netty-protobuf-rpc与protobuf-socket-rpc互通

最新推荐文章于 2022-06-01 15:02:15 发布

原创最新推荐文章于 2022-06-01 15:02:15 发布 · 2k 阅读

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本文介绍了protobuf-socket-rpc的使用注意事项，包括短连接管理、protobuf定义文件一致性及分片发送限制等内容，并针对网络不可用时的阻塞问题提出了改进方案。

关键所在：

1，protobuf-socket-rpc使用的是短连接，发送完成后，则需要将socket上行关闭

2，rpc.proto文件要统一

class NettyRpcPipelineFactory implements ChannelPipelineFactory {
	public ChannelPipeline getPipeline() throws Exception {
		ChannelPipeline p = Channels.pipeline();
//		p.addLast("frameDecoder", new LengthFieldBasedFrameDecoder(MAX_FRAME_BYTES_LENGTH, 0, 4, 0, 4));
		p.addLast("protobufDecoder",  new ProtobufDecoder(defaultInstance));
//		p.addLast("frameEncoder", new LengthFieldPrepender(4));
		p.addLast("protobufEncoder", new ProtobufEncoder());
		
		p.addLast("handler", handlerFactory.getChannelUpstreamHandler()); 
		return p;
	}
}
public class NettyRpcClientChannelUpstreamHandler extends SimpleChannelUpstreamHandler {

	@Override
	public void writeComplete(ChannelHandlerContext ctx, WriteCompletionEvent e) {

		try {
			NioSocketChannel ch = (NioSocketChannel) e.getChannel();
			DefaultSocketChannelConfig cfg = (DefaultSocketChannelConfig) ch
					.getConfig();
			Field f = DefaultSocketChannelConfig.class
					.getDeclaredField("socket");
			f.setAccessible(true);
			Socket socket = (Socket) f.get(cfg);
			socket.shutdownOutput();
		} catch (Exception e1) {
			e1.printStackTrace();
		}
	}
}

3, protobuf-socket-rpc不支持分片发送，对数据较大的数据包，3K以上，建议使用netty-probuf-rpc提供的rpc实现

4，无网络时，会造成netty阻塞，改动方法如下：

	public Message callBlockingMethod(MethodDescriptor method,RpcController controller, Message request, Message responsePrototype)
      throws ServiceException {
        BlockingRpcCallback callback = new BlockingRpcCallback();
        ResponsePrototypeRpcCallback rpcCallback = new ResponsePrototypeRpcCallback(controller, responsePrototype, callback);
        int nextSeqId = handler.getNextSeqId();
   
        Message Request = buildRequest(method, request);
        handler.registerCallback(nextSeqId, rpcCallback);

        ChannelFuture future = this.channel.write(Request);
        try {
            future.sync();
        }
        catch (InterruptedException e1) {
            e1.printStackTrace();
        }		
	synchronized(callback) {
	    while(!callback.isDone()) {
		try {
			callback.wait();
		} catch (InterruptedException e) {
			logger.warn("Interrupted while blocking", e);
			/* Ignore */
		}
	   }
	}
...
}