Probability of eviction with max-price=-1

Question

Is it possible to get data on the eviction rates for machines with max-price=-1?

Answer 1

In Azure Virtual Machines, the concept of max-price = -1 is associated with Spot VMs (previously called Low-Priority VMs). Setting max-price = -1 means that the Spot VM will use the current market price for the VM size, and you are willing to pay up to the on-demand price. This ensures that your Spot VM will not be evicted due to pricing constraints but still may be evicted due to capacity.

Eviction rates for Spot VMs depend on two main factors:

1. Capacity Availability: Azure prioritizes availability for pay-as-you-go VMs, so Spot VMs may be evicted when there is insufficient capacity in the region or VM size.
2. Price Flexibility: While max-price = -1 ensures you're willing to pay the highest possible price (up to on-demand rates), capacity-based evictions can still occur.

Azure does not provide real-time or historical eviction rate data for Spot VMs. However, some resources can help you assess the likelihood of eviction:

1. Azure Spot Eviction Rates: Azure occasionally publishes indicative eviction rates for certain VM sizes and regions. This data provides general trends but is not guaranteed. You can find these through the Azure portal or documentation.
2. Region and Size Trends: Eviction rates tend to vary by region and VM size. For example, popular VM sizes in high-demand regions are more likely to face evictions.

WHat I recommend :

• Consider using pay-as-you-go VMs instead of Spot VMs.
• Use Spot VM Scale Sets to manage multiple instances dynamically, minimizing the impact of individual evictions.
• Use Azure Advisor to assess and monitor available VM options.