Know All About Autoscaling On Heroku

Know All About Autoscaling On Heroku

Autoscaling is a method used to manage the traffic on the network. When the outbound traffic on average is higher or lower, in each instance, the default triggers dynamically tend to autoscale and adjust the computational resources to meet the demand - typically, the number of servers that manage the load of the application. 

So, if there is a spike of users on the application - with the auto-scaling method, the number of servers running behind the web application will increase too, and if the users decrease, and there is now no requirement of bulk servers, with autoscaling, the servers scale to as much quantity needed - No less no more. 

For instance, the lifeguards are hired more in summers, as that is the rush time. And hardly any lifeguards are employed in other seasons. Similarly, with the autoscaling methods, servers engaged to support your application in the peak time gets more in number and are reduced in the off-peak times - It adjusts according to needs.  

Though this autoscaling concept seems to be an incentive concept, as it works according to the demands and loads - Autoscaling has many other purposes to be activated in web applications. Let’s look at the purposes of autoscaling.

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The Purpose of Autoscaling

The servers are the limited resources which any organization has to pay for, even if they are kept ideal. However, as we all know, there are certain peak and off-peak hours, and if you have many servers already hired, not all servers come into use at a time. 

At times, your application might need additional servers too to do the needful. Thus, to not get stuck with more or fewer servers, autoscaling is used. It’s a concept based on balancing the servers based on traffic. Having autoscaling onboard are backed with other purposes as well, which are listed below:


  • Adding or Removing the Dynos - 

When Autoscaling is activated on your system, it helps to add or reduce dynos according to the application performance characteristics. So, when you have autoscaling, there is no need to manually set dynos whenever there is a rise or fall in the dyno requirements. It computes automatically according to traffic shifts. 

  • A Reactive Approach to Handle Traffic - 

One of the main purposes of auto-scaling is they have a reactive approach to handle traffic and respond to any changes in the traffic in real-time. With autoscaling, handling the traffic hike and crashing applications will not be a problem anymore. 

  • Offering Flexibility In Scaling Out - 

An application sees numerous traffic types in a day, and it’s not possible to manually keep an eye to add or withdraw dynos. For which, to handle dyno for different traffic-types throughout the day, autoscaling fits best. 

  • It Can Handle Any Immense Spike In The Traffic - 

The overall purpose of auto-scaling is, handling even the immense spike of traffic. It seamlessly merits new resources without further configuration and eminently takes care of any traffic spikes without disturbing any functionality of the application. 

  • Cost-Effective Solution - 

The core of autoscaling is that they are the cost-effective good to go solutions for any application. They use only required servers and do not engage more or less of them. When no ideal servers are resting in the background, the organization does not pay extra for those taken-over servers when not in use. And you pay for only what you use. So, not just autoscaling scales dynos, but it's a pocket-friendly scaling partner too. 

  • Gives Peace Of Mind - 

Fearing the crash of an application is normal when you do not have any autoscaling activated on your application. As it will only lead to not handling the traffic at peak hours. However, to have peace of mind, autoscaling is a must-have, to let the app work seamlessly, with efficiently monitoring and scaling dynos. 

  • It’s Automatic, And Thus Time-Saving - 

Another major purpose of owning autoscaling is, it’s completely automatic. When monitoring, configuration, and decommissioning is something required to scale dynos, autoscaling does it all, automatically abandoning the purpose of disturbing you to get permissions all the time. So, you see, it’s automatic and thus time-inexpensive.

Use A Threshold Alert To Monitor Your P95 Before Starting Autoscaling

There are two layers - Threshold and Milliseconds inside the Threshold. 

If you set your Threshold to P95 and milliseconds at 50, any transaction which took longer than 50 milliseconds will be calculated as exceeding the limit set.

As soon as the limit of transactions touches 5%, the Threshold alert or alarm will be activated. And all the workers will get notified about the recent spike in latency in transactions. 

