1MongoDB::MongoClient(3)User Contributed Perl DocumentatioMnongoDB::MongoClient(3)
2
6 MongoDB::MongoClient - A connection to a MongoDB server or multi-server
7 deployment
8
10 version v2.0.3
11
13 use MongoDB; # also loads MongoDB::MongoClient
14 # connect to localhost:27017
16 my $client = MongoDB::MongoClient->new;
17 # connect to specific host and port
19 my $client = MongoDB::MongoClient->new(
20 host => "mongodb://mongo.example.com:27017"
21 );
22 # connect to a replica set (set name *required*)
24 my $client = MongoDB::MongoClient->new(
25 host => "mongodb://mongo1.example.com,mongo2.example.com",
26 replica_set_name => 'myset',
27 );
28 # connect to a replica set with URI (set name *required*)
30 my $client = MongoDB::MongoClient->new(
31 host => "mongodb://mongo1.example.com,mongo2.example.com/?replicaSet=myset",
32 );
33 my $db = $client->get_database("test");
35 my $coll = $db->get_collection("people");
36 $coll->insert({ name => "John Doe", age => 42 });
38 my @people = $coll->find()->all();
39
41 The "MongoDB::MongoClient" class represents a client connection to one
42 or more MongoDB servers.
43 By default, it connects to a single server running on the local machine
45 listening on the default port 27017:
46 # connects to localhost:27017
48 my $client = MongoDB::MongoClient->new;
49 It can connect to a database server running anywhere, though:
51 my $client = MongoDB::MongoClient->new(host => 'example.com:12345');
53 See the "host" attribute for more options for connecting to MongoDB.
55 MongoDB can be started in authentication mode
57 <http://docs.mongodb.org/manual/core/authentication/>, which requires
58 clients to log in before manipulating data. By default, MongoDB does
59 not start in this mode, so no username or password is required to make
60 a fully functional connection. To configure the client for
61 authentication, see the "AUTHENTICATION" section.
62 The actual socket connections are lazy and created on demand. When the
64 client object goes out of scope, all socket will be closed. Note that
65 MongoDB::Database, MongoDB::Collection and related classes could hold a
66 reference to the client as well. Only when all references are out of
67 scope will the sockets be closed.
68
70 host
71 The "host" attribute specifies either a single server to connect to (as
72 "hostname" or "hostname:port"), or else a connection string URI with a
73 seed list of one or more servers plus connection options.
74 Defaults to the connection string URI "mongodb://localhost:27017".
76 For IPv6 support, you must have a recent version of IO::Socket::IP
78 installed. This module ships with the Perl core since v5.20.0 and is
79 available on CPAN for older Perls.
80 app_name
82 This attribute specifies an application name that should be associated
83 with this client. The application name will be communicated to the
84 server as part of the initial connection handshake, and will appear in
85 connection-level and operation-level diagnostics on the server
86 generated on behalf of this client. This may be set in a connection
87 string with the "appName" option.
88 The default is the empty string, which indicates a lack of an
90 application name.
91 The application name must not exceed 128 bytes.
93 auth_mechanism
95 This attribute determines how the client authenticates with the server.
96 Valid values are:
97 · NONE
99 · DEFAULT
101 · MONGODB-CR
103 · MONGODB-X509
105 · GSSAPI
107 · PLAIN
109 · SCRAM-SHA-1
111 If not specified, then if no username is provided, it defaults to NONE.
113 If a username is provided, it is set to DEFAULT, which chooses
114 SCRAM-SHA-1 if available or MONGODB-CR otherwise.
115 This may be set in a connection string with the "authMechanism" option.
117 auth_mechanism_properties
119 This is an optional hash reference of authentication mechanism specific
120 properties. See "AUTHENTICATION" for details.
121 This may be set in a connection string with the
123 "authMechanismProperties" option. If given, the value must be
124 key/value pairs joined with a ":". Multiple pairs must be separated by
125 a comma. If ": or "," appear in a key or value, they must be URL
126 encoded.
127 bson_codec
129 An object that provides the "encode_one" and "decode_one" methods, such
130 as from BSON. It may be initialized with a hash reference that will be
131 coerced into a new BSON object.
132 If not provided, a BSON object with default values will be generated.
134 compressors
136 An array reference of compression type names. Currently only "zlib" is
137 supported.
138 zlib_compression_level
140 An integer from "-1" to 9 specifying the compression level to use when
141 "compression" is set to "zlib".
142 Note: When the special value "-1" is given, the default compression
144 level will be used.
