Great progress! Seems that we are getting closer to pass the programm. Thanks @weynandkuijpers!
Overall that looks very good to me… I’d just like to comment on two things.
Here I would suggest to say that “…one or more specific farm(s) per location…” should be created. Multiple farms in one DC rack would give the opportunity for farmers to join together without having to share the same farm so rewards do not need to be splitt up between the co-farming partners. Since the specs will be defined against 3nodes it should be irrelevant whether or not they are based in only one farm or multiple farms. But of course Mixing of types of 3nodes in a single or multiple farm(s) running in one DC location should not be done.
I’ve been tripping over this since the topic was raised. I totaly agree that there should be maximum redundance as possible. But I’m unhappy with the definition of simply two routers per rack and I’m not sure what this is refering to in detail. I doubt that just having two routers would provide significantly more reliability to the setup. Let me try to explain my thougths on this: ISO 27001 (Tier 3 and higher) certification requires DCs to provide fail-safe internet connections respectively redundant networking infrastructure in general (as well as redundance/resiliency for any other technical aspect like power supply, cooling etc.). F. e. in our case the DC has two seperate feeds to the building connected to different backbones. The fail-safe networking infrastructure happens on multiple levels before even reaching the rack. With this in mind a second router would not give additional reliability except failover backup in case of hardware failures of the router(s) itself. If this is the only reason why a secound router should be used I’m fine with that. Also I think it would be much more efficient to think of precautions in order to reduce downtime in case of router hardware failure than providing a high availabilty router cluster (if thats what two routers per rack refer to). But even if we do so, when you think this through, the setup is still left with single-point-of-failure source(s): the switche(s). In order to overcome this problem it would be neccessary to also provide two switches (for LAN and physical public IP network each) and use link aggregation on the 3nodes to bundle NIC ports and connect those to separate switches. This would require corresponding network configurations on 3nodes and I doubt that this is already implemented in z-os. But that’s another story.
As far as I know the common way to setup a high availabilty router/firewall cluster with automatic and seamless failover would be using CARP (Common Address Redundancy Protocol). When using two separate internet connections (two different ISP) this comes with a highly ineffient way of how bandwith would be used. Since CARP uses one router as master and the second one as backup the seperate uplinks could not be used together (in compare to when using load balanced dual WAN f. e.). Apart from not every DC provides cross-connecting services for ISP uplinks from thrid parties. So this would only be bandwith efficient when both routers use the same WAN side uplink (maybe with a second gateway) but this would leave the switch/router/gateway on WAN side as a single-point-of-failure too.

So… I’d love to know how a setup of two routers should be configured in order to increase availabilty/resiliency. I think that it’s also important that the router hardware itself is reliable. We use a Dell R620 with redunant power supply units, dual CPU and raid-controller with a RAID-1 LUN on enterprise SSDs as router hardware with OPNsense as OS installed (I know this is absolutly oversized). We have an identical server ready (installed and patched) that we can use as backup. For now we would have to do this manualy but can be done in minutes. If required by gold certified framing specs we could set them both up as a high availabilty cluster if thats what will be required.
As I’m not on expert I may be overcomplicating this. Would be great if we could define the requirement of having two routers or two ISPs in more detail. What do you think?