Question

I am trying to send big zip files to a tomcat application using curl in a php script. Since it is a big zip file it is going to take some time on the tomcat server to unpack the zip file (about 2-5 minutes), but the curl request never waits more than 30 seconds before it just continue as if it had received an empty response.

Code I can reproduce problem with:

set_time_limit(0);

$uploadURL = 'http://192.168.0.2:8080/some/url/'
$userid = 'a-user';
$password = 'a-password';
$zipfile = '/tmp/myfile.zip';

$ch = curl_init($uploadURL);
curl_setopt($ch, CURLOPT_HEADER, array(
    'Connection: Keep-Alive',
    'Keep-Alive: 3600'
    ));
curl_setopt($ch, CURLOPT_VERBOSE, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_USERAGENT, "Mozilla/4.0 (compatible;)");
curl_setopt($ch, CURLOPT_USERPWD, $userid.":".$password);
curl_setopt($ch, CURLOPT_POST, true);
$post = array(
  "uploadMode" => "uploadOnly",
  "id" => $id,
  "numberOfFiles" => "1",
  "file"=>"@".$zipfile.";type=application/zip"
);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 45);
curl_setopt($ch, CURLOPT_POSTFIELDS, $post);
curl_setopt($ch, CURLOPT_TIMEOUT, 200);
$response = curl_exec($ch);

The only suspect I have left is that curl makes the request and then times out due to a certain number of seconds elapsing without any bytes being sent back or forth (aka between_bytes_timeout). But I cannot find a curl option to help with that, so I am hoping it is something else.

The tomcat server is in the clear, since I can make a request to it with my browser that can lasts hours without problems.

Answer 1

Chances are, that cURL just auto-cancels the request, because of the transfer rate being too low while your Tomcat is unpacking the zip.

This happens if the average transfer rate drops below CURLOPT_LOW_SPEED_LIMIT bytes/second for CURLOPT_LOW_SPEED_TIME seconds.

Try adding the appropriate options with a high time and/or low limit, e.g.:

curl_setopt($ch, CURLOPT_LOW_SPEED_LIMIT, 1);   // cancel if below 1 byte/second
curl_setopt($ch, CURLOPT_LOW_SPEED_TIME, 30);   // for a period of 30 seconds

To quicktest I’d recommend to use a TIME slightly higher than your Tomcat really needs to unpack a given test zip.