145 connect_timeout_ms
147 This attribute specifies the amount of time in milliseconds to wait for
148 a new connection to a server.
149 The default is 10,000 ms.
151 If set to a negative value, connection operations will block
153 indefinitely until the server replies or until the operating system
154 TCP/IP stack gives up (e.g. if the name can't resolve or there is no
155 process listening on the target host/port).
156 A zero value polls the socket during connection and is thus likely to
158 fail except when talking to a local process (and perhaps even then).
159 This may be set in a connection string with the "connectTimeoutMS"
161 option.
162 db_name
164 Optional. If an "auth_mechanism" requires a database for
165 authentication, this attribute will be used. Otherwise, it will be
166 ignored. Defaults to "admin".
167 This may be provided in the connection string URI as a path between the
169 authority and option parameter sections. For example, to authenticate
170 against the "admin" database (showing a configuration option only for
171 illustration):
172 mongodb://localhost/admin?readPreference=primary
174 heartbeat_frequency_ms
176 The time in milliseconds (non-negative) between scans of all servers to
177 check if they are up and update their latency. Defaults to 60,000 ms.
178 This may be set in a connection string with the "heartbeatFrequencyMS"
180 option.
181 j
183 If true, the client will block until write operations have been
184 committed to the server's journal. Prior to MongoDB 2.6, this option
185 was ignored if the server was running without journaling. Starting with
186 MongoDB 2.6, write operations will fail if this option is used when the
187 server is running without journaling.
188 This may be set in a connection string with the "journal" option as the
190 strings 'true' or 'false'.
191 local_threshold_ms
193 The width of the 'latency window': when choosing between multiple
194 suitable servers for an operation, the acceptable delta in milliseconds
195 (non-negative) between shortest and longest average round-trip times.
196 Servers within the latency window are selected randomly.
197 Set this to "0" to always select the server with the shortest average
199 round trip time. Set this to a very high value to always randomly
200 choose any known server.
201 Defaults to 15 ms.
203 See "SERVER SELECTION" for more details.
205 This may be set in a connection string with the "localThresholdMS"
207 option.
208 max_staleness_seconds
210 The "max_staleness_seconds" parameter represents the maximum
211 replication lag in seconds (wall clock time) that a secondary can
212 suffer and still be eligible for reads. The default is -1, which
213 disables staleness checks. Otherwise, it must be a positive integer.
214 Note: this will only be used for server versions 3.4 or greater, as
216 that was when support for staleness tracking was added.
217 If the read preference mode is 'primary', then "max_staleness_seconds"
219 must not be supplied.
220 The "max_staleness_seconds" must be at least the
222 "heartbeat_frequency_ms" plus 10 seconds (which is how often the server
223 makes idle writes to the oplog).
224 This may be set in a connection string with the "maxStalenessSeconds"
226 option.
227 max_time_ms
229 Specifies the maximum amount of time in (non-negative) milliseconds
230 that the server should use for working on a database command. Defaults
231 to 0, which disables this feature. Make sure this value is shorter
232 than "socket_timeout_ms".
233 Note: this will only be used for server versions 2.6 or greater, as
235 that was when the $maxTimeMS meta-operator was introduced.
236 You are strongly encouraged to set this variable if you know your
238 environment has MongoDB 2.6 or later, as getting a definitive error
239 response from the server is vastly preferred over a getting a network
240 socket timeout.
241 This may be set in a connection string with the "maxTimeMS" option.
243 monitoring_callback
245 Specifies a code reference used to receive monitoring events. See
246 MongoDB::Monitoring for more details.
247 password
249 If an "auth_mechanism" requires a password, this attribute will be
250 used. Otherwise, it will be ignored.
251 This may be provided in the connection string URI as a
253 "username:password" pair in the leading portion of the authority
254 section before a "@" character. For example, to authenticate as user
255 "mulder" with password "trustno1":
256 mongodb://mulder:trustno1@localhost
258 If the username or password have a ":" or "@" in it, they must be URL
260 encoded. An empty password still requires a ":" character.
261 port
263 If a network port is not specified as part of the "host" attribute,
264 this attribute provides the port to use. It defaults to 27107.
265 read_pref_mode
267 The read preference mode determines which server types are candidates
268 for a read operation. Valid values are:
269 · primary
271 · primaryPreferred
273 · secondary
275 · secondaryPreferred
277 · nearest
279 For core documentation on read preference see
281 <http://docs.mongodb.org/manual/core/read-preference/>.
282 This may be set in a connection string with the "readPreference"
284 option.
