15 articles
Every process that imports your app and calls start() runs its own scheduler. Count them, see what --preload and the dev reloaders really do, then pick one scheduler process and accept its trade-off.
The common crontab error messages, each traced to the source line that prints it in cronie, Debian cron, and BusyBox: what triggers each one, the retry prompt, the missing-newline errors, and what the daemon logs when nothing checked the file.
Hangfire resolves every job from a fresh DI scope and disposes it when the job returns. Here is what that means for DbContext, why ObjectDisposedException repeats on every retry, and the patterns that avoid it.
No beat process, a queue no worker reads, an unregistered task, a schedule under the wrong setting name, or two beats. How to confirm each cause from logs and inspect commands, and fix it.
Cron runs jobs with a short PATH, /bin/sh, and none of your shell startup files. What each cron implementation sets, how crontab variables work, and how to test a job in cron's environment.
Two emails or duplicate rows usually mean two launchers. Sort the runs by timing, prove the cause with cron's log, ps, and a one-line run record, then make the job safe to run twice.
Diagnose a stuck cron job, set limits with GNU timeout, systemd, and Kubernetes activeDeadlineSeconds, kill children that escape, clean up on SIGTERM, and get alerted when a run hangs.
Debian and Ubuntu cron log this when a job prints output and no sendmail exists to mail it. Where the output went, how cronie and BusyBox differ, and how to keep, silence, or deliver it.
What Processing means in Hangfire storage, how SQL Server and Redis requeue a job after a crash or deploy, why some jobs really hang, and how to recover without running work twice.
Why a Hangfire recurring job does not fire or execute, the dashboard check that confirms each cause, and how to get alerted the next time a scheduled run never happens.
Why Laravel scheduled tasks stop running in production, from a missing schedule:run entry to a stale withoutOverlapping lock, with a way to confirm each cause and the fix for it.
Start() never called, a paused group, a trigger with no next fire time, ERROR or BLOCKED states, a cron field off by one. How to confirm each cause from Quartz.NET itself, and the fix.
A cron job that stops running produces no error. How a dead man's switch catches it with heartbeats, schedules, and grace periods, plus a wrapper that keeps the job's exit code.
Confirm cron is running, find the crontab that owns the job, reproduce its environment, and check what actually ran. A practical Linux cron troubleshooting guide.
Cron's log shows a job started, not that it worked. Compare cron's log, output files, exit codes, and heartbeat monitoring, the only check that notices a job that never ran.