java.lang.UnsupportedOperationException: 反射 setAccessible(true) 已禁用(java.lang.UnsupportedOperationException: Reflective setAccessible(true) disabled)

问题 当我使用gradle run运行 Ktor 应用程序时, gradle run以下异常: 19:21:11.795 [main] DEBUG io.netty.util.internal.logging.InternalLoggerFactory - Using SLF4J as the default logging framework 19:21:11.810 [main] DEBUG io.netty.util.internal.PlatformDependent0 - -Dio.netty.noUnsafe: false 19:21:11.810 [main] DEBUG io.netty.util.internal.PlatformDependent0 - Java version: 11 19:21:11.811 [main] DEBUG io.netty.util.internal.PlatformDependent0 - sun.misc.Unsafe.theUnsafe: available 19:21:11.812 [main] DEBUG io.netty.util.internal.PlatformDependent0 - sun.misc.Unsafe.copyMemory: available 19:21:11.812 [main] DEBUG

2021-12-05 09:53:12    分类:技术分享    java   kotlin   netty   ktor

在底层使用 Netty 与 Tomcat 时,Spring webFlux 存在差异(Spring webFlux differrences when Netty vs Tomcat is used under the hood)

问题 我正在学习 spring webflux 并且我已经阅读了以下系列文章(第一,第二,第三) 在第三条中,我遇到了以下文字: 请记住,相同的应用程序代码运行在 Tomcat、Jetty 或 Netty 上。 目前,Tomcat 和 Jetty 支持是在 Servlet 3.1 异步处理之上提供的,因此它仅限于每个线程一个请求。 当相同的代码在 Netty 服务器平台上运行时,约束被解除,服务器可以同情地将请求分派到 Web 客户端。 只要客户端不阻塞,大家都开心。 netty 服务器和客户端的性能指标可能表现出相似的特征,但 Netty 服务器不限于处理每个线程的单个请求,因此它不使用大型线程池,我们可能会看到资源利用率的一些差异。 我们稍后将在本系列的另一篇文章中回到这一点。 首先,我没有看到该系列中较新的文章,尽管它是 2016 年写的。我很清楚 tomcat 默认有 100 个线程来处理请求,一个线程同时处理一个请求,但我没有理解短语it is limited to an request per thread是什么意思? 我也想知道 Netty 在那个具体案例中是如何工作的(我想了解与 Tomcat 的区别)。 每个线程可以处理 2 个请求吗? 回答1 目前有 2 个基本概念来处理对 Web 服务器的并行访问,它们具有各种优点和缺点: 阻塞非阻塞 阻止 Web 服务器

2021-12-05 04:18:15    分类:技术分享    java   tomcat   netty   spring-webflux   nonblocking

如何在其他类中阅读netty中的消息(How to read Message in netty in other class)

问题 我想在InboundHandler以外的类中的特定位置读取消息。 我在从 netty 框架调用的channelRead0方法中找不到读取它的方法。 例如: context.writeMessage("message"); String msg = context.readMessage; 如果这是不可能的,我如何将在channelRead0方法中获得的结果映射到我在另一个类中进行的特定调用? 回答1 Netty 框架被设计为异步驱动。 使用这个类比,它可以以最少的线程使用处理大量连接。 如果您正在创建一个使用 netty 框架将调用分派到远程位置的 api,您应该对您的调用使用相同的类比。 与其让你的 api 直接返回值,不如让它返回 Future<?> 或 Promise<?>。 在您的应用程序中实现这个系统的方法有多种,最简单的方法是创建一个自定义处理程序,将传入的请求映射到 FIFO 队列中的Promise s。 这方面的一个例子可能如下: 这很大程度上基于我过去提交的这个答案。 我们从将请求映射到我们管道中的请求的 out 处理程序开始: public class MyLastHandler extends SimpleInboundHandler<String> { private final SynchronousQueue<Promise<String>>

2021-11-30 04:00:26    分类:技术分享    java   netty

如何在netty中捕获所有异常(How to catch all exception in netty)

问题 据我所知,netty 通过覆盖方法 exceptionCaught() 处理异常。 但我想要的是一个可以处理所有异常输入或输出的处理程序。 所以,管道应该是这样的: InboundExceptionHandler - inboundHandler1 - inboundHandler2 - outboundHandler1 - outboundHandler2 - OutboundExceptionHandler 这意味着我应该在我的管道中放置 2 个异常处理程序,以头部和尾部分开。 但我觉得它看起来很丑。 有什么更好的主意吗? 回答1 您可以在管道的顶部/尾部只有一个入站和出站异常处理程序。 如果您想捕获所有异常,您可以执行以下操作(我假设这是 Netty 4.0): import io.netty.channel.*; import java.net.SocketAddress; public class ExceptionHandler extends ChannelDuplexHandler { @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) { // Uncaught exceptions from inbound handlers will

