CODEWITHSUNDEEP
long-polling
Kunal Singh
Kunal Singh

Reputation: 199

Cannot implement long polling

if(isset($_GET['actionid']) && isset($_GET['profileid']))
{
        $actionid = $_GET['actionid'];
        $profileid = $_GET['profileid'];
        $res = $database->news_poll($profileid,$actionid);
        $k = 0;
        while(!$NROW =$res->fetch_array())
        {
            usleep('50000000');
            $res = $database->news_poll($profileid,$actionid);
        }
        $action = actiontype_encode($NROW,'0',$json,$encode,$database);
        $data['action'] = $action;
        echo json_encode($data);
}

this is my script for polling the server for new data. but the working browser stops working only for my site. I guess the problem is that when a particular browser subscribes for the new data the connection is kept open so no further request can be made by the browser to same server. please explain if any problem.

Upvotes: 1

Views: 250

Answers (2)

Kunal Singh
Kunal Singh

Reputation: 199

I figured out the problem is that Apache serves multiple requests from a single client one at a time. So when a request is made to the long polling script at backend for new data that request hangs other requests from the same browser to the same server.

To overcome this drawback one needs to use node.js or tornado.

Upvotes: 0

cmc
cmc

Reputation: 4413

If there is any way at all you can, I recommend setting yourself up with NodeJS and SocketIO for long polling. Your web server needs to keep a request open for every connected user, and that is more than Apache/PHP can handle for very long.

If that's not possible I recommend short polling, doing a normal ajax request every 3 seconds. That's not perfect but manageble.

I answered a similar question recently with more details.

Regardless of language I strongly advise against writing your own long polling server, unless you want that to be your project for a couple of years. I have been in a project that used a home grown long polling server written C and then re-written in Java, and it was not pretty.

Upvotes: 1

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