Replacement of a spot instance about to be terminated by an on-demand instance

Question

According to AWS documentation, the termination of a SPOT instance is notified 2 minutes in advance. I would like to make sure my service keeps running, by replacing a SPOT instance that is notified to be deleted, by an on-demand instance.

Are there existing ways (either built-in AWS configuration or external tools) to automatically replace an EC2 SPOT instance by an on-demand instance when the SPOT instance is marked for termination?

E.J. Brennan E.J. Brennan · Accepted Answer · 2017-03-09T18:25:53

I don't think its possible to convert your running spot instance into an on-demand instance (if that is what you are asking), but if what you really meant is to spin-up a new ondemand instance, then generally you could do the following:

You should run a simple cron job on your instance that checks every 5 seconds for the termination notice, i.e.

#!/bin/bash
while true
    do
        if [ -z $(curl -Is http://169.254.169.254/latest/meta-data/spot/termination-time | head -1 | grep 404 | cut -d \  -f 2) ]
            then
                # Call your script to launch on-demand instance here.
                break
            else
                # Spot instance not yet marked for termination.
                sleep 5
        fi
    done

Replacement of a spot instance about to be terminated by an on-demand instance

3 Answers