{
  "id": "cuda/cuda-error-mps-client-failed",
  "signature": "CUDA error: MPS client failed to connect (cudaErrorMpsClientFailed)",
  "signature_zh": "CUDA 错误：MPS 客户端连接失败 (cudaErrorMpsClientFailed)",
  "regex": "CUDA error: MPS client failed to connect",
  "domain": "cuda",
  "category": "runtime_error",
  "subcategory": null,
  "root_cause": "The CUDA Multi-Process Service (MPS) control daemon is not running or has crashed, preventing a new MPS client from connecting to the shared GPU context.",
  "root_cause_type": "generic",
  "root_cause_zh": "CUDA 多进程服务 (MPS) 控制守护进程未运行或已崩溃，导致新的 MPS 客户端无法连接到共享 GPU 上下文。",
  "versions": [
    {
      "version": "CUDA 12.0",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "CUDA 12.1",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "CUDA 12.3",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "NVIDIA Driver 535.129.03",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "NVIDIA Driver 545.23.06",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "",
      "why_fails": "The error is not caused by missing or corrupt CUDA installations, but by a missing or unresponsive MPS daemon process.",
      "fail_rate": 0.8,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "The environment variable only changes the socket path; if the daemon is not running at that path, the connection still fails.",
      "fail_rate": 0.7,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "Start the MPS control daemon before launching the application: `export CUDA_MPS_PIPE_DIRECTORY=/tmp/nvidia-mps; nvidia-cuda-mps-control -d`",
      "success_rate": 0.9,
      "how": "Start the MPS control daemon before launching the application: `export CUDA_MPS_PIPE_DIRECTORY=/tmp/nvidia-mps; nvidia-cuda-mps-control -d`",
      "condition": "",
      "sources": []
    },
    {
      "action": "Disable MPS by unsetting CUDA_MPS_PIPE_DIRECTORY and restarting the process: `unset CUDA_MPS_PIPE_DIRECTORY`",
      "success_rate": 0.95,
      "how": "Disable MPS by unsetting CUDA_MPS_PIPE_DIRECTORY and restarting the process: `unset CUDA_MPS_PIPE_DIRECTORY`",
      "condition": "",
      "sources": []
    },
    {
      "action": "Check if MPS daemon is running and restart it: `ps aux | grep nvidia-cuda-mps-control; killall nvidia-cuda-mps-control; nvidia-cuda-mps-control -d`",
      "success_rate": 0.85,
      "how": "Check if MPS daemon is running and restart it: `ps aux | grep nvidia-cuda-mps-control; killall nvidia-cuda-mps-control; nvidia-cuda-mps-control -d`",
      "condition": "",
      "sources": []
    }
  ],
  "workarounds_zh": [
    "Start the MPS control daemon before launching the application: `export CUDA_MPS_PIPE_DIRECTORY=/tmp/nvidia-mps; nvidia-cuda-mps-control -d`",
    "Disable MPS by unsetting CUDA_MPS_PIPE_DIRECTORY and restarting the process: `unset CUDA_MPS_PIPE_DIRECTORY`",
    "Check if MPS daemon is running and restart it: `ps aux | grep nvidia-cuda-mps-control; killall nvidia-cuda-mps-control; nvidia-cuda-mps-control -d`"
  ],
  "transition_graph": {
    "leads_to": [],
    "preceded_by": [],
    "frequently_confused_with": []
  },
  "official_doc_url": "https://docs.nvidia.com/deploy/mps/index.html",
  "official_doc_section": null,
  "error_code": "cudaErrorMpsClientFailed (803)",
  "verification_tier": "ai_generated",
  "confidence": 0.88,
  "fix_success_rate": 0.82,
  "resolvable": "true",
  "first_seen": "2024-06-10",
  "last_confirmed": "2024-06-01",
  "last_updated": "2024-06-01",
  "evidence_count": 1,
  "tags": [],
  "locale": "en",
  "aliases": []
}