{"record":{"id":"fcf99257b3e2570f","repo":"sgl-project/sglang","slug":"sync-request-failed-error","errorCode":null,"errorMessage":"Sync request failed: {error}","messagePattern":"Sync request failed: (.+?)","errorType":"exception","errorClass":"RuntimeError","httpStatus":null,"severity":"critical","filePath":"python/sglang/compile_deep_gemm.py","lineNumber":164,"sourceCode":"                        payload[\"bootstrap_room\"] = [\n                            i * (2**63 // dp_size) + (i % cfg.tp_size)\n                            for i in range(dp_size)\n                        ]\n                    else:\n                        payload[\"input_ids\"] = (\n                            base_ids\n                            if dp_size == 1\n                            else [list(base_ids) for _ in range(dp_size)]\n                        )\n\n                    response = requests.post(\n                        f\"{base_url}/generate\",\n                        json=payload,\n                        timeout=600,\n                    )\n                    if response.status_code != 200:\n                        error = response.json()\n                        raise RuntimeError(f\"Sync request failed: {error}\")\n                # Other nodes should wait for the exit signal from Rank-0 node.\n                else:\n                    start_time_waiting = time.perf_counter()\n                    while proc.is_alive():\n                        if time.perf_counter() - start_time_waiting < timeout:\n                            time.sleep(10)\n                        else:\n                            raise TimeoutError(\"Waiting for main node timeout!\")\n                return proc\n        except requests.RequestException:\n            pass\n        time.sleep(10)\n    raise TimeoutError(\n        \"DeepGEMM Kernels compilation timeout.\"\n        \"\\n\\nFeel free and please restart the command.\"\n    )\n\n","sourceCodeStart":146,"sourceCodeEnd":182,"githubUrl":"https://github.com/sgl-project/sglang/blob/0132848349585cfe6aae51c4941cbae872505f8a/python/sglang/compile_deep_gemm.py#L146-L182","documentation":"Raised inside launch_server_process_and_send_one_request during DeepGEMM kernel compilation: after starting a server process, the rank-0 node POSTs a warmup /generate request, and a non-200 response triggers this RuntimeError carrying the server's JSON error body. It almost always reflects a crash/invalid-request in the compilation server, not in the HTTP client.","triggerScenarios":"Running sglang.compile_deep_gemm.run_compile where the launched server fails while handling the compilation-triggering generate request (kernel compile error, bad args, OOM); response.status_code != 200 from /generate.","commonSituations":"DeepGEMM JIT compilation failing on unsupported shapes/SM architecture; server args mismatched with the compile payload; CUDA toolchain issues during kernel build.","solutions":["Inspect the {error} JSON body and the server process logs (proc output) for the root cause.","Verify GPU/SM compatibility for DeepGEMM and CUDA_HOME/nvcc availability.","Retry with a clean DeepGEMM cache (remove ~/.cache/deep_gemm or DG_CACHE_DIR) to rule out a corrupted partial compile.","Ensure server args (tp size, dtype, context length) in compile_args match what the server supports."],"exampleFix":null,"handlingStrategy":"try-catch","validationCode":"resp = requests.post(f\"{base_url}/generate\", json=payload, timeout=600)\nif resp.status_code != 200:\n    log.error(\"server error body: %s\", resp.text)  # inspect before it becomes an exception","typeGuard":null,"tryCatchPattern":"try:\n    run_compile(...)\nexcept RuntimeError as e:\n    if \"Sync request failed\" in str(e):\n        inspect_server_logs(); clear_deep_gemm_cache(); retry_once()","preventionTips":["Run compile_deep_gemm on a node with a working nvcc and supported SM architecture first to validate.","Keep server args consistent with the compile payload (tp, dtype, context length).","Warm the DeepGEMM cache on one node before multi-node runs."],"tags":["sglang","deep-gemm","compilation","http-500","kernel-build"],"backgroundTag":"kernel-compilation-failed","analyzedSha":"0132848349585cfe6aae51c4941cbae872505f8a","analyzedAt":"2026-08-28T05:10:05.995Z","schemaVersion":2},"datasetVersion":"2026-08-28T06:17:29.519Z"}