: 3.6 Added support for mongodb+srv:// URIs. Added the ``retryWrites`` keyword argument and URI option. .. versionchanged:: 3.7 Added the ``driver`` keyword argument. .. versionchanged:: 3.5 Add ``username`` and ``password`` options. Document the ``authSource``, ``authMechanism``, and ``authMechanismProperties `` options. Deprecated the `socketKeepAlive` keyword argument and URI option. `socketKeepAlive` now defaults to ``True``. .. versionchanged:: 3.0 :class:`~pymongo.mongo_client.MongoClient` is now the one and only client class for a standalone server, mongos, or replica set. It includes the functionality that had been split into :class:`~pymongo.mongo_client.MongoReplicaSetClient`: it can connect to a replica set, discover all its members, and monitor the set for stepdowns, elections, and reconfigs. The :class:`~pymongo.mongo_client.MongoClient` constructor no longer blocks while connecting to the server or servers, and it no longer raises :class:`~pymongo.errors.ConnectionFailure` if they are unavailable, nor :class:`~pymongo.errors.ConfigurationError` if the user's credentials are wrong. Instead, the constructor returns immediately and launches the connection process on background threads. Therefore the ``alive`` method is removed since it no longer provides meaningful information; even if the client is disconnected, it may discover a server in time to fulfill the next operation. In PyMongo 2.x, :class:`~pymongo.MongoClient` accepted a list of standalone MongoDB servers and used the first it could connect to:: MongoClient(['host1.com:27017', 'host2.com:27017']) A list of multiple standalones is no longer supported; if multiple servers are listed they must be members of the same replica set, or mongoses in the same sharded cluster. The behavior for a list of mongoses is changed from "high availability" to "load balancing". Before, the client connected to the lowest-latency mongos in the list, and used it until a network error prompted it to re-evaluate all mongoses' latencies and reconnect to one of them. In PyMongo 3, the client monitors its network latency to all the mongoses continuously, and distributes operations evenly among those with the lowest latency. See :ref:`mongos-load-balancing` for more information. The ``connect`` option is added. The ``start_request``, ``in_request``, and ``end_request`` methods are removed, as well as the ``auto_start_request`` option. The ``copy_database`` method is removed, see the :doc:`copy_database examples ` for alternatives. The :meth:`MongoClient.disconnect` method is removed; it was a synonym for :meth:`~pymongo.MongoClient.close`. :class:`~pymongo.mongo_client.MongoClient` no longer returns an instance of :class:`~pymongo.database.Database` for attribute names with leading underscores. You must use dict-style lookups instead:: client['__my_database__'] Not:: client.__my_database__ """ if host is None: host = self.HOST if isinstance(host, string_type): 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 dbase = None opts = {} for entity in host: if "://" in entity: res = uri_parser.parse_uri(entity, port, warn=True) seeds.update(res["nodelist"]) username = res["username"] or username password = res["password"] or password dbase = res["database"] or dbase opts = res["options"] else: seeds.update(uri_parser.split_hosts(entity, port)) if not seeds: raise ConfigurationError("need to specify at least one host") # _pool_class, _monitor_class, and _condition_class are for deep # customization of PyMongo, e.g. Motor. pool_class = kwargs.pop('_pool_class', None) monitor_class = kwargs.pop('_monitor_class', None) condition_class = kwargs.pop('_condition_class', None) keyword_opts = kwargs keyword_opts['document_class'] = document_class if tz_aware is None: tz_aware = opts.get('tz_aware', False) if connect is None: connect = opts.get('connect', True) keyword_opts['tz_aware'] = tz_aware keyword_opts['connect'] = connect # Validate all keyword options. keyword_opts = dict(common.validate(k, v) for k, v in keyword_opts.items()) opts.update(keyword_opts) # Username and password passed as kwargs override user info in URI. username = opts.get("username", username) password = opts.get("password", password) if 'socketkeepalive' in opts: warnings.warn( "The socketKeepAlive option is deprecated. It now" "defaults to true and disabling it is not recommended, see " "https://docs.mongodb.com/manual/faq/diagnostics/" "#does-tcp-keepalive-time-affect-mongodb-deployments", DeprecationWarning, stacklevel=2) self.__options = options = ClientOptions( username, password, dbase, opts) self.__default_database_name = dbase self.__lock = threading.Lock() self.__cursor_manager = None self.__kill_cursors_queue = [] self._event_listeners = options.pool_options.event_listeners # Cache of existing indexes used by ensure_index ops. self.__index_cache = {} self.__index_cache_lock = threading.Lock() super(MongoClient, self).__init__(options.codec_options, options.read_preference, options.write_concern, options.read_concern) self.