Azure App Service

Cost considerations

It’s relatively easy to set up and scale up Azure App, but you can incur unwanted costs if you don’t plan and monitor it. To better gauge and manage your monthly spend, it is therefore important to understand the different elements in the App Service environment that are subject to charge.

The main resource charges are associated with compute resources for VM instances. These charges depend on the App Service plan tier and the number of VM instances deployed. The charges levied are based on the number of times the instances are online. It is highly recommended to monitor the usage of instances and identify areas where you can better manage it. This can help you significantly decrease your spending.

In addition to compute resources, Microsoft charges for some additional resources, including the following:

• App Service domains

• App Service certificates

• IP-based certificate bindings

• Storage for backup and diagnostic logging

• A virtual network for the Isolated tier ASE

There are various ways to optimize costs associated with App Service and related workloads. Here are just a few:

• Host multiple apps in a single plan One of the best ways to optimize costs is to collocate multiple apps within the same App Service plan. This will require you to analyze application and API loads to determine which apps to host together. On a related note, you can move apps to different App Service plans within the same region and resource group to optimize usage over time based on load analysis. You’ll want to consider this when deciding which plan to use to host your app.

• Use the Free or Shared tier to host test and dev workloads Using the Free or Shared tier for dev and test workloads can help keep costs low during those stages. These tiers are also an excellent choice for most environments for hosting functions, scripts, and code snippets, depending on their runtime and SLA requirements.

• Use the Standard tier or above to host production workloads Using the Standard tier or above to host production workloads ensures those workloads are covered by the App Service SLA. This is because the hardware available on these tiers provides much better performance than the hardware resources allocated to the Free and Shared tiers. The Standard and above tiers also offer better memory, storage, security, and scaling features.

• Use autoscaling Be aware that the cost of running workloads on the Standard or higher tiers is much higher. Therefore, to optimize costs, you should use autoscaling to remove VM instances when they are inactive. Autoscaling is supported in the Standard Dedicated tiers and can be used both to scale out and to scale in, ensuring that only the compute resources required are online.

• Reserve instances The Dedicated PremiumV3 and Isolated tiers enable you to reserve and pre-pay for instances at a discount for use later on. You can reserve between one and three years in advance; the longer the reservation period, the cheaper it is. If you know the minimum number of compute resources you will require for the next one to three years, it would be advisable to reserve them to obtain the significant cost benefit.

• Set up budgets Setting up a budget can help stakeholders keep better track of their costs and (hopefully) eliminate overspending. You can set up alerts to notify application admins if spending does exceed your budget, enabling them to take immediate action to reduce the spend.

• Monitor your spending Once your budget is in place, it is important to monitor your costs on a regular basis to identify unwanted spends and areas that might be ripe for optimization. Trend analysis of this data can also help in forecasting for future planning.

• Analyze in PowerBI or Excel You can export the data you collect over time when monitoring costs to Microsoft PowerBI or Microsoft Excel to analyze historical trends across datasets. You can do this on a scheduled basis—daily, weekly, or monthly—making it possible to perform a long-term analysis.

• Avoid post-deletion charges Even if you delete all the apps in an App Service plan, charges for that plan, and the number of VM instances deployed, will continue to apply. To avoid incurring these charges, you should delete the plan or scale it down to the Free tier. You can also remove other associated resources manually, such as the following:

  • Virtual networks created for the Isolated tier

  • The Key Vault used to store TLS/SSL certificates

  • Log Analytics workspaces for log ingestion and analysis

  • Backup and diagnostic logging storage accounts