PERL-568 Document replica set connection in MongoDB.pm and MongoClient

lib/MongoDB.pm

@@ -65,6 +65,11 @@ for L<MongoDB::MongoClient::new|MongoDB::MongoClient/ATTRIBUTES>.
 
 If an error occurs, a L<MongoDB::Error> object will be thrown.
 
+B<NOTE>: To connect to a replica set, a replica set name must be provided.
+For example, if the set name is "setA":
+
+    $client = MongoDB->connect("mongodb://example.com/?replicaSet=setA");
+
 =cut
 
 sub connect {

lib/MongoDB/MongoClient.pm

@@ -1526,6 +1526,11 @@ send_write_op
         replica_set_name => 'myset',
     );
 
+    # connect to a replica set with URI (set name *required*)
+    my $client = MongoDB::MongoClient->new(
+        host => "mongodb://mongo1.example.com,mongo2.example.com/?replicaSet=myset",
+    );
+
     my $db = $client->get_database("test");
     my $coll = $db->get_collection("people");