{
  "id": "nginx/no-live-upstreams-while-connecting-to-upstream",
  "signature": "no live upstreams while connecting to upstream",
  "signature_zh": "连接上游时没有可用的上游服务器",
  "regex": "no live upstreams while connecting to upstream",
  "domain": "nginx",
  "category": "network_error",
  "subcategory": null,
  "root_cause": "All upstream servers in the upstream block are marked as down or have failed health checks, leaving no available targets.",
  "root_cause_type": "generic",
  "root_cause_zh": "upstream块中的所有上游服务器均被标记为故障或健康检查失败，导致没有可用目标。",
  "versions": [
    {
      "version": "nginx 1.24.0",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "nginx 1.22.1",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "nginx 1.26.0",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "Increase worker_connections to 10240",
      "why_fails": "This error is about upstream availability, not connection limits. Increasing worker_connections cannot revive dead upstream servers.",
      "fail_rate": 0.95,
      "condition": "",
      "sources": []
    },
    {
      "action": "Set proxy_next_upstream to always retry",
      "why_fails": "proxy_next_upstream only works if there is at least one live upstream. If all are dead, retry logic is useless.",
      "fail_rate": 0.85,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "Check upstream server health and restart them: systemctl restart myapp. Also verify health_check settings in nginx.conf and ensure backup servers are defined: server backup1.example.com backup;",
      "success_rate": 0.9,
      "how": "Check upstream server health and restart them: systemctl restart myapp. Also verify health_check settings in nginx.conf and ensure backup servers are defined: server backup1.example.com backup;",
      "condition": "",
      "sources": []
    },
    {
      "action": "Temporarily mark a server as up with max_fails=0 fail_timeout=0 in the upstream block: server 10.0.0.1:8080 max_fails=0 fail_timeout=0;",
      "success_rate": 0.85,
      "how": "Temporarily mark a server as up with max_fails=0 fail_timeout=0 in the upstream block: server 10.0.0.1:8080 max_fails=0 fail_timeout=0;",
      "condition": "",
      "sources": []
    }
  ],
  "workarounds_zh": [
    "Check upstream server health and restart them: systemctl restart myapp. Also verify health_check settings in nginx.conf and ensure backup servers are defined: server backup1.example.com backup;",
    "Temporarily mark a server as up with max_fails=0 fail_timeout=0 in the upstream block: server 10.0.0.1:8080 max_fails=0 fail_timeout=0;"
  ],
  "transition_graph": {
    "leads_to": [],
    "preceded_by": [],
    "frequently_confused_with": []
  },
  "official_doc_url": "https://nginx.org/en/docs/http/ngx_http_upstream_module.html#upstream",
  "official_doc_section": null,
  "error_code": null,
  "verification_tier": "ai_generated",
  "confidence": 0.88,
  "fix_success_rate": 0.85,
  "resolvable": "true",
  "first_seen": "2024-01-20",
  "last_confirmed": "2024-06-01",
  "last_updated": "2024-06-01",
  "evidence_count": 1,
  "tags": [],
  "locale": "en",
  "aliases": []
}