penpot/backend/src/app/rpc/climit.clj
2024-04-15 14:27:24 +02:00

275 lines
8.8 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) KALEIDOS INC
(ns app.rpc.climit
"Concurrencly limiter for RPC."
(:refer-clojure :exclude [run!])
(:require
[app.common.exceptions :as ex]
[app.common.logging :as l]
[app.common.spec :as us]
[app.config :as cf]
[app.metrics :as mtx]
[app.rpc :as-alias rpc]
[app.rpc.climit.config :as-alias config]
[app.util.cache :as cache]
[app.util.services :as-alias sv]
[app.util.time :as dt]
[app.worker :as-alias wrk]
[clojure.edn :as edn]
[clojure.set :as set]
[clojure.spec.alpha :as s]
[datoteka.fs :as fs]
[integrant.core :as ig]
[promesa.exec :as px]
[promesa.exec.bulkhead :as pbh])
(:import
clojure.lang.ExceptionInfo
java.util.concurrent.atomic.AtomicLong))
(set! *warn-on-reflection* true)
(defn- id->str
([id]
(-> (str id)
(subs 1)))
([id key]
(if key
(str (-> (str id) (subs 1)) "/" key)
(id->str id))))
(defn- create-cache
[{:keys [::wrk/executor]}]
(letfn [(on-remove [key _ cause]
(let [[id skey] key]
(l/trc :hint "disposed" :id (id->str id skey) :reason (str cause))))]
(cache/create :executor executor
:on-remove on-remove
:keepalive "5m")))
(s/def ::config/permits ::us/integer)
(s/def ::config/queue ::us/integer)
(s/def ::config/timeout ::us/integer)
(s/def ::config
(s/map-of keyword?
(s/keys :opt-un [::config/permits
::config/queue
::config/timeout])))
(defmethod ig/prep-key ::rpc/climit
[_ cfg]
(assoc cfg ::path (cf/get :rpc-climit-config)))
(s/def ::path ::fs/path)
(defmethod ig/pre-init-spec ::rpc/climit [_]
(s/keys :req [::mtx/metrics ::wrk/executor ::path]))
(defmethod ig/init-key ::rpc/climit
[_ {:keys [::path ::mtx/metrics] :as cfg}]
(when (contains? cf/flags :rpc-climit)
(when-let [params (some->> path slurp edn/read-string)]
(l/inf :hint "initializing concurrency limit" :config (str path))
(us/verify! ::config params)
{::cache (create-cache cfg)
::config params
::mtx/metrics metrics})))
(s/def ::cache cache/cache?)
(s/def ::instance
(s/keys :req [::cache ::config]))
(s/def ::rpc/climit
(s/nilable ::instance))
(defn- create-limiter
[config [id skey]]
(l/trc :hint "created" :id (id->str id skey))
(pbh/create :permits (or (:permits config) (:concurrency config))
:queue (or (:queue config) (:queue-size config))
:timeout (:timeout config)
:type :semaphore))
(defn measure!
[metrics mlabels stats elapsed]
(let [mpermits (:max-permits stats)
permits (:permits stats)
queue (:queue stats)
queue (- queue mpermits)
queue (if (neg? queue) 0 queue)]
(mtx/run! metrics
:id :rpc-climit-queue
:val queue
:labels mlabels)
(mtx/run! metrics
:id :rpc-climit-permits
:val permits
:labels mlabels)
(when elapsed
(mtx/run! metrics
:id :rpc-climit-timing
:val (inst-ms elapsed)
:labels mlabels))))
(defn log!
