Ilker ManapandClaude Opus 5.5
7bb360fc78
doctor checks a node alone, and every check can pass while two nodes still cannot reach each other. ctl fabric-test A B asks B's agent for an ib_write_bw server and A's for the client, adapter by adapter as NCCL pairs them, one rail at a time, and grades each against its link's rate. It goes through the agents' streams, so there is no SSH between nodes; the agent installs perftest the first time, and names the RoCE v2 GID itself. The result is read from perftest's table by its heading, not a column number. Agents now list the requests they answer beyond the usual (Register.features), and the control plane refuses a test on one too old to answer instead of waiting minutes for it. The forwarding dispatcher carries the new capability, and its test says so: a missing forward would have made the command quietly unavailable in production. Not yet run over real InfiniBand or RoCE; this cluster has neither. Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>