Making CURL multi requests to the same server as slow as single request

Question

I am using a good Multi CURL interface called Rolling CURL

http://code.google.com/p/rolling-curl/issues/detail?id=20

It works fine, for example it gets data from 20 sites in around 3 seconds. The problem is that I need it to work on 200 - 300 sites that are on the SAME server. This takes around the same time that it takes to make a single CURL request in a loop which is around 10 minutes 47 seconds. So I am a bit stumped as to what to do. All I need to do is grab the HTTP code on each site. I have tried file_get_contents, PHP FTP functions, they are much slower.

Another thing is that when I run through a list of 12 + domains that are on the same server, it seems to block the request so I just don't get any data back at all on any of the sites. This problem will not occur when I run a list of less than 12. I am only fetching the header data of the sites so it shouldn't be that slow.

If anyone can help me or give me a detailed explanation on why this is happening with pointers on how I can overcome this problem I will be incredibly thankful.

Answer 1

That sounds like the library is throttling concurrent requests per server. Take a look if you can configure that. Eg this is in the source-code and also the description why:

class RollingCurl {
    /**
     * @var int
     *
     * Window size is the max number of simultaneous connections allowed.
     *
     * REMEMBER TO RESPECT THE SERVERS:
     * Sending too many requests at one time can easily be perceived
     * as a DOS attack. Increase this window_size if you are making requests
     * to multiple servers or have permission from the receving server admins.
     */
     private $window_size = 5;

Also this might be interesting for you:

• How can one check to see if a remote file exists using PHP?

To get the status code, normally a HEAD request is all you need to do, cUrl supports that.