Logical Node Boundary
Discussion
Logical Node Boundary identifies what the Logical Architecture treats as inside or outside a Logical Node for purposes of responsibility, interaction, traceability, and review.
A Logical Node Boundary separates the Logical Node from other Logical Nodes, external participants, Communication Endpoints, and implementation artifacts. It helps reviewers understand which responsibilities belong to the Logical Node and which interactions cross the Node boundary.
Logical Node Boundary does not imply a process, network, security, container, machine, or organizational boundary. Implementation and deployment profiles align those boundaries when alignment supports the selected realization. They may also realize several Logical Nodes within a single runtime artifact, or realize a single Logical Node across multiple runtime artifacts, when the implementation or deployment design requires that structure.
Definition
Logical separation identifying what the architecture treats as inside or outside a Logical Node.
Source
Specialization of Node, Communication Endpoint, and Traceability from Part 1, Sections 7.2, 7.6, and 7.10; informed by the distributed node material in the original FX Demo Reference Architecture.
Note
A Logical Node Boundary supports architectural reasoning. It does not prescribe deployment isolation.
Example
A logical policy evaluation Node has a boundary around policy evaluation responsibility, even when a later implementation packages the policy evaluation code with other services in the same process or container.