例如，通過Prometheus Remote Write方式寫入如下數據：

{
  "labels": {
    "instance": "127.0.0.1:9114",
    "job": "elasticsearch"
  },
  "metrics": {
    "up": 0.0,
    "scrape_samples_post_metric_relabeling": 0.0,
    "scrape_samples_scraped": 0.0,
    "scrape_duration_seconds": 4.45999E-4,
    "scrape_series_added": 0.0
  },
  "@timestamp": "1655717638795"
}

Prometheus API返回的維度字段會去掉前綴labels.，/api/v1/labels接口返回結果如下：

{
  "status" : "success",
  "data" : [
    "__name__",
    "instance",
    "job"
  ]
}
                

Prometheus API返回的指標字段會去掉前綴metrics.，/api/v1/metadata接口返回結果如下：

{
  "status" : "success",
  "data" : {
    "scrape_samples_post_metric_relabeling" : [
      {
        "type" : "gauge",
        "help" : "",
        "unit" : ""
      }
    ],
    "scrape_samples_scraped" : [
      {
        "type" : "gauge",
        "help" : "",
        "unit" : ""
      }
    ],
    "scrape_duration_seconds" : [
      {
        "type" : "gauge",
        "help" : "",
        "unit" : ""
      }
    ],
    "scrape_series_added" : [
      {
        "type" : "gauge",
        "help" : "",
        "unit" : ""
      }
    ],
    "up" : [
      {
        "type" : "gauge",
        "help" : "",
        "unit" : ""
      }
    ]
  }
}

如果您自定義了數據模型，則需要額外配置前后綴關鍵字，否則Prometheus API返回的就是實際的數據。配置前后綴關鍵字的示例如下：

PUT _time_stream/{name}
{
  "time_stream": {
    "labels_fields": "@labels.*_l",
    "metrics_fields": "@metrics.*_m",
    "label_prefix": "@labels.",
    "label_suffix": "_l",
    "metric_prefix": "@metrics.",
    "metric_suffix": "_m"
  }
}

POST /_time_stream/prom_write/{index}
---PB data---

在Prometheus中配置Remote Write，即可將Prometheus數據同步到Elasticsearch，配置示例如下：

remote_write:
  - url: "http://127.0.0.1:9200/_time_stream/prom_write/prom_index"
    basic_auth:
     username: elastic
     password: xxxx