What is it?
Spot servers in Spinup allow users to take advantage of unused spot capacity in AWS, which can save up to 70% on the cost of a server. There are some limitations when compared to regular servers.
For example, you can’t pick a specific instance type (such as m5.large) but just approximate size (e.g. small or large) and you will get assigned one based on availability. Also, there’s no way to estimate the hourly/monthly cost as it varies based on demand, but once the server is up and running you will be able to see a summary of the incurred costs and realized savings.
Currently, another limitation is that you are not able to power off Spot servers, change their size, or create images. There is a chance that a running Spot server will be preemptively shut down by AWS if demand increases. If that happens, your server should quickly come back up on a different instance but with the same IP address, preserving any files you had on the file system.
There is no way to increase the initial disk size of a Spot server, add additional disks, or take disk snapshots. We expect these limitations to eventually go away.
Some good use cases may include short-lived servers, dev/test environments, or anything that doesn’t require any of the above listed limitations.
How does it work?
Spinup Spot servers are based on AWS Spot Instances. We use Spot by NetApp (previously SpotInst) to schedule the spot reservation and manage instance failures, persistent IP addresses and persistent disk volumes.
How do I use it?
From your Spinup space create a new server as usual (in this case I’ve picked CentOS 8 but Spot should work with all OS flavors). You should see a Spot checkbox in the upper-right corner - clicking that will display the available spot sizes.
Selecting a size (in this case spot-micro) will show the specific instance types for that size. The Spot service will try to allocate an available instance in the listed order - so it will first try to create a t3a.micro - if one is not available it will try t3.micro, and lastly t2.micro.
As mentioned before, we cannot provide a cost estimate, but the cost will never exceed the cost of a regular instance (so in this case you can use the cost of a t3.micro as an estimate for worst-case scenario). In 99.9% of cases, the actual price for spot will be much lower. You can see details about the incurred costs and savings once the server is running.
Building the server should take the same amount of time as a regular server. In the space list it will have a special icon in the Details field so you can easily distinguish Spot servers.
From the server view you can see more information about the costs incurred by your Spot server and the savings compared to paying list price. In the Size field you can see that we got a t3a.micro instance. Also note that you are not able to Shut down, Resize, or Create image from Spot servers.
Note: Do not shut down a Spot server from the command line (e.g. shutdown -h now). Doing that will cause it to automatically get re-created on a new instance.