[action req-id stats limit-id limit-label params elapsed]
(let [mpermits (:max-permits stats)
queue (:queue stats)
queue (- queue mpermits)
queue (if (neg? queue) 0 queue)
level (if (pos? queue) :warn :trace)]
(l/log level
:hint action
:req req-id
:id limit-id
:label limit-label
:queue queue
:elapsed (some-> elapsed dt/format-duration)
:params (-> (select-keys params [::rpc/profile-id :file-id :profile-id])
(set/rename-keys {::rpc/profile-id :profile-id})
(update-vals str)))))
(def ^:private idseq (AtomicLong. 0))
(defn- invoke
[limiter metrics limit-id limit-key limit-label handler params]
(let [tpoint (dt/tpoint)
mlabels (into-array String [(id->str limit-id)])
limit-id (id->str limit-id limit-key)
stats (pbh/get-stats limiter)
req-id (.incrementAndGet ^AtomicLong idseq)]
(try
(measure! metrics mlabels stats nil)
(log! "enqueued" req-id stats limit-id limit-label params nil)
(px/invoke! limiter (fn []
(let [elapsed (tpoint)
stats (pbh/get-stats limiter)]
(measure! metrics mlabels stats elapsed)
(log! "acquired" req-id stats limit-id limit-label params elapsed)
(handler params))))
(catch ExceptionInfo cause
(let [{:keys [type code]} (ex-data cause)]
(if (= :bulkhead-error type)
(let [elapsed (tpoint)]
(log! "rejected" req-id stats limit-id limit-label params elapsed)
(ex/raise :type :concurrency-limit
:code code
:hint "concurrency limit reached"
:cause cause))
(throw cause))))
(finally
(let [elapsed (tpoint)
stats (pbh/get-stats limiter)]
(measure! metrics mlabels stats nil)
(log! "finished" req-id stats limit-id limit-label params elapsed))))))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; MIDDLEWARE
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(def ^:private noop-fn (constantly nil))
(def ^:private global-limits
[[:root/global noop-fn]
[:root/by-profile ::rpc/profile-id]])
(defn- get-limits
[cfg]
(when-let [ref (get cfg ::id)]
(cond
(keyword? ref)
[[ref]]
(and (vector? ref)
(keyword (first ref)))
[ref]
(and (vector? ref)
(vector? (first ref)))
(rseq ref)
:else
(throw (IllegalArgumentException. "unable to normalize limit")))))
(defn wrap
[{:keys [::rpc/climit ::mtx/metrics]} handler mdata]
(let [cache (::cache climit)
config (::config climit)
label (::sv/name mdata)]
(if climit
(reduce (fn [handler [limit-id key-fn]]
(if-let [config (get config limit-id)]
(let [key-fn (or key-fn noop-fn)]
(l/trc :hint "instrumenting method"
:method label
:limit (id->str limit-id)
:timeout (:timeout config)
:permits (:permits config)
:queue (:queue config)
:keyed (not= key-fn noop-fn))
(if (and (= key-fn ::rpc/profile-id)
(false? (::rpc/auth mdata true)))
;; We don't enforce by-profile limit on methods that does
;; not require authentication
handler
(fn [cfg params]
(let [limit-key (key-fn params)
cache-key [limit-id limit-key]
limiter (cache/get cache cache-key (partial create-limiter config))
handler (partial handler cfg)]
(invoke limiter metrics limit-id limit-key label handler params)))))
(do
(l/wrn :hint "no config found for specified queue" :id (id->str limit-id))
handler)))
handler
(concat global-limits (get-limits mdata)))
handler)))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; PUBLIC API
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(defn- build-exec-chain
[{:keys [::label ::rpc/climit ::mtx/metrics] :as cfg} f]
(let [config (get climit ::config)
cache (get climit ::cache)]
(reduce (fn [handler [limit-id limit-key :as ckey]]
(if-let [config (get config limit-id)]
(fn [cfg params]
(let [limiter (cache/get cache ckey (partial create-limiter config))
handler (partial handler cfg)]
(invoke limiter metrics limit-id limit-key label handler params)))
(do
(l/wrn :hint "config not found" :label label :id limit-id)
f)))
f
(get-limits cfg))))
(defn invoke!
"Run a function in context of climit.
Intended to be used in virtual threads."
[{:keys [::executor] :as cfg} f params]
(let [f (if (some? executor)
(fn [cfg params] (px/await! (px/submit! executor (fn [] (f cfg params)))))
f)
f (build-exec-chain cfg f)]
(f cfg params)))