285 read_pref_tag_sets
287 The "read_pref_tag_sets" parameter is an ordered list of tag sets used
288 to restrict the eligibility of servers, such as for data center
289 awareness. It must be an array reference of hash references.
290 The application of "read_pref_tag_sets" varies depending on the
292 "read_pref_mode" parameter. If the "read_pref_mode" is 'primary', then
293 "read_pref_tag_sets" must not be supplied.
294 For core documentation on read preference see
296 <http://docs.mongodb.org/manual/core/read-preference/>.
297 This may be set in a connection string with the "readPreferenceTags"
299 option. If given, the value must be key/value pairs joined with a ":".
300 Multiple pairs must be separated by a comma. If ": or "," appear in a
301 key or value, they must be URL encoded. The "readPreferenceTags"
302 option may appear more than once, in which case each document will be
303 added to the tag set list.
304 replica_set_name
306 Specifies the replica set name to connect to. If this string is non-
307 empty, then the topology is treated as a replica set and all server
308 replica set names must match this or they will be removed from the
309 topology.
310 This may be set in a connection string with the "replicaSet" option.
312 server_selection_timeout_ms
314 This attribute specifies the amount of time in milliseconds to wait for
315 a suitable server to be available for a read or write operation. If no
316 server is available within this time period, an exception will be
317 thrown.
318 The default is 30,000 ms.
320 See "SERVER SELECTION" for more details.
322 This may be set in a connection string with the
324 "serverSelectionTimeoutMS" option.
325 server_selection_try_once
327 This attribute controls whether the client will make only a single
328 attempt to find a suitable server for a read or write operation. The
329 default is true.
330 When true, the client will not use the "server_selection_timeout_ms".
332 Instead, if the topology information is stale and needs to be checked
333 or if no suitable server is available, the client will make a single
334 scan of all known servers to try to find a suitable one.
335 When false, the client will continually scan known servers until a
337 suitable server is found or the "serverSelectionTimeoutMS" is reached.
338 See "SERVER SELECTION" for more details.
340 This may be set in a connection string with the
342 "serverSelectionTryOnce" option.
343 socket_check_interval_ms
345 If a socket to a server has not been used in this many milliseconds, an
346 "ismaster" command will be issued to check the status of the server
347 before issuing any reads or writes. Must be non-negative.
348 The default is 5,000 ms.
350 This may be set in a connection string with the "socketCheckIntervalMS"
352 option.
353 socket_timeout_ms
355 This attribute specifies the amount of time in milliseconds to wait for
356 a reply from the server before issuing a network exception.
357 The default is 30,000 ms.
359 If set to a negative value, socket operations will block indefinitely
361 until the server replies or until the operating system TCP/IP stack
362 gives up.
363 A zero value polls the socket for available data and is thus likely to
365 fail except when talking to a local process (and perhaps even then).
366 This may be set in a connection string with the "socketTimeoutMS"
368 option.
369 ssl
371 ssl => 1
372 ssl => \%ssl_options
373 This tells the driver that you are connecting to an SSL mongodb
375 instance.
376 You must have IO::Socket::SSL 1.42+ and Net::SSLeay 1.49+ installed for
378 SSL support.
379 The "ssl" attribute takes either a boolean value or a hash reference of
381 options to pass to IO::Socket::SSL. For example, to set a CA file to
382 validate the server certificate and set a client certificate for the
383 server to validate, you could set the attribute like this:
384 ssl => {
386 SSL_ca_file => "/path/to/ca.pem",
387 SSL_cert_file => "/path/to/client.pem",
388 }
389 If "SSL_ca_file" is not provided, server certificates are verified
391 against a default list of CAs, either Mozilla::CA or an operating-
392 system-specific default CA file. To disable verification, you can use
393 "SSL_verify_mode => 0x00".
394 You are strongly encouraged to use your own CA file for increased
396 security.
397 Server hostnames are also validated against the CN name in the server
399 certificate using "SSL_verifycn_scheme => 'http'". You can use the
400 scheme 'none' to disable this check.
401 Disabling certificate or hostname verification is a security risk and
403 is not recommended.
404 This may be set to the string 'true' or 'false' in a connection string
406 with the "ssl" option, which will enable ssl with default
407 configuration. (A future version of the driver may support customizing
408 ssl via the connection string.)
409 username
411 Optional username for this client connection. If this field is set,
412 the client will attempt to authenticate when connecting to servers.
413 Depending on the "auth_mechanism", the "password" field or other
414 attributes will need to be set for authentication to succeed.
