Windows to Unix Migration

Partners HealthCare, located in Boston, Massachusetts, is the largest integrated healthcare network in the northeast United States. In addition to its two major urban academic medical centers, the Partners HealthCare System also includes community hospitals, specialty hospitals, community health centers and physician networks. Partners HealthCare delivers on its promise for high performance medicine, increased patient safety and reducing medical errors, improving efficiency and coordinating care for patients by leveraging a high performance integrated healthcare IT platform based on InterSystems Caché.

This Caché-based healthcare network, running on a Microsoft Windows platform, services over 8,000 concurrent users daily. Approximately 55,000 users access Caché-based information on a 24 X 7 basis. Within the Partners environment Caché handles 26 billion database accesses per day on average, with peaks of more than 30 billion per day.

In the spring of 2007 Partners embarked on an aggressive project to migrate the Caché platform off of Windows and on to a more stable UNIX environment. The migration effort was necessitated by the business need to increase stability, performance and capacity. The Windows client-server based production platform includes 5 database servers, over 60 application servers, 3.5 terabytes of production data and 120 Caché developers working in the environment. The Partners UNIX migration effort is currently at the end of its Phase 1 database tier migration.

This presentation will give an overview of the migration strategy employed, discuss some of the many problems faced, and review some of the lessons learned to date. Metrics will be presented comparing application and general platform performance results before and after migration of the database tier. Discussion will also focus around some of the surprising results uncovered not only with the new UNIX platform but also with respect to the legacy Windows environment.