opensearch-docs-cn/_monitoring-your-cluster/pa/rca/api.md

---
layout: default
title: API
parent: Root Cause Analysis
grand_parent: Performance Analyzer
nav_order: 1
redirect_from:
  - /monitoring-plugins/pa/rca/api/
---

# RCA API

## Sample request

```
# Request all available RCAs
GET localhost:9600/_plugins/_performanceanalyzer/rca

# Request a specific RCA
GET localhost:9600/_plugins/_performanceanalyzer/rca?name=HighHeapUsageClusterRca
```


## Sample response

```json
{
  "HighHeapUsageClusterRca": [{
    "rca_name": "HighHeapUsageClusterRca",
    "state": "unhealthy",
    "timestamp": 1587426650942,
    "HotClusterSummary": [{
      "number_of_nodes": 2,
      "number_of_unhealthy_nodes": 1,
      "HotNodeSummary": [{
        "host_address": "192.168.144.2",
        "node_id": "JtlEoRowSI6iNpzpjlbp_Q",
        "HotResourceSummary": [{
          "resource_type": "old gen",
          "threshold": 0.65,
          "value": 0.81827232588145373,
          "avg": NaN,
          "max": NaN,
          "min": NaN,
          "unit_type": "heap usage in percentage",
          "time_period_seconds": 600,
          "TopConsumerSummary": [{
              "name": "CACHE_FIELDDATA_SIZE",
              "value": 590702564
            },
            {
              "name": "CACHE_REQUEST_SIZE",
              "value": 28375
            },
            {
              "name": "CACHE_QUERY_SIZE",
              "value": 12687
            }
          ],
        }]
      }]
    }]
  }]
}
```