415 This may be provided in the connection string URI as a
417 "username:password" pair in the leading portion of the authority
418 section before a "@" character. For example, to authenticate as user
419 "mulder" with password "trustno1":
420 mongodb://mulder:trustno1@localhost
422 If the username or password have a ":" or "@" in it, they must be URL
424 encoded. An empty password still requires a ":" character.
425 w
427 The client write concern.
428 · 0 Unacknowledged. MongoClient will NOT wait for an acknowledgment
430 that the server has received and processed the request. Older
431 documentation may refer to this as "fire-and-forget" mode. This
432 option is not recommended.
433 · 1 Acknowledged. This is the default. MongoClient will wait until
435 the primary MongoDB acknowledges the write.
436 · 2 Replica acknowledged. MongoClient will wait until at least two
438 replicas (primary and one secondary) acknowledge the write. You can
439 set a higher number for more replicas.
440 · "all" All replicas acknowledged.
442 · "majority" A majority of replicas acknowledged.
444 In MongoDB v2.0+, you can "tag" replica members. With "tagging" you can
446 specify a custom write concern For more information see Data Center
447 Awareness <http://docs.mongodb.org/manual/data-center-awareness/>
448 This may be set in a connection string with the "w" option.
450 wtimeout
452 The number of milliseconds an operation should wait for "w" secondaries
453 to replicate it.
454 Defaults to 1000 (1 second).
456 See "w" above for more information.
458 This may be set in a connection string with the "wTimeoutMS" option.
460 read_concern_level
462 The read concern level determines the consistency level required of
463 data being read.
464 The default level is "undef", which means the server will use its
466 configured default.
467 If the level is set to "local", reads will return the latest data a
469 server has locally.
470 Additional levels are storage engine specific. See Read Concern
472 <http://docs.mongodb.org/manual/search/?query=readConcern> in the
473 MongoDB documentation for more details.
474 This may be set in a connection string with the the "readConcernLevel"
476 option.
477 retry_writes
479 Whether the client should use retryable writes for supported commands.
480 The default value is false, which means that no write commands will be
481 retried.
482 If this is set to a true value, then commands which support retryable
484 writes will be retried on certain errors, such as "not master" and
485 "node is recovering" errors.
486 This may be set in a connection string with the "retryWrites" option.
488 Note that this is only supported on MongoDB > 3.6 in Replica Set or
490 Shard Clusters, and will be ignored on other deployments.
491 Unacknowledged write operations also do not support retryable writes,
493 even when retry_writes has been enabled.
494 The supported single statement write operations are currently as
496 follows:
497 · "insert_one"
499 · "update_one"
501 · "replace_one"
503 · "delete_one"
505 · "find_one_and_delete"
507 · "find_one_and_replace"
509 · "find_one_and_update"
511 The supported multi statement write operations are as follows:
513 · "insert_many"
515 · "bulk_write"
517 The multi statement operations may be ether ordered or unordered. Note
519 that for "bulk_write" operations, the request may not include
520 update_many or delete_many operations.
521
523 read_preference
524 Returns a MongoDB::ReadPreference object constructed from
525 "read_pref_mode" and "read_pref_tag_sets"
526 The use of "read_preference" as a mutator has been removed. Read
528 preference is read-only. If you need a different read preference for a
529 database or collection, you can specify that in "get_database" or
530 "get_collection".
531 write_concern
533 Returns a MongoDB::WriteConcern object constructed from "w",
534 "write_concern" and "j".
535 read_concern
537 Returns a MongoDB::ReadConcern object constructed from
538 "read_concern_level".
539 topology_type
541 Returns an enumerated topology type. If the "replica_set_name" is set,
542 the value will be either 'ReplicaSetWithPrimary' or
543 'ReplicaSetNoPrimary' (if the primary is down or not yet discovered).
544 Without "replica_set_name", if there is more than one server in the
545 list of hosts, the type will be 'Sharded'.
546 With only a single host and no replica set name, the topology type will
548 start as 'Direct' until the server is contacted the first time, after
549 which the type will be 'Sharded' for a mongos or 'Single' for
550 standalone server or direct connection to a replica set member.
551 connect
553 $client->connect;
554 Calling this method is unnecessary, as connections are established
556 automatically as needed. It is kept for backwards compatibility.
557 Calling it will check all servers in the deployment which ensures a
558 connection to any that are available.
559 See "reconnect" for a method that is useful when using forks or
561 threads.
