Upgrade and scale an Azure API Management instance

  • Article

Customers can scale an Azure API Management instance in a dedicated service tier by adding and removing units. A unit is composed of dedicated Azure resources and has a certain load-bearing capacity expressed as a number of API calls per second. This number doesn't represent a call limit, but rather an estimated maximum throughput value to allow for rough capacity planning. Actual throughput and latency vary broadly depending on factors such as number and rate of concurrent connections, the kind and number of configured policies, request and response sizes, and backend latency.

Note

  • In the Basic, Standard, and Premium tiers of the API Management service, you can configure an instance to scale automatically based on a set of rules.
  • API Management instances in the Consumption tier scale automatically based on the traffic. Currently, you cannot upgrade from or downgrade to the Consumption tier.

The throughput and price of each unit depend on the service tier in which the unit exists. If you need to increase capacity for a service within a tier, you should add a unit. If the tier that is currently selected in your API Management instance doesn't allow adding more units, you need to upgrade to a higher-level tier.

Note

See API Management pricing for features, scale limits, and estimated throughput in each tier. To get more accurate throughput numbers, you need to look at a realistic scenario for your APIs. See Capacity of an Azure API Management instance.

Prerequisites

To follow the steps from this article, you must:

Upgrade and scale

You can choose between the following dedicated tiers: Developer, Basic, Standard, and Premium.

  • The Developer tier should be used to evaluate the service; it shouldn't be used for production. The Developer tier doesn't have SLA and you can't scale this tier (add/remove units).

  • Basic, Standard, and Premium are production tiers that have SLA and can be scaled. For pricing details and scale limits, see API Management pricing.

  • The Premium tier enables you to distribute a single Azure API Management instance across any number of desired Azure regions. When you initially create an Azure API Management service, the instance contains only one unit and resides in a single Azure region (the primary region).

    Additional regions can be easily added. When adding a region, you specify the number of units you want to allocate. For example, you can have one unit in the primary region and five units in some other region. You can tailor the number of units to the traffic you have in each region. For more information, see How to deploy an Azure API Management service instance to multiple Azure regions.

  • You can upgrade and downgrade to and from certain dedicated services tiers:

    • You can upgrade and downgrade to and from classic tiers (Developer, Basic, Standard, and Premium). Downgrading can remove some features. For example, downgrading to Standard or Basic from the Premium tier can remove virtual networks or multi-region deployment.

Note

The upgrade or scale process can take up to 15 to 45 minutes to apply. You get notified when it is done.

Scale your API Management instance

You can use the portal to scale your API Management instance. How you scale depends on the service tier you are using.

Scale API Management service in Azure portal

Add or remove units - classic service tiers

  1. Navigate to your API Management instance in the Azure portal.
  2. Select Locations from the left-hand menu.
  3. Select the row with the location you want to scale.
  4. Specify the new number of Units - use the slider if available, or select or type the number.
  5. Select Apply.

Note

In the Premium service tier, you can optionally configure availability zones and a virtual network in a selected location. For more information, see Deploy API Management service to an additional location.

Change your API Management service tier

  1. Navigate to your API Management instance in the Azure portal.
  2. Select Pricing tier in the menu.
  3. Select the desired service tier from the dropdown. Use the slider to specify the number of units for your API Management service after the change.
  4. Select Save.

Downtime during scaling up and down

If you're scaling from or to the Developer tier, there will be downtime. Otherwise, there is no downtime.

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