Failure Domain - Bryant McGill

# Failure Domain **Domain:** Reliability Engineering / Infrastructure **Doc Type:** Technical Concept Node **Maturity:** Developed ## Definition A **failure domain** is a set of components likely to lose function together because they share a dependency, location, control layer or disturbance. ## Governing Variable Failure-domain design governs blast radius: how much service one fault can remove. ## Material and Computational Manifestation A rack, power bus, coolant loop, network switch, software release, identity provider or geographic region can define a failure domain. Apparent redundancy is ineffective when supposedly independent paths converge on one hidden dependency. ## Relation to Governance Architecture allocates not only capability but consequence. [[wiki/Multiscale Stewardship|Multiscale Stewardship]] asks whether higher-order efficiency is destroying the diversity and local competence needed to prevent common-mode failure. ## Failure Modes The central failure is inaccurate boundary modeling: the system protects against the domain it documented while real dependencies cross it. Telemetry and post-incident evidence should revise the model rather than preserve a convenient diagram. ## Related Ontology [[wiki/Resilience|Resilience]] · [[wiki/Fault-Tolerant Computing|Fault-Tolerant Computing]] · [[wiki/Checkpointing|Checkpointing]] · [[wiki/Data Center|Data Center]] · [[wiki/Model Error|Model Error]]  ## American Infrastructure Route This entry is routed through [[collections/American Infrastructure|American Infrastructure]], the collection covering the physical and institutional construction of machine intelligence from the transistor to the town meeting, and across to [[collections/American|the American Collection]], which supplies the standard of conduct the same project is held to. The layer routers are [[wiki/Upstream Industrial Foundation|Upstream Industrial Foundation]], [[wiki/Electrical Supply and Reliability|Electrical Supply and Reliability]], [[wiki/Facilities and Thermal Management|Facilities and Thermal Management]], [[wiki/Rack and Cluster Integration|Rack and Cluster Integration]], [[wiki/Data Fabric and Storage|Data Fabric and Storage]], [[wiki/Compute and Accelerator Systems|Compute and Accelerator Systems]], [[wiki/Software and Orchestration|Software and Orchestration]], and [[wiki/Intelligence Delivery|Intelligence Delivery]]; the civic argument is carried by [[wiki/The American Buildout|The American Buildout]] and [[wiki/National Compute Capacity|National Compute Capacity]]. **Source articles:** [[articles/Vertically Integrating an AI Superpower from AI Factory to Citizen|Vertically Integrating an AI Superpower from AI Factory to Citizen]] · [[articles/The Gigawatt Is the New Measure of War|The Gigawatt Is the New Measure of War]]