Using spot instances

Overview of Spot Instances

Spot Instances allow access to preemptible VMs through an exchange-based mechanism by setting limit price bids. If your limit price is higher than the Market Price, then you will have access to the VMs. If the Market Price exceeds your limit price, you will be preempted with a 5 minute notification period.

This unique mechanism ensures that you have guaranteed access to compute when you want it. Similarly, it ensures you do not exceed a certain price. Every instance of the same type is always billed at the same price at any given time based on the the set of limit price bids.

Bids and Allocations

To create a Spot Instance, you must first create a bid. Bids persist until you cancel them and are for your chosen instance type, quantity, and limit price. When a Bid is successful in the market, it converts to an Allocation which means your instances will begin spinning up, access will be provided, and billing begins. Bids are all-or-nothing in that it will only convert to an Allocation if all quantities of instances will be successful in the market.

An Allocation can be either relinquished by you (which also cancels the bid), or can be preempted. When preempted, your bid remains and can be allocated again based on the market.

Placing a bid

On the Spot Market tab, click Place new bid to open the bidding modal. On this screen, you may select your instance type, bid name, limit price, and number of instances. Once submitted, if allocated immediately, an Allocation will appear and instances will begin provisioning. Bids will persist until canceled by the user.

Accessing your allocated Spot Instances

Connection details to your allocated Spot Instances can be found on the Instances tab. Note only the SSH keys that existed at time of creation will be added to the instance (i.e., adding new keys in Security will not automatically add to your spun-up instances).