Modernizing Legacy Application to AWS leveraging Citrix Virtual Apps (XenApp)
A large U.S. Government Agency required a turn-key solution to migrate its legacy mission-critical applications to the cloud. The target application was a legacy Windows-based client server application that had “fat-clients” deployed locally to hundreds of Windows workstations across the country. The agency needed a means to centralize the application, implement real-time capacity autoscaling, and provide cost-saving hardware consolidation. The legacy Windows client-server application migration required a quick turnaround to maintain the end user’s usability pattern.
Simple Technology Solutions (STS), under the Innovation Lab Program, conducted a technology assessment and identified the Citrix XenApp solution to migrate the legacy thick-client application with a web interface to the cloud on Amazon Web Services (AWS). STS engineers worked with the agency management team and implemented a Proof-of-Concept Citrix XenApp solution on a parallel stream in AWS and Google Cloud Platform (GCP). After the success of the initial Proof-of-Concept, STS engineers (with their stakeholders) scoped out a Citrix XenApp prototype in the AWS non-production environment as the next experiment. With prioritized objectives, STS engineers developed a high-level Citrix infrastructure design for a highly available, auto scalable infrastructure to support Personal Identity Verification (PIV) based Single Sign-on authentication facility within their portal application.
STS set up an AWS-based Citrix platform that could be streamlined without the need to manage agency hardware infrastructure in service centers across the nation. Citrix Virtual Workspace (XenApp) was identified as the best solution for their needs without requiring a major code change. The STS team worked quickly to setup the platform and streamline the process by leveraging Infrastructure as Code (IaC) scripting, architecture and security analysis, testing, and implementation. CHEF, a Continuous Automation software, automated the application configuration management. STS engineers planned and implemented the prototype design after a successful Proof-of-Concept deployment.
Citrix Virtual Workspace (XenApp) automates installations and updates on cloud-based servers to ensure high-performance, high-availability, and scalable solutions to meet and exceed performance expectations. With the XenApp automation, the agency’s end-users were able to launch applications remotely, conduct business operations, and run queries on the centralized AWS Relational Database Service (RDS) database. STS configured the full solution in a pre-production environment to automate the entire process. The team then migrated a Window client-based solution re-hosted in a Windows 2016 server to achieve backward compatibility with minimal disruption of service. STS successfully migrated a critical legacy client-server application that served thousands of users across multiple service centers into a centralized cloud based solution that meets or exceeds the required performance metrics for the application.