PHP infinite loop is stopping on first minute of every hour - php

Question

Any idea why a simple infinite loop stops on the very first minute of every hour? For instance, 21:01, 22:01, 23:01, etc.
The server is running Ubuntu 12.04 and the PHP script is launched using command: "php -f test.php"
while (1 == 1) {
echo "test";
sleep(30);
}
Any help is appreciated.
UPDATE: It doesn't matter whether I run the script 16:05 or 16:49, it will stop on 17:01, so the issue is not related to the set_time_limit value.
UPDATE: If the script has to sleep for an hour and then echo "test", the "test" will not be echoed. The script stops it's work without finishing the loop itself.
UPDATE: It seems that I've found out what's killing the script. I've set the PHP script to report All errors and right before the *:01 time comes up, I get the text: Terminated. I've Googled that the script might get Terminated by OOM killer and, unfortunately, I don't have permission to change it's settings on my current VPS. I'm switching to VDS and will try to modify OOM killer settings.

Answer 1

i guess it's because of Limits the maximum execution time on php .
if you want repeat a script every day , hour and minute you should use Cronjob to call your script every time you need.
cronjob available in popular web hosts like direct admin and cpanel
for example you can use below command for run your script every one minute
*/1 * * * * /usr/local/bin/php -q /home/user/domains/domain.com/public_html/script.php
if you want run script every second you can set maximum execution to one minute and repeat a code every second in it and use cronjob to call it every minute

Answer 2

If you are using php file through apache i.e. as a URL then you should do
ini_set('max_execution_time', 0); //0=NOLIMIT
If you are running through CLI this should not be happening generally
UPDATE
Below are few Notes form php.net. I hope it will help you
Warning This function has no effect when PHP is running in safe mode.
There is no workaround other than turning off safe mode or changing
the time limit in the php.ini.
Note: The set_time_limit() function and the configuration directive
max_execution_time only affect the execution time of the script
itself. Any time spent on activity that happens outside the execution
of the script such as system calls using system(), stream operations,
database queries, etc. is not included when determining the maximum
time that the script has been running. This is not true on Windows
where the measured time is real.
So, it is possible that PHP code doesn't actually breaks. But, any other conenction/call is getting broken.

Answer 3

On my ubuntu system there is a script in /etc/cron.d/php5
# /etc/cron.d/php5: crontab fragment for php5
# This purges session files older than X, where X is defined in seconds
# as the largest value of session.gc_maxlifetime from all your php.ini
# files, or 24 minutes if not defined. See /usr/lib/php5/maxlifetime
# Look for and purge old sessions every 30 minutes
09,39 * * * * root [ -x /usr/lib/php5/maxlifetime ] && [ -x /usr/lib/php5/sessionclean ] && [ -d /var/lib/php5 ] && /usr/lib/php5/sessionclean /var/lib/php5 $(/usr/lib/php5/maxlifetime)
That script /usr/lib/php5/maxliftime will check for param
session.gc_maxlifetime
in any php.ini file located at /etc/php5/*/php.ini
Check for that value via
cd /etc/php5
grep -ri gc_maxlifetime .
If there is a value 3600 you should got it.