__all_credentials = {} creds = options.credentials if creds: self._cache_credentials(creds.source, creds) self._topology_settings = TopologySettings( seeds=seeds, replica_set_name=options.replica_set_name, pool_class=pool_class, pool_options=options.pool_options, monitor_class=monitor_class, condition_class=condition_class, local_threshold_ms=options.local_threshold_ms, server_selection_timeout=options.server_selection_timeout, heartbeat_frequency=options.heartbeat_frequency) self._topology = Topology(self._topology_settings) if connect: self._topology.open() def target(): client = self_ref() if client is None: return False # Stop the executor. MongoClient._process_periodic_tasks(client) return True executor = periodic_executor.PeriodicExecutor( interval=common.KILL_CURSOR_FREQUENCY, min_interval=0.5, target=target, name="pymongo_kill_cursors_thread") # We strongly reference the executor and it weakly references us via # this closure. When the client is freed, stop the executor soon. self_ref = weakref.ref(self, executor.close) self._kill_cursors_executor = executor executor.open() def _cache_credentials(self, source, credentials, connect=False): """Save a set of authentication credentials. The credentials are used to login a socket whenever one is created. If `connect` is True, verify the credentials on the server first. """ # Don't let other threads affect this call's data. all_credentials = self.__all_credentials.copy() if source in all_credentials: # Nothing to do if we already have these credentials. if credentials == all_credentials[source]: return raise OperationFailure('Another user is already authenticated ' 'to this database. You must logout first.') if connect: server = self._get_topology().select_server( writable_preferred_server_selector) # get_socket() logs out of the database if logged in with old # credentials, and logs in with new ones. with server.get_socket(all_credentials) as sock_info: sock_info.authenticate(credentials) # If several threads run _cache_credentials at once, last one wins. self.__all_credentials[source] = credentials def _purge_credentials(self, source): """Purge credentials from the authentication cache.""" self.__all_credentials.pop(source, None) def _cached(self, dbname, coll, index): """Test if `index` is cached.""" cache = self.__index_cache now = datetime.datetime.utcnow() with self.__index_cache_lock: 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, dbname, 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 with self.__index_cache_lock: if dbname not in self.__index_cache: self.__index_cache[dbname] = {} self.__index_cache[dbname][collection] = {} self.__index_cache[dbname][collection][index] = expire elif collection not in self.__index_cache[dbname]: self.__index_cache[dbname][collection] = {} self.__index_cache[dbname][collection][index] = expire else: self.__index_cache[dbname][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. """ with self.__index_cache_lock: 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 _server_property(self, attr_name): """An attribute of the current server's description. If the client is not connected, this will block until a connection is established or raise ServerSelectionTimeoutError if no server is available. Not threadsafe if used multiple times in a single method, since the server may change. In such cases, store a local reference to a ServerDescription first, then use its properties. """ server = self._topology.select_server( writable_server_selector) return getattr(server.description, attr_name) def watch(self, pipeline=None, full_document='default', resume_after=None, max_await_time_ms=None, batch_size=None, collation=None, start_at_operation_time=None, session=None): """Watch changes on this cluster. Performs an aggregation with an implicit initial ``$changeStream`` stage and returns a :class:`~pymongo.change_stream.ClusterChangeStream` cursor which iterates over changes on all databases on this cluster. Introduced in MongoDB 4.0. .. code-block:: python with client.watch() as stream: for change in stream: print(change) The :class:`~pymongo.change_stream.ClusterChangeStream` iterable blocks until the next change document is returned or an error is raised. If the :meth:`~pymongo.change_stream.ClusterChangeStream.next` method encounters a network error when retrieving a batch from the server, it will automatically attempt to recreate the cursor such that no change events are missed. Any error encountered during the resume attempt indicates there may be an outage and will be raised. .. code-block:: python try: with client.watch( [{'$match': {'operationType': 'insert'}}]) as stream: for insert_change in stream: print(insert_change) except pymongo.errors.PyMongoError: # The ChangeStream encountered an unrecoverable error or the # resume attempt failed to recreate the cursor. logging.error('...') For a precise description of the resume process see the `change streams specification`_. :Parameters: - `pipeline` (optional): A list of aggregation pipeline stages to append to an initial ``$changeStream`` stage. Not all pipeline stages are valid after a ``$changeStream`` stage, see the MongoDB documentation on change streams for the supported stages. - `full_document` (optional): The fullDocument to pass as an option to the ``$changeStream`` stage. Allowed values: 'default', 'updateLookup'. Defaults to 'default'. When set to 'updateLookup', the change notification for partial updates will include both a delta describing the changes to the document, as well as a copy of the entire document that was changed from some time after the change occurred. - `resume_after` (optional): The logical starting point for this change stream. - `max_await_time_ms` (optional): The maximum time in milliseconds for the server to wait for changes before responding to a getMore operation. - `batch_size` (optional): The maximum number of documents to return per batch. - `collation` (optional): The :class:`~pymongo.collation.Collation` to use for the aggregation. - `start_at_operation_time` (optional): If provided, the resulting change stream will only return changes that occurred at or after the specified :class:`~bson.timestamp.Timestamp`. Requires MongoDB >= 4.0. - `session` (optional): a :class:`~pymongo.client_session.ClientSession`. :Returns: A :class:`~pymongo.change_stream.ClusterChangeStream` cursor. .. versionadded:: 3.7 .. mongodoc:: changeStreams .. _change streams specification: https://github.com/mongodb/specifications/blob/master/source/change-streams/change-streams.rst """ return ClusterChangeStream( self.admin, pipeline, full_document, resume_after, max_await_time_ms, batch_size, collation, start_at_operation_time, session ) @property def event_listeners(self): """The event listeners registered for this client. See :mod:`~pymongo.monitoring` for details. """ return self._event_listeners.event_listeners @property def address(self): """(host, port) of the current standalone, primary, or mongos, or None. Accessing :attr:`address` raises :exc:`~.errors.InvalidOperation` if the client is load-balancing among mongoses, since there is no single address. Use :attr:`nodes` instead. If the client is not connected, this will block until a connection is established or raise ServerSelectionTimeoutError if no server is available. .. versionadded:: 3.0 """ topology_type = self._topology._description.topology_type if topology_type == TOPOLOGY_TYPE.Sharded: raise InvalidOperation( 'Cannot use "address" property when load balancing among' ' mongoses, use "nodes" instead.') if topology_type not in (TOPOLOGY_TYPE.ReplicaSetWithPrimary, TOPOLOGY_TYPE.Single): return None return self._server_property('address') @property def primary(self): """The (host, port) of the current primary of the replica set. Returns ``None`` if this client is not connected to a replica set, there is no primary, or this client was created without the `replicaSet` option. .. versionadded:: 3.0 MongoClient gained this property in version 3.0 when MongoReplicaSetClient's functionality was merged in. """ return self._topology.get_primary() @property def secondaries(self): """The secondary members known to this client. A sequence of (host, port) pairs. Empty if this client is not connected to a replica set, there are no visible secondaries, or this client was created without the `replicaSet` option. .. versionadded:: 3.0 MongoClient gained this property in version 3.0 when MongoReplicaSetClient's functionality was merged in. """ return self._topology.get_secondaries() @property def arbiters(self): """Arbiters in the replica set. A sequence of (host, port) pairs. Empty if this client is not connected to a replica set, there are no arbiters, or this client was created without the `replicaSet` option. """ return self._topology.get_arbiters() @property def is_primary(self): """If this client is connected to a server that can accept writes. True if the current server is a standalone, mongos, or the primary of a replica set. If the client is not connected, this will block until a connection is established or raise ServerSelectionTimeoutError if no server is available. """ return self._server_property('is_writable') @property def is_mongos(self): """If this client is connected to mongos. If the client is not connected, this will block until a connection is established or raise ServerSelectionTimeoutError if no server is available.. """ return self._server_property('server_type') == SERVER_TYPE.Mongos @property def max_pool_size(self): """The maximum allowable number of concurrent connections to each connected server. Requests to a server will block if there are `maxPoolSize` outstanding connections to the requested server. Defaults to 100. Cannot be 0. When a server's pool has reached `max_pool_size`, operations for that server 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. """ return self.__options.pool_options.max_pool_size @property def min_pool_size(self): """The minimum required number of concurrent connections that the pool will maintain to each connected server. Default is 0. """ return self.__options.pool_options.min_pool_size @property def max_idle_time_ms(self): """The maximum number of milliseconds that a connection can remain idle in the pool before being removed and replaced. Defaults to `None` (no limit). """ seconds = self.__options.pool_options.max_idle_time_seconds if seconds is None: return None return 1000 * seconds @property def nodes(self): """Set of all currently connected servers. .. warning:: When connected to a replica set the value of :attr:`nodes` can change over time as :class:`MongoClient`'s view of the replica set changes. :attr:`nodes` can also be an empty set when :class:`MongoClient` is first instantiated and hasn't yet connected to any servers, or a network partition causes it to lose connection to all servers. """ description = self._topology.description return frozenset(s.address for s in description.known_servers) @property def max_bson_size(self): """The largest BSON object the connected server accepts in bytes. If the client is not connected, this will block until a connection is established or raise ServerSelectionTimeoutError if no server is available. """ return self._server_property('max_bson_size') @property def max_message_size(self): """The largest message the connected server accepts in bytes. If the client is not connected, this will block until a connection is established or raise ServerSelectionTimeoutError if no server is available. """ return self._server_property('max_message_size') @property def max_write_batch_size(self): """The maxWriteBatchSize reported by the server. If the client is not connected, this will block until a connection is established or raise ServerSelectionTimeoutError if no server is available. Returns a default value when connected to server versions prior to MongoDB 2.6. """ return self._server_property('max_write_batch_size') @property def local_threshold_ms(self): """The local threshold for this instance.""" return self.