first off, i am confident that libcurl's curl_multi api is significantly faster than a headless browser. even if running under PHP (which is a much slower language than say C), i recon it would be faster than a headless browser, but let's put it to the test, benchmarking it using the code from https://stackoverflow.com/a/54353191/1067003 ,
benchmark this PHP script (using php's curl_multi api, which is a wrapper around libcurl's curl_multi api)
<?php
declare(strict_types=1);
$urls=array();
for($i=0;$i<100000;++$i){
$urls[]="http://ratma.net/";
}
validate_urls($urls,500,1000,false,false,false);
// if return_fault_reason is false, then the return is a simple array of strings of urls that validated.
// otherwise it's an array with the url as the key containing array(bool validated,int curl_error_code,string reason) for every url
function validate_urls(array $urls, int $max_connections, int $timeout_ms = 10000, bool $consider_http_300_redirect_as_error = true, bool $return_fault_reason) : array
{
if ($max_connections < 1) {
throw new InvalidArgumentException("max_connections MUST be >=1");
}
foreach ($urls as $key => $foo) {
if (!is_string($foo)) {
throw new InvalidArgumentException("all urls must be strings!");
}
if (empty($foo)) {
unset($urls[$key]); //?
}
}
unset($foo);
// DISABLED for benchmarking purposes: $urls = array_unique($urls); // remove duplicates.
$ret = array();
$mh = curl_multi_init();
$workers = array();
$work = function () use (&$ret, &$workers, &$mh, &$return_fault_reason) {
// > If an added handle fails very quickly, it may never be counted as a running_handle
while (1) {
curl_multi_exec($mh, $still_running);
if ($still_running < count($workers)) {
break;
}
$cms=curl_multi_select($mh, 10);
//var_dump('sr: ' . $still_running . " c: " . count($workers)." cms: ".$cms);
}
while (false !== ($info = curl_multi_info_read($mh))) {
//echo "NOT FALSE!";
//var_dump($info);
{
if ($info['msg'] !== CURLMSG_DONE) {
continue;
}
if ($info['result'] !== CURLM_OK) {
if ($return_fault_reason) {
$ret[$workers[(int)$info['handle']]] = array(false, $info['result'], "curl_exec error " . $info['result'] . ": " . curl_strerror($info['result']));
}
} elseif (CURLE_OK !== ($err = curl_errno($info['handle']))) {
if ($return_fault_reason) {
$ret[$workers[(int)$info['handle']]] = array(false, $err, "curl error " . $err . ": " . curl_strerror($err));
}
} else {
$code = (string)curl_getinfo($info['handle'], CURLINFO_HTTP_CODE);
if ($code[0] === "3") {
if ($consider_http_300_redirect_as_error) {
if ($return_fault_reason) {
$ret[$workers[(int)$info['handle']]] = array(false, -1, "got a http " . $code . " redirect, which is considered an error");
}
} else {
if ($return_fault_reason) {
$ret[$workers[(int)$info['handle']]] = array(true, 0, "got a http " . $code . " redirect, which is considered a success");
} else {
$ret[] = $workers[(int)$info['handle']];
}
}
} elseif ($code[0] === "2") {
if ($return_fault_reason) {
$ret[$workers[(int)$info['handle']]] = array(true, 0, "got a http " . $code . " code, which is considered a success");
} else {
$ret[] = $workers[(int)$info['handle']];
}
} else {
// all non-2xx and non-3xx are always considered errors (500 internal server error, 400 client error, 404 not found, etcetc)
if ($return_fault_reason) {
$ret[$workers[(int)$info['handle']]] = array(false, -1, "got a http " . $code . " code, which is considered an error");
}
}
}
curl_multi_remove_handle($mh, $info['handle']);
assert(isset($workers[(int)$info['handle']]));
unset($workers[(int)$info['handle']]);
curl_close($info['handle']);
}
}
//echo "NO MORE INFO!";
};
foreach ($urls as $url) {
while (count($workers) >= $max_connections) {
//echo "TOO MANY WORKERS!
";
$work();
}
$neww = curl_init($url);
if (!$neww) {
trigger_error("curl_init() failed! probably means that max_connections is too high and you ran out of resources", E_USER_WARNING);
if ($return_fault_reason) {
$ret[$url] = array(false, -1, "curl_init() failed");
}
continue;
}
$workers[(int)$neww] = $url;
curl_setopt_array($neww, array(
CURLOPT_NOBODY => 1,
CURLOPT_SSL_VERIFYHOST => 0,
CURLOPT_SSL_VERIFYPEER => 0,
CURLOPT_TIMEOUT_MS => $timeout_ms
));
curl_multi_add_handle($mh, $neww);
//curl_multi_exec($mh, $unused_here); LIKELY TO BE MUCH SLOWER IF DONE IN THIS LOOP: TOO MANY SYSCALLS
}
while (count($workers) > 0) {
//echo "WAITING FOR WORKERS TO BECOME 0!";
//var_dump(count($workers));
$work();
}
curl_multi_close($mh);
return $ret;
}
and benchmark it with doing the same in a headless browser, i dare you
for the record, ratma.net is in Canada, and here is from another datacenter but also in Canada:
foo@foo:/srv/http/default/www# time php foo.php
real 0m32.606s
user 0m19.561s
sys 0m12.991s
it completed 100,000 requests in 32.6 seconds, that means 3067 requests per second. i haven't actually checked, but i expect a headless browser to perform significantly worse than that.
(ps note that this script does not download the entire content, and it issue a HTTP HEAD request instead of a HTTP GET request, if you want it to download the entire content then replace CURLOPT_NOBODY=>1
with CURLOPT_WRITEFUNCTION=>function($ch,string $data){return strlen($data);}
)