MongoDB\Driver\Server::getLatency

Returns the latency of this server in milliseconds

&reftitle.description; final public ``integer``null```MongoDB\Driver\Server::getLatency`

Returns the latency of this server in milliseconds. This is the client's measured round trip time of a `hello` command.

&reftitle.parameters; &no.function.parameters;
&reftitle.returnvalues;

Returns the latency of this server in milliseconds, or &null; if no latency has been measured (e.g. client is connected to a load balancer).

&reftitle.errors;

&mongodb.throws.argumentparsing;

&reftitle.changelog;

&Version; | &Description;
PECL mongodb 1.11.0 | This method will return &null; if no latency has been measured. In earlier versions, an integer was always returned and an unset value might be reported as `-1`.

&reftitle.examples;

### `MongoDB\Driver\Server::getLatency` example

    <?php

    $manager = new MongoDB\Driver\Manager("mongodb://localhost:27017/");

    $rp = new MongoDB\Driver\ReadPreference(MongoDB\Driver\ReadPreference::RP_PRIMARY);
    $server = $manager->selectServer($rp);

    var_dump($server->getLatency());

    ?>

&example.outputs.similar;

    int(592)

&reftitle.seealso;

- `MongoDB\Driver\Server::getInfo`
- `MongoDB\Driver\ServerDescription::getRoundTripTime`
- Server Discovery and Monitoring Specification