__options.local_threshold_ms @property def server_selection_timeout(self): """The server selection timeout for this instance in seconds.""" return self.__options.server_selection_timeout @property def retry_writes(self): """If this instance should retry supported write operations.""" return self.__options.retry_writes def _is_writable(self): """Attempt to connect to a writable server, or return False. """ topology = self._get_topology() # Starts monitors if necessary. try: svr = topology.select_server(writable_server_selector) # When directly connected to a secondary, arbiter, etc., # select_server returns it, whatever the selector. Check # again if the server is writable. return svr.description.is_writable except ConnectionFailure: return False def _end_sessions(self, session_ids): """Send endSessions command(s) with the given session ids.""" try: # Use SocketInfo.command directly to avoid implicitly creating # another session. with self._socket_for_reads( ReadPreference.PRIMARY_PREFERRED) as (sock_info, slave_ok): if not sock_info.supports_sessions: return for i in range(0, len(session_ids), common._MAX_END_SESSIONS): spec = SON([('endSessions', session_ids[i:i + common._MAX_END_SESSIONS])]) sock_info.command( 'admin', spec, slave_ok=slave_ok, client=self) except PyMongoError: # Drivers MUST ignore any errors returned by the endSessions # command. pass def close(self): """Cleanup client resources and disconnect from MongoDB. On MongoDB >= 3.6, end all server sessions created by this client by sending one or more endSessions commands. Close all sockets in the connection pools and stop the monitor threads. If this instance is used again it will be automatically re-opened and the threads restarted. .. versionchanged:: 3.6 End all server sessions created by this client. """ session_ids = self._topology.pop_all_sessions() if session_ids: self._end_sessions(session_ids) # Run _process_periodic_tasks to send pending killCursor requests # before closing the topology. self._process_periodic_tasks() self._topology.close() def set_cursor_manager(self, manager_class): """DEPRECATED - Set this client's cursor manager. Raises :class:`TypeError` if `manager_class` is not a subclass of :class:`~pymongo.cursor_manager.CursorManager`. A cursor manager handles closing cursors. Different managers can implement different policies in terms of when to actually kill a cursor that has been closed. :Parameters: - `manager_class`: cursor manager to use .. versionchanged:: 3.3 Deprecated, for real this time. .. versionchanged:: 3.0 Undeprecated. """ warnings.warn( "set_cursor_manager is Deprecated", DeprecationWarning, stacklevel=2) manager = manager_class(self) if not isinstance(manager, CursorManager): raise TypeError("manager_class must be a subclass of " "CursorManager") self.__cursor_manager = manager def _get_topology(self): """Get the internal :class:`~pymongo.topology.Topology` object. If this client was created with "connect=False", calling _get_topology launches the connection process in the background. """ self._topology.open() return self._topology @contextlib.contextmanager def _get_socket(self, server): try: with server.get_socket(self.__all_credentials) as sock_info: yield sock_info except NetworkTimeout: # The socket has been closed. Don't reset the server. # Server Discovery And Monitoring Spec: "When an application # operation fails because of any network error besides a socket # timeout...." raise except NotMasterError: # "When the client sees a "not master" error it MUST replace the # server's description with type Unknown. It MUST request an # immediate check of the server." self._reset_server_and_request_check(server.description.address) raise except ConnectionFailure: # "Client MUST replace the server's description with type Unknown # ... MUST NOT request an immediate check of the server." self.__reset_server(server.description.address) raise except OperationFailure as exc: if exc.code in helpers._RETRYABLE_ERROR_CODES: # Do not request an immediate check since the server is likely # shutting down. self.__reset_server(server.description.address) raise def _socket_for_writes(self): server = self._get_topology().select_server(writable_server_selector) return self._get_socket(server) @contextlib.contextmanager def _socket_for_reads(self, read_preference): assert read_preference is not None, "read_preference must not be None" # Get a socket for a server matching the read preference, and yield # sock_info, slave_ok. Server Selection Spec: "slaveOK must be sent to # mongods with topology type Single. If the server type is Mongos, # follow the rules for passing read preference to mongos, even for # topology type Single." # Thread safe: if the type is single it cannot change. topology = self._get_topology() single = topology.description.topology_type == TOPOLOGY_TYPE.Single server = topology.select_server(read_preference) with self._get_socket(server) as sock_info: slave_ok = (single and not sock_info.is_mongos) or ( read_preference != ReadPreference.PRIMARY) yield sock_info, slave_ok def _send_message_with_response(self, operation, exhaust=False, address=None): """Send a message to MongoDB and return a Response. :Parameters: - `operation`: a _Query or _GetMore object. - `read_preference` (optional): A ReadPreference. - `exhaust` (optional): If True, the socket used stays checked out. It is returned along with its Pool in the Response. - `address` (optional): Optional address when sending a message to a specific server, used for getMore. """ with self.