Reliability

az graph query -q "
resources
| where resourceGroup =~ '<rg>'
| where type =~ 'microsoft.web/serverfarms'
| where kind contains 'functionapp' or kind =~ 'linux' or kind =~ 'elastic'
| project name, sku=sku.name, zoneRedundant=properties.zoneRedundant, location
" --subscriptions <sub-id>

az functionapp show --name <app> --resource-group <rg> \
  --query "{minInstances:siteConfig.minimumElasticInstanceCount}" -o table

# Enable zone redundancy on plan
az resource update \
  --resource-group <rg> \
  --name <plan-name> \
  --resource-type "Microsoft.Web/serverfarms" \
  --set properties.zoneRedundant=true

# Enable zone redundancy + set min capacity
az appservice plan update \
  --name <plan-name> \
  --resource-group <rg> \
  --number-of-workers 2

az resource update \
  --resource-group <rg> \
  --name <plan-name> \
  --resource-type "Microsoft.Web/serverfarms" \
  --set properties.zoneRedundant=true

# Set minimum elastic instances per app
az resource update \
  --resource-group <rg> \
  --name <app-name> \
  --resource-type "Microsoft.Web/sites" \
  --set properties.siteConfig.minimumElasticInstanceCount=2

import { app } from "@azure/functions";

app.http('health', {
  methods: ['GET'],
  authLevel: 'anonymous',
  route: 'health',
  handler: async () => ({ status: 200, body: 'OK' })
});

import azure.functions as func

app = func.FunctionApp()

@app.route(route="health", methods=["GET"], auth_level=func.AuthLevel.ANONYMOUS)
def health(req: func.HttpRequest) -> func.HttpResponse:
    return func.HttpResponse("OK", status_code=200)

[Function("Health")]
public IActionResult Health([HttpTrigger(AuthorizationLevel.Anonymous, "get", Route = "health")] HttpRequest req)
{
    return new OkObjectResult("OK");
}

az webapp config set \
  --name <app-name> \
  --resource-group <rg> \
  --generic-configurations '{"healthCheckPath": "/api/health"}'

module appServicePlan 'br/public:avm/res/web/serverfarm:0.5.0' = {
  params: {
    skuName: 'FC1'
    reserved: true
    zoneRedundant: true  // ← ADD
  }
}

module appServicePlan 'br/public:avm/res/web/serverfarm:0.5.0' = {
  params: {
    skuName: 'EP1'
    reserved: true
    zoneRedundant: true      // ← ADD
    skuCapacity: 2           // ← ADD (min 2 for ZR)
  }
}

// On the function app resource:
resource functionApp 'Microsoft.Web/sites@2023-12-01' = {
  properties: {
    siteConfig: {
      minimumElasticInstanceCount: 2  // ← ADD
    }
  }
}

resource "azurerm_service_plan" "plan" {
  sku_name               = "FC1"
  os_type                = "Linux"
  zone_balancing_enabled = true  # ← ADD
}

# Premium plan:
resource "azurerm_service_plan" "plan" {
  sku_name               = "EP1"
  os_type                = "Linux"
  zone_balancing_enabled = true  # ← ADD
  worker_count           = 2     # ← ADD
}

resource "azurerm_linux_function_app" "func" {
  site_config {
    minimum_elastic_instance_count = 2  # ← ADD (Premium only)
  }
}