在PHP中查找服务器响应时间

Question

I am using the following code to find the server response time.

<?php
// check responsetime for a webbserver
function pingDomain($domain){
    $starttime = microtime(true);
    // supress error messages with @
    $file      = @fsockopen($domain, 80, $errno, $errstr, 10);
    $stoptime  = microtime(true);
    $status    = 0;

    if (!$file){
        $status = -1;  // Site is down
    }
    else{
        fclose($file);
        $status = ($stoptime - $starttime) * 1000;
        $status = floor($status);
    }
    return $status;
}
?>

I tested some websites using this code, and it returns that server response time is around 40 to 120 milliseconds. But when i open these sites its taking me around 2-4 seconds to get the first byte.

The server response time calculated by https://developers.google.com/speed/pagespeed/insights/ is also almost 2-4 seconds. So whats wrong with that code?

Answer 1

You make no HTTP request to the server, but open a socket. What you are measuring here is not a server response time but a connection time.

You can try to load a page to get total connection, response, and data transfer time, e.g.:

file_get_contents("http://$domain/")

To retrieve header only:

get_headers("http://$domain/")

Or you can use curl for even more control.