Github user coderplay commented on a diff in the pull request:
https://github.com/apache/spark/pull/1907#discussion_r16134481
--- Diff: core/src/main/scala/org/apache/spark/network/netty/server.scala
---
@@ -0,0 +1,290 @@
+/*
+ * 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.spark.network.netty
+
+import java.io.FileInputStream
+import java.net.InetSocketAddress
+import java.nio.channels.FileChannel
+
+import io.netty.bootstrap.ServerBootstrap
+import io.netty.buffer.{ByteBuf, PooledByteBufAllocator}
+import io.netty.channel._
+import io.netty.channel.epoll.{EpollEventLoopGroup,
EpollServerSocketChannel}
+import io.netty.channel.nio.NioEventLoopGroup
+import io.netty.channel.oio.OioEventLoopGroup
+import io.netty.channel.socket.SocketChannel
+import io.netty.channel.socket.nio.NioServerSocketChannel
+import io.netty.channel.socket.oio.OioServerSocketChannel
+import io.netty.handler.codec.{MessageToByteEncoder, LineBasedFrameDecoder}
+import io.netty.handler.codec.string.StringDecoder
+import io.netty.util.CharsetUtil
+import org.apache.spark.storage.{TestBlockId, FileSegment, BlockId}
+
+import org.apache.spark.{Logging, SparkConf}
+import org.apache.spark.util.Utils
+
+
+// TODO: Remove dependency on BlockId. This layer should not be coupled
with storage.
+
+// TODO: PathResolver is not general enough. It only works for on-disk
blocks.
+
+// TODO: Allow user-configured port
+
+/** A simple main function for testing the server. */
+object BlockServer {
+ def main(args: Array[String]): Unit = {
+ new BlockServer(new SparkConf, new PathResolver {
+ override def getBlockLocation(blockId: BlockId): FileSegment = {
+ val file = new java.io.File(blockId.asInstanceOf[TestBlockId].id)
+ new FileSegment(file, 0, file.length())
+ }
+ })
+ Thread.sleep(1000000)
+ }
+}
+
+
+/**
+ * Server for serving Spark data blocks. This should be used together with
[[BlockFetchingClient]].
+ *
+ * Protocol for requesting blocks (client to server):
+ * One block id per line, e.g. to request 3 blocks:
"block1\nblock2\nblock3\n"
+ *
+ * Protocol for sending blocks (server to client):
+ * frame-length (4 bytes), block-id-length (4 bytes), block-id,
block-data.
+ *
+ * frame-length should not include the length of itself.
+ * If frame-length is negative, then this is an error message rather
than block-data. The real
+ * length is the absolute value of the frame-length.
+ *
+ */
+private[spark]
+class BlockServer(conf: SparkConf, pResolver: PathResolver) extends
Logging {
+
+ def port: Int = _port
+
+ private var _port: Int = 0
+ private var bootstrap: ServerBootstrap = _
+ private var channelFuture: ChannelFuture = _
+
+ init()
+
+ /** Initialize the server. */
+ private def init(): Unit = {
+ bootstrap = new ServerBootstrap
+ val bossThreadFactory =
Utils.namedThreadFactory("spark-shuffle-server-boss")
+ val workerThreadFactory =
Utils.namedThreadFactory("spark-shuffle-server-worker")
+
+ // Use only one thread to accept connections, and 2 * num_cores for
worker.
+ def initNio(): Unit = {
+ val bossGroup = new NioEventLoopGroup(1, bossThreadFactory)
+ val workerGroup = new NioEventLoopGroup(0, workerThreadFactory)
+ bootstrap.group(bossGroup,
workerGroup).channel(classOf[NioServerSocketChannel])
+ }
+ def initOio(): Unit = {
+ val bossGroup = new OioEventLoopGroup(1, bossThreadFactory)
+ val workerGroup = new OioEventLoopGroup(0, workerThreadFactory)
+ bootstrap.group(bossGroup,
workerGroup).channel(classOf[OioServerSocketChannel])
+ }
+ def initEpoll(): Unit = {
+ val bossGroup = new EpollEventLoopGroup(1, bossThreadFactory)
+ val workerGroup = new EpollEventLoopGroup(0, workerThreadFactory)
+ bootstrap.group(bossGroup,
workerGroup).channel(classOf[EpollServerSocketChannel])
+ }
+
+ conf.get("spark.shuffle.io.mode", "auto").toLowerCase match {
+ case "nio" => initNio()
+ case "oio" => initOio()
+ case "epoll" => initEpoll()
+ case "auto" =>
+ // For auto mode, first try epoll (only available on Linux), then
nio.
+ try {
+ initEpoll()
+ } catch {
+ // TODO: Should we log the throwable? But that always happen on
non-Linux systems.
+ // Perhaps the right thing to do is to check whether the system
is Linux, and then only
+ // call initEpoll on Linux.
+ case e: Throwable => initNio()
+ }
+ }
+
+ // Use pooled buffers to reduce temporary buffer allocation
+ bootstrap.option(ChannelOption.ALLOCATOR,
PooledByteBufAllocator.DEFAULT)
+ bootstrap.childOption(ChannelOption.ALLOCATOR,
PooledByteBufAllocator.DEFAULT)
+
+ // Various (advanced) user-configured settings.
