NAME

       mongoc_client_get_handshake_description - mongoc_client_get_handshake_description()

SYNOPSIS

          mongoc_server_description_t *
          mongoc_client_get_handshake_description (mongoc_client_t *client,
                                                   uint32_t server_id,
                                                   bson_t *opts,
                                                   bson_error_t *error)
             BSON_GNUC_WARN_UNUSED_RESULT;

       Returns a description constructed from the initial handshake response to a server.

DESCRIPTION

       mongoc_client_get_handshake_description()            is            distinct           from
       mongoc_client_get_server_description(). mongoc_client_get_server_description()  returns  a
       server  description  constructed  from  monitoring,  which  may  differ  from  the  server
       description constructed from the connection handshake.

       mongoc_client_get_handshake_description() will attempt to establish a  connection  to  the
       server  if a connection was not already established. It will perform the MongoDB handshake
       and authentication if required.

       Use this function only for building a language  driver  that  wraps  the  C  Driver.  When
       writing applications in C, higher-level functions automatically select a suitable server.

   Single-threaded client behavior
       Single-threaded clients only have one active connection to each server. The one connection
       is used for both monitoring and application operations. However,  the  server  description
       returned  by  mongoc_client_get_handshake_description()  may  still differ from the server
       description returned by mongoc_client_get_server_description(). Notably, if connected to a
       load      balanced      cluster,      the      server      description     returned     by
       mongoc_client_get_server_description()  will  describe  the  load   balancer   server   (‐
       mongoc_server_description_type()  will  return "LoadBalancer"). And the server description
       returned by mongoc_client_get_handshake_description() will describe the backing server.

PARAMETERS

       • client: A mongoc_client_t.

       • server_id: The ID of the server. This can be obtained from  the  server  description  of
         mongoc_client_select_server().

       • opts: Unused. Pass NULL.

       • error: An optional location for a bson_error_t or NULL.

RETURNS

       A mongoc_server_description_t that must be freed with mongoc_server_description_destroy().
       If a connection has not been successfully established to a server, returns NULL and  error
       is filled out.

SEE ALSO

       • mongoc_client_select_server() To select a server from read preferences.

       • mongoc_client_get_server_description()  To obtain the server description from monitoring
         for a server.

       • mongoc_server_description_type() To obtain the type of server from a server description.

AUTHOR

       MongoDB, Inc

COPYRIGHT

       2017-present, MongoDB, Inc