merlimat commented on a change in pull request #548: PIP-1 - Introduce Pulsar proxy component URL: https://github.com/apache/incubator-pulsar/pull/548#discussion_r126274730
########## File path: pulsar-proxy/src/main/java/org/apache/pulsar/proxy/server/DirectProxyHandler.java ########## @@ -0,0 +1,181 @@ +/** + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ + +package org.apache.pulsar.proxy.server; + +import java.net.URI; +import java.net.URISyntaxException; + +import org.apache.pulsar.client.api.Authentication; +import org.apache.pulsar.common.api.Commands; +import org.apache.pulsar.common.api.PulsarDecoder; +import org.apache.pulsar.common.api.PulsarLengthFieldFrameDecoder; +import org.apache.pulsar.common.api.proto.PulsarApi.CommandConnected; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import io.netty.bootstrap.Bootstrap; +import io.netty.buffer.PooledByteBufAllocator; +import io.netty.channel.Channel; +import io.netty.channel.ChannelFuture; +import io.netty.channel.ChannelHandlerContext; +import io.netty.channel.ChannelInitializer; +import io.netty.channel.ChannelOption; +import io.netty.channel.socket.SocketChannel; +import io.netty.util.concurrent.Future; +import io.netty.util.concurrent.FutureListener; + +public class DirectProxyHandler { + + private Channel inboundChannel; + Channel outboundChannel; + + private final Authentication authentication; + + public DirectProxyHandler(ProxyService service, ProxyConnection proxyConnection, String targetBrokerUrl) { + this.authentication = service.getClientAuthentication(); + this.inboundChannel = proxyConnection.ctx().channel(); + + // Start the connection attempt. + Bootstrap b = new Bootstrap(); + // Tie the backend connection on the same thread to avoid context switches when passing data between the 2 + // connections + b.option(ChannelOption.ALLOCATOR, PooledByteBufAllocator.DEFAULT); + b.group(inboundChannel.eventLoop()).channel(inboundChannel.getClass()).option(ChannelOption.AUTO_READ, false); + b.handler(new ChannelInitializer<SocketChannel>() { + @Override + protected void initChannel(SocketChannel ch) throws Exception { + ch.pipeline().addLast("frameDecoder", + new PulsarLengthFieldFrameDecoder(PulsarDecoder.MaxFrameSize, 0, 4, 0, 4)); + ch.pipeline().addLast(new ProxyBackendHandler()); + } + }); + + URI targetBroker; + try { + // targetBrokerUrl is coming in the "hostname:6650" form, so we need to extract host and port + targetBroker = new URI("pulsar://" + targetBrokerUrl); + } catch (URISyntaxException e) { + log.warn("[{}] Failed to parse broker url '{}'", inboundChannel, targetBrokerUrl, e); + inboundChannel.close(); + return; + } + + ChannelFuture f = b.connect(targetBroker.getHost(), targetBroker.getPort()); + outboundChannel = f.channel(); + f.addListener(future -> { + if (!future.isSuccess()) { + // Close the connection if the connection attempt has failed. + inboundChannel.close(); + } + }); + } + + enum BackendState { + Init, HandshakeCompleted + } + + public class ProxyBackendHandler extends PulsarDecoder implements FutureListener<Void> { + + private BackendState state = BackendState.Init; + + @Override + public void channelActive(ChannelHandlerContext ctx) throws Exception { + // Send the Connect command to broker + String authData = ""; + if (authentication.getAuthData().hasDataFromCommand()) { + authData = authentication.getAuthData().getCommandData(); + } + outboundChannel + .writeAndFlush(Commands.newConnect(authentication.getAuthMethodName(), authData, "Pulsar proxy")); + outboundChannel.read(); + } + + @Override + public void channelRead(final ChannelHandlerContext ctx, Object msg) throws Exception { + switch (state) { + case Init: + if (log.isDebugEnabled()) { + log.debug("[{}] [{}] Received msg on broker connection: {}", inboundChannel, outboundChannel, + msg.getClass()); + } + + // Do the regular decoding for the Connected message + super.channelRead(ctx, msg); + break; + + case HandshakeCompleted: + inboundChannel.writeAndFlush(msg).addListener(this); + break; + + default: + break; + } + + } + + @Override + public void operationComplete(Future<Void> future) throws Exception { + // This is invoked when the write operation on the paired connection is completed + if (future.isSuccess()) { + outboundChannel.read(); Review comment: No, the auto-read on the channel is set to false. The reason is to adapt to the speed of the slowest connection. So, we read 1 buffer from `c1`, write into `c2`. When the write is completed (meaning we were able to write on the socket because the TCP send window was open), then we read the next buffer. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
