Microsoft have announced the preview of Azure Spot Virtual Machines – to replace the current preview of Azure low-priority Virtual Machines, which will be retired January 1, 2020.
They’ve been around for several years, particularly prominent in the world of Amazon AWS. They provide access to unused resources within a cloud datacentre at a significant discount – but the resources can be recalled by the datacentre provider almost immediately. Microsoft use the term “evicted” and your VMs can be evicted in one of two scenarios:
*More on that shortly
If you subscribe to scheduled events, you’ll get a 30-second warning prior to a Spot machine being evicted.
The fact that Spot Virtual Machines can stop running with almost no notice clearly means the don’t make sense in every case, but there are certain scenarios where they can work very well such as:
Anything where one (or more) VMs suddenly going offline won’t cause a huge issue. Either a workload that can continue with reduced resources (albeit more slowly) and/or a workload that can simply pick up where it left off later on.
Pricing will be variable depending on the available capacity of your chosen VM in that Azure region, and the current prices will be available to see within the Azure portal – as per this screenshot from the Microsoft announcement:
Google say you can reach discounts of up to 80% while Amazon & Microsoft both claim up to 90%.
Absolutely yes – to a degree.
Spot virtual machines can be a great way of reducing virtual machine costs in the cloud (not just in Azure) when used in the right places. In so many areas, effective management of cloud requires a more intimate knowledge and understanding of what your business is doing with its technology stack – and effective use of Spot instances is another great example.
The deployment and management of Spot instances is, of course, the purview of another team – but working to ensure your cloud cost strategy is fully optimised is all ITAM!
As an initial step, I’d suggest:
Remember, while this is a new announcement from Microsoft, Spot virtual machines already exist with Amazon AWS while Google have “Preemptible VM Instances”.
Microsoft announcement – https://azure.microsoft.com/en-gb/blog/announcing-the-preview-of-azure-spot-virtual-machines/
Microsoft Spot FAQs – https://azure.microsoft.com/en-us/pricing/spot/