Scheduler hierarchies to aid peta-scale cloud simulations with DISSECT-CF

IaaS cloud simulators are frequently used for evaluating new scheduling practices. Unfortunately, most of these simulators scarcely allow the evaluation of larger-scale cloud infrastructures (i.e., with physical machine counts over a few thousand). Thus, they are seldom applicable for evaluating infrastructures available in commercial cloud settings (e.g., users mostly do not wait for simulations to complete in such settings). DISSECT-CF was shown to be better scaling than several other simulators, but peta-scale infrastructures with often millions of CPU cores were out of scope for DISSECT-CF as well. This paper reveals a hierarchical scheduler extension of DISSECT-CF that not only allows its users to evaluate peta-scale infrastructure behaviour, but also opens possibilities for analysing new multi-cloud scheduling techniques. The paper then analyses the performance of the extended simulator through large-scale synthetic workloads and compares its performance to DISSECT-CF's past behaviour. Based on the analysis, the paper concludes with recommended simulation setups that will allow the evaluation of new schedulers for peta-scale clouds in a timely fashion (e.g., within minutes)