Specify Connection Options

Overview

This page describes the MongoDB connection and authentication options available in the C++ driver.

Set Connection Options

You can configure your connection by specifying options in the connection URI or by passing an instance of the mongocxx::options::client class as the client_options parameter to the mongocxx::client constructor.

Note

You can specify some connection options only in the connection URI, and others only in an the client_options parameter. You might need to combine these methods to specify all the options that you need.

Using the Connection URI

When you construct a mongocxx::client object, you can pass in a mongocxx::uri object that represents your connection URI. This connection URI can include connection options as <name>=<value> pairs. In the following example, the connection URI contains the tls option with a value of true and the tlsCertificateKeyFile option with a value of path/to/file.pem:

#include <mongocxx/uri.hpp>
#include <mongocxx/client.hpp>
#include <mongocxx/instance.hpp>
int main()
{
    mongocxx::instance instance;
    mongocxx::uri uri("mongodb://<hostname>:<port>/?tls=true&tlsCertificateKeyFile=path/to/file.pem");
    mongocxx::client client(uri);
}

Using a `mongocxx::options::client` Object

The mongocxx::client constructor includes a client_options parameter that accepts an instance of the mongocxx::options::client class. You can specify certain options in the client_options parameter instead of including them in your connection URI.

The following example shows how to use the client_options parameter to set connection options:

#include <mongocxx/uri.hpp>
#include <mongocxx/client.hpp>
#include <mongocxx/instance.hpp>
int main()
{
    mongocxx::instance instance;
    mongocxx::options::client client_options;
    mongocxx::options::tls tls_options;
    tls_options.pem_file("/path/to/file.pem");
    client_options.tls_opts(tls_options);
    mongocxx::uri uri("mongodb://<hostname>:<port>/?tls=true");
    mongocxx::client client(uri, client_options);
}

Read Connection Options

After constructing a mongocxx::client object, you can read the values of certain connection options by using properties of the mongocxx::uri object.

The following example shows how to read the value of the tls connection options by using the tls() property:

#include <mongocxx/uri.hpp>
#include <mongocxx/client.hpp>
#include <mongocxx/instance.hpp>
int main()
{
    mongocxx::instance instance;
    mongocxx::uri uri("mongodb://<hostname>:<port>/?tls=true");
    mongocxx::client client(uri);
    auto is_tls_enabled = uri.tls();
}

The following sections show the corresponding mongocxx::uri property for each connection option that supports it.

Connection URI Options

The following sections describe the connection options that you can set in the connection URI passed to the C++ driver. Each connection option links to the MongoDB Server manual and to its corresponding mongocxx::uri property, if supported.

Replica Set Options

Connection URI Option	`mongocxx::uri` Member
`directConnection`	direct_connection()
`replicaSet`	replica_set()

Connection Options

TLS Options

Connection URI Option	`mongocxx::uri` Member
`tls`	tls()
`tlsCertificateKeyFile`	tls_certificate_key_file()
`tlsCertificateKeyFilePassword`	tls_certificate_key_file_password()
`tlsCAFile`	tls_ca_file()
`tlsAllowInvalidCertificates`	tls_allow_invalid_certificates()
`tlsAllowInvalidHostnames`	tls_allow_invalid_hostnames()
`tlsInsecure`	tls_insecure()
`tlsDisableCertificateRevocationCheck`	tls_disable_certificate_revocation_check()
`tlsDisableOCSPEndpointCheck`	tls_disable_ocsp_endpoint_check()

Tip

You can set most TLS options by using the client_options parameter. See the mongocxx::options::tls API documentation for more information.

Timeout Options

Connection URI Option	`mongocxx::uri` Member
`connectTimeoutMS`	connect_timeout_ms()
`socketTimeoutMS`	socket_timoeout_ms()

Compression Options

Connection URI Option	`mongocxx::uri` Member
`compressors`	compressors()
`zlibCompressionLevel`	zlib_compression_level()

Connection Pool Options

Connection URI Option	`mongocxx::uri` Member
`maxPoolSize`	max_pool_size()
`waitQueueTimeoutMS`	wait_queue_timeout_ms()

Write Concern Options

Connection URI Option	`mongocxx::uri` Member
`w`	write_concern()
`wtimeoutMS`	N/A
`journal`	N/A

Read Concern Options

Connection URI Option	`mongocxx::uri` Member
`readConcernLevel`	read_concern()

Read Preference Options

Connection URI Option	`mongocxx::uri` Member
`readPreference`	read_preference()
`maxStalenessSeconds`	N/A
`readPreferenceTags`	N/A

Authentication Options

Connection URI Option	`mongocxx::uri` Member
`authMechanism`	auth_mechanism()
`authMechanismProperties`	auth_mechanism_properties()
`authSource`	auth_source()

Server Selection and Discovery Options

Connection URI Option	`mongocxx::uri` Member
`localThresholdMS`	local_threshold_ms()
`serverSelectionTimeoutMS`	server_selection_timeout_ms()
`serverSelectionTryOnce`	server_selection_try_once()
`heartbeatFrequencyMS`	heartbeat_frequency_ms()
`socketCheckIntervalMS`	N/A

Miscellaneous Configuration

Connection URI Option	`mongocxx::uri` Member
`appName`	appname()
`enableOverloadRetargeting`	enable_overload_retargeting()
`maxAdaptiveRetries`	max_adaptive_retries()
`retryReads`	retry_reads()
`retryWrites`	retry_writes()
`loadBalanced`	N/A
`srvMaxHosts`	srv_max_hosts()

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