Microsoft Azure Architect Design (AZ-304) Practice Test

To meet the SLA of 99.99% uptime while hosting 20 databases with varying usage patterns on Azure, what would be the recommended approach?

1. An elastic pool containing 20 Azure SQL databases

2. 20 databases on a single Azure SQL server in an availability set

3. 20 instances of Azure SQL Database serverless

4. 20 databases on a Microsoft SQL server running in an Azure VM

The correct answer is: An elastic pool containing 20 Azure SQL databases

Utilizing an elastic pool containing 20 Azure SQL databases is the recommended approach to achieve a service level agreement (SLA) of 99.99% uptime while effectively handling varying usage patterns. This method allows you to allocate a shared set of resources across multiple databases, which optimizes performance and resource utilization based on the fluctuating demand of each database. Elastic pools facilitate scaling by providing a collective set of performance resources that can dynamically adjust to the needs of any database within the pool. This is particularly advantageous in scenarios where the usage patterns are unpredictable or vary significantly from one database to another. Here, the pooled resources help ensure that all databases can maintain high performance without the risk of over-provisioning resources for individual databases that may not be consistently active. This approach also simplifies management and cost considerations, as the pricing model is based on the resources utilized rather than a fixed allocation for each database. Consequently, it supports cost efficiency while ensuring that performance and availability requirements are met, thus effectively adhering to the desired SLA. In contrast, maintaining all 20 databases on a single Azure SQL server in an availability set would not provide the level of granular resource management and performance optimization that elastic pools offer, particularly with diverse utilization patterns. Serverless instances are designed for