Authors: Ariane Solis
Abstract: The ongoing reliance on legacy UNIX systems such as Solaris, AIX, and HP-UX in mission-critical enterprise environments poses significant challenges to maintaining high availability (HA) as these platforms age. Traditional HA clustering techniques—rooted in physical infrastructure, proprietary clustering software, and tightly coupled storage systems—struggle to adapt to the elasticity, fault tolerance, and operational flexibility offered by cloud environments like Amazon Web Services (AWS). This review explores the architectural shift from legacy on-premises HA clusters to AWS-based and hybrid high availability designs for UNIX workloads. It evaluates key AWS services such as EC2, Elastic Load Balancer (ELB), CloudWatch, Auto Scaling, and Route 53 in building redundant and failover-capable environments tailored for UNIX applications. The paper highlights the challenges of migrating UNIX workloads to AWS, including hardware-bound licensing, kernel-level dependencies, shared storage constraints, and clustering heartbeat mechanisms. Strategies for bridging these limitations—through hybrid models, emulation platforms (e.g., Charon-SSP for Solaris and AIX), and containerized service proxies—are analyzed. Key components of AWS-native HA design are reviewed, including EC2 auto-recovery, cross-AZ EBS, elastic IP remapping, and application-aware health monitoring via CloudWatch and Lambda functions. Hybrid clustering configurations linking on-prem systems to AWS—emerge as transitional models, allowing legacy workloads to benefit from cloud-based failover and storage resiliency while maintaining control over core services. The review includes real-world case studies across finance, healthcare, and manufacturing that demonstrate the feasibility and impact of AWS-based HA clustering for UNIX systems. It concludes with a comparative analysis of traditional versus cloud-based HA architectures, along with future directions involving serverless orchestration and AI-driven failover decision-making. Overall, the review provides a structured roadmap for IT architects seeking to modernize legacy UNIX platforms with the resilience and scalability of AWS.
DOI: https://doi.org/10.5281/zenodo.15803836
