Is skipping mysql queries possible?

jaymoore_299

Is there any way I can skip a mysql query if it takes too long?

I have a mysql query that tracks traffic to my site and if the query takes too long then the page simply fails to load. If I put this on the bottom of the page the page loads but I get the headers already sent error message. Is there a way I can skip a query if it takes over, say 2 seconds to finish?

hutchic

no(90% sure), as you can't have multiple processes with PHP.

For this to work prior to the mysql_query you'd need to spawn a second process (man fork in *nix).

The process you just spawned would monitor the execution time while the first process proceeds to try the sql_query.

Plasma

The proper fix would be to find out why its taking so long and fix it.

Sxooter

Does MySQL have a query timeout setting? Most databases do.

Well, I just wandered through the docs, and couldn't find a query timeout setting. How odd.

csn

There are several timeout vars here.

Sxooter

But none of those seem to be a query timeout. But I'm not a MySQL guru. there could be some timeout for it that I'm missing.

csn

Hmm, you're right. Only some timeout vars for inactivity. PHP doesn't seem to have such a var either. I remember mysql having 'delayed queries' - maybe that might help.

hutchic

Try posting the query or posting some more details about it. You said it tracks traffic is it mostly inserts?

Try to find the exact spot the page times out. ie comment out the query does the page work?

Put $start = microtime( ); right before the query and right after the query
$end = microtime( );
echo $end - $start;

to see exactly how long the query takes (if it finishes at all)

I was once told (don't know if this is true) that you could call a script through an image tag which would be a seperate request and not slow the load time of the calling page.

Calling page:
<img src="image.php" width="1" height="1" alt=""/>

Image.php

<?
Header("Content-Type: image/gif");
include("sql_query.php");

echo base64_decode("R01GOD1HAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEOw==");
?>

It makes sense in theory since from the browser's point of view it's just an image that's taking a long time to load so it will give up on it at a certain point. Still doesn't garantee the script finishes executing but it should "crash nicely" :queasy: Or just make the image the first thing the browser tries to grab.

Roger_Ramjet

That's a cool trick, Hutchic. Had not thought of that, would have used an iframe myself but an image tag should work well.

Drakla

Using images as web bugs used to be so much easier, and great for checking if somebody was lying about not reading your email until a minute ago, or finding out if somebody has been reading your email. Most sites and Thunderbird filter them out now... sigh.