Block countries you are not allowed to serve
GeoIP at the edge or in PHP, applied to earning and signup rather than to content, with a message that says what happened.
Tagged “locking”
3 entries
Stop two cron runs from overlapping
A non-blocking file lock in three lines, and why a database flag is the wrong tool for this particular job.
Run a cron job on hosting that has no cron
A key-gated HTTP entry point plus a lock file, so an external pinger can drive your scheduled work without letting anyone else drive it.