__lock: # If needed, restart kill-cursors thread after a fork. self._kill_cursors_executor.open() topology = self._get_topology() if address: server = topology.select_server_by_address(address) if not server: raise AutoReconnect('server %s:%d no longer available' % address) else: server = topology.select_server(operation.read_preference) # If this is a direct connection to a mongod, *always* set the slaveOk # bit. See bullet point 2 in server-selection.rst#topology-type-single. set_slave_ok = ( topology.description.topology_type == TOPOLOGY_TYPE.Single and server.description.server_type != SERVER_TYPE.Mongos) or ( operation.read_preference != ReadPreference.PRIMARY) return self._reset_on_error( server, server.send_message_with_response, operation, set_slave_ok, self.__all_credentials, self._event_listeners, exhaust) def _reset_on_error(self, server, func, *args, **kwargs): """Execute an operation. Reset the server on network error. Returns fn()'s return value on success. On error, clears the server's pool and marks the server Unknown. Re-raises any exception thrown by fn(). """ try: return func(*args, **kwargs) except NetworkTimeout: # The socket has been closed. Don't reset the server. raise except ConnectionFailure: self.__reset_server(server.description.address) raise def _retry_with_session(self, retryable, func, session, bulk): """Execute an operation with at most one consecutive retries Returns func()'s return value on success. On error retries the same command once. Re-raises any exception thrown by func(). """ retryable = (retryable and self.retry_writes and session and not session._in_transaction) last_error = None retrying = False def is_retrying(): return bulk.retrying if bulk else retrying # Increment the transaction id up front to ensure any retry attempt # will use the proper txnNumber, even if server or socket selection # fails before the command can be sent. if retryable: session._start_retryable_write() if bulk: bulk.started_retryable_write = True while True: try: server = self._get_topology().select_server( writable_server_selector) supports_session = ( session is not None and server.description.retryable_writes_supported) with self._get_socket(server) as sock_info: if retryable and not supports_session: if is_retrying(): # A retry is not possible because this server does # not support sessions raise the last error. raise last_error retryable = False return func(session, sock_info, retryable) except ServerSelectionTimeoutError: if is_retrying(): # The application may think the write was never attempted # if we raise ServerSelectionTimeoutError on the retry # attempt. Raise the original exception instead. raise last_error # A ServerSelectionTimeoutError error indicates that there may # be a persistent outage. Attempting to retry in this case will # most likely be a waste of time. raise except ConnectionFailure as exc: if not retryable or is_retrying(): raise if bulk: bulk.retrying = True else: retrying = True last_error = exc except BulkWriteError as exc: if not retryable or is_retrying(): raise # Check the last writeConcernError to determine if this # BulkWriteError is retryable. wces = exc.details['writeConcernErrors'] wce = wces[-1] if wces else {} if wce.get('code', 0) not in helpers._RETRYABLE_ERROR_CODES: raise if bulk: bulk.retrying = True else: retrying = True last_error = exc except OperationFailure as exc: if not retryable or is_retrying(): raise if exc.code not in helpers._RETRYABLE_ERROR_CODES: raise if bulk: bulk.retrying = True else: retrying = True last_error = exc def _retryable_write(self, retryable, func, session): """Internal retryable write helper.""" with self._tmp_session(session) as s: return self._retry_with_session(retryable, func, s, None) def __reset_server(self, address): """Clear our connection pool for a server and mark it Unknown.""" self._topology.reset_server(address) def _reset_server_and_request_check(self, address): """Clear our pool for a server, mark it Unknown, and check it soon.""" self._topology.reset_server_and_request_check(address) def __eq__(self, other): if isinstance(other, self.__class__): return self.address == other.address return NotImplemented def __ne__(self, other): return not self == other def _repr_helper(self): def option_repr(option, value): """Fix options whose __repr__ isn't usable in a constructor.""" if option == 'document_class': if value is dict: return 'document_class=dict' else: return 'document_class=%s.%s' % (value.__module__, value.__name__) if option in common.TIMEOUT_VALIDATORS and value is not None: return "%s=%s" % (option, int(value * 1000)) return '%s=%r' % (option, value) # Host first... options = ['host=%r' % [ '%s:%d' % (host, port) if port is not None else host for host, port in self._topology_settings.seeds]] # ... then everything in self._constructor_args... options.extend( option_repr(key, self.__options._options[key]) for key in self._constructor_args) # ... then everything else. options.extend( option_repr(key, self.__options._options[key]) for key in self.__options._options if key not in set(self._constructor_args) and key != 'username' and key != 'password') return ', '.join(options) def __repr__(self): return ("MongoClient(%s)" % (self._repr_helper(),)) def __getattr__(self, name): """Get a database by name. Raises :class:`~pymongo.errors.InvalidName` if an invalid database name is used. :Parameters: - `name`: the name of the database to get """ if name.startswith('_'): raise AttributeError( "MongoClient has no attribute %r. To access the %s" " database, use client[%r]." % (name, name, name)) return self.