Advances in Large-scale Distributed, Real-time, & Embedded Systems

1. Advances in Large-scale Distributed, Real-time, & Embedded Systems Douglas C. Schmidt d.schmidt@vanderbilt.edu Professor of EECS Vanderbilt University Nashville, Tennessee

2. The Evolution of DRE Systems The Future • Network-centric & larger-scale • Stringent simultaneous quality of service (QoS) demands • e.g., availability, security, throughput, scalability • Part of larger systems • Dynamic context The Past • Stringent quality of service (QoS) demands • e.g., latency, jitter, footprint • Resourceconstrained

3. Evolution of DRE System Development BSE IOM BSE BSE IOM IOM IOM IOM IOM CLI IOM BSE BSE BSE IOM SM CM IOM IOM SS7 IP IOM IOM RX TX IOM BSE BSE BSE IOM IOM IOM RTOS IOM IOM Technology Problems DRE systems have historically tended to be: Stovepiped Proprietary Brittle & non-adaptive Expensive Vulnerable Air Frame Nav HUD AP FLIR GPS IFF Cyclic Exec • Historically, mission-critical DRE applications were built directly atop hardware • Tedious • Error-prone • Costly over lifecycles

4. Evolution of DRE System Development BSE IOM BSE BSE IOM IOM IOM IOM IOM IOM BSE BSE BSE IOM IOM IOM DRE Applications DRE Applications IOM IOM IOM BSE BSE BSE IOM Middleware Services Middleware Services IOM IOM IOM IOM Middleware Middleware Operating Sys & Protocols Operating Sys & Protocols Hardware & Networks Hardware & Networks Technology Problems DRE systems have historically tended to be: Stovepiped Proprietary Brittle & non-adaptive Expensive Vulnerable • Middleware has effectively factored out many reusable mechanisms & services from what was traditionally DRE application responsibility • Middleware is no longer primary DRE system performance bottleneck • Historically, mission-critical apps were built directly atop hardware • Tedious • Error-prone • Costly over lifecycles

5. DRE Systems: The Challenges Ahead CORBA Apps J2EE Apps .NET Apps CORBA Services J2EE Services .NET Services Load Balancer FT CORBA Workload & Replicas CORBA J2EE .NET Connections & priority bands RT/DP CORBA + DRTSJ RTOS + RT Java CPU & memory Network latency & bandwidth IntServ + Diffserv • There is a limit to how much application functionality can be factored into broadly reusable COTS middleware • System infrastructure has become extremely complicated to use, configure, & provision statically & dynamically • There are now multiple middleware technologies to choose from DRE Applications Middleware Services Middleware Operating Sys & Protocols Hardware & Networks

6. Promising Approach:Model DrivenMiddleware DRE Applications Middleware Services Middleware Operating Sys & Protocols Hardware & Networks Distributed system Solution approach: Integrate model-based software technologies with QoS-enabled component middleware • e.g., standard technologies are emerging that can: • Model • Analyze • Synthesize & optimize • Provision& deploy • multiple layers of QoS-enabled middleware & applications • These technologies are guided by patterns & implemented by component frameworks • Partial specialization is essential for inter-/intra-layer optimization <CONFIGURATION_PASS> <HOME> <…> <COMPONENT> <ID> <…></ID> <EVENT_SUPPLIER> <…events this component supplies…> </EVENT_SUPPLIER> </COMPONENT> </HOME> </CONFIGURATION_PASS> Goal is not to replace programmers per se – it is to provide higher-level domain-specific languages for middleware developers & users