562 disconnect
564 $client->disconnect;
565 Drops all connections to servers.
567 reconnect
569 $client->reconnect;
570 This method closes all connections to the server, as if "disconnect"
572 were called, and then immediately reconnects. It also clears the
573 session cache. Use this after forking or spawning off a new thread.
574 topology_status
576 $client->topology_status;
577 $client->topology_status( refresh => 1 );
578 Returns a hash reference with server topology information like this:
580 {
582 'topology_type' => 'ReplicaSetWithPrimary'
583 'replica_set_name' => 'foo',
584 'last_scan_time' => '1433766895.183241',
585 'servers' => [
586 {
587 'address' => 'localhost:50003',
588 'ewma_rtt_ms' => '0.223462326',
589 'type' => 'RSSecondary'
590 },
591 {
592 'address' => 'localhost:50437',
593 'ewma_rtt_ms' => '0.268435456',
594 'type' => 'RSArbiter'
595 },
596 {
597 'address' => 'localhost:50829',
598 'ewma_rtt_ms' => '0.737782272',
599 'type' => 'RSPrimary'
600 }
601 },
602 }
603 If the 'refresh' argument is true, then the topology will be scanned to
605 update server data before returning the hash reference.
606 start_session
608 $client->start_session;
609 $client->start_session( $options );
610 Returns a new MongoDB::ClientSession with the supplied options.
612 will throw a "MongoDB::ConfigurationError" if sessions are not
614 supported by the connected MongoDB deployment.
615 the options hash is an optional hash which can have the following keys:
617 · "causalConsistency" - Enable Causally Consistent reads for this
619 session. Defaults to true.
620 for more information see "options" in MongoDB::ClientSession.
622 list_databases
624 # get all information on all databases
625 my @dbs = $client->list_databases;
626 # get only the foo databases
628 my @foo_dbs = $client->list_databases({ filter => { name => qr/^foo/ } });
629 Lists all databases with information on each database. Supports
631 filtering by any of the output fields under the "filter" argument, such
632 as:
633 · "name"
635 · "sizeOnDisk"
637 · "empty"
639 · "shards"
641 database_names
643 my @dbs = $client->database_names;
644 # get only the foo database names
646 my @foo_dbs = $client->database_names({ filter => { name => qr/^foo/ } });
647 List of all database names on the MongoDB server. Supports filters in
649 the same way as "list_databases".
650 get_database, db
652 my $database = $client->get_database('foo');
653 my $database = $client->get_database('foo', $options);
654 my $database = $client->db('foo', $options);
655 Returns a MongoDB::Database instance for the database with the given
657 $name.
658 It takes an optional hash reference of options that are passed to the
660 MongoDB::Database constructor.
661 The "db" method is an alias for "get_database".
663 get_namespace, ns
665 my $collection = $client->get_namespace('test.foo');
666 my $collection = $client->get_namespace('test.foo', $options);
667 my $collection = $client->ns('test.foo', $options);
668 Returns a MongoDB::Collection instance for the given namespace. The
670 namespace has both the database name and the collection name separated
671 with a dot character.
672 This is a quick way to get a collection object if you don't need the
674 database object separately.
675 It takes an optional hash reference of options that are passed to the
677 MongoDB::Collection constructor. The intermediate MongoDB::Database
678 object will be created with default options.
679 The "ns" method is an alias for "get_namespace".
681 fsync(\%args)
683 $client->fsync();
684 A function that will forces the server to flush all pending writes to
686 the storage layer.
687 The fsync operation is synchronous by default, to run fsync
689 asynchronously, use the following form:
690 $client->fsync({async => 1});
692 The primary use of fsync is to lock the database during backup
694 operations. This will flush all data to the data storage layer and
695 block all write operations until you unlock the database. Note: you can
696 still read while the database is locked.
697 $conn->fsync({lock => 1});
699 fsync_unlock
701 $conn->fsync_unlock();
702 Unlocks a database server to allow writes and reverses the operation of
704 a $conn->fsync({lock => 1}); operation.
705 watch
707 Watches for changes on the cluster.
708 Perform an aggregation with an implicit initial $changeStream stage and
710 returns a MongoDB::ChangeStream result which can be used to iterate
711 over the changes in the cluster. This functionality is available since
712 MongoDB 4.0.
713 my $stream = $client->watch();
715 my $stream = $client->watch( \@pipeline );
716 my $stream = $client->watch( \@pipeline, \%options );
717 while (1) {
719 # This inner loop will only run until no more changes are
721 # available.
