A Survey on Resource Management Solutions, Challenges, and Emerging Opportunities in Fog Computing

Fog computing positions computation and storage resources in close proximity to data sources, promising millisecond-scale responsiveness and data handling that the distant cloud cannot deliver. Over the past decade, researchers have proposed a constellation of mechanisms such as virtualisation, latency-aware service placement, predictive load balancing, rapid state migration, replica-centric fault tolerance, energyadaptive scaling, QoS orchestration, and locality-sensitive caching, where each addressing a slice of the management challenge. However, these contributions often operate in isolation, optimise a single metric, or assume benign network and energy conditions, leaving unanswered questions about cross-layer interactions and deployment realism. This survey consolidates the state-of-art studies into a coherent pipeline view of fog resource management, tracing how hardware evolves into an elastic, fault-resilient micro-cloud. The analysis distils convergent design patterns, exposes hidden assumptions, and highlights goals among layers. Building on these insights the paper identifies cross-cutting research opportunities such as device-centric observability, federated resource markets, on-device continual learning, sustainable operations, and jurisdiction-aware SLA management. These paradigms must be addressed before fog infrastructures can underpin safety-critical and continent-spanning services. By mapping current achievements to unresolved challenges, the survey offers researchers and practitioners a clear agenda for the next wave of fog innovation.