The latest articles on DEV Community by Brian Marete (@brianmarete). https://dev.to/brianmarete https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F692994%2F13b8e94a-77d2-4c97-9676-f2f5d824d343.jpeg https://dev.to/brianmarete en Brian Marete Mon, 13 Jun 2022 07:41:46 +0000 https://dev.to/brianmarete/scheduling-jobs-on-heroku-3854 https://dev.to/brianmarete/scheduling-jobs-on-heroku-3854 <p><a href="https://elements.heroku.com/addons/scheduler">Heroku Scheduler</a> is a free Heroku add-on that runs any command that can be run in your application at scheduled time intervals, similar to cron jobs in a Linux server.</p> <h2> Installation </h2> <p>The add-on is free but you will need to use it on a verified Heroku account. You can verify your account by adding a credit card to your account. To install using the Heroku CLI, run this command in your application folder:<br> </p> <div class="highlight js-code-highlight"> <pre class="highlight shell"><code><span class="nv">$ </span>heroku addons:create scheduler:standard </code></pre> </div> <p>The add-on can also be installed from the 'Resources' section in the Heroku application dashboard. Just search for 'Heroku Scheduler' and follow the prompts to install the add-on.</p> <h2> Usage </h2> <p>Once installed, the add-on can be accessed from the Resources section. Click on 'Heroku Scheduler' from your listed add-ons and it will navigate to a new page where you can create your first job.</p> <p><a href="https://res.cloudinary.com/practicaldev/image/fetch/s--4o-KxWEt--/c_limit%2Cf_auto%2Cfl_progressive%2Cq_auto%2Cw_880/https://dev-to-uploads.s3.amazonaws.com/uploads/articles/8t7clymji75w94n7gh70.png" class="article-body-image-wrapper"><img src="https://res.cloudinary.com/practicaldev/image/fetch/s--4o-KxWEt--/c_limit%2Cf_auto%2Cfl_progressive%2Cq_auto%2Cw_880/https://dev-to-uploads.s3.amazonaws.com/uploads/articles/8t7clymji75w94n7gh70.png" alt="Scheduler start page" width="880" height="148"></a></p> <p>This page can also be accessed from from the CLI<br> </p> <div class="highlight js-code-highlight"> <pre class="highlight shell"><code><span class="nv">$ </span>heroku addons:open scheduler </code></pre> </div> <p>Clicking on 'Create job' opens a form to the side</p> <p><a href="https://res.cloudinary.com/practicaldev/image/fetch/s--YlLTRU-S--/c_limit%2Cf_auto%2Cfl_progressive%2Cq_auto%2Cw_880/https://dev-to-uploads.s3.amazonaws.com/uploads/articles/zxbtipda2too8llhdo21.png" class="article-body-image-wrapper"><img src="https://res.cloudinary.com/practicaldev/image/fetch/s--YlLTRU-S--/c_limit%2Cf_auto%2Cfl_progressive%2Cq_auto%2Cw_880/https://dev-to-uploads.s3.amazonaws.com/uploads/articles/zxbtipda2too8llhdo21.png" alt="Job editor" width="800" height="1702"></a></p> <p>Suppose we have a script called <code>emailUpdates.js</code> that sends a daily email to users of our app at 6 PM. We can run this script using the scheduler by</p> <ol> <li>Set schedule to 'Every day at...' 6:00 PM (The default timezone is UTC so you'll need to offset this to your desired time)</li> <li>Set command to <code>node emailUpdates.js</code>. Heroku suggests placing your scripts in a <code>bin</code> folder so if your script is located there, the command would be <code>node ./bin/emailUpdates.js</code>. </li> <li>Click save job</li> </ol> <p>The job to run can be any command that can be run in your application. In a node.js app, this could be a script defined in the <code>scripts</code> section of your <code>package.json</code> file.</p> <h2> Limitations </h2> <p>Scheduled jobs are meant to execute short running tasks or enqueue longer running tasks into a background job queue. Anything that takes longer than a couple of minutes to complete should use a <a href="https://devcenter.heroku.com/articles/background-jobs-queueing">worker dyno</a> to run.</p> <p>A dyno started by scheduler will not run longer than its scheduling interval. For example, for a job that runs every 10 minutes, dynos will be terminated after running for approximately 10 minutes.</p> <p>So that's how schedule simple tasks on Heroku. For more details, you can view the official documentation <a href="https://devcenter.heroku.com/articles/scheduler">here</a>.</p> heroku