My previous blog post talked about reducing Azure costs using Reserved Instances and Azure Hybrid Use Rights. Using this strategy, Azure VM Costs can be reduced by up to 64%.
However, there are other Azure cost reduction strategies that can be based on the type of virtual machine deployed. Specifically, Burstable and Spot Instances. I will also discuss an older cost reduction strategy that no longer is appealing—basic instances.
Early in Azure, the only cost reduction method available was to use Basic machine types instead of standard machine types that are now common. Using a primary machine type reduces cost by about 18%, but severely limits some performance of the machine. Additionally, only very limited machine types are supported, and new standard machine types are available that perform much better at a reduced cost. If you are using Basic machine types, you should convert to standard machines in one of the new version types to get better performance at a lower price.
Burstable VMs are the particular machine types that are available as standard types and are designed for workloads that typically have very low CPU usage. Examples include low usage web servers, small usage databases, and other workloads that only occasionally use CPU. The cost savings compared to standard servers is about 15%, and they can be used with both Azure Hybrid Use and Reserved instances. When a Burstable VM is running, it will accrue CPU credits that can be spent on CPU bursts.
Spot Instances are a recent addition. A Spot Instance runs when Azure has capacity and must be able to be shut down from time to time. You can set up the machine so that it runs so long as there is capacity and only shuts down when Azure needs the capacity or set the machine to turn off if the spot pricing gets above a specific value. The price paid is the sum of the hours run times the Spot price of the machine when running. This is ideal for batch workloads where cost minimization is essential, but availability is not. Spot Instances cannot be Burstable and cannot be combined with Reserved Instances.
Have any questions about these Azure cost reduction strategies? Please contact us at any time.