How to implement constant monitoring of articles in php?

Question

PHP

Hello.
There is a site where info is updated on average every 3-4 minutes, maybe earlier, or maybe later, depending on the time of day.
Now I have implemented this through a php parser, which I run once a minute. It works around the clock and monitors the change, if there are changes, it puts it in the database.
Q:
Can it be made easier? Is it possible to optimize it, to simplify tracking? Because you have to monitor 5 sites at once.
For example, to find out if the changes have passed or not, if so, then parse the site, if not, then nothing needs to be done.

Answer 1

you send the header
if the response is 304, then nothing has changed, if 200 - you download
it, of course, if the server is configured that way

Answer 2

Good afternoon. Perhaps the LinkUpdater service will help you .