722 while (my $change = $stream->next) {
723 # process $change
724 }
725 }
726 The returned stream will not block forever waiting for changes. If you
728 want to respond to changes over a longer time use "maxAwaitTimeMS" and
729 regularly call "next" in a loop.
730 See "watch" in MongoDB::Collection for details on usage and available
732 options.
733
735 MongoDB can operate as a single server or as a distributed system. One
736 or more servers that collectively provide access to a single logical
737 set of MongoDB databases are referred to as a "deployment".
738 There are three types of deployments:
740 · Single server – a stand-alone mongod database
742 · Replica set – a set of mongod databases with data replication and
744 fail-over capability
745 · Sharded cluster – a distributed deployment that spreads data across
747 one or more shards, each of which can be a replica set. Clients
748 communicate with a mongos process that routes operations to the
749 correct share.
750 The state of a deployment, including its type, which servers are
752 members, the server types of members and the round-trip network latency
753 to members is referred to as the "topology" of the deployment.
754 To the greatest extent possible, the MongoDB driver abstracts away the
756 details of communicating with different deployment types. It
757 determines the deployment topology through a combination of the
758 connection string, configuration options and direct discovery
759 communicating with servers in the deployment.
760
762 MongoDB uses a pseudo-URI connection string to specify one or more
763 servers to connect to, along with configuration options.
764 NOTE: any non-printable ASCII characters should be UTF-8 encoded and
766 converted URL-escaped characters.
767 To connect to more than one database server, provide host or host:port
769 pairs as a comma separated list:
770 mongodb://host1[:port1][,host2[:port2],...[,hostN[:portN]]]
772 This list is referred to as the "seed list". An arbitrary number of
774 hosts can be specified. If a port is not specified for a given host,
775 it will default to 27017.
776 If multiple hosts are given in the seed list or discovered by talking
778 to servers in the seed list, they must all be replica set members or
779 must all be mongos servers for a sharded cluster.
780 A replica set MUST have the "replicaSet" option set to the replica set
782 name.
783 If there is only single host in the seed list and "replicaSet" is not
785 provided, the deployment is treated as a single server deployment and
786 all reads and writes will be sent to that host.
787 Providing a replica set member as a single host without the set name is
789 the way to get a "direct connection" for carrying out administrative
790 activities on that server.
791 The connection string may also have a username and password:
793 mongodb://username:password@host1:port1,host2:port2
795 The username and password must be URL-escaped.
797 A optional database name for authentication may be given:
799 mongodb://username:password@host1:port1,host2:port2/my_database
801 Finally, connection string options may be given as URI attribute pairs
803 in a query string:
804 mongodb://host1:port1,host2:port2/?ssl=1&wtimeoutMS=1000
806 mongodb://username:password@host1:port1,host2:port2/my_database?ssl=1&wtimeoutMS=1000
807 The currently supported connection string options are:
809 *appName *authMechanism *authMechanism.SERVICE_NAME *compressors
811 *connectTimeoutMS *journal *readPreference *readPreferenceTags
812 *replicaSet *ssl *w *wtimeoutMS *zlibCompressionLevel
813 See the official MongoDB documentation on connection strings for more
815 on the URI format and connection string options:
816 <http://docs.mongodb.org/manual/reference/connection-string/>.
817
819 For a single server deployment or a direct connection to a mongod or
820 mongos, all reads and writes and sent to that server. Any read-
821 preference is ignored.
822 When connected to a deployment with multiple servers, such as a replica
824 set or sharded cluster, the driver chooses a server for operations
825 based on the type of operation (read or write), the types of servers
826 available and a read preference.
827 For a replica set deployment, writes are sent to the primary (if
829 available) and reads are sent to a server based on the
830 "read_preference" attribute, which defaults to sending reads to the
831 primary. See MongoDB::ReadPreference for more.
832 For a sharded cluster reads and writes are distributed across mongos
834 servers in the seed list. Any read preference is passed through to the
835 mongos and used by it when executing reads against shards.
836 If multiple servers can service an operation (e.g. multiple mongos
838 servers, or multiple replica set members), one is chosen at random from
839 within the "latency window". The server with the shortest average
840 round-trip time (RTT) is always in the window. Any servers with an
841 average round-trip time less than or equal to the shortest RTT plus the
842 "local_threshold_ms" are also in the latency window.
843 If a suitable server is not immediately available, what happens next
845 depends on the "server_selection_try_once" option.
846 If that option is true, a single topology scan will be performed.
848 Afterwards if a suitable server is available, it will be returned;
849 otherwise, an exception is thrown.
