penpot/backend/src/app/metrics.clj
2021-09-30 11:48:14 +02:00

297 lines
8.9 KiB
Clojure

;; This Source Code Form is subject to the terms of the Mozilla Public
;; License, v. 2.0. If a copy of the MPL was not distributed with this
;; file, You can obtain one at http://mozilla.org/MPL/2.0/.
;;
;; Copyright (c) UXBOX Labs SL
(ns app.metrics
(:require
[app.common.exceptions :as ex]
[app.common.logging :as l]
[clojure.spec.alpha :as s]
[integrant.core :as ig])
(:import
io.prometheus.client.CollectorRegistry
io.prometheus.client.Counter
io.prometheus.client.Gauge
io.prometheus.client.Summary
io.prometheus.client.Histogram
io.prometheus.client.exporter.common.TextFormat
io.prometheus.client.hotspot.DefaultExports
io.prometheus.client.jetty.JettyStatisticsCollector
org.eclipse.jetty.server.handler.StatisticsHandler
java.io.StringWriter))
(declare instrument-vars!)
(declare instrument)
(declare create-registry)
(declare create)
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Entry Point
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(defn- handler
[registry _request]
(let [samples (.metricFamilySamples ^CollectorRegistry registry)
writer (StringWriter.)]
(TextFormat/write004 writer samples)
{:headers {"content-type" TextFormat/CONTENT_TYPE_004}
:body (.toString writer)}))
(s/def ::definitions
(s/map-of keyword? map?))
(defmethod ig/pre-init-spec ::metrics [_]
(s/keys :opt-un [::definitions]))
(defmethod ig/init-key ::metrics
[_ {:keys [definitions] :as cfg}]
(l/info :action "initialize metrics")
(let [registry (create-registry)
definitions (reduce-kv (fn [res k v]
(->> (assoc v :registry registry)
(create)
(assoc res k)))
{}
definitions)]
{:handler (partial handler registry)
:definitions definitions
:registry registry}))
(s/def ::handler fn?)
(s/def ::registry #(instance? CollectorRegistry %))
(s/def ::metrics
(s/keys :req-un [::registry ::handler]))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Implementation
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(defn create-registry
[]
(let [registry (CollectorRegistry.)]
(DefaultExports/register registry)
registry))
(defmacro with-measure
[& {:keys [expr cb]}]
`(let [start# (System/nanoTime)
tdown# ~cb]
(try
~expr
(finally
(tdown# (/ (- (System/nanoTime) start#) 1000000))))))
(defn make-counter
[{:keys [name help registry reg labels] :as props}]
(let [registry (or registry reg)
instance (.. (Counter/build)
(name name)
(help help))
_ (when (seq labels)
(.labelNames instance (into-array String labels)))
instance (.register instance registry)]
{::instance instance
::fn (fn [{:keys [by labels] :or {by 1}}]
(if labels
(.. ^Counter instance
(labels (into-array String labels))
(inc by))
(.inc ^Counter instance by)))}))
(defn make-gauge
[{:keys [name help registry reg labels] :as props}]
(let [registry (or registry reg)
instance (.. (Gauge/build)
(name name)
(help help))
_ (when (seq labels)
(.labelNames instance (into-array String labels)))
instance (.register instance registry)]
{::instance instance
::fn (fn [{:keys [cmd by labels] :or {by 1}}]
(if labels
(let [labels (into-array String [labels])]
(case cmd
:inc (.. ^Gauge instance (labels labels) (inc by))
:dec (.. ^Gauge instance (labels labels) (dec by))))
(case cmd
:inc (.inc ^Gauge instance by)
:dec (.dec ^Gauge instance by))))}))
(def default-quantiles
[[0.75 0.02]
[0.99 0.001]])
(defn make-summary
[{:keys [name help registry reg labels max-age quantiles buckets]
:or {max-age 3600 buckets 6 quantiles default-quantiles} :as props}]
(let [registry (or registry reg)
