Github user zhijiangW commented on a diff in the pull request:
https://github.com/apache/flink/pull/4509#discussion_r141377486
--- Diff:
flink-runtime/src/main/java/org/apache/flink/runtime/io/network/netty/CreditBasedClientHandler.java
---
@@ -0,0 +1,283 @@
+/*
+ * 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.flink.runtime.io.network.netty;
+
+import org.apache.flink.core.memory.MemorySegment;
+import org.apache.flink.core.memory.MemorySegmentFactory;
+import org.apache.flink.runtime.io.network.buffer.Buffer;
+import org.apache.flink.runtime.io.network.buffer.FreeingBufferRecycler;
+import
org.apache.flink.runtime.io.network.netty.exception.LocalTransportException;
+import
org.apache.flink.runtime.io.network.netty.exception.RemoteTransportException;
+import
org.apache.flink.runtime.io.network.netty.exception.TransportException;
+import
org.apache.flink.runtime.io.network.partition.PartitionNotFoundException;
+import
org.apache.flink.runtime.io.network.partition.consumer.InputChannelID;
+import
org.apache.flink.runtime.io.network.partition.consumer.RemoteInputChannel;
+
+import org.apache.flink.shaded.guava18.com.google.common.collect.Maps;
+import
org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandlerContext;
+import
org.apache.flink.shaded.netty4.io.netty.channel.ChannelInboundHandlerAdapter;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.net.SocketAddress;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.atomic.AtomicReference;
+
+class CreditBasedClientHandler extends ChannelInboundHandlerAdapter {
+
+ private static final Logger LOG =
LoggerFactory.getLogger(CreditBasedClientHandler.class);
+
+ private final ConcurrentMap<InputChannelID, RemoteInputChannel>
inputChannels = new ConcurrentHashMap<>();
+
+ private final AtomicReference<Throwable> channelError = new
AtomicReference<>();
+
+ /**
+ * Set of cancelled partition requests. A request is cancelled iff an
input channel is cleared
+ * while data is still coming in for this channel.
+ */
+ private final ConcurrentMap<InputChannelID, InputChannelID> cancelled =
Maps.newConcurrentMap();
+
+ private volatile ChannelHandlerContext ctx;
+
+ //
------------------------------------------------------------------------
+ // Input channel/receiver registration
+ //
------------------------------------------------------------------------
+
+ void addInputChannel(RemoteInputChannel listener) throws IOException {
+ checkError();
+
+ if (!inputChannels.containsKey(listener.getInputChannelId())) {
+ inputChannels.put(listener.getInputChannelId(),
listener);
+ }
+ }
+
+ void removeInputChannel(RemoteInputChannel listener) {
+ inputChannels.remove(listener.getInputChannelId());
+ }
+
+ void cancelRequestFor(InputChannelID inputChannelId) {
+ if (inputChannelId == null || ctx == null) {
+ return;
+ }
+
+ if (cancelled.putIfAbsent(inputChannelId, inputChannelId) ==
null) {
+ ctx.writeAndFlush(new
NettyMessage.CancelPartitionRequest(inputChannelId));
+ }
+ }
+
+ //
------------------------------------------------------------------------
+ // Network events
+ //
------------------------------------------------------------------------
+
+ @Override
+ public void channelActive(final ChannelHandlerContext ctx) throws
Exception {
+ if (this.ctx == null) {
+ this.ctx = ctx;
+ }
+
+ super.channelActive(ctx);
+ }
+
+ @Override
+ public void channelInactive(ChannelHandlerContext ctx) throws Exception
{
+ // Unexpected close. In normal operation, the client closes the
connection after all input
+ // channels have been removed. This indicates a problem with
the remote task manager.
+ if (!inputChannels.isEmpty()) {
+ final SocketAddress remoteAddr =
ctx.channel().remoteAddress();
+
+ notifyAllChannelsOfErrorAndClose(new
RemoteTransportException(
+ "Connection unexpectedly closed by
remote task manager '" + remoteAddr + "'. "
+ + "This might indicate
that the remote task manager was lost.",
+ remoteAddr));
+ }
+
+ super.channelInactive(ctx);
+ }
+
+ /**
+ * Called on exceptions in the client handler pipeline.
+ *
+ * <p> Remote exceptions are received as regular payload.
+ */
+ @Override
+ public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause)
throws Exception {
+
+ if (cause instanceof TransportException) {
+ notifyAllChannelsOfErrorAndClose(cause);
+ } else {
+ final SocketAddress remoteAddr =
ctx.channel().remoteAddress();
+
+ final TransportException tex;
+
+ // Improve on the connection reset by peer error message
+ if (cause instanceof IOException
+ &&
cause.getMessage().equals("Connection reset by peer")) {
+
+ tex = new RemoteTransportException("Lost
connection to task manager '" + remoteAddr + "'. " +
+ "This indicates that the remote task
manager was lost.", remoteAddr, cause);
+ } else {
+ tex = new
LocalTransportException(cause.getMessage(), ctx.channel().localAddress(),
cause);
+ }
+
+ notifyAllChannelsOfErrorAndClose(tex);
+ }
+ }
+
+ @Override
+ public void channelRead(ChannelHandlerContext ctx, Object msg) throws
Exception {
+ try {
+ decodeMsg(msg);
+ } catch (Throwable t) {
+ notifyAllChannelsOfErrorAndClose(t);
+ }
+ }
+
+ private void notifyAllChannelsOfErrorAndClose(Throwable cause) {
+ if (channelError.compareAndSet(null, cause)) {
+ try {
+ for (RemoteInputChannel inputChannel :
inputChannels.values()) {
+ inputChannel.onError(cause);
+ }
+ } catch (Throwable t) {
+ // We can only swallow the Exception at this
point. :(
+ LOG.warn("An Exception was thrown during error
notification of a remote input channel.", t);
+ } finally {
+ inputChannels.clear();
+
+ if (ctx != null) {
+ ctx.close();
+ }
+ }
+ }
+ }
+
+ //
------------------------------------------------------------------------
+
+ /**
+ * Checks for an error and rethrows it if one was reported.
+ */
+ private void checkError() throws IOException {
+ final Throwable t = channelError.get();
+
+ if (t != null) {
+ if (t instanceof IOException) {
+ throw (IOException) t;
+ } else {
+ throw new IOException("There has been an error
in the channel.", t);
+ }
+ }
+ }
+
+ @Override
+ public void channelReadComplete(ChannelHandlerContext ctx) throws
Exception {
+ super.channelReadComplete(ctx);
--- End diff --
It also keeps the same with current `PartitionRequestClientHandler`, then I
can remove it.
---
