https://github.com/evolution-gaming/smetrics

Generic interface to abstract from metrics vendors and their implementations
https://github.com/evolution-gaming/smetrics

cats cats-effect prometheus scala

Last synced: 3 months ago
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Generic interface to abstract from metrics vendors and their implementations

• Host: GitHub
• URL: https://github.com/evolution-gaming/smetrics
• Owner: evolution-gaming
• License: mit
• Created: 2019-06-21T08:04:10.000Z (over 5 years ago)
• Default Branch: master
• Last Pushed: 2024-01-15T11:12:27.000Z (about 1 year ago)
• Last Synced: 2024-01-15T13:19:37.751Z (about 1 year ago)
• Topics: cats, cats-effect, prometheus, scala
• Language: Scala
• Size: 266 KB
• Stars: 7
• Watchers: 8
• Forks: 10
• Open Issues: 48
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# SMetrics

[![Build Status](https://github.com/evolution-gaming/smetrics/workflows/CI/badge.svg)](https://github.com/evolution-gaming/smetrics/actions?query=workflow%3ACI)

[![Coverage Status](https://coveralls.io/repos/evolution-gaming/smetrics/badge.svg)](https://coveralls.io/r/evolution-gaming/smetrics)

[![Codacy Badge](https://api.codacy.com/project/badge/Grade/04fb0fd38072413cb032d8a5e7c9def5)](https://www.codacy.com/app/evolution-gaming/smetrics?utm_source=github.com&utm_medium=referral&utm_content=evolution-gaming/smetrics&utm_campaign=Badge_Grade)

[![Version](https://img.shields.io/badge/version-click-blue)](https://evolution.jfrog.io/artifactory/api/search/latestVersion?g=com.evolutiongaming&a=smetrics_2.13&repos=public)

[![License: MIT](https://img.shields.io/badge/License-MIT-yellowgreen.svg)](https://opensource.org/licenses/MIT)

## Features:

* tagless final api via [cats](https://typelevel.org/cats/)

* improved abstraction for matching labels names and label values

* resource safety

* detaching metrics backend - prometheus dependency is one of the backend implementations

## Example of http metrics

let's declare interface for metrics, that seems reasonable for http client 

```scala

trait HttpMetrics[F[_]] {

  def latency(client: String, method: String, resource: String, duration: FiniteDuration): F[Unit]

  def count(client: String, method: String, resource: String, success: Boolean): F[Unit]

  def enqueue(client: String): F[Unit]

  def dequeue(client: String): F[Unit]

}

```

now let's implement `HttpMetrics` using `CollectorRegistry`

```scala

  import com.evolutiongaming.smetrics.MetricsHelper._

  import com.evolutiongaming.smetrics.{CollectorRegistry, LabelNames, Quantile, Quantiles}

  def httpMetrics[F[_]: Monad](collectorRegistry: CollectorRegistry[F]): Resource[F, HttpMetrics[F]] = {

    for {

      latencySummary <- collectorRegistry.summary(

        "http_client_latency",

        "Latency of HTTP requests processing in seconds",

        Quantiles(

          Quantile(value = 0.5, error = 0.05),

          Quantile(value = 0.9, error = 0.05),

          Quantile(value = 0.99, error = 0.005)),

        LabelNames("client_name", "method", "resource"))

      

      resultCounter <- collectorRegistry.counter(

        "http_client_response_result",

        "Status of HTTP responses",

        LabelNames("client_name", "method", "resource", "result"))

      

      queueGauge <- collectorRegistry.gauge(

        "http_client_queue",

        "Queue of incoming http calls",

        LabelNames("client_name"))

    } yield {

      new HttpMetrics[F] {

    

        def latency(client: String, method: String, resource: String, duration: FiniteDuration) = {

          latencySummary

            .labels(client, method, resource)

            .observe(duration.toNanos.nanosToSeconds)

        }

    

        def count(client: String, method: String, resource: String, success: Boolean) = {

          resultCounter

            .labels(client, method, resource, if (success) "success" else "error")

            .inc()

        }

    

        def enqueue(client: String) = {

          queueGauge

            .labels(client)

            .inc()

        }

    

        def dequeue(client: String) = {

          queueGauge

            .labels(client)

            .dec()

        }

      }

    }

  }

```

So you can see, `httpMetrics` function requires instance of `CollectorRegistry`.

Right now there are two options available:

* `CollectorRegistry.empty` - often used in tests

* `CollectorRegistryPrometheus` - which will create `smetrics.CollectorRegistry` out of `io.prometheus.CollectorRegistry` using [prometheus/client_java](github.com/prometheus/client_java) under the hood

Return type is `Resource[F, _]` rather than `F[_]` because most often underlying metrics implementation upon a call registers your metrics with shared registry.

Hence `release` hook of `Resource` being used in order to de-register particular metrics from shared registry.

## Setup

```scala

addSbtPlugin("com.evolution" % "sbt-artifactory-plugin" % "0.0.2")

libraryDependencies += "com.evolutiongaming" %% "smetrics" % "0.3.1"

libraryDependencies += "com.evolutiongaming" %% "smetrics-prometheus" % "0.3.1"

```