P.C. Rossin College of Engineering and Applied Science RESEARCH C O M P U T E R S C I E N C E & E N G I N E E R I N G C O M P U T E R S C I E N C E & E N G I N E E R I N G Middleware for Adaptive Applications Across Heterogeneous Environments and Systems Qiang Wang, Prof. Liang Cheng Awareness types Awareness Measurement what to measureHow to measure Network awarenessLink capacity, available bandwidth, latency, jitter.Active probing tools Device awarenessCPU/memory usage, display size/refresh rate, batteryOperating System APIs User awarenessA user’s service expectationsGraphic User Interfaces Application awarenessInternal states a applicationsExport to a shared space Environ. AwarenessPhysical and environmental dataWireless sensor networks Today's computing environments are dynamic, heterogeneous, and best-effort. An application’s Quality of Service may degrade significantly or become even unacceptable when resources are changed, especially for mobile applications. Adaptive applications can adapt to the dynamic nature of the network and system resources based on current, historical, and/or expected information. Adaptive applications are notoriously difficult to develop. Ad-hoc solutions suffer from code tangling, programming complexity and poor code reusability. MARCHES project investigates an open source middleware (AwareWare) for adaptive applications. Awareness Acquisition FEAT (Fish Eye Available-bandwidth Tool) : a new end-to-end available-bandwidth measurement tool.  Actively probe the network to create self-induced congestion.  A new dynamic pattern of probing packets: Fisheye Stream.  Based on historical information, use more probing packets in a most profitable range.  Create a more sharp turn at the turning point.  Generate accurate available bandwidth estimation. AwareWare architecture overview Motivations Awareness Data Management  System independent query and notification interfaces  A hybrid architecture with flexible consistency controls to improve the performance of mobile applications  Feedback control loop to awareness data measurement tools  Pulling method  Pushing method Dynamic Reconfiguration Dynamic reconfiguration for C/C++ DLL components CORBA components Wireless Sensor Networks  Separation of component construction and composition  Applications = components “wired” together  Adaptation = run time reconfiguration of components Adaptation Reconfiguration Reconfiguration Example  Desktop sharing and live video applications  Measure bandwidth information  Decide whether or not use the compression  Dynamically reconfiguration  Improved QoS of video delivery Wireless Sensor Network reconfiguration  Reconfiguration by replacing the whole executable image inside each sensor nodes  Over the air broadcast  Limited resources on sensors  Broadcast storm in a densely deployed WSN Reconfiguration in progress for a 20X20 WSN time WSN Reconfiguration system Insider view of the reconfiguration Component reconfiguration mechanism Performance comparisons