stopping and restarting a cron job

n4ows

I am working on a cron script that will be executed every x minutes, probably every 60 minutes.

On the first execution of the day, an xml file will be loaded and validated, and a timer file will be created and timestamped. Each block of the xml file will be sent off to a processing script which will return that block of xml with a status of success or failure as an attribute at the node name. That node will be saved to a daily activity file with the attribute set to success or failure. Also, at the end of the execution of this script, the time file is unset.

On all the subsequent executions of the day, (run until all nodes return success), I check the timer file to see if the timer file exists. If it does, I check the timestamp to see if the process is stuck. This will also mean that the last iteration of my script is still running. If it is determined that the script is “stuck”, then I want to stop the old script and proceed with the current iteration. If it is determined that the script is not stuck, but running normally, then I want the current script to go to sleep and check again in 10 minutes.

My question is how to stop the script that is already running to all the current script to continue???

mykg4orce

Its hard to tell without knowing what your script is actually doing. And at first glance what does this have to do with PHP! lol

mykg4orce

oh i c now...this part of your other post

n4ows

okay, well, I have kicked a cron of a php script off, but this script is already running and has gotten hung up some how. So, I want to kill the old script and let the current script. Maybe this is a *nix thing, but I need some direction on where to look.

n4ows

My cron script will stop normally if it runs through each node. It's kind of complicated, but my script calls a function that someone else on my team wrote that pulls xml data from another source. Currently we do those pulls through a browser and they can take up to 30 minutes to pull the data back. However, occasionally the data pulls just die for no known reason. If that happens, my script is sitting there waiting for a response from this other script/function forever, unless it's stopped somehow. I have a timer file that writes a timestamp and report name each time I come to the top of my foreach loop. That's how I know how long the script has been running.

n4ows

Okay, here it is:

function takePulse ($pulse) {			// More than one process is running
	global $debug;
	global $lastPid;
//	Adjust minutes for run_limit here
	$minutes = 5;		
	$micro = 1000000;
	$sec = 60;
	$run_limit = $micro * $sec * $minutes;

$handle = @fopen($pulse,"r");
$contents = array();
$i = 0;
while (!feof($handle)) {
	$contents[$i] = fread($handle, 8192);
	$i++;
}
fclose($handle);
$last = $i - 1;
$check_time = microtime(true);
list($pulse_pid,$pulse_time) = explode("|",$contents[$last]);
$run_time = $check_time - $pulse_time;

//	kill one of the processes, either the old one or the new one
	if ($run_time > $run_limit) {
		$kill = shell_exec("kill -9 $pulse_pid");
		unlink($pulse);
		touch($pulse);
		if ($debug > 0) { echo "touched: $pulse\n\n"; }
		list($result,$message) = explode("|",pulse($pulse,"w"));
		$message = "Killed OLD Process ($pulse_pid)";
		$result = "Killed|$pulse_pid";
	} else {
		$kill = shell_exec("kill -9 $lastPid");
		$message = "Killed NEW Process ($lastPid)";
		$result = "Killed|$lastPid";
	}
	if ($debug > 0) { echo "+++ takePulse --- message: $message\n"; }
	return $result;
}

This might not be the best way to do it, but it works. If the process hasn't exceeded the time limit, then I stop the newly started script. Else, if it has exceeded the time limit, then I stop the first script. Should not have more than two running at any given time.

Thanks...