Cron tasks. And some theory?

Question

Task Schedulers

When studying php, I got to cron tasks.
Of course, he googled. But there were a couple of incomprehensible moments.
1. How are advanced crontasks different from regular crontasks?
2. When running a cron task, will there be a large load on the server (if updates need to be performed on 1000 sites)?
3. With each call to the site (once a minute), will the site that is being checked suffer from something (traffic, load, etc.)?

Answer 1

1. xs, the fact is that further you learn about Gearman and Celery, and kroner will disappear
   
2. the load is exactly the same as running without cron. That is, there is, of course
   
3. once a minute for a normally working site - you can. But it’s better to check every 5 minutes, it doesn’t happen that you lay down for a minute and immediately got up, and at the same time the connection time is fast and does not slow down
   
4. curl_setopt($curlInit,CURLOPT_CONNECTTIMEOUT,10); little, 60 seconds and write down the response time in the database, analyze
   
5. hosting is free, good inexpensive paid, 2 months free