[ https://issues.apache.org/jira/browse/SPARK-24578?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Shixiong Zhu reassigned SPARK-24578: ------------------------------------ Assignee: Wenbo Zhao > Reading remote cache block behavior changes and causes timeout issue > -------------------------------------------------------------------- > > Key: SPARK-24578 > URL: https://issues.apache.org/jira/browse/SPARK-24578 > Project: Spark > Issue Type: Bug > Components: Spark Core > Affects Versions: 2.3.0, 2.3.1 > Reporter: Wenbo Zhao > Assignee: Wenbo Zhao > Priority: Blocker > Fix For: 2.3.2, 2.4.0 > > > After Spark 2.3, we observed lots of errors like the following in some of our > production job > {code:java} > 18/06/15 20:59:42 ERROR TransportRequestHandler: Error sending result > ChunkFetchSuccess{streamChunkId=StreamChunkId{streamId=91672904003, > chunkIndex=0}, > buffer=org.apache.spark.storage.BlockManagerManagedBuffer@783a9324} to > /172.22.18.7:60865; closing connection > java.io.IOException: Broken pipe > at sun.nio.ch.FileDispatcherImpl.write0(Native Method) > at sun.nio.ch.SocketDispatcher.write(SocketDispatcher.java:47) > at sun.nio.ch.IOUtil.writeFromNativeBuffer(IOUtil.java:93) > at sun.nio.ch.IOUtil.write(IOUtil.java:65) > at sun.nio.ch.SocketChannelImpl.write(SocketChannelImpl.java:471) > at > org.apache.spark.network.protocol.MessageWithHeader.writeNioBuffer(MessageWithHeader.java:156) > at > org.apache.spark.network.protocol.MessageWithHeader.copyByteBuf(MessageWithHeader.java:142) > at > org.apache.spark.network.protocol.MessageWithHeader.transferTo(MessageWithHeader.java:123) > at > io.netty.channel.socket.nio.NioSocketChannel.doWriteFileRegion(NioSocketChannel.java:355) > at > io.netty.channel.nio.AbstractNioByteChannel.doWrite(AbstractNioByteChannel.java:224) > at > io.netty.channel.socket.nio.NioSocketChannel.doWrite(NioSocketChannel.java:382) > at > io.netty.channel.AbstractChannel$AbstractUnsafe.flush0(AbstractChannel.java:934) > at > io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.flush0(AbstractNioChannel.java:362) > at > io.netty.channel.AbstractChannel$AbstractUnsafe.flush(AbstractChannel.java:901) > at > io.netty.channel.DefaultChannelPipeline$HeadContext.flush(DefaultChannelPipeline.java:1321) > at > io.netty.channel.AbstractChannelHandlerContext.invokeFlush0(AbstractChannelHandlerContext.java:776) > at > io.netty.channel.AbstractChannelHandlerContext.invokeFlush(AbstractChannelHandlerContext.java:768) > at > io.netty.channel.AbstractChannelHandlerContext.flush(AbstractChannelHandlerContext.java:749) > at > io.netty.channel.ChannelOutboundHandlerAdapter.flush(ChannelOutboundHandlerAdapter.java:115) > at > io.netty.channel.AbstractChannelHandlerContext.invokeFlush0(AbstractChannelHandlerContext.java:776) > at > io.netty.channel.AbstractChannelHandlerContext.invokeFlush(AbstractChannelHandlerContext.java:768) > at > io.netty.channel.AbstractChannelHandlerContext.flush(AbstractChannelHandlerContext.java:749) > at io.netty.channel.ChannelDuplexHandler.flush(ChannelDuplexHandler.java:117) > at > io.netty.channel.AbstractChannelHandlerContext.invokeFlush0(AbstractChannelHandlerContext.java:776) > at > io.netty.channel.AbstractChannelHandlerContext.invokeFlush(AbstractChannelHandlerContext.java:768) > at > io.netty.channel.AbstractChannelHandlerContext.flush(AbstractChannelHandlerContext.java:749) > at > io.netty.channel.DefaultChannelPipeline.flush(DefaultChannelPipeline.java:983) > at io.netty.channel.AbstractChannel.flush(AbstractChannel.java:248) > at > io.netty.channel.nio.AbstractNioByteChannel$1.run(AbstractNioByteChannel.java:284) > at > io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:163) > at > io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:403) > at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:463) > at > io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858) > at > io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:138) > {code} > > Here is a small reproducible for a small cluster of 2 executors (say host-1 > and host-2) each with 8 cores. Here, the memory of driver and executors are > not an import factor here as long as it is big enough, say 20G. > {code:java} > val n = 100000000 > val df0 = sc.parallelize(1 to n).toDF > val df = df0.withColumn("x0", rand()).withColumn("x0", rand() > ).withColumn("x1", rand() > ).withColumn("x2", rand() > ).withColumn("x3", rand() > ).withColumn("x4", rand() > ).withColumn("x5", rand() > ).withColumn("x6", rand() > ).withColumn("x7", rand() > ).withColumn("x8", rand() > ).withColumn("x9", rand()) > df.cache; df.count > (1 to 10).toArray.par.map { i => println(i); > df.groupBy("x1").agg(count("value")).show() } > {code} > > In the above example, we generate a random DataFrame of size around 7G; cache > it and then perform a parallel DataFrame operations by using `array.par.map`. > Because of the parallel computation, with high possibility, some task could > be scheduled to a host-2 where it needs to read the cache block data from > host-1. This follows the code path of > [https://github.com/apache/spark/blob/master/core/src/main/scala/org/apache/spark/storage/BlockManager.scala#L691] > and then tries to transfer a big block (~ 500MB) of cache block from host-1 > to host-2. Often, this big transfer makes the cluster suffer time out issue > (it will retry 3 times, each with 120s timeout, and then do recompute to put > the cache block into the local MemoryStore). > We couldn't to reproduce the same issue in Spark 2.2.1. From the log of Spark > 2.2.1, we found that > {code:java} > 18/06/16 17:23:47 DEBUG BlockManager: Getting local block rdd_3_0 > 18/06/16 17:23:47 TRACE BlockInfoManager: Task 0 trying to acquire read lock > for rdd_3_0 > 18/06/16 17:23:47 DEBUG BlockManager: Block rdd_3_0 was not found > 18/06/16 17:23:47 DEBUG BlockManager: Getting remote block rdd_3_0 > 18/06/16 17:23:47 DEBUG BlockManager: Block rdd_3_0 not found > 18/06/16 17:23:47 TRACE BlockInfoManager: Task 0 trying to put rdd_3_0 > 18/06/16 17:23:47 TRACE BlockInfoManager: Task 0 trying to acquire read lock > for rdd_3_0 > 18/06/16 17:23:47 TRACE BlockInfoManager: Task 0 trying to acquire write lock > for rdd_3_0 > 18/06/16 17:23:47 TRACE BlockInfoManager: Task 0 acquired write lock for > rdd_3_0 > 18/06/16 17:23:58 INFO MemoryStore: Block rdd_3_0 stored as values in memory > (estimated size 538.2 MB, free 11.1 GB) > {code} > That is, when a task is scheduled to a host-2 where it needs to read the > cache block rdd_3_0 data from host-1, the endpoint of > `master.getLocations(..)` ( see > [https://github.com/apache/spark/blob/v2.2.1/core/src/main/scala/org/apache/spark/storage/BlockManager.scala#L622]) > reports a remote cache block is not found and triggered the recompute. > -I believe this behavior change is introduced by this change set > [https://github.com/apache/spark/commit/e1960c3d6f380b0dfbba6ee5d8ac6da4bc29a698#diff-2b643ea78c1add0381754b1f47eec132]- > > We have two questions here > # what is the right behavior, should we re-compute or should we transfer > block from remote? > # if we should transfer from remote, why the performance is so bad for cache > block? > -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org