Apache and PHP ver 4..looks like a bug...

byteclock · 03-13-2006, 02:16 AM

Hi gurus! I have a hosting server and last month have noticed a weird thing with php and apache. Some of my users creates buggy php pages, which generates in cicle errors , hundreds of MB, which then PHP tries to send to the user!!!! Sure my server dies quickly because those error pages are kept in memory..

I believe you can get down any server you want if for example you run in cicle a

PHP Code:



$handle=fopen(a non-existent url or something not available) 
while(!$feof($handle)) 
{ 
//do something 
}

king of that page will run for 30 seconds, this is by default the time a cicle can run, will generate Gigs of errors, which PHP will try to send to the user..I can solve this problem just by dissabling from php.ini display_errors=No..Any other solution??? because i stil want my users to be able to read their errors...

thanks

jiml8 · 03-13-2006, 07:34 PM

You can't protect against that kind of coding error; the developer should know to always check the validity of a file handle before using it.

If your developers aren't that sophisticated (amateurs or students) then you need to limit them. You do this by limiting their resources. In this case, I would limit both their memory access and their CPU time; cut the script off at 5 seconds CPU and you'll keep your server alive.

byteclock · 03-14-2006, 08:07 AM

well thank you jiml8 for the answer, it seems logical, since nothing could be done to solve that problem, that minimising the run time to 5 sec could stop very nasty scripts. bad programming style or some mistakes sure could not be stopped by any ways.. thank again..

onjoo · 03-14-2006, 08:53 AM

Well you can produce the same thing in almost every programming language

Code:

while(true){
 do nothing...
}

That kind of loops can be made. It's just bad coding if you don't check variables in some point or if you let the program run endlessly

You can adjust how php handles the files:
Modify these :
- max_execution_time
- memory_limit

byteclock · 03-15-2006, 07:56 AM

Actually the problem with error output of php engine remains.. I am not a programmer to judge php developers, but i cant undertand how do they allow php to send back hundreds of MB??? On my server a endless loop that runs for 30 sec generates 1-1,5 Gbytes, which then are sent back to the user..how do you like that

????