es - elasticsearch - aggs - metrics - rate

世界上并没有完美的程序，但是我们并不因此而沮丧，因为写程序就是一个不断追求完美的过程。

问：rate有什么特点？
答：

问：rate如何使用？
答：

DELETE /rate_test

PUT /rate_test
{
  "mappings": {
    "properties": {
      "date": {"type": "date"},
      "num": {"type": "integer"}
    }
  }
}

POST /rate_test/_bulk
{"index": {"_id": 1}}
{"date": "2020-01-01", "num": 3}
{"index": {"_id": 2}}
{"date": "2020-01-10", "num": 7}
{"index": {"_id": 3}}
{"date": "2020-03-01", "num": 5}
{"index": {"_id": 4}}
{"date": "2020-03-05", "num": 9}
{"index": {"_id": 5}}
{"date": "2020-05-11", "num": 1}

# 年 - 每个月num和 * 12
GET /rate_test/_search
{
  "size": 0,
  "aggs": {
    "date_aggs": {
      "date_histogram": {
        "field": "date",
        "calendar_interval": "month"
      },
      "aggs": {
        "rate_aggs": {
          "rate": {
            "field": "num",
            "unit": "year"
          }
        }
      }
    }
  }
}

# 结果
{
  "took" : 2,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 5,
      "relation" : "eq"
    },
    "max_score" : null,
    "hits" : [ ]
  },
  "aggregations" : {
    "date_aggs" : {
      "buckets" : [
        {
          "key_as_string" : "2020-01-01T00:00:00.000Z",
          "key" : 1577836800000,
          "doc_count" : 2,
          "rate_aggs" : {
            "value" : 120.0
          }
        },
        {
          "key_as_string" : "2020-02-01T00:00:00.000Z",
          "key" : 1580515200000,
          "doc_count" : 0,
          "rate_aggs" : {
            "value" : 0.0
          }
        },
        {
          "key_as_string" : "2020-03-01T00:00:00.000Z",
          "key" : 1583020800000,
          "doc_count" : 2,
          "rate_aggs" : {
            "value" : 168.0
          }
        },
        {
          "key_as_string" : "2020-04-01T00:00:00.000Z",
          "key" : 1585699200000,
          "doc_count" : 0,
          "rate_aggs" : {
            "value" : 0.0
          }
        },
        {
          "key_as_string" : "2020-05-01T00:00:00.000Z",
          "key" : 1588291200000,
          "doc_count" : 1,
          "rate_aggs" : {
            "value" : 12.0
          }
        }
      ]
    }
  }
}

# 日 - 每个月num的和 / 30
GET /rate_test/_search
{
  "size": 0,
  "aggs": {
    "date_aggs": {
      "date_histogram": {
        "field": "date",
        "calendar_interval": "month"
      },
      "aggs": {
        "rate_aggs": {
          "rate": {
            "field": "num",
            "unit": "day"
          }
        }
      }
    }
  }
}

# 结果
{
  "took" : 0,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 5,
      "relation" : "eq"
    },
    "max_score" : null,
    "hits" : [ ]
  },
  "aggregations" : {
    "date_aggs" : {
      "buckets" : [
        {
          "key_as_string" : "2020-01-01T00:00:00.000Z",
          "key" : 1577836800000,
          "doc_count" : 2,
          "rate_aggs" : {
            "value" : 0.3225806451612903
          }
        },
        {
          "key_as_string" : "2020-02-01T00:00:00.000Z",
          "key" : 1580515200000,
          "doc_count" : 0,
          "rate_aggs" : {
            "value" : 0.0
          }
        },
        {
          "key_as_string" : "2020-03-01T00:00:00.000Z",
          "key" : 1583020800000,
          "doc_count" : 2,
          "rate_aggs" : {
            "value" : 0.45161290322580644
          }
        },
        {
          "key_as_string" : "2020-04-01T00:00:00.000Z",
          "key" : 1585699200000,
          "doc_count" : 0,
          "rate_aggs" : {
            "value" : 0.0
          }
        },
        {
          "key_as_string" : "2020-05-01T00:00:00.000Z",
          "key" : 1588291200000,
          "doc_count" : 1,
          "rate_aggs" : {
            "value" : 0.03225806451612903
          }
        }
      ]
    }
  }
}

# 月 - 每个月num的和
GET /rate_test/_search
{
  "size": 0,
  "aggs": {
    "date_aggs": {
      "date_histogram": {
        "field": "date",
        "calendar_interval": "month"
      },
      "aggs": {
        "rate_aggs": {
          "rate": {
            "field": "num",
            "unit": "month"
          }
        }
      }
    }
  }
}

# 结果
{
  "took" : 1,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 5,
      "relation" : "eq"
    },
    "max_score" : null,
    "hits" : [ ]
  },
  "aggregations" : {
    "date_aggs" : {
      "buckets" : [
        {
          "key_as_string" : "2020-01-01T00:00:00.000Z",
          "key" : 1577836800000,
          "doc_count" : 2,
          "rate_aggs" : {
            "value" : 10.0
          }
        },
        {
          "key_as_string" : "2020-02-01T00:00:00.000Z",
          "key" : 1580515200000,
          "doc_count" : 0,
          "rate_aggs" : {
            "value" : 0.0
          }
        },
        {
          "key_as_string" : "2020-03-01T00:00:00.000Z",
          "key" : 1583020800000,
          "doc_count" : 2,
          "rate_aggs" : {
            "value" : 14.0
          }
        },
        {
          "key_as_string" : "2020-04-01T00:00:00.000Z",
          "key" : 1585699200000,
          "doc_count" : 0,
          "rate_aggs" : {
            "value" : 0.0
          }
        },
        {
          "key_as_string" : "2020-05-01T00:00:00.000Z",
          "key" : 1588291200000,
          "doc_count" : 1,
          "rate_aggs" : {
            "value" : 1.0
          }
        }
      ]
    }
  }
}