max execution time problems.

juschillinnow

I have a script that may take upwards of half an hour to completely run. As you can imagine the page was timing out with max execution error. I stopped this by putting set_time_limit(20) at the top of the while loops.

Problem is now that it seems that one of two things are happening.....

1.) Can a browser run out of memory or does it flush itself?

(I'm using windows as a platform)

2.) If not is there a way to trick PHP into believing that the script has stopped and is starting again without actually doing it?

Any suggestions for scripts of this magnitude?

sarahk

that sounds really interesting.

Often when you are writing programs you have little bits of debug output

starting setup...
finished setup...
creating ids...
processing phase 1

and so on. In this case you can use metarefresh effectively. Cut your code up into finite pieces all of which will run in the time allowed (ie no timeout) and have these as separate scripts or parts of a script. Then each page calls the next part and passes it the info it needs to proceed. It might be a database record id or a session id or it could even use cookies.

You might need to create temporary tables to store progress to prevent the program having to start over every time but I bet that you can do this with a bit of lateral thinking and not too much effort.

ereptur

Usually when I found that I got that error, it was because of an infinite loop in which I specified a while() statement but forgot to put in a condition that would eventually cause it to break out.

You probably want to make sure that that isn't the case.

sarahk

Good point. Must admit I was working on the basis that the code wasn't buggy, just complex or with alot of data to manage. It's a pretty major process which takes minutes to run anyway.

juschillinnow

you were right when you said that there was a lot of data to manage. NO bugs. I'm sure of it.

The reason I no is that it pulls records of a database (about 50,000) and then processes several files for each record.

If I use a test table to do this with about 10 entries. I works fine. I have even had our team here go through the records and look for any characters that might be making it crash. such as a ' or a " or a / or some character like that.

So no bugs. Yeah,...I got problems if I can't get this thing working. Seems PHP isn't so great for this type of job. Probably should have gone with C++ or something

sarahk

I'd get the list of 50,000 ids and chuck them in a table with a flag. Then use meta refresh to call another script. This selects (limit 1) the first unprocessed id, does the work and finishes - by sending out a page & using metarefresh to call itself all over again.

Depending on the run time you may be able to process more than one each cycle.

You may also be able to use headers rather than metarefresh. I don't have a strong preference. You will also be able to output a simple "Processing XYZ" so you can see the progress.

good luck