instance (doto (Summary/build)
(.name name)
(.help help))
_ (when (seq quantiles)
(.maxAgeSeconds ^Summary instance max-age)
(.ageBuckets ^Summary instance buckets))
_ (doseq [[q e] quantiles]
(.quantile ^Summary instance q e))
_ (when (seq labels)
(.labelNames instance (into-array String labels)))
instance (.register instance registry)]
{::instance instance
::fn (fn [{:keys [val labels]}]
(if labels
(.. ^Summary instance
(labels (into-array String labels))
(observe val))
(.observe ^Summary instance val)))}))
(def default-histogram-buckets
[1 5 10 25 50 75 100 250 500 750 1000 2500 5000 7500])
(defn make-histogram
[{:keys [name help registry reg labels buckets]
:or {buckets default-histogram-buckets}}]
(let [registry (or registry reg)
instance (doto (Histogram/build)
(.name name)
(.help help)
(.buckets (into-array Double/TYPE buckets)))
_ (when (seq labels)
(.labelNames instance (into-array String labels)))
instance (.register instance registry)]
{::instance instance
::fn (fn [{:keys [val labels]}]
(if labels
(.. ^Histogram instance
(labels (into-array String labels))
(observe val))
(.observe ^Histogram instance val)))}))
(defn create
[{:keys [type] :as props}]
(case type
:counter (make-counter props)
:gauge (make-gauge props)
:summary (make-summary props)
:histogram (make-histogram props)))
(defn wrap-counter
([rootf mobj]
(let [mdata (meta rootf)
origf (::original mdata rootf)]
(with-meta
(fn
([a]
((::fn mobj) nil)
(origf a))
([a b]
((::fn mobj) nil)
(origf a b))
([a b c]
((::fn mobj) nil)
(origf a b c))
([a b c d]
((::fn mobj) nil)
(origf a b c d))
([a b c d & more]
((::fn mobj) nil)
(apply origf a b c d more)))
(assoc mdata ::original origf))))
([rootf mobj labels]
(let [mdata (meta rootf)
origf (::original mdata rootf)]
(with-meta
(fn
([a]
((::fn mobj) {:labels labels})
(origf a))
([a b]
((::fn mobj) {:labels labels})
(origf a b))
([a b & more]
((::fn mobj) {:labels labels})
(apply origf a b more)))
(assoc mdata ::original origf)))))
(defn wrap-summary
([rootf mobj]
(let [mdata (meta rootf)
origf (::original mdata rootf)]
(with-meta
(fn
([a]
(with-measure
:expr (origf a)
:cb #((::fn mobj) {:val %})))
([a b]
(with-measure
:expr (origf a b)
:cb #((::fn mobj) {:val %})))
([a b & more]
(with-measure
:expr (apply origf a b more)
:cb #((::fn mobj) {:val %}))))
(assoc mdata ::original origf))))
([rootf mobj labels]
(let [mdata (meta rootf)
origf (::original mdata rootf)]
(with-meta
(fn
([a]
(with-measure
:expr (origf a)
:cb #((::fn mobj) {:val % :labels labels})))
([a b]
(with-measure
:expr (origf a b)
:cb #((::fn mobj) {:val % :labels labels})))
([a b & more]
(with-measure
:expr (apply origf a b more)
:cb #((::fn mobj) {:val % :labels labels}))))
(assoc mdata ::original origf)))))
(defn instrument-vars!
[vars {:keys [wrap] :as props}]
(let [obj (create props)]
(cond
(instance? Counter (::instance obj))
(doseq [var vars]
(alter-var-root var (or wrap wrap-counter) obj))
(instance? Summary (::instance obj))
(doseq [var vars]
(alter-var-root var (or wrap wrap-summary) obj))
:else
(ex/raise :type :not-implemented))))
(defn instrument
[f {:keys [wrap] :as props}]
(let [obj (create props)]
(cond
(instance? Counter (::instance obj))
((or wrap wrap-counter) f obj)
(instance? Summary (::instance obj))
((or wrap wrap-summary) f obj)
(instance? Histogram (::instance obj))
((or wrap wrap-summary) f obj)
:else
(ex/raise :type :not-implemented))))
(defn instrument-jetty!
[^CollectorRegistry registry ^StatisticsHandler handler]
(doto (JettyStatisticsCollector. handler)
(.register registry))
nil)