{
  "study_id": "dash0-qwen235b-prefill-thinking-run2-ttft-tight-topology",
  "hardware": {
    "gpu_count": 8,
    "gpu_model": "H20",
    "host_candidates": [
      "dash0"
    ]
  },
  "model": {
    "model_id": "qwen3-235b-a22b-256k-0717-internal",
    "served_model_name": "qwen3-235b-prefill"
  },
  "engine": {
    "engine_name": "vllm",
    "engine_version": "internal-on-dash0",
    "exec_path": "/usr/local/bin/vllm",
    "cwd": "/home/admin/cpfs/wjh/aituner/aituner",
    "host": "127.0.0.1",
    "port": 18125,
    "healthcheck_path": "/v1/models",
    "ready_timeout_s": 1800,
    "request_timeout_s": 1800,
    "launch_args": [
      "serve",
      "/home/admin/resource/model/464482ce.qwen3-235b-a22b/256k-0717"
    ],
    "base_envs": {
      "CUDA_VISIBLE_DEVICES": "0,1,2,3,4,5,6,7",
      "VLLM_USE_V1": "1",
      "VLLM_ATTENTION_BACKEND": "FLASH_ATTN",
      "VLLM_QUANTIZATION_LAYER_WISE": "1",
      "VLLM_MOE_USE_DEEPEP": "0",
      "VLLM_MOE_BALANCED_GATING": "0",
      "VLLM_MOE_RANDOM_GATING": "0",
      "VLLM_FUSED_MOE_CHUNK_SIZE": "4096",
      "VLLM_DP_META_USE_CPU_GROUP": "0",
      "VLLM_MLA_FP8_ATTENTION": "0",
      "VLLM_MOE_EXPERTS_OVERLAP": "0",
      "VLLM_USE_FLASHINFER_SAMPLER": "0",
      "VLLM_RESPONSE_TIMEOUT": "290",
      "VLLM_FP8_USE_BLADNN": "1",
      "VLLM_MOE_USE_BLADNN": "1",
      "VLLM_USE_DEEP_GEMM": "0",
      "VLLM_PD_TRY_CONNECT_TIMEOUT_SECONDS": "120",
      "VLLM_DEEP_GEMM_WARMUP": "skip",
      "DEEPEP_LL_COMBINE_USE_FP8": "1",
      "DEEPEP_LL_BUFFER_FP8_OPT": "1",
      "DEEPEP_LL_DISPATCH_USE_NVL": "1",
      "DEEPEP_LL_COMBINE_USE_NVL": "1",
      "ACCL_LOW_LATENCY_OPTIMIZE": "2",
      "ACCL_WRITEBATCH_OPT": "2",
      "ACCL_IBV_MTU": "9000",
      "ACCL_TX_DEPTH": "1024",
      "ACCL_RETRANSMIT_TIMEOUT": "17",
      "NVSHMEM_IBGDA_NUM_RC_PER_PE": "4",
      "BLLM_KVTRANS_RDMA_SP": "2",
      "NCCL_SOCKET_IFNAME": "eth1",
      "NVSHMEM_BOOTSTRAP_UID_SOCK_IFNAME": "eth1",
      "GLOO_SOCKET_IFNAME": "eth1"
    },
    "base_flags": {
      "host": "127.0.0.1",
      "port": 18125,
      "served-model-name": "qwen3-235b-prefill",
      "tensor-parallel-size": 4,
      "gpu-memory-utilization": 0.85,
      "enable-prefix-caching": true,
      "enable-chunked-prefill": true,
      "max-num-batched-tokens": 8192,
      "disable-hybrid-kv-cache-manager": true,
      "max-model-len": 262144,
      "block-size": 64,
      "max-num-seqs": 64,
      "quantization": "fp8",
      "cuda-graph-sizes": [
        16,
        32,
        64,
        96,
        128,
        160,
        192,
        224,
        256,
        288,
        320,
        352,
        384,
        416,
        448,
        480,
        512,
        544,
        576,
        608,
        640,
        672,
        704,
        736,
        768,
        800,
        832,
        864,
        896,
        928,
        960,
        992,
        1024
      ],
      "compilation-config": "{\"cudagraph_mode\":\"PIECEWISE\",\"use_inductor\":false,\"custom_ops\":[\"all\"],\"max_cudagraph_capture_size\":2048}",
