Provided by: libmongodb-perl_0.702.1+ds-1ubuntu1_amd64 
NAME
MongoDB::Connection - A connection to a MongoDB server (DEPRECATED)
VERSION
version 0.702.1
DEPRECATED
NOTE: "MongoDB::Connection" is DEPRECATED as of version 0.502.0 of the MongoDB CPAN
distribution. It is no longer maintained and will be removed in a future version. Use
MongoDB::MongoClient instead.
SYNOPSIS
The MongoDB::Connection class creates a connection to the MongoDB server.
By default, it connects to a single server running on the local machine listening on the
default port:
# connects to localhost:27017
my $connection = MongoDB::Connection->new;
It can connect to a database server running anywhere, though:
my $connection = MongoDB::Connection->new(host => 'example.com:12345');
See the "host" section for more options for connecting to MongoDB.
MULTITHREADING
Cloning instances of this class is disabled in Perl 5.8.7+, so forked threads will have to
create their own connections to the database.
SEE ALSO
Core documentation on connections: <http://dochub.mongodb.org/core/connections>.
ATTRIBUTES
host
Server or servers to connect to. Defaults to "mongodb://localhost:27017".
To connect to more than one database server, use the format:
mongodb://host1[:port1][,host2[:port2],...[,hostN[:portN]]]
An arbitrary number of hosts can be specified.
The connect method will return success if it can connect to at least one of the hosts
listed. If it cannot connect to any hosts, it will die.
If a port is not specified for a given host, it will default to 27017. For example, to
connecting to "localhost:27017" and "localhost:27018":
$conn = MongoDB::Connection->new("host" => "mongodb://localhost,localhost:27018");
This will succeed if either "localhost:27017" or "localhost:27018" are available.
The connect method will also try to determine who is master if more than one server is
given. It will try the hosts in order from left to right. As soon as one of the hosts
reports that it is master, the connect will return success. If no hosts report themselves
as masters, the connect will die, reporting that it could not find a master.
If username and password are given, success is conditional on being able to log into the
database as well as connect. By default, the driver will attempt to authenticate with the
admin database. If a different database is specified using the "db_name" property, it
will be used instead.
w
Only supported in MongoDB server version 1.5+.
The default number of mongod slaves to replicate a change to before reporting success for
all operations on this collection.
Defaults to 1 (just the current master).
If this is not set, a safe insert will wait for 1 machine (the master) to ack the
operation, then return that it was successful. If the master has slaves, the slaves may
not yet have a record of the operation when success is reported. Thus, if the master goes
down, the slaves will never get this operation.
To prevent this, you can set "w" to a value greater than 1. If you set "w" to <N>, it
means that safe operations must have succeeded on the master and "N-1" slaves before the
client is notified that the operation succeeded. If the operation did not succeed or
could not be replicated to "N-1" slaves within the timeout (see "wtimeout" below), the
safe operation will fail (croak).
Some examples of a safe insert with "w" set to 3 and "wtimeout" set to 100:
The master inserts the document, but 100 milliseconds pass before the slaves have a chance
to replicate it. The master returns failure and the client croaks.
The master inserts the document and two or more slaves replicate the operation within 100
milliseconds. The safe insert returns success.
The master inserts the document but there is only one slave up. The safe insert times out
and croaks.
MongoDB server version 2.0+: "majority" and Data Center Awareness
As of MongoDB 2.0+, the 'w' parameter can be passed strings. This can be done by passing
it the string "majority" this will wait till the majority of of the nodes in the replica
set have received the data. For more information see:
http://www.mongodb.org/display/DOCS/getLastError+Command#getLastErrorCommand-majority
This can be useful for "Data Center Awareness." In v2.0+, you can "tag" replica members.
With "tagging" you can specify a new "getLastErrorMode" where you can create new rules on
how your data is replicated. To used you getLastErrorMode, you pass in the name of the
mode to the 'w' parameter. For more infomation see:
http://www.mongodb.org/display/DOCS/Data+Center+Awareness
wtimeout
The number of milliseconds an operation should wait for "w" slaves to replicate it.
Defaults to 1000 (1 second).
See "w" above for more information.
j
If true, awaits the journal commit before returning. If the server is running without
journaling, it returns immediately, and successfully.
auto_reconnect
Boolean indicating whether or not to reconnect if the connection is interrupted. Defaults
to 1.
auto_connect
Boolean indication whether or not to connect automatically on object construction.