2021-11-29 19:32:49    分类:技术分享    java   exception-handling   netty

Facing NoSuchMethodError for io.netty.util.AttributeKey.valueOf() method with grpc and protobuf Hello world example

After running GreetingServerTest.java tests I am getting below given errors. I am using grpc 1.1.0-SNAPSHOT libraries and trying to implement basic Helloword example of grpc given in there git repo. Can anybody please suggest which libraries I am missing or there's anything else I need to do. java.lang.NoSuchMethodError: io.netty.util.AttributeKey.valueOf(Ljava/lang/Class;Ljava/lang/String;)Lio/netty/util/AttributeKey; at io.grpc.netty.Utils.<clinit>(Utils.java:87) at io.grpc.netty.NettyServer.allocateSharedGroups(NettyServer.java:187) at io.grpc.netty.NettyServer.start(NettyServer.java:116)

2021-11-29 01:20:59    分类:问答    java   maven-2   netty   protocol-buffers   grpc-java

Does AsyncHttpClient knows how many threads to allocate for all the HTTP requests

I'm evaluating AsyncHttpClient for big loads (~1M HTTP requests). For each request I would like to invoke a callback using the AsyncCompletionHandler which will just insert the result into a blocking queue My question is: if I'm sending asynchronous requests in a tight loop, how many threads will the AsyncHttpClient use? (I know you can set the max but apparently you take a risk of losing requests, I've seen it here) I'm currently using the Netty implementation with these versions: async-http-client v1.9.33 netty v3.10.5.Final I don't mind using other versions if there are any optimization in

2021-11-28 18:07:46    分类:问答    java   multithreading   http   netty   asynchttpclient

latency in netty due to passing requests from boss thread to worker thread?

I have some questions about Netty (Server Side), TCP/IP applications; I am wondering if there can be latency because of netty (due to missing configuration etc.) while passing the request from boss thread to worker thread ? I am using : new OrderedMemoryAwareThreadPoolExecutor(350, 0, 0, 1, TimeUnit.SECONDS); Actually, I set max thread count 350 as I am not sure about the optimal number. I log simultaneous working thread count every minute and it seems that average is too low (barely exceeds 10). So I will decrease this number as it is not required. Is there any other parameters,important

2021-11-28 10:58:22    分类:问答    java   performance   tcp   netty   tcplistener

Why do we really need multiple netty boss threads?

I'm really confused about the number of threads for a boss group. I can't figure out a scenario where we need more than one boss thread. In do we need more than a single thread for boss group? the creator of Netty says multiple boss threads are useful if we share NioEventLoopGroup between different server bootstraps, but I don't see the reason for it. Consider this simple Echo server: public class EchoServer { private final int port; private List<ChannelFuture> channelFutures = new ArrayList<ChannelFuture>(2); public EchoServer(int port) { this.port = port; } public void start() throws

2021-11-27 20:15:27    分类:问答    netty

in netty, we can only write and receive data less than 1024bytes: how we can write or receive more?

When writing 2048bytes in on handler, the messageRevieved method should be called twice to receive the all data... how I can receive the 2048bytes data in Code Server: public class Server{ public static void main(String[] args){ ChannelFactory factory=new NioServerSocketChannelFactory( Executors.newCachedThreadPool(), Executors.newCachedThreadPool()); ServerBootstrap bootstrap=new ServerBootstrap(factory); bootstrap.setPipelineFactory(new CarPipelineFactory()); bootstrap.setOption("child.tcpNoDelay", true); bootstrap.setOption("child.keepAlive", true); bootstrap.bind(new InetSocketAddress(8989

2021-11-27 20:04:05    分类:问答    netty

Boundaries between Services, Filters, and Codecs in Finagle

Netty, which is used within Finagle, uses a pipeline of "handlers" to sequentially process in and out bound data. Netty examples, and included libraries, show various handlers used for things such as authentication, protocol codecs, and the actual business logic of the service. Finagle appears to take the handler concept, and instead directly offer API users codecs, filters, and services. While these have varying signatures, new users of Finagle are left with the tasks of deciding which to use in order to implement each portion of their overall server. Instead of merely deciding where to break

2021-11-27 19:29:18    分类:问答    scala   netty   finagle