In one embodiment, a node in a computer network joins a global ring associated with a distributed hash table (DHT), and maintains a DHT routing table and DHT database for the global ring. In addition, the node may determine a particular service class for which the node is configured, and may join a particular service-based sub-ring according to the particular service class, where all nodes of the particular service-based sub-ring are within the global ring. As such, a service-based DHT routing table and service-based DHT database may be maintained for the particular service-based sub-ring, such that DHT operations identified by the particular service class are routed to the particular service-based sub-ring (e.g., by a portal node).