In order to efficiently utilize the resources of the HAEC server, the B06 group carries out runtime service consolidation. This process requires identifying, quantifying, and mitigating the effects of interference among services which compete for similar resources. We aim to classify services both according to their resource consumption characteristics and the temporal characteristics of their workload. Moreover, we investigate the time variations of workloads to determine the frequency of service consolidation. In addition to these tasks, we aim to extend the power consumption model we developed in Phase I to estimate the power consumption of optical interconnects. This is useful to measure the energy-proportionality of different adaptation strategies.

Role within the CRC 912

This project establishes collaboration with projects B01 (Aßmann), B02 (Baader), B03 (Baier), B04 (Härtig) and B05 (Lehner). The groups of projects B01 (Aßmann) and B06 (Schill/Dargie) develop in collaboration different types of protocols to support horizontal and vertical contract negotiations. Moreover, the two collaborate to support runtime adaptation and dynamic software reconfiguration. The project will be responsible to compute the optimal runtime adaptation strategy based on global knowledge of service execution, but requires knowledge of local software configuration to actually undertake adaptation. Project B01 (Aßmann) ensures that a given adaptation strategy is feasible and provides alternatives if it is not feasible. Context information is an essential input for the runtime adaptation and can be obtained from different sources in various forms (abstractions). Project B02 (Baader) provides a formal ontology language to describe contexts and reasoning services to recognize high-level348 B06 Energy-Aware Service Execution contexts. The sensoric interfaces provided by project B04 (Härtig) will be employed to gain access into lower-level information pertaining to the load of a system and the energy consumption of hardware resources. From project B05 (Lehner), context information is obtained as a partially processed low-level data that can be further processed by B06 (Schill/Dargie). All these sources enrich the service execution platform with context information that will be processed by triggers to reason about conditions that lead to adaptation. In return, project B06 (Schill/Dargie) provides projects B02 (Baader), B04 (Härtig) and B05 (Lehner) with requirements in the form of the type and quality of contexts that are required. Moreover, B06 (Schill/Dargie) provides runtime commands to B01 (Aßmann) and B04 (Härtig) to reconfigure software and hardware resources. The group of this project B06 (Schill/Dargie) collaborates with B03 (Baier) to formally analyze the long-term performance and energy consumption of adaptation behaviors.

Staff

Principal Investigators

• Prof. Dr. rer. nat. habil. Dr. h. c. Alexander Schill
• PD Dr.-Ing. habil. Waltenegus Dargie

PhD Students

• Mr. Markus Hähnel

former staff

• M. Sc. Frehiwot Melak Arega
• Dipl.-Inf. Christoph Möbius
• M. Sc. Kateryna Rybina