Can there be multiple eventloop threads for Netty UDP server?

1
votes

I'm trying to build a UDP server based on Netty to continuously publish events (about 500 events per second) to different clients based on client subscription (a few UDP request/response messages are exchanged before a subscription setup).

The design is to have a few producer/consumer threads created by Java Executors. Once a messages is generated, consumer threads will write it to the UDP channel.

The observation is there's only one EventLoop thread working for that UDP channel in server end, and it is quite busy with writing messages to socket, so the response to the 2nd and later client's subscription request is quite slow.

So wondering if any way to enable multiple worker threads for NIO UDP server end, so that one or a few threads busy with writing publishing events to socket, we still have other threads to process new client subscription requests without delay. Any suggestions are much appreciated.

btw, server-side Netty handlers are quite simple: a logging handler, a decoder hander, a encoder handler, and a subscription handler.

1
javamultithreadingnetty
Could you show me your code？Maybe you can set Bootstrap bootstrap = new Bootstrap() .group(new NioEventLoopGroup(N)); to create N threads. - Mattia Dinosaur
Thanks @mattia. Here's the code snipper - code Bootstrap udpBoot = new Bootstrap(); udpBoot.group(new NioEventLoopGroup(10).channel(NioDatagramChannel.class).option(ChannelOption.SO_BROADCAST, true).option(ChannelOption.SO_REUSEADDR, true).handler(new ChannelInitializer<Datagram>(){ @Override protected void initChannel(DatagramChannel ch) throws Exception {ch.pipeline().addLast(loggingHandler).addLast(new MyDatagramToPojoDecoder(adapter)).addLast(new MyPojoToDatagramEncoder(adapter)).addLast(new MySessionHandler(service)).addLast(new MySubscriptionHandler(service));}});code - Wei Song
I guess Netty is allocating EventLoop threads to different channels, however in UDP, there's only one channel, this way only eventloop thread is working. - Wei Song

1 Answers

0
votes

Short answer in general no... As a Channel is always tied to one EventLoop there will only be one Thread handling it. That said if you use the native epoll transport (which only works on linux) you can use EpollChannelOption.SO_REUSEPORT to bind multiple Channels to the same port which are handled by different EventLoops and so Threads.