Allocating a Serverless Database in SQL Azure

I’m pretty big on the SQL Azure Serverless SKU. It allows you to scale databases up and down automatically within a band of between 0.75 and 40 vCores on Gen5 hardware. It also supports auto-pausing which can shut down the entire database during periods of inactivity. I’m provisioning a bunch of databases for a client and we’re not sure what performance tier is going to be needed. Eventually we may move to an elastic pool but initially we wanted to allocate the databases in a serverless configuration so we can ascertain a performance envelope. We wanted to allocate the resources in a terraform template but had a little trouble figuring it out.

Traditionally we’ve been using the resource azurerm_sql_database for our databases but this provider is starting to be deprecated in favour of azurerm_mssql_database which has better support for some of the more modern concept in SQL Azure. The documentation is pretty good for it but while there was a min_capacity we couldn’t find an equivalent max_capacity. Turns out you can set the max capacity using the SKU. So we had something like

resource "azurerm_mssql_database" "database" {
  name                        = var.database_name
  server_id                   = var.database_server_id
  max_size_gb                 = var.database_max_size_gb
  auto_pause_delay_in_minutes = -1
  min_capacity                = 1
  sku_name                    = "GP_S_Gen5_6"
  tags = {
    environment = var.prefix
  }
  short_term_retention_policy {
    retention_days = 14
  }
}

This allocates a database with a capacity of between 1 and 6 vCPU that has auto pause disabled. The S in the GP_S_Gen5_6 stands for serverless and the 6 denotes the maximum capacity.