WordPress
WordPress cron jobs: how scheduled work actually runs
WordPress calls its scheduler WP-Cron, but it is not identical to a traditional operating-system cron daemon. By default, WordPress checks for due tasks when requests reach the application, which has implications for low-traffic sites and busy sites with many scheduled jobs.
Scheduled tasks can affect user requests
Plugin updates, ecommerce events, queue processing, email, cleanup, publishing, backups, and other plugins may schedule work. If too much runs during a normal page request, visitors can experience slower responses.
Low traffic can delay due work
A site receiving few requests may not trigger WP-Cron exactly when a task becomes due. For time-sensitive workloads, a real server cron can call the WordPress scheduler at a predictable interval.
Look for duplicated or stuck events
A broken plugin can schedule excessive events or repeatedly fail the same job. Review the event list and application logs before simply increasing server resources.
Separate heavy jobs from peak traffic when possible
Backups, imports, indexing, reports, and other expensive work can compete with visitor traffic. Schedule them intentionally and monitor their CPU, memory, I/O, database, and execution time.