Node-RED runtime and external MQTT broker: Effect of disabling the built‑in editor on subscription persistence

Goal: Reduce the resource footprint of a Node‑RED instance handling low‑traffic IoT telemetry by disabling the built‑in editor while preserving reliable MQTT communication (QoS 1/2) to an external broker.

Uncertainty: Turning off the editor via httpAdminRoot: false removes the admin HTTP server, but it is unclear whether any internal services that MQTT nodes rely on—for example, flow redeployment, context‑store synchronization, or keep‑alive handling—depend on that server. Consequently, it is unknown if disabling the editor impacts the ability of MQTT nodes to maintain or restore subscriptions after a restart or during brief network interruptions.

Specific questions:

• Does setting httpAdminRoot: false prevent MQTT nodes from automatically re‑establishing QoS 1/2 subscriptions after a Node‑RED restart?
• Are persisted subscriptions affected when the admin interface is disabled, or do they behave identically to the editor‑enabled case?
• Is there a measurable difference in CPU or memory usage for an idle MQTT‑only flow when the editor is off versus on?