https://foojayio.github.io/website/today/author/michael-roeschter/Articles written by Michael Roeschter on foojay.io - Friends of OpenJDKHugoen-usThu, 11 Feb 2021 09:12:23 +0000https://foojayio.github.io/website/today/safe-writing-to-files-in-iot-and-industrial-systems/Thu, 11 Feb 2021 09:12:23 +0000https://foojayio.github.io/website/today/safe-writing-to-files-in-iot-and-industrial-systems/<p>Especially on IoT devices, file corruption on shutdown is a common concern. This article discusses how to write to disk safely in Java, combining disk sync, shutdown hooks, and atomic renaming of files.</p> <h3 id="h3-0-files-on-disk-can-still-easily-become-corrupted">Files On Disk Can Still Easily Become Corrupted</h3> <p>For performance optimization, file systems write to disks asynchronously resulting in potential corruption when a hard system shutdowns occurs through power off or crashes.</p> <p>As this has become a rare experience for desktop and server users, it comes as a surprise to many developers working on IoT devices and industrial computers that hard power cuts are a common operational scenario and storage is far less robust than expected.</p>