{
  "id": "python/sqlalchemy-operational-server-closed-connection",
  "signature": "sqlalchemy.exc.OperationalError: (psycopg2.OperationalError) server closed the connection unexpectedly\\n\\tThis probably means the server terminated abnormally\\n\\tbefore or while processing the request.",
  "signature_zh": "sqlalchemy.exc.OperationalError：(psycopg2.OperationalError) 服务器意外关闭连接。这可能意味着服务器在处理请求之前或期间异常终止。",
  "regex": "sqlalchemy\\.exc\\.OperationalError:\\ \\(psycopg2\\.OperationalError\\)\\ server\\ closed\\ the\\ connection\\ unexpectedly\\\\n\\\\tThis\\ probably\\ means\\ the\\ server\\ terminated\\ abnormally\\\\n\\\\tbefore\\ or\\ while\\ processing\\ the\\ request\\.",
  "domain": "python",
  "category": "network_error",
  "subcategory": null,
  "root_cause": "Database server crashed, network timeout, or connection pool exhausted.",
  "root_cause_type": "generic",
  "root_cause_zh": "数据库服务器崩溃、网络超时或连接池耗尽。",
  "versions": [
    {
      "version": "3.x",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "Increasing connection pool size arbitrarily.",
      "why_fails": "Does not address root cause like server load or network issues.",
      "fail_rate": 0.5,
      "condition": "",
      "sources": []
    },
    {
      "action": "Restarting the application without checking database health.",
      "why_fails": "Server may still be down; error will recur.",
      "fail_rate": 0.4,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "Implement retry logic with exponential backoff.",
      "success_rate": 0.85,
      "how": "from tenacity import retry, stop_after_attempt, wait_exponential\n@retry(stop=stop_after_attempt(3), wait=wait_exponential(multiplier=1, min=4, max=10))\ndef query_db():\n    with Session(engine) as session:\n        return session.execute(text('SELECT 1'))",
      "condition": "",
      "sources": []
    },
    {
      "action": "Check database server logs and restart if necessary.",
      "success_rate": 0.9,
      "how": "systemctl status postgresql\nsystemctl restart postgresql",
      "condition": "",
      "sources": []
    }
  ],
  "workarounds_zh": [],
  "transition_graph": {
    "leads_to": [],
    "preceded_by": [],
    "frequently_confused_with": []
  },
  "official_doc_url": null,
  "official_doc_section": null,
  "error_code": null,
  "verification_tier": "ai_generated",
  "confidence": 0.85,
  "fix_success_rate": 0.8,
  "resolvable": "true",
  "first_seen": "2024-03-20",
  "last_confirmed": "2025-01-01",
  "last_updated": "2025-01-01",
  "evidence_count": 0,
  "tags": [],
  "locale": "en",
  "aliases": []
}