Using Ajax to refresh/redirect page

CRichardson

I have developed a script which gathers a number of mysql results and puts them into a queue.

The script will refresh itself after each result and move on to the next.

I am wanting this script to be run via a cron-job. However, cron does not support META refresh nor PHP header.

Is there a way to do this using AJAX as oppose to META refresh?

Regards
Chris

Weedpacket

CRichardson wrote:
I am wanting this script to be run via a cron-job. However, cron does not support META refresh nor PHP header.

😕 cron doesn't support anything except running programs on the computer. What the script can or can't do depends on the script. If you think "cron does not support META refresh nor PHP header", what makes you think it would support AJAX or any sort of JavaScript for that matter?

dagon

you may need to run the script via cron by calling it with wget, that way it runs as if called by a web browser rather than called on the command line.

CRichardson

I am hoping and guessing that it might support AJAX. Does it?

CRichardson

dagon;10891568 wrote:
you may need to run the script via cron by calling it with wget, that way it runs as if called by a web browser rather than called on the command line.

How do I go about running the script via cron using wget?

HalfaBee

No, AJAX is just Javascript, this looks like an issue that needs to be handled in a loop in the php script.

CRichardson

HalfaBee;10891605 wrote:
No, AJAX is just Javascript, this looks like an issue that needs to be handled in a loop in the php script.

So cron does not support any client side technologies such as Javascript?

The script has to query about 3000 rows, each time collecting and building data about that row which takes up to 10-30 seconds each time! Meaning the script needs to keep refreshing itself to keep server resources low.

Cron is set to run the script hourly, which is vital.

Weedpacket

All cron does is run the program you tell it to when you tell it to.

If that program isn't doing what you want then that program is the problem.

From what you've described, it sounds like the program you have cron running to do this job is very poorly written for the task you've given it - but that's not cron's fault.

dagon

you can call a web browser to load a web page via cron and therefore run the js (ajax), but i have to agree with Weedpacket about the suitability of this approach. Perhaps if you told us what you where trying to achieve some one may come up with a better solution

CRichardson

dagon;10891664 wrote:
you can call a web browser to load a web page via cron and therefore run the js (ajax), but i have to agree with Weedpacket about the suitability of this approach. Perhaps if you told us what you where trying to achieve some one may come up with a better solution

Every hour the script is run.

The script selects data from a database- on average 3000 results are returned.

Each row will have an e-mail and a URL. The script retrieves data from the URL, builds an e-mail and sends it.

dagon

nothing in what it does requires ajax, it could be all php then calling the script via cron using php on the command line would be a simple task.

CRichardson

dagon;10891751 wrote:
nothing in what it does requires ajax, it could be all php then calling the script via cron using php on the command line would be a simple task.

The script is all php and is called on the command line using cron.

The reason for me needing to refresh the page is down to the script timing out and eating up server resources.

dagon

set_time_limit(0);

CRichardson

dagon;10891763 wrote:
set_time_limit(0);

That works in stopping PHP from timing out however, with 3000 results each needing on average 2 seconds processing time, the database and http server soon die!

dagon

define 'die', you can have a db connection open for ever and running from the command line there is no http server involved

HalfaBee

If you have 3000 rows and 2 secs per row, this is going to take 100+ minutes to run, so you can't have it run every hour if you do it in one script.

If you really need that much time for each row, you will have to have 2 or 3 scripts running at the same time to process it all in one hour.
Hopefully this is on a dedicated server. 🙂

dagon

at work we send 2-10 a second depending on size (average is 60k as we embed all images) they are running in a background task, php on the command line never had a time out issue. Of course this is our machine(s), cant see any host out there allowing it on anything but a dedicated box.

Weedpacket

So is it 2 seconds per row or 10-30 seconds per row? 🙂

I hate to think what it needs to do every hour that takes so long with so little data. If it took 2 seconds to do all 3000 rows it would make more sense.

CRichardson

Weedpacket;10891779 wrote:
So is it 2 seconds per row or 10-30 seconds per row? 🙂

I hate to think what it needs to do every hour that takes so long with so little data. If it took 2 seconds to do all 3000 rows it would make more sense.

It's for private business owners. It queries external RSS feeds which provide vital data. So it can take up to 30 seconds per row if the feed is slow to respond.

Would looking into multi-thread simulation help?

Weedpacket

See Halfabee's most recent comment.