NNathanael FETUE·1d agoPairing a RoCE request with its ACK, and why the queue-pair number is not enoughAn RC packet carries only its destination QP, so a write and its ACK name different QPs. The key that pairs them in XDP, and the ACKs not to trust.4 min read·pegasus-nathanael-tech.hashnode.dev1
NNathanael FETUE·3d agoBusy polling or events ? Timing one RDMA write, and why perftest says halfBuilding AgentXDP, part 13. Part 12 gave the testbed four links. This part gives it a stopwatch. In part 6, 20 ms of ACK delay left every RDMA error counter at zero. A delay shows up in one place: how5 min read·pegasus-nathanael-tech.hashnode.dev23C
NNathanael FETUE·Nov 5Four rails on one VM: a multi-link RDMA testbed without losing SSHOne NIC per rail, four rails on one VM: computed names, a priority collision a test caught, and one slow link that sped the others up.5 min read·pegasus-nathanael-tech.hashnode.dev1
WWeiwei Zhang·Nov 41.6T Ethernet vs. InfiniBand: A Technical Guide to Next-Generation AI Network ArchitectureExplore 1.6T Ethernet vs. InfiniBand for AI networking. Learn about RoCEv2, RDMA, PFC, ECN, DCQCN, GPU communication, and optical connectivity.10 min read·aicplight.hashnode.dev
NNathanael FETUE·Nov 1Week 2: from a sensor to an agentA week turning one XDP sensor into an agent: what a host can really measure on RDMA, the parts it took, and what is still not proven.4 min read·pegasus-nathanael-tech.hashnode.dev2O
NNathanael FETUE·Oct 30Attaching XDP without leaving a trace: bpf_link, kill -9 and a signal mask nobody testsBuilding AgentXDP, part 9. Previous: part 8, a lock-free queue broken on purpose. Next: part 10, a metrics endpoint a slow client cannot stall. An observability agent must do no harm. If it crashes, o4 min read·pegasus-nathanael-tech.hashnode.dev
WWeiwei Zhang·Oct 13How InfiniBand XDR and 800G RoCE Handle Congestion in AI ClustersExplore how InfiniBand XDR and 800G RoCE manage network congestion in AI clusters. Learn how RDMA, PFC, ECN, and tail latency affect distributed training performance, scalability, and network design.6 min read·aicplight.hashnode.dev
NNathanael FETUE·Oct 7My RoCE testbed passed. It was lyingA RoCE testbed passed its test while no RDMA write completed. How bpftrace on kfree_skb found the firewall dropping every packet.6 min read·pegasus-nathanael-tech.hashnode.dev1N
WWeiwei Zhang·Aug 18RoCE Explained: How RDMA over Ethernet Enables Scalable AI InferenceExplore RoCE v2 networks with RDMA, lossless Ethernet, RoCE adapters, switches, and InfiniBand comparisons for AI inference, cloud, and HPC scenarios.6 min read·aicplight.hashnode.dev
Aania0-art·Jul 260: Let's enjoy reading the paper!This blog post is for sharing the research paper only and does not involve specific technical details.9 min read·once2twice.hashnode.dev
