http://simonwillison.net/2023-11-29T17:49:31+00:00Simon Willison2023-11-29T17:49:31+00:002023-11-29T17:49:31+00:00https://simonwillison.net/2023/Nov/29/announcing-deno-cron/#atom-tag

<p><strong><a href="https://deno.com/blog/cron">Announcing Deno Cron</a></strong></p> Scheduling tasks in deployed applications is surprisingly difficult. Deno clearly understand this, and they’ve added a new Deno.cron(name, cron_definition, callback) mechanism for running a JavaScript function every X minutes/hours/etc.</p> <p>As with several other recent Deno features, there are two versions of the implementation. The first is an in-memory implementation in the Deno open source binary, while the second is a much more robust closed-source implementation that runs in Deno Deploy:</p> <p>“When a new production deployment of your project is created, an ephemeral V8 isolate is used to evaluate your project’s top-level scope and to discover any Deno.cron definitions. A global cron scheduler is then updated with your project’s latest cron definitions, which includes updates to your existing crons, new crons, and deleted crons.”</p> <p>Two interesting features: unlike regular cron the Deno version prevents cron tasks that take too long from ever overlapping each other, and a backoffSchedule: [1000, 5000, 10000] option can be used to schedule attempts to re-run functions if they raise an exception. <p>Tags: <a href="https://simonwillison.net/tags/cron">cron</a>, <a href="https://simonwillison.net/tags/deno">deno</a></p>

2009-04-08T14:04:45+00:002009-04-08T14:04:45+00:00https://simonwillison.net/2009/Apr/8/cron/#atom-tag

<p><strong><a href="http://code.google.com/appengine/docs/python/config/cron.html">App Engine: Scheduled Tasks With Cron</a></strong></p> Cron tasks simply hit a URL on your application, and can be run as frequently as once a minute. They made up their own syntax, which much nicer than traditional unix cron. <p>Tags: <a href="https://simonwillison.net/tags/cron">cron</a>, <a href="https://simonwillison.net/tags/google">google</a>, <a href="https://simonwillison.net/tags/google-app-engine">google-app-engine</a></p>

2008-06-27T09:48:53+00:002008-06-27T09:48:53+00:00https://simonwillison.net/2008/Jun/27/cron/#atom-tag

<p><strong><a href="http://blog.unixdaemon.net/cgi-bin/blosxom.pl/sysadmin/cron_commandments.html">The Cron Commandments</a></strong></p> How to write well-behaved cron scripts, from Dean Wilson. <p>Tags: <a href="https://simonwillison.net/tags/cron">cron</a>, <a href="https://simonwillison.net/tags/dean-wilson">dean-wilson</a>, <a href="https://simonwillison.net/tags/unix">unix</a></p>