Hai Dinh-Tuan

Hai Dinh-Tuan

Open-source 5G core implementations deploy network functions as always-on processes that consume resources even when idle. This inefficiency is most acute in private and edge deployments with sporadic traffic. Serverless5GC is an architecture that maps each 3GPP control-plane procedure to an independent Function-as-a-Service invocation, allowing scale-to-zero operation without modifying the standard N2 interface. The system decomposes 12~network functions (Release~15-17) into 31~serverless procedures, fronted by an SCTP/NGAP proxy that bridges unmodified RAN equipment to an HTTP-based serverless backend. Evaluation against Open5GS and free5GC across five traffic scenarios (idle to 20~registrations/s burst) shows that Serverless5GC achieves median registration latency of 406-522ms, on par with the C-based Open5GS baseline (403-606ms), while maintaining 100% success across 3,000 registrations. A resource-time cost model shows that the serverless deployment (0.002GB-seconds per registration) is cheaper than the always-on baseline when the cluster operates below a 0.65 duty cycle, when two or more tenants share the platform, or on managed FaaS platforms up to 609reg/s. Under worst-case cold-start conditions where all 31 function pods are evicted simultaneously, the system sustains zero failures and converges to warm-start latency within 4-5 seconds.

Hai Dinh-Tuan

Migrating stateful microservices in Kubernetes requires careful state management because in-memory state is lost when a container restarts. For StatefulSet-managed workloads, the problem is compounded by identity constraints that prohibit two pods with the same ordinal from running simultaneously, forcing a sequential stop-recreate cycle with a median 38.5s of service downtime. This paper presents SHADOW Seamless Handoff And Zero-Downtime Orchestrated Workload Migration, a Kubernetes-native framework that implements the Message-based Stateful Microservice Migration (MS2M) approach as a Kubernetes Operator. SHADOW introduces the ShadowPod strategy, where a shadow pod is created from a CRIU checkpoint image on the target node while the source pod continues serving traffic, allowing concurrent operation during message replay. For StatefulSet workloads, an identity swap procedure with the ExchangeFence mechanism re-checkpoints the shadow pod, creates a StatefulSet-owned replacement, and drains both message queues to guarantee zero message loss during the handoff. An evaluation on a bare-metal Kubernetes cluster with 280 migration runs across four configurations and seven message rates (10--120msg/s) shows that, compared to the sequential baseline on the same StatefulSet workload, the ShadowPod strategy reduces the restore phase by up to 92%, eliminates service downtime entirely, and reduces total migration time by up to 77%, with zero message loss across all 280 runs.

Hai Dinh-Tuan, Felix Beierle, Sandro Rodriguez Garzon

In recent decades, it has become a significant tendency for industrial manufacturers to adopt decentralization as a new manufacturing paradigm. This enables more efficient operations and facilitates the shift from mass to customized production. At the same time, advances in data analytics give more insights into the production lines, thus improving its overall productivity. The primary objective of this paper is to apply a decentralized architecture to address new challenges in industrial analytics. The main contributions of this work are therefore two-fold: (1) an assessment of the microservices' feasibility in industrial environments, and (2) a microservices-based architecture for industrial data analytics. Also, a prototype has been developed, analyzed, and evaluated, to provide further practical insights. Initial evaluation results of this prototype underpin the adoption of microservices in industrial analytics with less than 20ms end-to-end processing latency for predicting movement paths for 100 autonomous robots on a commodity hardware server. However, it also identifies several drawbacks of the approach, which is, among others, the complexity in structure, leading to higher resource consumption.