Best practice is to have everything(rrdcached, pollers, mysql, dns, etc) in one place. From there you can poll your devices.
- You need to use remote pollers if some devices are not reachable directly. (one reason can be NAT)
- There are some slow devices (normally very old switches) that needs a lot of time to be polled. If you’re doing 5 minutes polling (standard), make sure that’s possible. You can do some tweaks for some devices.
- DNS, make sure is very close to your LibreNMS servers.
- I would skip docker, you will need a lot of resources. It also depends if you have switches with 48 ports and a lot of other sensors or just servers with few metrics.
I’m currently polling close to 3k devices (mostly switches) with 6-7 pollers with a load of 20-30% per poller. Our devices are all over the world, from China, Europe, South Africa, US, Brazil and Mexico.
We did a small test, putting a remote polling in Miami and we discover that is slower than polling directly from Frankfurt (where our LibreNMS is located).
If you have other questions, i’m here to answer you 