Cron Jobs are closed on my server and server admin doesn\'t accept open it. Because , cron jobs slowing server etc. So, i need an alternative.
I have to run a php fi
Depends on your access on the box.
PHP itself will not be able to run standalone that well. You could do a script which tries to increase it’s execution time constantly, sleeping and checking for new jobs regularly. But that is sub-optimal as you’ll have to access it via browser once, and the script would have to make sure it only runs once.
With shell access you could run the php script on the shell, which would prevent it from being callable from public and having to run it via webbrowser.
With shell access you could also run a program that provides a (cron) service for you. Be it a Java, Python, or other program.
Cron jobs shouldn’t slow the server always. That depends on the job that is run. If it’s your jobs that are so expensive your admin will probably not be okay with working around the closed cron jobs and slowing the server again anyway and may take further action to prevent you from working around.