ADVANCED_CONNECTIONS(3)

NAME
Advanced_Connections - None

CONNECTING TO A REPLICA SET

Connecting to a replica set is much like connecting to a standalone MongoDB server. Simply specify the replica set name using the ?replicaSet=myreplset URI option.

#include <bson.h>
#include <mongoc.h>

int
main (int   argc,
      char *argv[])
{
    mongoc_client_t *client;

    mongoc_init ();

    /* Create our MongoDB Client */
    client = mongoc_client_new ("mongodb://host01:27017,host02:27017,host03:27017/?replicaSet=myreplset");

    /* Do some work */
    /* TODO */

    /* Clean up */
    mongoc_client_destroy (client);
    mongoc_cleanup ();

    return 0;
}

NOTE
    Multiple hostnames can be specified in the MongoDB connection string URI, with a comma separating hosts in the seed list.

    It is recommended to use a seed list of members of the replica set to allow the driver to connect to any node.

CONNECTING TO A SHARDED CLUSTER

To connect to a sharded cluster , specify the mongos nodes the client should connect to. The C Driver will automatically detect that it has connected to a mongos sharding server.

If more than one hostname is specified, a seed list will be created to attempt failover between the mongos instances.

NOTE
    Specifying the replicaSet parameter when connecting to a mongos sharding server is invalid.

#include <bson.h>
#include <mongoc.h>

int
main (int   argc,
      char *argv[])
{
    mongoc_client_t *client;

    mongoc_init ();

    /* Create our MongoDB Client */
    client = mongoc_client_new ("mongodb://myshard01:27017/");

    /* Do something with client ... */

    /* Free the client */
    mongoc_client_destroy (client);

    mongoc_cleanup ();

    return 0;
}

CONNECTING TO AN IPV6 ADDRESS

The MongoDB C Driver will automatically resolve IPv6 addresses from host names. However, to specify an IPv6 address directly, wrap the address in [] \&.

mongoc_uri_t *uri = mongoc_uri_new ("mongodb://[::1]:27017");

CONNECTING TO A UNIX DOMAIN SOCKET

On UNIX-like systems, the C Driver can connect directly to a MongoDB server using a UNIX domain socket. Simply pass the path to the socket, which must be suffixed with .sock \&.

mongoc_uri_t *uri = mongoc_uri_new ("mongodb:///tmp/mysocket.sock");

NOTE
    Connecting directly to a UNIX domain socket is not a common practice.

ADDITIONAL CONNECTION OPTIONS

A variety of connection options for the MongoDB URI can be found here \&.

COLOPHON
This page is part of MongoDB C Driver. Please report any bugs at https://jira.mongodb.org/browse/CDRIVER.