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Create a new connection to a MongoDB replica set.

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, ConnectionFailure is raised. If auto-reconnection will be performed, AutoReconnect will be raised. Application code should handle this exception (recognizing that the operation failed) and then continue to execute.

Raises ConnectionFailure if the connection cannot be made.

The hosts_or_uri parameter can be a full mongodb URI, in addition to a string of host:port pairs (e.g. ‘host1:port1,host2:port2’). If hosts_or_uri is None ‘localhost:27017’ will be used.

Note

Instances of MongoReplicaSetClient start a background task to monitor the state of the replica set. This allows it to quickly respond to changes in replica set configuration. Before discarding an instance of MongoReplicaSetClient make sure you call close() to ensure that the monitor task is cleanly shut down.

Note

A MongoReplicaSetClient created before a call to os.fork() is invalid after the fork. Applications should either fork before creating the client, or recreate the client after a fork.

Parameters : hosts_or_uri (optional): A MongoDB URI or string of host:port pairs. If a host is an IPv6 literal it must be enclosed in ‘[‘ and ‘]’ characters following the RFC2732 URL syntax (e.g. ‘[::1]’ for localhost) max_pool_size (optional): The maximum number of connections each 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, datetime instances returned as values in a document by this MongoReplicaSetClient will be timezone aware (otherwise they will be naive) replicaSet: (required) The name of the replica set to connect to. The driver will verify that each host it connects to is a member of this replica set. Can be passed as a keyword argument or as a MongoDB URI option. Other optional parameters can be passed as keyword arguments: host: For compatibility with MongoClient. If both host and hosts_or_uri are specified host takes precedence. port: For compatibility with MongoClient. The default port number to use for hosts. socketTimeoutMS: (integer) How long (in milliseconds) a send or receive on a socket can take before timing out. connectTimeoutMS: (integer) How long (in milliseconds) a connection can take to be opened before timing out. auto_start_request: If True, each thread that accesses this MongoReplicaSetClient has a socket allocated to it for the thread’s lifetime, for each member of the set. For ReadPreference PRIMARY, auto_start_request=True ensures consistent reads, even if you read after an unacknowledged write. For read preferences other than PRIMARY, there are no consistency guarantees. Default to False. use_greenlets: If True, use a background Greenlet instead of a background thread to monitor state of replica set. Additionally, start_request() assigns a greenlet-local, rather than thread-local, socket. use_greenlets with MongoReplicaSetClient requires Gevent to be installed. Write Concern options: w: (integer or string) 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. Ignored if the server is running without journaling. fsync: If True force the database to fsync all files before returning. When used with j the server awaits the next group commit before returning. Read preference options: read_preference: The read preference for this client. See ReadPreference for available options. tag_sets: Read from replica-set members with these tags. To 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.” MongoReplicaSetClient tries each set of tags in turn until it finds a set of tags with at least one matching member. secondary_acceptable_latency_ms: (integer) Any replica-set member whose ping time is within secondary_acceptable_latency_ms of the nearest member may accept reads. Default 15 milliseconds. Ignored by mongos and must be configured on the command line. See the localThreshold option for more information. SSL configuration: ssl: If True, create the connection to the servers 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.

Changed in version 2.5: Added additional ssl options

New in version 2.4.

disconnect()¶

Disconnect from the replica set primary, unpin all members, and refresh our view of the replica set.

close()¶

Close this client instance.

This method first terminates the replica set monitor, then disconnects from all members of the replica set.

Warning

This method stops the replica set monitor task. The replica set monitor is required to properly handle replica set configuration changes, including a failure of the primary. Once close() is called this client instance must not be reused.

Changed in version 2.2.1: The close() method now terminates the replica set monitor.

alive()¶

Return False if there has been an error communicating with the primary, else True.

This method attempts to check the status of the primary with minimal I/O. The current thread / greenlet retrieves a socket (its request socket if it’s in a request, or a random idle socket if it’s not in a request) from the primary’s connection pool and checks whether calling select on it raises an error. If there are currently no idle sockets, or if there is no known primary, alive() will attempt to actually find and connect to the primary.

A more certain way to determine primary availability is to ping it:

client.admin.command('ping') c[db_name] || c.db_name

Get the db_name Database on MongoReplicaSetClient c.