__getitem__(name) def __getitem__(self, name): """Get a database by name. Raises :class:`~pymongo.errors.InvalidName` if an invalid database name is used. :Parameters: - `name`: the name of the database to get """ return database.Database(self, name) def close_cursor(self, cursor_id, address=None): """DEPRECATED - Send a kill cursors message soon with the given id. Raises :class:`TypeError` if `cursor_id` is not an instance of ``(int, long)``. What closing the cursor actually means depends on this client's cursor manager. This method may be called from a :class:`~pymongo.cursor.Cursor` destructor during garbage collection, so it isn't safe to take a lock or do network I/O. Instead, we schedule the cursor to be closed soon on a background thread. :Parameters: - `cursor_id`: id of cursor to close - `address` (optional): (host, port) pair of the cursor's server. If it is not provided, the client attempts to close the cursor on the primary or standalone, or a mongos server. .. versionchanged:: 3.7 Deprecated. .. versionchanged:: 3.0 Added ``address`` parameter. """ warnings.warn( "close_cursor is deprecated.", DeprecationWarning, stacklevel=2) if not isinstance(cursor_id, integer_types): raise TypeError("cursor_id must be an instance of (int, long)") self._close_cursor(cursor_id, address) def _close_cursor(self, cursor_id, address): """Send a kill cursors message with the given id. What closing the cursor actually means depends on this client's cursor manager. If there is none, the cursor is closed asynchronously on a background thread. """ if self.__cursor_manager is not None: self.__cursor_manager.close(cursor_id, address) else: self.__kill_cursors_queue.append((address, [cursor_id])) def _close_cursor_now(self, cursor_id, address=None, session=None): """Send a kill cursors message with the given id. What closing the cursor actually means depends on this client's cursor manager. If there is none, the cursor is closed synchronously on the current thread. """ if not isinstance(cursor_id, integer_types): raise TypeError("cursor_id must be an instance of (int, long)") if self.__cursor_manager is not None: self.__cursor_manager.close(cursor_id, address) else: try: self._kill_cursors( [cursor_id], address, self._get_topology(), session) except PyMongoError: # Make another attempt to kill the cursor later. self.__kill_cursors_queue.append((address, [cursor_id])) def kill_cursors(self, cursor_ids, address=None): """DEPRECATED - Send a kill cursors message soon with the given ids. Raises :class:`TypeError` if `cursor_ids` is not an instance of ``list``. :Parameters: - `cursor_ids`: list of cursor ids to kill - `address` (optional): (host, port) pair of the cursor's server. If it is not provided, the client attempts to close the cursor on the primary or standalone, or a mongos server. .. versionchanged:: 3.3 Deprecated. .. versionchanged:: 3.0 Now accepts an `address` argument. Schedules the cursors to be closed on a background thread instead of sending the message immediately. """ warnings.warn( "kill_cursors is deprecated.", DeprecationWarning, stacklevel=2) if not isinstance(cursor_ids, list): raise TypeError("cursor_ids must be a list") # "Atomic", needs no lock. self.__kill_cursors_queue.append((address, cursor_ids)) def _kill_cursors(self, cursor_ids, address, topology, session): """Send a kill cursors message with the given ids.""" listeners = self._event_listeners publish = listeners.enabled_for_commands if address: # address could be a tuple or _CursorAddress, but # select_server_by_address needs (host, port). server = topology.select_server_by_address(tuple(address)) else: # Application called close_cursor() with no address. server = topology.select_server(writable_server_selector) try: namespace = address.namespace db, coll = namespace.split('.', 1) except AttributeError: namespace = None db = coll = "OP_KILL_CURSORS" spec = SON([('killCursors', coll), ('cursors', cursor_ids)]) with server.get_socket(self.__all_credentials) as sock_info: if sock_info.max_wire_version >= 4 and namespace is not None: sock_info.command(db, spec, session=session, client=self) else: if publish: start = datetime.datetime.now() request_id, msg = message.kill_cursors(cursor_ids) if publish: duration = datetime.datetime.now() - start # Here and below, address could be a tuple or # _CursorAddress. We always want to publish a # tuple to match the rest of the monitoring # API. listeners.publish_command_start( spec, db, request_id, tuple(address)) start = datetime.datetime.now() try: sock_info.send_message(msg, 0) except Exception as exc: if publish: dur = ((datetime.datetime.now() - start) + duration) listeners.publish_command_failure( dur, message._convert_exception(exc), 'killCursors', request_id, tuple(address)) raise if publish: duration = ((datetime.datetime.now() - start) + duration) # OP_KILL_CURSORS returns no reply, fake one. reply = {'cursorsUnknown': cursor_ids, 'ok': 1} listeners.publish_command_success( duration, reply, 'killCursors', request_id, tuple(address)) # This method is run periodically by a background thread. def _process_periodic_tasks(self): """Process any pending kill cursors requests and maintain connection pool parameters.""" address_to_cursor_ids = defaultdict(list) # Other threads or the GC may append to the queue concurrently. while True: try: address, cursor_ids = self.__kill_cursors_queue.pop() except IndexError: break address_to_cursor_ids[address].extend(cursor_ids) # Don't re-open topology if it's closed and there's no pending cursors. if address_to_cursor_ids: topology = self._get_topology() for address, cursor_ids in address_to_cursor_ids.items(): try: self._kill_cursors( cursor_ids, address, topology, session=None) except Exception: helpers._handle_exception() try: self._topology.update_pool() except Exception: helpers._handle_exception() def __start_session(self, implicit, **kwargs): # Driver Sessions Spec: "If startSession is called when multiple users # are authenticated drivers MUST raise an error with the error message # 'Cannot call startSession when multiple users are authenticated.'" authset = set(self.