使用Clojure进行服务器编程 [英] Server programming with Clojure

问题描述

如何在Clojure中实现10k连接echo服务器？

How to implement 10k connections echo server in Clojure?

clojure.contrib.server-socket不是答案，因为它为每个连接创建一个新的操作系统线程。

clojure.contrib.server-socket is not the answer since it crates a new OS thread for every connection.

推荐答案

Clojure的伟大之处在于，所有这些伟大的库都有JVM，例如 netty ，这些都是高度优化，可配置和精心设计的。这样的东西应该让你去：

The great thing about Clojure is you have all these great libraries out there for the JVM like netty, which are highly optimized, configurable, and well thought out. Something like this should get you going:

(ns netty
  (:gen-class)
  (:import
     [java.net InetSocketAddress]
     [java.util.concurrent Executors]
     [org.jboss.netty.bootstrap ServerBootstrap]
     [org.jboss.netty.channel Channels ChannelPipelineFactory
                              SimpleChannelHandler]
     [org.jboss.netty.channel.socket.nio NioServerSocketChannelFactory]
     [org.jboss.netty.buffer ChannelBuffers]))

(declare make-handler)

(defn start
  "Start a Netty server. Returns the pipeline."
  [port handler]
  (let [channel-factory (NioServerSocketChannelFactory.
                          (Executors/newCachedThreadPool)
                          (Executors/newCachedThreadPool))
        bootstrap (ServerBootstrap. channel-factory)
        pipeline (.getPipeline bootstrap)]
    (.addLast pipeline "handler" (make-handler))
    (.setOption bootstrap "child.tcpNoDelay", true)
    (.setOption bootstrap "child.keepAlive", true)
    (.bind bootstrap (InetSocketAddress. port))
    pipeline))

(defn make-handler
  "Returns a Netty handler."
  []
  (proxy [SimpleChannelHandler] []
    (channelConnected [ctx e]
      (let [c (.getChannel e)]
        (println "Connected:" c)))

    (channelDisconnected [ctx e]
      (let [c (.getChannel e)]
        (println "Disconnected:" c)))

    (messageReceived [ctx e]
      (let [c (.getChannel e)
            cb (.getMessage e)
            msg (.toString cb "UTF-8")]
        (println "Message:" msg "from" c)))

    (exceptionCaught
      [ctx e]
      (let [throwable (.getCause e)]
        (println "@exceptionCaught" throwable))
      (-> e .getChannel .close))))

这篇关于使用Clojure进行服务器编程的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！