Aug 2026· Proceedings of the ACM SIGCOMM 2026 Conference· 0 citations· 65 references
TL;DR
STORM is presented, a NIC-level scheduler for all types of RDMA workloads using NIC-only information: the known RDMA request size, and per-queue-pair backlog, and converts these signals into a small number of extra priority levels on the wire and prioritizes requests that are either near completion or blocking queued dependent work.
Abstract
Remote Direct Memory Access (RDMA) is increasingly used as a shared communication substrate across datacenter workloads with very different scheduling needs, from request-response services and storage fan-out to AI training collectives. Proper request scheduling can reduce communication time, but in practice, no RDMA flow scheduling is enabled in datacenters, leaving traffic to simple fair sharing. We present STORM, a NIC-level scheduler for all types of RDMA workloads using NIC-only information: the known RDMA request size, and per-queue-pair backlog. STORM converts these signals into a small number of extra priority levels on the wire and prioritizes requests that are either near completion or blocking queued dependent work. STORM requires no application hints and works with both in-order RoCEv2 and newer RDMA stacks that tolerate reordering. We prototype STORM on an FPGA NIC with negligible overhead. Across representative cloud and LLM training workloads, STORM reduces training iteration time by up to 12% and reduces average and P99 flow completion slowdown by up to 90% compared to fair scheduling.
Evaluation on representative workloads demonstrates that P2CS achieves performance comparable to in-network mechanisms while significantly reducing complexity and cost, and requires minimal software changes making it readily deployable in today's datacenter infrastructure.
Ali Munir, Xiaolin Pang, Junyi Zhang· Proceedings of the ACM SIGCO...· 0 citations
To achieve high-throughput and low-latency Remote Direct Memory Access (RDMA) communication in data center networks, load balancing is critical for preventing congestion and ensuring that traffic is efficiently distributed across available network paths. However, existing schemes may not effectively detect rerouting opportunities in continuous RDMA packet streams and may degrade in-order delivery, limiting their applicability to RDMA traffic. To address these limitations, we propose ProLet, a load balancing scheme that enables proactive probing and reroutes elephant flows at flowlet granularity in lossless RDMA networks. ProLet dynamically fine-tunes per-destination top-of-rack timeouts and enables effective in-network flowlet identification based on real-time network conditions. Meanwhile, it leverages lightweight mice flows as proactive probes to maintain network-wide congestion awareness. This allows ProLet to reroute elephant flows before congestion accumulates, mitigating the persistent queue buildup inherent in subflow-based schemes. Extensive numerical evaluations demonstrate that ProLet reduces average and tail flow completion time slowdowns by 69% and 79%, respectively, compared to state-of-the-art load balancing schemes.
Hong Wang, Jinhao Luo, J. Tan et al.· Asia-Pacific Workshop on Net...· 0 citations
Results show up to 2.3x lower remote-access overhead compared to TCP-based designs, a 13% increase in cluster-wide memory utilization at rack scale, and up to 63% reduction in miss rate for memory-constrained tenants under skewed workloads.
A queueing network (QN) model of the rebalance process of the process used in MongoDB is developed, and a preliminary evaluation of performance prediction by the QN model via simulations is described, to understand the impact of different parameters of the rebalance process.
G. Paterakis, E. Ntallaris, K. Magoutis et al.· International Symposium on C...· 0 citations
Modern distributed AI workloads run across hundreds of accelerators, making communication a major bottleneck. Existing communication libraries remain largely buffer-centric because user and communication buffers are managed separately, causing redundant data copies or costly user-buffer registration. This paper presents StrataCL, a zero-redundancy and fabric-native communication library for production supernodes. StrataCL introduces registration-on-allocation to realize user-buffer direct communication, and designs communication operators with workload-balanced NPU-core partitioning and NPU-driven SDMA offloading to exploit supernode architecture features. On the Huawei CloudMatrix384, StrataCL improves collective bus bandwidth by up to 1.6x and improves MoE dispatch/combine bus bandwidth by up to 1.4x. Across three production workloads, StrataCL improves LLM inference throughput by 1.9x, reduces P99 TTFT by 2.2x, and reduces LLM and Recsys training iteration time by 1.4x and 1.3x, respectively.
Tiancheng Hu, Jin Qin, Yuzheng Wang et al.· 0 citations