Stale While Revalidate (SWR) is a strategy to first return the data from the cache, then send the fetch request, and finally come up with the up-to-date data.
PHP
Laravel Deadlocks: Queue Jobs That Already Ran End Up in failed_jobs
Below MySQL 8.0.1, or on a server Laravel misreads, workers reserve jobs with a plain FOR UPDATE and can deadlock on the DELETE. One tinker line shows which lock yours use. Read more