Scalable failure recovery for high-performance data aggregation

Many high-performance tools, applications and infrastructures, such as Paradyn, STAT, TAU, Ganglia, SuperMon, Astrolabe, Borealis, and MRNet, use data aggregation to synthesize large data sets and reduce data volumes while retaining relevant information content. Hierarchical or tree-based overlay networks (TBONs) are often used to execute data aggregation operations in a scalable, piecewise fashion. In this paper, we present state compensation, a scalable failure recovery model for high-bandwidth, low-latency TBON computations. By leveraging inherently redundant state information found in many TBON computations, state compensation avoids explicit state replication (for example, process checkpoints and message logging) and incurs no overhead in the absence of failures. Further, when failures do occur, state compensation uses a weak data consistency model and localized protocols that allow processes to recover from failures independently and responsively. Based on a formal specification of our data aggregation model, we have validated state compensation and identified its assumptions and limitations: state compensation requires that data aggregation operations be associative, commutative and idempotent. In this paper, we describe the fundamental state compensation concepts and a prototype implementation integrated into the MRNet TBON infrastructure. Our experiments with this framework suggest that for TBONs supporting up to millions of application processes, state compensation can yield millisecond recovery latencies and inconsequential application perturbation.