effect-io-ai

Package: effect
Module: Metric

Metric.frequency

Creates a Frequency metric which can be used to count the number of occurrences of a string.

When to use

Use when you need a metric for counting how often a specific event or incident occurs.

Details

The optional description describes the frequency, and attributes attach dimensions to it. Use preregisteredWords to initialize occurrence counts for known string values before updates arrive.

Example (Creating frequency metrics)

import { Data, Effect, Metric } from "effect"

class FrequencyError extends Data.TaggedError("FrequencyError")<{
  readonly operation: string
}> {}

const program = Effect.gen(function*() {
  // Create a frequency metric for HTTP status codes
  const statusFrequency = Metric.frequency("http_status_codes", {
    description: "Frequency of HTTP response status codes",
    preregisteredWords: ["200", "404", "500"] // Pre-register common codes
  })

  // Create a frequency metric for user actions
  const userActionFrequency = Metric.frequency("user_actions", {
    description: "Frequency of user actions performed",
    attributes: { application: "web-app" }
  })

  // Create a frequency metric for error types
  const errorTypeFrequency = Metric.frequency("error_types", {
    description: "Frequency of different error types"
  })

  // Record different occurrences
  yield* Metric.update(statusFrequency, "200") // Success response
  yield* Metric.update(statusFrequency, "200") // Another success
  yield* Metric.update(statusFrequency, "404") // Not found error
  yield* Metric.update(statusFrequency, "500") // Server error
  yield* Metric.update(statusFrequency, "200") // Another success

  yield* Metric.update(userActionFrequency, "login")
  yield* Metric.update(userActionFrequency, "view_dashboard")
  yield* Metric.update(userActionFrequency, "login")
  yield* Metric.update(userActionFrequency, "logout")

  yield* Metric.update(errorTypeFrequency, "ValidationError")
  yield* Metric.update(errorTypeFrequency, "NetworkError")
  yield* Metric.update(errorTypeFrequency, "ValidationError")

  // Get frequency counts
  const statusCounts = yield* Metric.value(statusFrequency)
  const actionCounts = yield* Metric.value(userActionFrequency)
  const errorCounts = yield* Metric.value(errorTypeFrequency)

  // statusCounts.occurrences will be:
  // Map { "200" => 3, "404" => 1, "500" => 1 }
  // actionCounts.occurrences will be:
  // Map { "login" => 2, "view_dashboard" => 1, "logout" => 1 }
  // errorCounts.occurrences will be:
  // Map { "ValidationError" => 2, "NetworkError" => 1 }

  return { statusCounts, actionCounts, errorCounts }
})

Signature

declare const frequency: (name: string, options?: { readonly description?: string | undefined; readonly attributes?: Metric.Attributes | undefined; readonly preregisteredWords?: ReadonlyArray<string> | undefined; }) => Frequency

Source

Since v2.0.0