PHP 통신: 네트워크 지연 문제를 해결하는 방법은 무엇입니까?

<?php
$multiHandle = curl_multi_init();

$handles = array();

$urls = array(
    'http://example.com/request1',
    'http://example.com/request2',
    'http://example.com/request3'
);

foreach ($urls as $url) {
    $handle = curl_init($url);

    curl_setopt($handle, CURLOPT_RETURNTRANSFER, true);

    curl_multi_add_handle($multiHandle, $handle);

    $handles[] = $handle;
}

$running = null;

do {
    curl_multi_exec($multiHandle, $running);

    curl_multi_select($multiHandle);
} while ($running > 0);

$responses = array();

foreach ($handles as $handle) {
    $responses[] = curl_multi_getcontent($handle);

    curl_multi_remove_handle($multiHandle, $handle);

    curl_close($handle);
}

curl_multi_close($multiHandle);

print_r($responses);
?>

<?php
$urls = array(
    'http://example.com/request1',
    'http://example.com/request2',
    'http://example.com/request3'
);

$responses = array();

foreach ($urls as $url) {
    $pid = pcntl_fork();

    if ($pid == -1) {
        die('Could not fork');
    }

    if ($pid) {
        // Parent process
        pcntl_wait($status);
    } else {
        // Child process
        $response = file_get_contents($url);

        if ($response !== false) {
            $responses[] = $response;
        }

        exit();
    }
}

print_r($responses);
?>

<?php
$key = 'request';

if (file_exists($key)) {
    $response = file_get_contents($key);
} else {
    $response = file_get_contents('http://example.com/request');

    file_put_contents($key, $response);
}

echo $response;
?>

<?php
$handle = curl_init();

curl_setopt($handle, CURLOPT_URL, 'http://example.com/request');
curl_setopt($handle, CURLOPT_RETURNTRANSFER, true);
curl_setopt($handle, CURLOPT_CONNECTTIMEOUT, 2);
curl_setopt($handle, CURLOPT_KEEPALIVE, true);

$response = curl_exec($handle);

curl_close($handle);

echo $response;
?>