I would argue a bit on this. This upcoming official Docker image (in which we could apply different config file to get it became a privileged, unprivileged Relay node or a Core node etc.) just provides an easily configurable and standardized platform to run Cardano nodes as services. But, to protect the privileged nodes the Core nodes which are the only delegates in the Cardano network is crucial.
In my understanding, an Ada Pool can have
- one and only one (stateful) Core node which should or must be hidden and protected, and
- any number of (stateless) privileged (can only communicate to the core nodes and unprivileged nodes) and
- unprivileged Relay nodes (communicate only w/ the privileged nodes and edge nodes) which can be attacked and destroyed any time.
So, relay nodes are the easy examples of using the Docker images in some Docker clustering solutions (Kubernetes or Docker Swarm etc.), but the core must be protected. Means does not matter if any relay node is down we can easily bring up as many relay nodes as we need, but when the core is down, that pool is down and then we are losing money. That’s why the Core nodes are not really affected by DDoS from the outside of the world as they’re hidden and DDoS-ing relays does not really matter.
In addition, as only a Core node can be a delegate (AFAIK currently only ~20 exists, hidden behind a few relay nodes that are managed by IOHK), despite any Daedalous wallet (edge node) can be a slot leader, therefore it’s crucial that the Core must be up when it’s required (at Coin tossing time and at block generation time etc.).
Anyway, as I mentioned it before, the architecture of a pool is one and only one Core node w/ several privileged relay nodes that can communicate w/ that the core. Therefore similar statements that guarantee 99.999% or even I saw 100% uptime is a bit misleading as the pool will be online only when the Core is up because relays are just acting as proxies and a pool only have one Core node which is a SPOF from the Pool’s point of view.
However, AFAIK, a Core must only be available when its required for Coin tossing and block generating, so as an example: statistically, a pool can be up 100% (means it was up when it’s required) despite it was physically up only 97%.
Anyway, I do not know what are the monopoly incentives of having relay nodes and how the rewards and fees can be or are adjusted (as it has operational cost to maintain cores and the optional unprivileged/privileged nodes) as I did not find anything in the source code.