Aleph connection leak

core.clj

(ns aleph-conn-leak.core
  (:require [aleph.http :as http]
            [org.httpkit.server :as hkit]
            [manifold.deferred :as d]
            [taoensso.timbre :as log])
  (:import (java.net InetAddress InetSocketAddress)))

(comment
  dependencies are as follows

  [[org.clojure/clojure "1.8.0"]
   [com.taoensso/timbre "4.7.4"]
   [aleph "0.4.1"]
   [http-kit "2.1.16"]])

(defn handler [_]
  {:status 200
   :body "Hello, world"})

(defn start-server []
  (hkit/run-server #'handler {:port 9992
                              :ip "localhost"}))

(def server (start-server))

(def client-pool (http/connection-pool {:keep-alive? true
                                        :connections-per-host 128}))


(defn make-request []
  (http/post "http://localhost:9992" {:headers {"Connection" "Close"} ;; this is important
                                      :pool client-pool}))

(defn make-requests [num-reqs]
  (let [req-count (atom 0)]
    (->> (repeatedly num-reqs #(make-request))
         (map #(d/chain % (fn [_]
                            (log/infof "---> Request done: %s"
                                       (swap! req-count inc))
                            :ok)))
         doall
         (apply d/zip))))


;; fails with ExceptionInfo connection was closed  clojure.core/ex-info (core.clj:4617)
@(make-requests 100)