# Rate Processor

# Overview

Computes the difference between consecutive samples per unit of time (rate period).

Used to compute rate of change when the underlying metric measures a continuously incrementing counter.

# Parameters

Name	Type	Description
period	object	Rate period. Supports NANOSECOND time unit.
counter	boolean	If true, negative differences between consecutive samples are ignored. Default: true.

# Request

[
  {
    "startDate": "2018-03-05T10:00:00Z",
    "endDate": "2018-03-05T12:00:00Z",
    "entity": "nurswgvml007",
    "metric": "net.tx_bytes",
    "tags": {
        "name": [
            "*"
        ]
    },
    "rate": {
        "period": {"count": 1, "unit": "MINUTE"},
        "counter": true
    }
  }
]

# Rate Period

• If rate period is not specified, the function returns the difference between consecutive values. If samples are (time0, value0) and (time1, value1) the result is value1 - value0.

• If rate period is specified, the function calculates the rate of change for each sample:

(value1 - value0) / (time1 - time0) * ratePeriod.

ratePeriod = rate.count * rate.unit (in milliseconds)
if (value1 > value0) {
  resultValue = (value1 - value0) / (time1 - time0) * ratePeriod;
  aggregator.addValue(time1, resultValue);
}

# NANOSECOND Period Example

# Request

[
  {
    "startDate": "2018-09-03T12:00:00Z",
    "endDate": "2018-09-03T12:05:00Z",
    "timeFormat": "iso",
    "entity": "e-nano",
    "metric": "m-nano",
    "rate": {
      "period": {
        "count": 1,
        "unit": "NANOSECOND"
      }
    }
  }
]

# Response

[
  {
    "entity": "e-nano",
    "metric": "m-nano",
    "tags": {},
    "type": "HISTORY",
    "aggregate": {
      "type": "DETAIL"
    },
    "rate": {
      "period": {
        "count": 1,
        "unit": "NANOSECOND"
      },
      "counter": true
    },
    "data": [
      {"d":"2018-09-03T12:00:00.002Z","v":0.7},
      {"d":"2018-09-03T12:00:00.003Z","v":0.1},
      {"d":"2018-09-03T12:00:00.004Z","v":0.4}
    ]
  }
]