Defaults to 1.
timeout
Connection timeout in milliseconds. Defaults to 20000.
username
Username for this connection. Optional. If this and the password field are set, the
connection will attempt to authenticate on connection/reconnection.
password
Password for this connection. Optional. If this and the username field are set, the
connection will attempt to authenticate on connection/reconnection.
db_name
Database to authenticate on for this connection. Optional. If this, the username, and
the password fields are set, the connection will attempt to authenticate against this
database on connection/reconnection. Defaults to "admin".
query_timeout
# set query timeout to 1 second
my $conn = MongoDB::Connection->new(query_timeout => 1000);
# set query timeout to 6 seconds
$conn->query_timeout(6000);
This will cause all queries (including "find_one"s and "run_command"s) to die after this
period if the database has not responded.
This value is in milliseconds and defaults to the value of "timeout" in MongoDB::Cursor.
$MongoDB::Cursor::timeout = 5000;
# query timeout for $conn will be 5 seconds
my $conn = MongoDB::Connection->new;
A value of -1 will cause the driver to wait forever for responses and 0 will cause it to
die immediately.
This value overrides "timeout" in MongoDB::Cursor.
$MongoDB::Cursor::timeout = 1000;
my $conn = MongoDB::Connection->new(query_timeout => 10);
# timeout for $conn is 10 milliseconds
max_bson_size
This is the largest document, in bytes, storable by MongoDB. The driver queries MongoDB on
connection to determine this value. It defaults to 4MB.
find_master
If this is true, the driver will attempt to find a master given the list of hosts. The
master-finding algorithm looks like:
for host in hosts
if host is master
return host
else if host is a replica set member
master := replica set's master
return master
If no master is found, the connection will fail.
If this is not set (or set to the default, 0), the driver will simply use the first host
in the host list for all connections. This can be useful for directly connecting to
slaves for reads.
If you are connecting to a slave, you should check out the "slave_okay" in MongoDB::Cursor
documentation for information on reading from a slave.
You can use the "ismaster" command to find the members of a replica set:
my $result = $db->run_command({ismaster => 1});
The primary and secondary hosts are listed in the "hosts" field, the slaves are in the
"passives" field, and arbiters are in the "arbiters" field.
ssl
This tells the driver that you are connecting to an SSL mongodb instance.
This option will be ignored if the driver was not compiled with the SSL flag. You must
also be using a database server that supports SSL.
dt_type
Sets the type of object which is returned for DateTime fields. The default is DateTime.
Other acceptable values are DateTime::Tiny and "undef". The latter will give you the raw
epoch value rather than an object.
METHODS
connect
$connection->connect;
Connects to the mongo server. Called automatically on object construction if
"auto_connect" is true.
database_names
my @dbs = $connection->database_names;
Lists all databases on the mongo server.
get_database($name)
my $database = $connection->get_database('foo');
Returns a MongoDB::Database instance for database with the given $name.
get_master
$master = $connection->get_master
Determines which host of a paired connection is master. Does nothing for a non-paired
connection. This need never be invoked by a user, it is called automatically by internal
functions. Returns the index of the master connection in the list of connections or -1 if
it cannot be determined.
authenticate ($dbname, $username, $password, $is_digest?)
$connection->authenticate('foo', 'username', 'secret');
Attempts to authenticate for use of the $dbname database with $username and $password.
Passwords are expected to be cleartext and will be automatically hashed before sending
over the wire, unless $is_digest is true, which will assume you already did the hashing on
yourself.
See also the core documentation on authentication:
<http://dochub.mongodb.org/core/authentication>.
send($str)
my ($insert, $ids) = MongoDB::write_insert('foo.bar', [{name => "joe", age => 40}]);
$conn->send($insert);
Low-level function to send a string directly to the database. Use MongoDB::write_insert,
MongoDB::write_update, MongoDB::write_remove, or MongoDB::write_query to create a valid
string.
recv(\%info)
my $cursor = $conn->recv({ns => "foo.bar"});
Low-level function to receive a response from the database. Returns a "MongoDB::Cursor".
At the moment, the only required field for $info is "ns", although "request_id" is likely
to be required in the future. The $info hash will be automatically created for you by
MongoDB::write_query.
fsync(\%args)
$conn->fsync();
A function that will forces the server to flush all pending writes to the storage layer.
The fsync operation is synchronous by default, to run fsync asynchronously, use the
following form:
$conn->fsync({async => 1});
The primary use of fsync is to lock the database during backup operations. This will flush
all data to the data storage layer and block all write operations until you unlock the
database. Note: you can still read while the database is locked.
$conn->fsync({lock => 1});
fsync_unlock()
$conn->fsync_unlock();
Unlocks a database server to allow writes and reverses the operation of a
$conn->fsync({lock => 1}); operation.
AUTHORS
• Florian Ragwitz <rafl@debian.org>
• Kristina Chodorow <kristina@mongodb.org>
• Mike Friedman <mike.friedman@10gen.com>
COPYRIGHT AND LICENSE
This software is Copyright (c) 2013 by 10gen, Inc..
This is free software, licensed under:
The Apache License, Version 2.0, January 2004