Switching between a Vps/Dedi to a Cloud service (Like AWS/Google)

Question

Im planning to host my app on a vps or a dedi but at the same time i want some security if there is downtime with the vps. is there a way i can host the app on the dedi and whenever there is any outage of any sort with the dedi the cloud takes over and there is no outage.

Answer 1

You can have your app hosted by any number of providers. "No outage" is a difficult task without a highly available load balancer. And gets expensive quicly. With cloud deployments, you can take advantage of minor outage scenarios where you may have an outage, but back online with click of a few buttons.

No Outage Config

You would need at least two load balancers in a DNS Round-Robin configuration.

VPS Server (Cloud at cost) - HAProxy / NGINX - load balancing between all known application members - Application process - Apache, Node.js, pyton, ruby, etc..

Dedicated Cloud (Google Computer, AWS, Azure) - HAProxy / NGINX - load balancer between all known application members - Application process - Apahce, Node.js, python, ruby, etc...

Minor Outage Config

If you wanted a minor outage scenario. - Place application code onto EC2 or other cloud storage - Sync application storage to EC2 or other cloud storage (cron.hourly script to dump mysql) - Script the install of your application from a base Linux/Windows image

With the above configuration, you would just need to 'spin up' the server on any cloud provider, install your app via script (few minutes) and restore the application data (few more minutes depending on volume). Then just change your DNS entry. (Ensure you have a small TTL <= 5 mins)

Answer 2

It looks like you want what they call "cloud VPS" - a virtual machine that is backed by a high-availability system, making them more resilient to hardware outages. Look for VMs backed not simply by OpenVZ/KVM/Xen (sadly, many of those will be falsely advertized as "cloud"), but those backed by a system of shared storage so that in case the physical machine that your VM is running on crashes, the worst case is that it reboots soon afterwards on another physical machine, and best case you don't notice anything because it gets migrated live. For example, I've used such a service based on Cloudstack.