850 If that option is false, the driver will do topology scans repeatedly
852 looking for a suitable server. When more than
853 "server_selection_timeout_ms" milliseconds have elapsed since the start
854 of server selection without a suitable server being found, an exception
855 is thrown.
856 Note: the actual maximum wait time for server selection could be as
858 long "server_selection_timeout_ms" plus the amount of time required to
859 do a topology scan.
860
862 When the client first needs to find a server for a database operation,
863 all servers from the "host" attribute are scanned to determine which
864 servers to monitor. If the deployment is a replica set, additional
865 hosts may be discovered in this process. Invalid hosts are dropped.
866 After the initial scan, whenever the servers have not been checked in
868 "heartbeat_frequency_ms" milliseconds, the scan will be repeated. This
869 amortizes monitoring time over many of operations. Additionally, if a
870 socket has been idle for a while, it will be checked before being used
871 for an operation.
872 If a server operation fails because of a "not master" or "node is
874 recovering" error, or if there is a network error or timeout, then the
875 server is flagged as unavailable and exception will be thrown. See
876 MongoDB::Errors for exception types.
877 If the error is caught and handled, the next operation will rescan all
879 servers immediately to update its view of the topology. The driver can
880 continue to function as long as servers are suitable per "SERVER
881 SELECTION".
882 When catching an exception, users must determine whether or not their
884 application should retry an operation based on the specific operation
885 attempted and other use-case-specific considerations. For automating
886 retries despite exceptions, consider using the Try::Tiny::Retry module.
887
889 Warning: industry best practices, and some regulations, require the use
890 of TLS 1.1 or newer.
891 Some operating systems or versions may not provide an OpenSSL version
893 new enough to support the latest TLS protocols. If your OpenSSL
894 library version number is less than 1.0.1, then support for TLS 1.1 or
895 newer is not available. Contact your operating system vendor for a
896 solution or upgrade to a newer operating system distribution.
897 See also the documentation for Net::SSLeay for details on installing
899 and compiling against OpenSSL.
900 TLS connections in the driver rely on the default settings provided by
902 IO::Socket::SSL, but allow you to pass custom configuration to it.
903 Please read its documentation carefully to see how to control your TLS
904 configuration.
905
907 The MongoDB server provides several authentication mechanisms, though
908 some are only available in the Enterprise edition.
909 MongoDB client authentication is controlled via the "auth_mechanism"
911 attribute, which takes one of the following values:
912 NOTE: MONGODB-CR was deprecated with the release of MongoDB 3.6 and is
914 no longer supported by MongoDB 4.0.
915 · MONGODB-CR -- legacy username-password challenge-response (< 4.0)
917 · SCRAM-SHA-1 -- secure username-password challenge-response (3.0+)
919 · MONGODB-X509 -- SSL client certificate authentication (2.6+)
921 · PLAIN -- LDAP authentication via SASL PLAIN (Enterprise only)
923 · GSSAPI -- Kerberos authentication (Enterprise only)
925 The mechanism to use depends on the authentication configuration of the
927 server. See the core documentation on authentication:
928 <http://docs.mongodb.org/manual/core/access-control/>.
929 Usage information for each mechanism is given below.
931 MONGODB-CR and SCRAM-SHA-1 (for username/password)
933 These mechanisms require a username and password, given either as
934 constructor attributes or in the "host" connection string.
935 If a username is provided and an authentication mechanism is not
937 specified, the client will use SCRAM-SHA-1 for version 3.0 or later
938 servers and will fall back to MONGODB-CR for older servers.
939 my $mc = MongoDB::MongoClient->new(
941 host => "mongodb://mongo.example.com/",
942 username => "johndoe",
943 password => "trustno1",
944 );
945 my $mc = MongoDB::MongoClient->new(
947 host => "mongodb://johndoe:trustno1@mongo.example.com/",
948 );
949 Usernames and passwords will be UTF-8 encoded before use. The password
951 is never sent over the wire -- only a secure digest is used. The
952 SCRAM-SHA-1 mechanism is the Salted Challenge Response Authentication
953 Mechanism defined in RFC 5802 <http://tools.ietf.org/html/rfc5802>.
954 The default database for authentication is 'admin'. If another
956 database name should be used, specify it with the "db_name" attribute
957 or via the connection string.
958 db_name => auth_db
960 mongodb://johndoe:trustno1@mongo.example.com/auth_db
962 MONGODB-X509 (for SSL client certificate)
964 X509 authentication requires SSL support (IO::Socket::SSL), requires
965 that a client certificate be configured in the ssl parameters, and
966 requires specifying the "MONGODB-X509" authentication mechanism.
