CODEWITHSUNDEEP
coldfusion
j-p
j-p

Reputation: 3818

coldfusion / browser timeout

I have a template doing a boat load of manipulations, I expect it to take 30-45 minutes to complete it's processing... I've had SOME success in setting my application and session vars to timeout @ 2 hr. and I've set my request timeout to 9999 (which should be 2.77 hrs)...

However - there seems to be a magic threshold - somewhere around the 20 min mark, my browser goes to a white screen (no output) and it appears as though the CF engine has also stopped working on my task...

can anyone suggest a reliable way to keep this process going - until it's done or my astronomical timeout occurs? in addition , is there any way to push feedback to the browser so it doesn't time out....I've tried cfflush, but that doesn't seem to do it.

Upvotes: 0

Views: 747

Answers (5)

Andy Gee
Andy Gee

Reputation: 3315

I had the same problem. Generally the browser will timeout after 3 minutes of nothing being sent from the server. For most of these long operations I was able to periodically output a dot to keep the browser alive but when it came to some extremely long queries importing 20M records from a server side CSV file I had to think of another way.

cUrl was the answer.

So here's what I did.

<?
function get_page($page)
{
    $ch = curl_init($page);
    curl_setopt($ch, CURLOPT_TIMEOUT, 0);
    curl_setopt($ch, CURLOPT_NOPROGRESS,false);
    curl_setopt($ch, CURLOPT_PROGRESSFUNCTION,'progress');
    curl_setopt($ch, CURLOPT_BUFFERSIZE, 128);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_exec($ch);
}

function progress($clientp,$dltotal,$dlnow,$ultotal,$ulnow='')
{
    echo '. ';
    flush();
    return(0);
}



get_page('http://www.example.com/my_extremely_long_operation_script.php');

?>

Even with no output from the server, curl updates the download progress periodically.

Solved!

Upvotes: 0

Nate
Nate

Reputation: 2881

I strongly suggest refactoring the code to use a simple messaging / queue system. It wouldn't take but 30 minutes to implement (or write a simple one from scratch!) and would provide a lot of benefits over and above solving this issue.

For example, its not a pass/fail for the entire operation. If you hit a snag at say the 1.5 hour mark, you won't be re-doing the entire process again, only parts which fail.

Doing it this way there is literally no limit to how much processing you can do because you'll be adding and removing from the stack as needed.

If you give a little more background, I'd be happy to help you figure out logical divisions to make it possible.

Upvotes: 1

Adrian J. Moreno
Adrian J. Moreno

Reputation: 14859

Please do not store queries in session like that. Depending on the size of the query and the number of concurrent users in the system, you could easily run out of memory, causing some current and all subsequent requests to fail.

The database should be more than able to handle the heavy lifting. I'd hazard a guess that much of the processing you're doing in the application could be re-factored to happen directly on the database and save you a considerable amount of time.

Regardless, you should look into something like CFTHREAD as Sean mentioned, a scheduled task or a queuing system to handle a long process like this. The user most likely doesn't want to wait for the process to end before seeing the next screen. If they're told up front that the process is lengthy, they'll cope with waiting as long as they can move on to other tasks.

Upvotes: 0

Sean Coyne
Sean Coyne

Reputation: 3884

You could use cfthread to run the process in a separate thread and then on the page you are accessing in the browser, you could use javascript to periodically poll the system to check on its status. For example, inside the long running process in cfthread, as you work through, you could set a application variables indicating that the process is still running and how far along it is, and retrieve and report those in the browser. When its complete, you could clear the variables, or set a complete flag, etc, and your browser report page will be able to indicate that it is complete.

Upvotes: 2

Bradley Moore
Bradley Moore

Reputation: 748

If you have a process running for that long, then you'll want to run it as a scheduled task.

I imagine your browser is the one dying.

Did you check to see if the request is still running?

<cfsetting requesttimeout= "3600" /> will set the page to last for an hour. If you run it as a scheduled task, then session timeout shouldn't affect anything.

Upvotes: 0

Related Questions