+ conf.getOption("spark.shuffle.io.backLog").foreach { backLog =>
+ bootstrap.option[java.lang.Integer](ChannelOption.SO_BACKLOG,
backLog.toInt)
+ }
+ // Note: the optimal size for receive buffer and send buffer should be
+ // latency * network_bandwidth.
+ // Assuming latency = 1ms, network_bandwidth = 10Gbps
+ // buffer size should be ~ 1.25MB
+ conf.getOption("spark.shuffle.io.receiveBuffer").foreach { receiveBuf
=>
+ bootstrap.option[java.lang.Integer](ChannelOption.SO_RCVBUF,
receiveBuf.toInt)
+ }
+ conf.getOption("spark.shuffle.io.sendBuffer").foreach { sendBuf =>
+ bootstrap.option[java.lang.Integer](ChannelOption.SO_SNDBUF,
sendBuf.toInt)
+ }
+
+ bootstrap.childHandler(new ChannelInitializer[SocketChannel] {
+ override def initChannel(ch: SocketChannel): Unit = {
+ ch.pipeline
+ .addLast("frameDecoder", new LineBasedFrameDecoder(1024)) //
max block id length 1024
+ .addLast("stringDecoder", new StringDecoder(CharsetUtil.UTF_8))
+ //.addLast("stringEncoder", new StringEncoder(CharsetUtil.UTF_8))
+ .addLast("blockHeaderEncoder", new BlockHeaderEncoder)
+ .addLast("handler", new BlockServerHandler(pResolver))
+ }
+ })
+
+ channelFuture = bootstrap.bind(new InetSocketAddress(_port))
+ channelFuture.sync()
+
+ val addr =
channelFuture.channel.localAddress.asInstanceOf[InetSocketAddress]
+ _port = addr.getPort
+ }
+
+ /** Shutdown the server. */
+ def stop(): Unit = {
+ if (channelFuture != null) {
+ channelFuture.channel().close().awaitUninterruptibly()
+ channelFuture = null
+ }
+ if (bootstrap != null && bootstrap.group() != null) {
+ bootstrap.group().shutdownGracefully()
+ }
+ if (bootstrap != null && bootstrap.childGroup() != null) {
+ bootstrap.childGroup().shutdownGracefully()
+ }
+ bootstrap = null
+ }
+}
+
+
+/** A handler that writes the content of a block to the channel. */
+class BlockServerHandler(p: PathResolver)
+ extends SimpleChannelInboundHandler[String] with Logging {
+
+ override def channelRead0(ctx: ChannelHandlerContext, blockId: String):
Unit = {
+ // client in the form of hostname:port
+ val client = {
+ val remoteAddr =
ctx.channel.remoteAddress.asInstanceOf[InetSocketAddress]
+ remoteAddr.getHostName + ":" + remoteAddr.getPort
+ }
+
+ // A helper function to send error message back to the client.
+ def respondWithError(error: String): Unit = {
+ ctx.writeAndFlush(new BlockHeader(-1, blockId,
Some(error))).addListener(
+ new ChannelFutureListener {
+ override def operationComplete(future: ChannelFuture) {
+ if (!future.isSuccess) {
+ // TODO: Maybe log the success case as well.
+ logError(s"Error sending error back to $client",
future.cause)
+ ctx.close()
+ }
+ }
+ }
+ )
+ }
+
+ logTrace(s"Received request from $client to fetch block $blockId")
+
+ var fileChannel: FileChannel = null
+ var offset: Long = 0
+ var blockLength: Long = 0
+
+ // First make sure we can find the block.
+ try {
+ val segment = p.getBlockLocation(BlockId(blockId))
+ fileChannel = new FileInputStream(segment.file).getChannel
+ offset = segment.offset
+ blockLength = segment.length
+ } catch {
+ case e: Exception =>
+ // If we fail to find the block and get its size, send error back.
+ logError(s"Error opening block $blockId for request from $client",
e)
+ blockLength = -1
+ respondWithError(e.getMessage)
+ }
+
+ // Send error message back if the block is too large. Even though we
are capable of sending
+ // large (2G+) blocks, the receiving end cannot handle it so let's
fail fast.
+ // Once we fixed the receiving end to be able to process large blocks,
this should be removed.
+ // Also make sure we update BlockHeaderEncoder to support length > 2G.
+ if (blockLength > Int.MaxValue) {
+ respondWithError(s"Block $blockId size ($blockLength) greater than
2G")
+ }
+
+ // Found the block. Send it back.
+ if (fileChannel != null && blockLength >= 0) {
+ val listener = new ChannelFutureListener {
+ override def operationComplete(future: ChannelFuture) {
+ if (future.isSuccess) {
+ logTrace(s"Sent block $blockId ($blockLength B) back to
$client")
+ } else {
+ logError(s"Error sending block $blockId to $client; closing
connection", future.cause)
+ ctx.close()
+ }
+ }
+ }
+ val region = new DefaultFileRegion(fileChannel, offset, blockLength)
+ ctx.writeAndFlush(new BlockHeader(blockLength.toInt,
blockId)).addListener(listener)
+ ctx.writeAndFlush(region).addListener(listener)
--- End diff --
What will happen if write blockheader fail? The former listener will close
the connection then the latter listener call ctx.close() again?
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastruct...@apache.org or file a JIRA ticket
with INFRA.
---
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org
For additional commands, e-mail: reviews-h...@spark.apache.org
