Start & Stop PHP Script from Backend Administrativ

问题:

I'm trying to create a webpage that will allow me to start and stop of a PHP script. The script is part of the backend of a site, and will need to access, read data from, process that data, and update a database on the same server the script exists on. Additionally, I'd like the webpage to allow an administrator to view the current status (running or stopped), and even link to logs created by the script. I'm starting to go down the path of learning about PHP's exec, passthru, and related functions. Is this the correct path to take? Are there other ways to do this that would be more suitable? Is it possible to do this in a platform agnostic way? I'm developing on a LAMPP+CakePHP stack in Windows, and would like the functionality to exist on any webhost I choose.

回答1:

I've done this in a recent job but it's probably overkill for you. I did a job processor and it basically sets 2 tables in the database, 2 objects at a minimum and 2 controllers at a minimum.

The first part is the job processing unit, it is composed of a job processor controller that manages the request to start or continue a job and it comes with two activerow models JobQueue and Job. You can remove the queue, but it's always practical to have queing in such systems so you can say that 2,3,4 jobs could execute at once.

The queue is only that, it's a slot that gets several jobs attached to it and it has a queue status to determine if it is running right now or not.

The job is a virtual object that maps to a job table describing what has to be done. In my implementation, i have created an interface that must be implemented into the called controller and a field + a type in the database. The Job instanciates the controller class to call (not the job processor controler, another controler that manages the operation to do) and calls a method in it to start the task processing.

Now, to get tricky, i forced my system to run on a dedicated server just for that portion because i didn't want the task to load the main server or jam the processing queue of Apache. So i had two servers and my Queue class was in charge of calling via an ip address a page on another server to run the job on that server specifically. When the job was done, it called itself back using a HTTP request to restart processing and do the next task. If no task was left, then it would simply die normally.

The advantage of doing it this way is that it doesn't require a cronjob (as long as your script is super stable and cannot crash) because it gets triggered by you when you want it and then you can let it go and it calls itself back with a fsockopen to trigger another page view that triggers the next job.

Work units

It is important to understand that if your jobs are very large, you should segment them. I used the principle of a "work unit" to describe 1 part the job has to do any number of times. Then the Queue Processor became a time manager too so that he could detect if a job took more than X seconds, it would simply defer the rest of the steps for later and call itself back and continue were he was at. That way, you don't need to "set time limit" and you don't jam your server while a 30s script gets executed.

I hope this helps!

回答2:

To run a script which run continually, you need think to that:

• Your php script should be launched as CLI (command line) by a job scheduler like cron or something else. Don't forget that your web server configuration defined a timeout on executed script.

• To run 24h a day, maybe you imagine to implement an infinite loop. In that case, you can write a test like jobIsActive which read in a file or in the database every loop if the job should be executed or not. If you click on the button just change the job status (update file, db ...). Your both button can stop the treatment or activate it but doesn't stop the infinite loop.

• An infinite loop isn't the most elegant solution, why don't you write an entry in the cron tab to execute the job each night and a click on a button can fired it manually.