https://www.pistack.xyz/tags/file-locking/ Recent content in File-Locking on Pi Stack Hugo en-us Sun, 27 Sep 2026 00:00:00 +0000 https://www.pistack.xyz/posts/2026-09-27-file-locking-libraries-filelock-flock-proper-lockfile-comparison/ Sun, 27 Sep 2026 00:00:00 +0000 https://www.pistack.xyz/posts/2026-09-27-file-locking-libraries-filelock-flock-proper-lockfile-comparison/ <p>Two replicas of your self-hosted job runner wake up at 02:00. Both decide it is their turn to rebuild the nightly report. Both read the same state file, both write the same output, and by morning you have a half-written CSV plus a duplicate charge in your invoicing table. Nothing in your infrastructure was misconfigured — you simply never told the two processes that the file is a shared resource. That is a <em>file locking</em> problem, and it is solved in application code, not by adding another container.</p>