RocketMQ4.3.X關於設置useEpollNativeSelector = true報錯問題

前一陣子剛整理完RocketMQ4.3.x版本的相關配置的工作，接下來就來測試一下改變參數會帶來什麼好的結果

首先我就選中了useEpollNativeSelector 這個參數

預設這個參數是 false

這個參數的意思就是是否啟用Epoll IO模型。Linux環境建議開啟

然後我就打開了這個參數試試看看會不會生效

首先是namesrv 弄了一個配置文件指向啟動

然後啟動namesrv

sh bin/mqnamesrv -c conf/namesrv.conf 

很不幸拋出了一個異常

java.lang.IllegalStateException: incompatible event loop type: io.netty.channel.nio.NioEventLoop
	at io.netty.channel.AbstractChannel$AbstractUnsafe.register(AbstractChannel.java:411)
	at io.netty.channel.SingleThreadEventLoop.register(SingleThreadEventLoop.java:72)
	at io.netty.channel.SingleThreadEventLoop.register(SingleThreadEventLoop.java:60)
	at io.netty.channel.MultithreadEventLoopGroup.register(MultithreadEventLoopGroup.java:64)
	at io.netty.bootstrap.AbstractBootstrap.initAndRegister(AbstractBootstrap.java:320)
	at io.netty.bootstrap.AbstractBootstrap.doBind(AbstractBootstrap.java:271)
	at io.netty.bootstrap.AbstractBootstrap.bind(AbstractBootstrap.java:235)
	at org.apache.rocketmq.remoting.netty.NettyRemotingServer.start(NettyRemotingServer.java:212)
	at org.apache.rocketmq.namesrv.NamesrvController.start(NamesrvController.java:156)
	at org.apache.rocketmq.namesrv.NamesrvStartup.start(NamesrvStartup.java:154)
	at org.apache.rocketmq.namesrv.NamesrvStartup.main0(NamesrvStartup.java:58)
	at org.apache.rocketmq.namesrv.NamesrvStartup.main(NamesrvStartup.java:51)

通過拋出的異常追查一下源碼

源碼位置

發現在執行構造函數的時候初始化的是下麵代碼 90-143行

public NettyRemotingServer(final NettyServerConfig nettyServerConfig,
        final ChannelEventListener channelEventListener) {
        super(nettyServerConfig.getServerOnewaySemaphoreValue(), nettyServerConfig.getServerAsyncSemaphoreValue());
        this.serverBootstrap = new ServerBootstrap();
        this.nettyServerConfig = nettyServerConfig;
        this.channelEventListener = channelEventListener;

        int publicThreadNums = nettyServerConfig.getServerCallbackExecutorThreads();
        if (publicThreadNums <= 0) {
            publicThreadNums = 4;
        }

        this.publicExecutor = Executors.newFixedThreadPool(publicThreadNums, new ThreadFactory() {
            private AtomicInteger threadIndex = new AtomicInteger(0);

            @Override
            public Thread newThread(Runnable r) {
                return new Thread(r, "NettyServerPublicExecutor_" + this.threadIndex.incrementAndGet());
            }
        });

        this.eventLoopGroupBoss = new NioEventLoopGroup(1, new ThreadFactory() {
            private AtomicInteger threadIndex = new AtomicInteger(0);

            @Override
            public Thread newThread(Runnable r) {
                return new Thread(r, String.format("NettyBoss_%d", this.threadIndex.incrementAndGet()));
            }
        });

        if (useEpoll()) {
            this.eventLoopGroupSelector = new EpollEventLoopGroup(nettyServerConfig.getServerSelectorThreads(), new ThreadFactory() {
                private AtomicInteger threadIndex = new AtomicInteger(0);
                private int threadTotal = nettyServerConfig.getServerSelectorThreads();

                @Override
                public Thread newThread(Runnable r) {
                    return new Thread(r, String.format("NettyServerEPOLLSelector_%d_%d", threadTotal, this.threadIndex.incrementAndGet()));
                }
            });
        } else {
            this.eventLoopGroupSelector = new NioEventLoopGroup(nettyServerConfig.getServerSelectorThreads(), new ThreadFactory() {
                private AtomicInteger threadIndex = new AtomicInteger(0);
                private int threadTotal = nettyServerConfig.getServerSelectorThreads();

                @Override
                public Thread newThread(Runnable r) {
                    return new Thread(r, String.format("NettyServerNIOSelector_%d_%d", threadTotal, this.threadIndex.incrementAndGet()));
                }
            });
        }

        loadSslContext();
    }

也就是說這裡接收鏈接的線程池 eventLoopGroupBoss 永遠都是 NioEventLoopGroup  如果設置了useEpollNativeSelector=true就會初始化EpollEventLoopGroup這個類處理請求

這樣就會造成兩種線程模型的不相容狀態

導致出現異常 java.lang.IllegalStateException: incompatible event loop type: io.netty.channel.nio.NioEventLoop

按常理說阿裡的人不會出現這樣的低級錯誤啊

回頭又看了看github的bug列表果然有人提這個問題bug還是開啟狀態

？？？？為什麼？

難道是我使用配置有問題嗎？還是哪裡理解有誤那？知道的網友可以告訴我啊！！！！

最新消息我也提交了bug維護人員已經修改bug但是要等到4.4.1版本才可以修正