__all_credentials.values()) if len(authset) > 1: raise InvalidOperation("Cannot call start_session when" " multiple users are authenticated") # Raises ConfigurationError if sessions are not supported. server_session = self._get_server_session() opts = client_session.SessionOptions(**kwargs) return client_session.ClientSession( self, server_session, opts, authset, implicit) def start_session(self, causal_consistency=True, default_transaction_options=None): """Start a logical session. This method takes the same parameters as :class:`~pymongo.client_session.SessionOptions`. See the :mod:`~pymongo.client_session` module for details and examples. Requires MongoDB 3.6. It is an error to call :meth:`start_session` if this client has been authenticated to multiple databases using the deprecated method :meth:`~pymongo.database.Database.authenticate`. A :class:`~pymongo.client_session.ClientSession` may only be used with the MongoClient that started it. :Returns: An instance of :class:`~pymongo.client_session.ClientSession`. .. versionadded:: 3.6 """ return self.__start_session( False, causal_consistency=causal_consistency, default_transaction_options=default_transaction_options) def _get_server_session(self): """Internal: start or resume a _ServerSession.""" return self._topology.get_server_session() def _return_server_session(self, server_session, lock): """Internal: return a _ServerSession to the pool.""" return self._topology.return_server_session(server_session, lock) def _ensure_session(self, session=None): """If provided session is None, lend a temporary session.""" if session: return session try: # Don't make implicit sessions causally consistent. Applications # should always opt-in. return self.__start_session(True, causal_consistency=False) except (ConfigurationError, InvalidOperation): # Sessions not supported, or multiple users authenticated. return None @contextlib.contextmanager def _tmp_session(self, session, close=True): """If provided session is None, lend a temporary session.""" if session: # Don't call end_session. yield session return s = self._ensure_session(session) if s and close: with s: # Call end_session when we exit this scope. yield s elif s: try: # Only call end_session on error. yield s except Exception: s.end_session() raise else: yield None def _send_cluster_time(self, command, session): topology_time = self._topology.max_cluster_time() session_time = session.cluster_time if session else None if topology_time and session_time: if topology_time['clusterTime'] > session_time['clusterTime']: cluster_time = topology_time else: cluster_time = session_time else: cluster_time = topology_time or session_time if cluster_time: command['$clusterTime'] = cluster_time def _receive_cluster_time(self, reply, session): cluster_time = reply.get('$clusterTime') self._topology.receive_cluster_time(cluster_time) if session is not None: session._advance_cluster_time(cluster_time) session._advance_operation_time(reply.get("operationTime")) def server_info(self, session=None): """Get information about the MongoDB server we're connected to. :Parameters: - `session` (optional): a :class:`~pymongo.client_session.ClientSession`. .. versionchanged:: 3.6 Added ``session`` parameter. """ return self.admin.command("buildinfo", read_preference=ReadPreference.PRIMARY, session=session) def list_databases(self, session=None, **kwargs): """Get a cursor over the databases of the connected server. :Parameters: - `session` (optional): a :class:`~pymongo.client_session.ClientSession`. - `**kwargs` (optional): Optional parameters of the `listDatabases command `_ can be passed as keyword arguments to this method. The supported options differ by server version. :Returns: An instance of :class:`~pymongo.command_cursor.CommandCursor`. .. versionadded:: 3.6 """ cmd = SON([("listDatabases", 1)]) cmd.update(kwargs) admin = self._database_default_options("admin") res = admin.command(cmd, session=session) # listDatabases doesn't return a cursor (yet). Fake one. cursor = { "id": 0, "firstBatch": res["databases"], "ns": "admin.$cmd", } return CommandCursor(admin["$cmd"], cursor, None) def list_database_names(self, session=None): """Get a list of the names of all databases on the connected server. :Parameters: - `session` (optional): a :class:`~pymongo.client_session.ClientSession`. .. versionadded:: 3.6 """ return [doc["name"] for doc in self.list_databases(session, nameOnly=True)] def database_names(self, session=None): """**DEPRECATED**: Get a list of the names of all databases on the connected server. :Parameters: - `session` (optional): a :class:`~pymongo.client_session.ClientSession`. .. versionchanged:: 3.7 Deprecated. Use :meth:`list_database_names` instead. .. versionchanged:: 3.6 Added ``session`` parameter. """ warnings.warn("database_names is deprecated. Use list_database_names " "instead.", DeprecationWarning, stacklevel=2) return self.list_database_names(session) def drop_database(self, name_or_database, session=None): """Drop a database. Raises :class:`TypeError` if `name_or_database` is not an instance of :class:`basestring` (:class:`str` in python 3) or :class:`~pymongo.database.Database`. :Parameters: - `name_or_database`: the name of a database to drop, or a :class:`~pymongo.database.Database` instance representing the database to drop - `session` (optional): a :class:`~pymongo.client_session.ClientSession`. .. versionchanged:: 3.6 Added ``session`` parameter. .. note:: The :attr:`~pymongo.mongo_client.MongoClient.write_concern` of this client is automatically applied to this operation when using MongoDB >= 3.4. .. versionchanged:: 3.4 Apply this client's write concern automatically to this operation when connected to MongoDB >= 3.4. """ name = name_or_database if isinstance(name, database.Database): name = name.name if not isinstance(name, string_type): raise TypeError("name_or_database must be an instance " "of %s or a Database" % (string_type.