Setting the Threshold alert to monitor your P95 before starting auto-scaling is necessary - because when you have left your servers to autoscale, you will definitely not monitor it every time. And there might be glitches that are causing latency.

So, to get notified about the transaction getting late will be a warning, post which you can fix the issue. It’s one of the main events that must happen before starting autoscaling. Serverless Tools

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Automated Scaling of Heroku Dynos Configuration

Where there is an application, there is the need for autoscaling. And when there is a need, there is a search for the most prominent add-on that can help application autoscale without conflicts.

For situations when your application faces highs and lows in the traffic, to manage the servers and react to those traffic demands, Heroku’s IronWorker add-on can help you best in the same. 

Heroku’s autoscaling add-on completes your background work, keeps the workflow of your application lightning-fast, processes tasks real-soon, it is very easy to set up, and can be integrated with your existing application.

You can use coding languages including PHP, NodeJS, Python, Ruby, .NET, Java, and Go - any that you are familiar with. 

To scale the dynos with Heroku, go by the following steps to configure the Heroku IronWorker Add-on. 


  • On the Heroku Dashboard, you can configure auto-scaling from the app's Resources tab. 
  • Next to your web dyno details, click on the Enable Auto Scaling button. 
  • When you click on the enable autoscaling, you will be directed to the setup page. You must proceed with those settings to complete the configuration. 
  • Using the text box, or slider, restrict the allowed autoscaling range. When you set the range, you will see the cost associated with the specified range just below the slider panel. While dyno count is all set, it will never go beyond the specified limit. 

NOTE: The dyno limit cannot be less than 1. 


  • In the next step, the box in the middle asks you to specify the Desired P95 Response Time. In that, you can set up the milliseconds, that is, the response time. If you are not familiar with what the response time should be, go by the suggestion in the box. 
  • Going to the next box, you must enable the Email Notifications. You should allow email only when you want all your team members to get notifications when Web Dynos touch the upper limit. 
  • When you are done customizing the settings, you can now click on the confirm. With the button Confirm clicked, your auto-scaling with custom settings is enabled. 

Though the Autoscaling Heroku dynos with Iron Worker must look like a hectic task, as you can see, it’s not. It’s just as easy as serving the cupcake. All you have to do is, follow the above-mentioned simple steps, and you are done with the settings. 

Limitations of Auto Scaling With Heroku

There is nothing in this world that comes without limitations. Even we people have certain boundaries of limitation and so as these Heroku’s add-ons. So, let’s see the limitation post which you can decide if Heroku IronWorker is a good fit for you. 

Dyno Scaling Limitation

There are different Dynos that Heroku’s add-on IronWorker accommodates, and there are distinct limitations of those too. You must check out the Dyno types and their clear limitations on the given link. 


In order to activate autoscaling, you might have to tune your worker count, Postgres connection pool, or even add-on plan(s) to bear the changes in web dyno formation. Tune finely to leave no chores that would let you fall from the crack. 

So, if you have checked the limitations or IronWorker Add-on for different Dynos and those suit your application, you can configure them with your app and fine-tune them to leverage the benefits. 

Know All About Autoscaling On Heroku

Wrapping up

An application that is open to all users can face unlimited fluctuation in traffic throughout the day. For which, if you hire a professional to monitor servers and manually adjust them, it would not just cost you highly, but the manual work might not go faster as the automatic auto-scaling would go - because of which, your application might have to have often downtimes. 

To let your application sail smoothly, you must get the IronWorker Heroku add-on that will automate the scaling of your application. With easy charts, you can better understand how to scale your app or customize the settings, get alerts feeds, it’s time-saving, very easy to integrate, and most importantly, as it keeps your app running on the smooth path, it keeps it your mind at peace too. It protects your application from latency, downscaling and manages the traffic well to keep the performance upright. Get the 14 days free trial of the IronWorker Heroku add-on, or get the IronWorker add-on at just Starting price of $18/mo.

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