In the past, you may have written a cron configuration entry for each task you needed to schedule on your server. However, this can quickly become a pain because your task schedule is no longer in source control and you must SSH into your server to view your existing cron entries or add additional entries
When using the scheduler, only a single crontab entry is needed on your server.
Add a new entry to your crontab to run
bin/cronjob.php every minute.
Your server crontab could now look something like:
* * * * * /usr/bin/php /var/www/example.com/bin/cronjob.php 1>> /dev/null 2>&1
Your scheduler is up and running, now you can add your jobs without worrying anymore about the crontab.
These libraries can be used to define and execute cronjob tasks. There are more, of course.
Locks are used to guarantee exclusive access to some shared resource.
A lock can be used to ensure that the server starts only one specific cronjob or console command at the same time.