<p>Google has an offer called preemptible VMs which are VMs that do not guarantee to be available all the time and which are shut down once every 24 hours.</p>

<p>Our goal is to deploy a failsave (to a certain degree) kubernetes cluster with those VM by having enough backup VMs to handle the case that one VM is shutdown. <a href="https://medium.com/pixboost/save-cash-by-running-kubernetes-services-on-preemptible-vms-in-google-cloud-cca02809ae09" rel="nofollow noreferrer">This</a> article describe a simple scenario where preemptible VMs are used to run an image service. This scenario is simple because there is no database or message broker involved running on preemptible VMs.</p>

<p>Is it possible to run a whole (microservice-based) application including databases and message brokers with only preemptible VMs?</p>

<p>Further Questions that we have:</p>

<ol>
<li>When do the preemptible VMs get shut down usually? Is it usually the case that if one VM gets shut down, all the other are too (at the same time)?</li>
<li>How log is the downtime of a preemptible VM getting restarted?</li>
</ol>

<p>Any guidance that helps answering those questions and/or helping us configure such a cluster is apprechiated.</p>

user2074945
<p>Regarding your questions: </p>

<p><em>1.-When do the preemptible VMs get shut down usually? Is it usually the case that if one VM gets shut down, all the other are too (at the same time)?</em></p>

<p><strong>A</strong>:The lifetime for preemptible VMs is no more than 24 hours, they can be shutdown whenever Google need the resources between this lifetime, find more information about limitations <a href="https://cloud.google.com/compute/docs/instances/preemptible#limitations" rel="nofollow noreferrer">here</a>. Resetting the counter means that you manually stop and start the instances, however keep in mind that the <a href="https://cloud.google.com/compute/docs/instances/preemptible#preemption_selection" rel="nofollow noreferrer">selection</a> will preempt instances that were recently launched most recently.</p>

<p><em>2.-How log is the downtime of a preemptible VM getting restarted?</em></p>

<p><strong>A</strong>: If you mean where you can see the logs of Compute Engine that notices you when an instance was terminated, you can use Stackdriver Logging. </p>
