Apache spark 作业在SparkStreaming中排队

我在AmazonEC2上有一个三节点的spark集群，其中两个在1-a可用区，一个在1-b可用区。我开始使用2个核心的火花流。一个核心将被接收器消耗，剩下的另一个核心将用于任务处理。当任务处理的执行器在1-a区域上运行时，它工作得非常好。但是，如果任务处理的执行器从1-b区域开始，批处理作业将大量排队，处理时间将持续增加。我附上下面的截图：

还有，一旦我犯了这个错误。因此，我在

/etc/hosts

中为每个spark节点创建了条目。但尽管如此，它还是把工作排成了队。有谁能帮我指出这个问题吗

FetchFailed(BlockManagerId(0, ip-x-x-x-x, 49445), shuffleId=32, mapId=0, reduceId=1, message=
org.apache.spark.shuffle.FetchFailedException: Failed to connect to ip-x-x-x-x:49445
    at org.apache.spark.storage.ShuffleBlockFetcherIterator.throwFetchFailedException(ShuffleBlockFetcherIterator.scala:323)
    at org.apache.spark.storage.ShuffleBlockFetcherIterator.next(ShuffleBlockFetcherIterator.scala:300)
    at org.apache.spark.storage.ShuffleBlockFetcherIterator.next(ShuffleBlockFetcherIterator.scala:51)
    at scala.collection.Iterator$$anon$11.next(Iterator.scala:328)
    at scala.collection.Iterator$$anon$13.hasNext(Iterator.scala:371)
    at scala.collection.Iterator$$anon$11.hasNext(Iterator.scala:327)
    at org.apache.spark.util.CompletionIterator.hasNext(CompletionIterator.scala:32)
    at org.apache.spark.InterruptibleIterator.hasNext(InterruptibleIterator.scala:39)
    at org.apache.spark.util.collection.ExternalSorter.insertAll(ExternalSorter.scala:197)
    at org.apache.spark.shuffle.BlockStoreShuffleReader.read(BlockStoreShuffleReader.scala:103)
    at org.apache.spark.rdd.ShuffledRDD.compute(ShuffledRDD.scala:98)
    at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:306)
    at org.apache.spark.rdd.RDD.iterator(RDD.scala:270)
    at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:38)
    at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:306)
    at org.apache.spark.rdd.RDD.iterator(RDD.scala:270)
    at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:73)
    at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:41)
    at org.apache.spark.scheduler.Task.run(Task.scala:89)
    at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:214)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.io.IOException: Failed to connect to ip-x-x-x-x:49445
    at org.apache.spark.network.client.TransportClientFactory.createClient(TransportClientFactory.java:216)
    at org.apache.spark.network.client.TransportClientFactory.createClient(TransportClientFactory.java:167)
    at org.apache.spark.network.netty.NettyBlockTransferService$$anon$1.createAndStart(NettyBlockTransferService.scala:90)
    at org.apache.spark.network.shuffle.RetryingBlockFetcher.fetchAllOutstanding(RetryingBlockFetcher.java:140)
    at org.apache.spark.network.shuffle.RetryingBlockFetcher.access$200(RetryingBlockFetcher.java:43)
    at org.apache.spark.network.shuffle.RetryingBlockFetcher$1.run(RetryingBlockFetcher.java:170)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
    at java.util.concurrent.FutureTask.run(FutureTask.java:262)
    ... 3 more
Caused by: java.nio.channels.UnresolvedAddressException
    at sun.nio.ch.Net.checkAddress(Net.java:107)
    at sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:649)
    at io.netty.channel.socket.nio.NioSocketChannel.doConnect(NioSocketChannel.java:209)
    at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.connect(AbstractNioChannel.java:207)
    at io.netty.channel.DefaultChannelPipeline$HeadContext.connect(DefaultChannelPipeline.java:1097)
    at io.netty.channel.AbstractChannelHandlerContext.invokeConnect(AbstractChannelHandlerContext.java:471)
    at io.netty.channel.AbstractChannelHandlerContext.connect(AbstractChannelHandlerContext.java:456)
    at io.netty.channel.ChannelOutboundHandlerAdapter.connect(ChannelOutboundHandlerAdapter.java:47)
    at io.netty.channel.AbstractChannelHandlerContext.invokeConnect(AbstractChannelHandlerContext.java:471)
    at io.netty.channel.AbstractChannelHandlerContext.connect(AbstractChannelHandlerContext.java:456)
    at io.netty.channel.ChannelDuplexHandler.connect(ChannelDuplexHandler.java:50)
    at io.netty.channel.AbstractChannelHandlerContext.invokeConnect(AbstractChannelHandlerContext.java:471)
    at io.netty.channel.AbstractChannelHandlerContext.connect(AbstractChannelHandlerContext.java:456)
    at io.netty.channel.AbstractChannelHandlerContext.connect(AbstractChannelHandlerContext.java:438)
    at io.netty.channel.DefaultChannelPipeline.connect(DefaultChannelPipeline.java:908)
    at io.netty.channel.AbstractChannel.connect(AbstractChannel.java:203)
    at io.netty.bootstrap.Bootstrap$2.run(Bootstrap.java:166)
    at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:357)
    at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:357)
    at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:111)
    ... 1 more