Question

Earlier today I noticed some calls to php fwrite failing as the destination socket was in a mixed state. There were numerous connections stuck in SYN_SENT and were seemingly not coming back as failures.

What is the best way to detect this and simply time out the connection if x bits haven’t bit transmitted over the wire?

Answer 1

I believe you are looking for stream_set_timeout. An example:

stream_set_timeout($fp, 2);
fwrite($fp, "GET / HTTP/1.0\r\n\r\n");

You can check whether a time-out happens by checking the meta data of the stream:

$info = stream_get_meta_data($fp);
// $info['timed_out'] == true : time-out has happened