Large(ish) Deployment

[Gabriel Marais]

Good morning,

I was wondering if there is anyone that would offer their 
comments/tips/experience with deploying Unbound on a large(ish) scale.

We are looking at moving away from dnsmasq to something more 
"structured" in order to achieve the following :-

1. Service around 20 000 devices with DNS Caching services
2. Have a more structured deployment: having a few dns edges caches 
linked to master caches which will be using Root servers for lookups
3. DNS Stats - which we currently do not have on dnsmasq


We are planning to have a few edge caches & masters running in a 
containerized environment (Ubuntu with LXD) behind a load balancer to 
provide the service.


My questions are:-

1. How many edge caches & masters would be required to service around 20 
000 devices?
2. Which Distro are you using? Are there any advantages using something 
like freeBSD over Ubuntu?
3. Is it advisable to have the standard out-the-box implementation of 
Unbound and deploy more containers in order to meet the desired 20 000 
devices or is it advised to change the configs/kernel parameters in 
order to make available more sockets and less containers?


Regards

Gabriel