      "speculative-config": "{\"method\":\"eagle3\",\"num_speculative_tokens\":1,\"hf_overrides\":{\"rope_scaling\":{\"type\":\"yarn\",\"factor\":128,\"original_max_position_embeddings\":2048,\"semi_dynamic\":false,\"dynamic\":true},\"num_experts\":0},\"model\":\"/home/admin/resource/model/464482ce.qwen3-235b-a22b/0717-eagle-0820\"}",
      "hf-overrides": "{\"architectures\":[\"Qwen3MoeForCausalLM\"],\"model_type\":\"qwen3_moe\"}",
      "kv-cache-dtype": "fp8",
      "disable-log-requests": true
    },
    "tunable_envs": [
      "VLLM_ENABLE_TORCH_COMPILE"
    ],
    "tunable_flags": [
      "tensor-parallel-size",
      "data-parallel-size",
      "enable-expert-parallel",
      "expert-parallel-size",
      "gpu-memory-utilization",
      "max-num-batched-tokens",
      "max-num-seqs",
      "block-size",
      "enable-prefix-caching",
      "enable-chunked-prefill"
    ],
    "topology_constraints": {
      "require_tp_dp_product_equals_gpu_count": false,
      "require_ep_size_leq_tp_dp_product": true,
      "require_ep_size_divides_tp_dp_product": true,
      "require_enable_expert_parallel_when_ep_gt_one": true,
      "validate_cuda_graph_sizes_divisible_by_tp_when_tp_ep_reduce_scatter": true,
      "allowed_tp_dp_products": [
        4,
        8
      ],
      "allowed_tensor_parallel_sizes": [
        4,
        8
      ],
      "allowed_data_parallel_sizes": [
        1,
        2
      ],
      "allowed_expert_parallel_sizes": [
        1,
        2,
        4,
        8
      ]
    },
    "python_executable": "python3"
  },
  "trace": {
    "windows_path": "/home/admin/cpfs/wjh/aituner/aituner/trace_windows/windows.json",
    "window_id": "thinking_w20260327_1000",
    "request_mode": "chat",
    "completion_tokens_override": 1,
    "u_field": "sampling_u",
    "timestamp_field": "timestamp",
    "max_concurrency": 64,
    "replay_time_scale": 1.0,
    "early_stop_max_lag_s": 180.0,
    "early_stop_max_elapsed_s": 1200.0
  },
  "slo": {
    "target_pass_rate": 0.95,
    "ttft_rule": {
      "kind": "step_ms",
      "buckets": [
        {
          "max_input_tokens": 8191,
          "threshold_ms": 2000
        },
        {
          "max_input_tokens": 32767,
          "threshold_ms": 4000
        },
        {
          "threshold_ms": 6000
        }
      ]
    }
  },
  "search": {
    "low": 0.0,
    "high": 0.125,
    "tolerance": 0.001,
    "max_probes": 6,
    "sample_seed": 20260325
  },
  "llm": {
    "system_prompt": "You are tuning a prefill-dominated vLLM serving stack. The trace replay forces completion length to exactly 1 token, so optimize for TTFT under the configured stepped SLO. Propose one launch-safe config patch that increases the maximum feasible sampling_u while respecting the topology constraints and avoiding known launch failures.",
    "max_history_trials": 8,
    "endpoint": {
      "provider": "codex",
      "model": "gpt-5.4",
      "stream": true,
      "api_key_env": "OPENAI_API_KEY",
      "timeout_s": 240
    }
  }
}