Issue link: https://resources.awscloud.com/i/1496544
In traditional on-premises environments, some performance tools are provided by the database itself, such as the EXPLAIN command and MySQL slow query log. Other performance monitoring tools run outside the database, and you can set up a system in the cloud to run these. But cloud vendors have been assiduously developing per‐ formance tools that run natively in the cloud, usually for no extra charge. You should definitely make use of what the vendor offers. Databases that are performing poorly on-premises won't magically start performing well just because you moved them to the cloud! But the move can be helpful in some cases, such as when your on- premises database environment didn't have the capability to support a demand from the application for a large number of IOPS. Handling high availability This task is critical nowadays, when people will abandon a website if it fails to load within two or three seconds. On-premises, this task requires the advance purchase of adequate processing power, plus the configuration of load balancers. In the cloud, you can choose autoscaling and configure your database to run in multiple zones. A multizone database can automatically fail over to another AZ if the first zone fails. Similarly, you can offer your data in multiple regions for both high availability and local storage. New Tasks for the DBA in the Cloud When you run your databases in a cloud environment, you encounter tasks that, in most cases, you never had to worry about in a datacenter. These tasks include a new orientation toward costs and tracking your database licenses in the cloud. Planning operational costs The fundamental calculations for total cost of ownership (TCO) and return on investment (ROI) change radically in the cloud. As men‐ tioned in "Provisioning" on page 14, you usually pay for particular instances and particular amounts of time in the cloud, instead of buying fixed infrastructure up front. However, you need to factor in many other things that are not directly related to databases. For instance, locating the database in regions closer to the users can reduce networking costs and perhaps even generate new business. 18 | Chapter 2: The Changing Role of the DBA in the Cloud