Inject a different factory function that creates a fixed sized request queue.

cloure-jetty-q-snipet.clj

(def jetty-req-q (java.util.concurrent.ArrayBlockingQueue. configuration/http-queue-length))

(defn create-threadpool [options]
  (let [pool (org.eclipse.jetty.util.thread.QueuedThreadPool. (options :max-threads configuration/http-max-threads)
                                (options :min-threads configuration/http-min-threads)
                                0
                                jetty-req-q)]
    (.setMinThreads pool (options :min-threads configuration/http-min-threads))
    (when (:daemon? options false)
      (.setDaemon pool true))
    pool))

(alter-var-root #'ring.adapter.jetty/create-threadpool
                (constantly create-threadpool))