967 my $mc = MongoDB::MongoClient->new(
969 host => "mongodb://sslmongo.example.com/",
970 ssl => {
971 SSL_ca_file => "certs/ca.pem",
972 SSL_cert_file => "certs/client.pem",
973 },
974 auth_mechanism => "MONGODB-X509",
975 );
976 Note: Since MongoDB Perl driver v1.8.0, you no longer need to specify a
978 "username" parameter for X509 authentication; the username will be
979 extracted automatically from the certificate.
980 PLAIN (for LDAP)
982 This mechanism requires a username and password, which will be UTF-8
983 encoded before use. The "auth_mechanism" parameter must be given as a
984 constructor attribute or in the "host" connection string:
985 my $mc = MongoDB::MongoClient->new(
987 host => "mongodb://mongo.example.com/",
988 username => "johndoe",
989 password => "trustno1",
990 auth_mechanism => "PLAIN",
991 );
992 my $mc = MongoDB::MongoClient->new(
994 host => "mongodb://johndoe:trustno1@mongo.example.com/authMechanism=PLAIN",
995 );
996 GSSAPI (for Kerberos)
998 Kerberos authentication requires the CPAN module Authen::SASL and a
999 GSSAPI-capable backend.
1000 On Debian systems, Authen::SASL may be available as
1002 "libauthen-sasl-perl"; on RHEL systems, it may be available as
1003 "perl-Authen-SASL".
1004 The Authen::SASL::Perl backend comes with Authen::SASL and requires the
1006 GSSAPI CPAN module for GSSAPI support. On Debian systems, this may be
1007 available as "libgssapi-perl"; on RHEL systems, it may be available as
1008 "perl-GSSAPI".
1009 Installing the GSSAPI module from CPAN rather than an OS package
1011 requires "libkrb5" and the "krb5-config" utility (available for
1012 Debian/RHEL systems in the "libkrb5-dev" package).
1013 Alternatively, the Authen::SASL::XS or Authen::SASL::Cyrus modules may
1015 be used. Both rely on Cyrus "libsasl". Authen::SASL::XS is preferred,
1016 but not yet available as an OS package. Authen::SASL::Cyrus is
1017 available on Debian as "libauthen-sasl-cyrus-perl" and on RHEL as
1018 "perl-Authen-SASL-Cyrus".
1019 Installing Authen::SASL::XS or Authen::SASL::Cyrus from CPAN requires
1021 "libsasl". On Debian systems, it is available from "libsasl2-dev"; on
1022 RHEL, it is available in "cyrus-sasl-devel".
1023 To use the GSSAPI mechanism, first run "kinit" to authenticate with the
1025 ticket granting service:
1026 $ kinit johndoe@EXAMPLE.COM
1028 Configure MongoDB::MongoClient with the principal name as the
1030 "username" parameter and specify 'GSSAPI' as the "auth_mechanism":
1031 my $mc = MongoDB::MongoClient->new(
1033 host => 'mongodb://mongo.example.com',
1034 username => 'johndoe@EXAMPLE.COM',
1035 auth_mechanism => 'GSSAPI',
1036 );
1037 Both can be specified in the "host" connection string, keeping in mind
1039 that the '@' in the principal name must be encoded as "%40":
1040 my $mc = MongoDB::MongoClient->new(
1042 host =>
1043 'mongodb://johndoe%40EXAMPLE.COM@mongo.example.com/?authMechanism=GSSAPI',
1044 );
1045 The default service name is 'mongodb'. It can be changed with the
1047 "auth_mechanism_properties" attribute or in the connection string.
1048 auth_mechanism_properties => { SERVICE_NAME => 'other_service' }
1050 mongodb://.../?authMechanism=GSSAPI&authMechanismProperties=SERVICE_NAME:other_service
1052
1054 You MUST call the "reconnect" method on any MongoDB::MongoClient
1055 objects after forking or spawning a thread.
1056
1058 · David Golden <david@mongodb.com>
1059 · Rassi <rassi@mongodb.com>
1061 · Mike Friedman <friedo@friedo.com>
1063 · Kristina Chodorow <k.chodorow@gmail.com>
1065 · Florian Ragwitz <rafl@debian.org>
1067
1069 This software is Copyright (c) 2019 by MongoDB, Inc.
1070 This is free software, licensed under:
1072 The Apache License, Version 2.0, January 2004
1074perl v5.28.1 2019-02-07 MongoDB::MongoClient(3)