For a dashboard application I'm checking if some websites are online and also their response time. I'm doing this in PHP with a the function fsockopen() and I'm getting the response time by using the microtime() function.
For a couple websites that I'm checking I'm getting just under 1 millisecond, because they run on the same server as my application. After some hard debugging I found out that almost 1 out of 4 times when I check if they're online, the response time I'm getting is ~1000ms. But the weird thing is that site is either under 1 millisecond or almost exactly 1000 milliseconds.
This is how I check the website status
$start = microtime(true);
$fp = fsockopen($host->getIp(), $host->getPort(), $errCode, $errStr, 10);
$end = microtime(true);
fclose($fp);
And I calculate the milliseconds like this
$ms = ($end - $start) * 1000
I'm really suspicious about the fact that it's always the same websites and that it's always almost exactly 1 second. I'm wondering how this is possible and maybe how I could be able to fix it if it's not my fault. One of my theories is that the server of the website somewhere goes to sleep for a second when there have been a couple of requests.
I hope someone can help me with finding the solution of this problem.