{
  "id": "elasticsearch/shard-request-cache-eviction-memory-pressure",
  "signature": "ElasticsearchException: shard request cache eviction triggered memory pressure, current heap usage [85%]",
  "signature_zh": "Elasticsearch异常：分片请求缓存逐出触发内存压力，当前堆使用率 [85%]",
  "regex": "ElasticsearchException: shard request cache eviction triggered memory pressure, current heap usage \\[\\d+%\\]",
  "domain": "elasticsearch",
  "category": "resource_error",
  "subcategory": null,
  "root_cause": "The shard request cache grows too large under high query load, causing frequent evictions that increase heap pressure and degrade performance.",
  "root_cause_type": "generic",
  "root_cause_zh": "在高查询负载下，分片请求缓存增长过大，导致频繁逐出，增加堆压力并降低性能。",
  "versions": [
    {
      "version": "7.17.0",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "8.11.0",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "8.12.0",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "",
      "why_fails": "Larger heap delays evictions but doesn't solve the root cause of excessive caching; cache can grow unbounded and cause GC issues.",
      "fail_rate": 0.7,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "Disabling cache increases query latency for repeated queries, especially in dashboards or reporting scenarios.",
      "fail_rate": 0.65,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "Reduce cache size by setting `indices.requests.cache.size: 1%` in `elasticsearch.yml` to limit heap usage.",
      "success_rate": 0.8,
      "how": "Reduce cache size by setting `indices.requests.cache.size: 1%` in `elasticsearch.yml` to limit heap usage.",
      "condition": "",
      "sources": []
    },
    {
      "action": "Use explicit query caching with `?request_cache=true` only for queries that benefit from it, and set `index.requests.cache.enable: false` on indices with high write volume.",
      "success_rate": 0.85,
      "how": "Use explicit query caching with `?request_cache=true` only for queries that benefit from it, and set `index.requests.cache.enable: false` on indices with high write volume.",
      "condition": "",
      "sources": []
    },
    {
      "action": "Monitor cache eviction rates via `GET _nodes/stats/indices/request_cache` and optimize queries to reduce cache churn.",
      "success_rate": 0.9,
      "how": "Monitor cache eviction rates via `GET _nodes/stats/indices/request_cache` and optimize queries to reduce cache churn.",
      "condition": "",
      "sources": []
    }
  ],
  "workarounds_zh": [
    "Reduce cache size by setting `indices.requests.cache.size: 1%` in `elasticsearch.yml` to limit heap usage.",
    "Use explicit query caching with `?request_cache=true` only for queries that benefit from it, and set `index.requests.cache.enable: false` on indices with high write volume.",
    "Monitor cache eviction rates via `GET _nodes/stats/indices/request_cache` and optimize queries to reduce cache churn."
  ],
  "transition_graph": {
    "leads_to": [],
    "preceded_by": [],
    "frequently_confused_with": []
  },
  "official_doc_url": "https://www.elastic.co/guide/en/elasticsearch/reference/current/shard-request-cache.html",
  "official_doc_section": null,
  "error_code": "ES_SHARD_CACHE_EVICTION_MEM",
  "verification_tier": "ai_generated",
  "confidence": 0.88,
  "fix_success_rate": 0.83,
  "resolvable": "true",
  "first_seen": "2024-09-01",
  "last_confirmed": "2024-06-01",
  "last_updated": "2024-06-01",
  "evidence_count": 1,
  "tags": [],
  "locale": "en",
  "aliases": []
}