__name__,)) self._purge_index(name) with self._socket_for_writes() as sock_info: self[name]._command( sock_info, "dropDatabase", read_preference=ReadPreference.PRIMARY, write_concern=self._write_concern_for(session), parse_write_concern_error=True, session=session) def get_default_database(self): """DEPRECATED - Get the database named in the MongoDB connection URI. >>> uri = 'mongodb://host/my_database' >>> client = MongoClient(uri) >>> db = client.get_default_database() >>> assert db.name == 'my_database' >>> db = client.get_database() >>> assert db.name == 'my_database' Useful in scripts where you want to choose which database to use based only on the URI in a configuration file. .. versionchanged:: 3.5 Deprecated, use :meth:`get_database` instead. """ warnings.warn("get_default_database is deprecated. Use get_database " "instead.", DeprecationWarning, stacklevel=2) if self.__default_database_name is None: raise ConfigurationError('No default database defined') return self[self.__default_database_name] def get_database(self, name=None, codec_options=None, read_preference=None, write_concern=None, read_concern=None): """Get a :class:`~pymongo.database.Database` with the given name and options. Useful for creating a :class:`~pymongo.database.Database` with different codec options, read preference, and/or write concern from this :class:`MongoClient`. >>> client.read_preference Primary() >>> db1 = client.test >>> db1.read_preference Primary() >>> from pymongo import ReadPreference >>> db2 = client.get_database( ... 'test', read_preference=ReadPreference.SECONDARY) >>> db2.read_preference Secondary(tag_sets=None) :Parameters: - `name` (optional): The name of the database - a string. If ``None`` (the default) the database named in the MongoDB connection URI is returned. - `codec_options` (optional): An instance of :class:`~bson.codec_options.CodecOptions`. If ``None`` (the default) the :attr:`codec_options` of this :class:`MongoClient` is used. - `read_preference` (optional): The read preference to use. If ``None`` (the default) the :attr:`read_preference` of this :class:`MongoClient` is used. See :mod:`~pymongo.read_preferences` for options. - `write_concern` (optional): An instance of :class:`~pymongo.write_concern.WriteConcern`. If ``None`` (the default) the :attr:`write_concern` of this :class:`MongoClient` is used. - `read_concern` (optional): An instance of :class:`~pymongo.read_concern.ReadConcern`. If ``None`` (the default) the :attr:`read_concern` of this :class:`MongoClient` is used. .. versionchanged:: 3.5 The `name` parameter is now optional, defaulting to the database named in the MongoDB connection URI. """ if name is None: if self.__default_database_name is None: raise ConfigurationError('No default database defined') name = self.__default_database_name return database.Database( self, name, codec_options, read_preference, write_concern, read_concern) def _database_default_options(self, name): """Get a Database instance with the default settings.""" return self.get_database( name, codec_options=DEFAULT_CODEC_OPTIONS, read_preference=ReadPreference.PRIMARY, write_concern=DEFAULT_WRITE_CONCERN) @property def is_locked(self): """Is this server locked? While locked, all write operations are blocked, although read operations may still be allowed. Use :meth:`unlock` to unlock. """ ops = self._database_default_options('admin').current_op() return bool(ops.get('fsyncLock', 0)) def fsync(self, **kwargs): """Flush all pending writes to datafiles. Optional parameters can be passed as keyword arguments: - `lock`: If True lock the server to disallow writes. - `async`: If True don't block while synchronizing. - `session` (optional): a :class:`~pymongo.client_session.ClientSession`. .. note:: Starting with Python 3.7 `async` is a reserved keyword. The async option to the fsync command can be passed using a dictionary instead:: options = {'async': True} client.fsync(**options) .. versionchanged:: 3.6 Added ``session`` parameter. .. warning:: `async` and `lock` can not be used together. .. warning:: MongoDB does not support the `async` option on Windows and will raise an exception on that platform. """ self.admin.command("fsync", read_preference=ReadPreference.PRIMARY, **kwargs) def unlock(self, session=None): """Unlock a previously locked server. :Parameters: - `session` (optional): a :class:`~pymongo.client_session.ClientSession`. .. versionchanged:: 3.6 Added ``session`` parameter. """ cmd = SON([("fsyncUnlock", 1)]) with self._socket_for_writes() as sock_info: if sock_info.max_wire_version >= 4: try: with self._tmp_session(session) as s: sock_info.command( "admin", cmd, session=s, client=self) except OperationFailure as exc: # Ignore "DB not locked" to replicate old behavior if exc.code != 125: raise else: message._first_batch(sock_info, "admin", "$cmd.sys.unlock", {}, -1, True, self.codec_options, ReadPreference.PRIMARY, cmd, self._event_listeners) def __enter__(self): return self def __exit__(self, exc_type, exc_val, exc_tb): self.close() def __iter__(self): return self def __next__(self): raise TypeError("'MongoClient' object is not iterable") next = __next__