Issue No. 07 - July (1996 vol. 7)
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/71.508252
<p><b>Abstract</b>—We rigorously analyze load sharing (LS) in a distributed real-time system, called HARTS (Hexagonal Architecture for Real-Time Systems), while considering LS-related communication activities, such as task transfers and state-change broadcasts.</p><p>First, we give an overview of the general distributed real-time LS approach described in [<ref rid="bibl07241" type="bib">1</ref>], [<ref rid="bibl07242" type="bib">2</ref>], and then adapt it to HARTS by exploiting the topological properties of HARTS. Second, we model task arrival/completion/transfer activities in HARTS as a continuous-time Markov chain from which we derive the distribution of queue length and the rate of generating LS-related traffic—task transfer-out rate and state-region change broadcast rate. Third, we derive the distribution of packet delivery time as a function of LS-related traffic rates by characterizing the hexagonal mesh topology and the virtual cut-through capability of HARTS. Finally, we derive the distribution of task waiting time (the time a task is queued for execution plus the time it would spend if the task is to be transferred), from which the probability of a task failing to complete in time, called the <it>probability of dynamic failure</it>, can be computed.</p><p>The results obtained from our analytic models are verified through event-driven simulations, and can be used to study the effects of varying various design parameters on the performance of LS while considering the details of LS-related communication activities.</p>
Dynamic failure, distributed real-time systems, wrapped hexagonal mesh, virtual cut-through, point-to-point broadcasts, adaptive load sharing, queuing models, performance analysis.
K. G. Shin and C. Hou, "Evaluation of Load Sharing in HARTS with Consideration of Its Communication Activities," in IEEE Transactions on Parallel & Distributed Systems, vol. 7, no. , pp. 724-739, 1996.