This study is intended to contribute for higher availability property of stateful singleton components with user sessions lasting significantly long duration. As availability tactic, the study focuses on replication. Management of state synchronization of long lasting stateful user sessions during switch-over is among the main challenges of this study. The main goals of this book project are: 1. Scientific contribution for distributed fault-tolerant computing with respect to singleton component replication which handles many stateful parallel connections. To attain this goal, the project will need to design strategies via using scientific methodologies and document the outcomes by writing well written formal report. 2. Advance the design strategies of the first goal to improve the availability of singleton components via designing and evaluating a prototype. The following are the functionalities which are currently envisioned: · Synchronize stateful connection session data to replica singleton component · Synchronize parallel connection sessions, and · Synchronize processed cache of physical memory.