Availability of Spot-Instances

Hi Robin,

Please find answers to your query below:

I would like to know if there is a way to estimate when a Spot-Instance will be available again after it has been evicted?

After a Spot VM is evicted, there’s no guaranteed time for when capacity will return because it's based on dynamic factors like other customers’ usage of the same VM SKU in that region and Azure’s internal capacity planning for reserved workloads.

However you can try to Start the VM once it's deallocated (or deleted) and if it's successfully started (or created) then that would mean that the capacity is restored for that moment.

does Azure provide historical data that shows typical patterns for Spot Instance availability and eviction cycles?

Yes Azure does provide the historical data for each VM Size available for Spot instance.

You can find them via below options:

1. You can refer Price History and Eviction rate in Size recommendation option while selecting the VM Size while creating it from Azure Portal.
   

To know more, please refer to the 15th point in the documentation: https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/spot-vm-size-recommendation#azure-portal

1. You can also access relevant Spot VM SKU data through Azure Resource Graph. Get pricing history in the last 90 days and eviction rates for the last 28 trailing days to identify SKUs that better meet your specific needs. Spot pricing history and eviction rates data are available in the SpotResources table. Spot eviction rates sample query:

      SpotResources 
      | where type =~ 'microsoft.compute/skuspotevictionrate/location' 
      | where sku.name in~ ('standard_d2s_v4', 'standard_d4s_v4') 
      | where location in~ ('eastus', 'southcentralus') 
      | project skuName = tostring(sku.name), location, spotEvictionRate = tostring(properties.evictionRate) 
      | order by skuName asc, location asc
   

   For more details, please refer: https://learn.microsoft.com/en-us/azure/virtual-machines/spot-vms?wt.mc_id=searchAPI_azureportal_inproduct_rmskilling&sessionId=7dfb5e3e48084ee8a87445cbed4a0146#azure-resource-graph