The Premium tier of Azure API Management (APIM) does support zone redundancy, but it does not enable automatic zone redundancy by default. For high availability within a region, it's still necessary to distribute API Management units across three availability zones manually to ensure that your instance is resilient to zone-level failures.
Key Points:
- Zone Redundancy Support in Premium Tier: The Premium tier of API Management supports deploying across multiple availability zones within a region, but this requires explicitly provisioning the APIM units across the zones.
- High Availability with Availability Zones: To achieve high availability (HA) and zone redundancy, you should scale your API Management service by increasing the number of units and distributing them across the availability zones in the region. Azure will handle balancing the units across zones, but you need to provision enough units (at least 3, one for each zone) to benefit from the redundancy.
- Scaling API Management: You increase the number of units in the Premium tier via the Azure portal, CLI, or ARM templates. When you increase the units, Azure distributes those units across the three availability zones to provide zone redundancy.
Summary:
While the Premium tier of APIM supports zone redundancy, it’s necessary to manually increase the number of units to ensure that API Management is deployed across three availability zones for high availability. Without scaling the units, zone redundancy would not be automatically provided.
Let me know if you need further clarification or help with configuring this!