Raises InvalidName if an invalid database name is used.

seeds¶

The seed list used to connect to this replica set.

A sequence of (host, port) pairs.

hosts¶

All active and passive (priority 0) replica set members known to this client. This does not include hidden or slaveDelay members, or arbiters.

A sequence of (host, port) pairs.

primary¶

The (host, port) of the current primary of the replica set.

Returns None if there is no primary.

secondaries¶

The secondary members known to this client.

A sequence of (host, port) pairs.

arbiters¶

The arbiters known to this client.

A sequence of (host, port) pairs.

is_mongos¶

If this instance is connected to mongos (always False).

New in version 2.3.

max_pool_size¶

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 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.

Changed in version 2.6.

document_class¶

Default class to use for documents returned from this client.

tz_aware¶

Does this client return timezone-aware datetimes?

max_bson_size¶

Returns the maximum size BSON object the connected primary accepts in bytes. Defaults to 4MB in server < 1.7.4. Returns 0 if no primary is available.

max_message_size¶

Returns the maximum message size the connected primary accepts in bytes. Returns 0 if no primary is available.

auto_start_request¶

Is auto_start_request enabled?

read_preference¶

The read preference mode for this instance.

See ReadPreference for available options.

New in version 2.1.

tag_sets¶

Set tag_sets to a list of dictionaries like [{‘dc’: ‘ny’}] to read only from members whose dc tag has the value "ny". To 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.” ReplicaSetConnection tries each set of tags in turn until it finds a set of tags with at least one matching member.

See also

Data-Center Awareness

New in version 2.3.

secondary_acceptable_latency_ms¶

Any replica-set member whose ping time is within secondary_acceptable_latency_ms of the nearest member may accept reads. Defaults to 15 milliseconds.

See ReadPreference.

New in version 2.3.

Note

secondary_acceptable_latency_ms is ignored when talking to a replica set through a mongos. The equivalent is the localThreshold command line option.

write_concern¶

The default write concern for this instance.

Supports dict style access for getting/setting write concern options. Valid options include:

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). Setting 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. Ignored if the server is running without journaling. fsync: If True force the database to fsync all files before returning. When used with j the server awaits the next group commit before returning. >>> m = pymongo.MongoClient() >>> m.write_concern {} >>> m.write_concern = {'w': 2, 'wtimeout': 1000} >>> m.write_concern {'wtimeout': 1000, 'w': 2} >>> m.write_concern['j'] = True >>> m.write_concern {'wtimeout': 1000, 'j': True, 'w': 2} >>> m.write_concern = {'j': True} >>> m.write_concern {'j': True} >>> # Disable write acknowledgement and write concern ... >>> m.write_concern['w'] = 0

Note

Accessing write_concern returns its value (a subclass of dict), not a copy.

Warning

If you are using Connection or ReplicaSetConnection make sure you explicitly set w to 1 (or a greater value) or safe to True. Unlike calling set_lasterror_options(), setting an option in write_concern does not implicitly set safe to True.

database_names()¶

Get a list of the names of all databases on the connected server.

drop_database(name_or_database)¶

Drop a database.

Raises TypeError if name_or_database is not an instance of basestring (str in python 3) or Database

Parameters : name_or_database: the name of a database to drop, or a Database instance representing the database to drop copy_database(from_name, to_name[, from_host=None[, username=None[, password=None]]])¶

Copy a database, potentially from another host.

Raises TypeError if from_name or to_name is not an instance of basestring (str in python 3). Raises InvalidName if to_name is not a valid database name.

If from_host is None the current host is used as the source. Otherwise the database is copied from from_host.

If the source database requires authentication, username and password must be specified.

Parameters : from_name: the name of the source database to_name: the name of the target database from_host (optional): host name to copy from username (optional): username for source database password (optional): password for source database

Note

Specifying username and password requires server version >= 1.3.3+.

get_default_database()¶

Get the database named in the MongoDB connection URI.

>>> uri = 'mongodb://host/my_database' >>> client = MongoReplicaSetClient(uri) >>> db = client.get_default_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.

close_cursor(cursor_id, _conn_id)¶

Close a single database cursor.

Raises TypeError if cursor_id is not an instance of (int, long). What closing the cursor actually means depends on this client’s cursor manager.

Parameters : cursor_id: id of cursor to close

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