In software I have developed separately, I have noticed that most systems will periodically delete files within the temporary directory hierarchy that have not been accessed recently, and that includes lock files for long running processes. I have never noticed the lock file associated with a postgreSQL socket be missing though.
Does PostgreSQL periodically touch the lock file so it won’t be deleted? Alternatively, does PostgreSQL simply re-create the lock file if it has been deleted? I know the documentation says to never “manually”’delete one of those lock files.