問題背景：
使用雲上的虛擬環境搭建測試集群，導入一些數據，在本地idea做些debug調試，但是發現本地idea連接不上測試環境
集群內部配置hosts映射是內網映射(內網ip與主機名映射),本地只能通過公網ip訪問集群
本地ide連不上內網ip，報的也是這個錯誤6000ms超時，連接不到內網ip(client要連內網ip是肯定連不上的)
報錯信息如下:
WARN BlockReaderFactory: I/O error constructing remote block reader.
org.apache.hadoop.net.ConnectTimeoutException: 60000 millis timeout while waiting for channel to be ready for connect. ch : java.nio.channels.SocketChannel[connection-pending remote=/10.0.0.10:9866]
at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:533)
at org.apache.hadoop.hdfs.DFSClient.newConnectedPeer(DFSClient.java:3101)
at org.apache.hadoop.hdfs.BlockReaderFactory.nextTcpPeer(BlockReaderFactory.java:755)
at org.apache.hadoop.hdfs.BlockReaderFactory.getRemoteBlockReaderFromTcp(BlockReaderFactory.java:670)
at org.apache.hadoop.hdfs.BlockReaderFactory.build(BlockReaderFactory.java:337)
at org.apache.hadoop.hdfs.DFSInputStream.blockSeekTo(DFSInputStream.java:576)
at org.apache.hadoop.hdfs.DFSInputStream.readWithStrategy(DFSInputStream.java:800)
at org.apache.hadoop.hdfs.DFSInputStream.read(DFSInputStream.java:847)
at java.io.DataInputStream.read(DataInputStream.java:100)
at org.apache.hadoop.util.LineReader.fillBuffer(LineReader.java:180)
at org.apache.hadoop.util.LineReader.readDefaultLine(LineReader.java:216)
at org.apache.hadoop.util.LineReader.readLine(LineReader.java:174)
at org.apache.hadoop.mapred.LineRecordReader.skipUtfByteOrderMark(LineRecordReader.java:206)
at org.apache.hadoop.mapred.LineRecordReader.next(LineRecordReader.java:244)
at org.apache.hadoop.mapred.LineRecordReader.next(LineRecordReader.java:47)
at org.apache.spark.rdd.HadoopRDD$$anon$1.getNext(HadoopRDD.scala:277)
at org.apache.spark.rdd.HadoopRDD$$anon$1.getNext(HadoopRDD.scala:214)
at org.apache.spark.util.NextIterator.hasNext(NextIterator.scala:73)
at org.apache.spark.InterruptibleIterator.hasNext(InterruptibleIterator.scala:37)
at scala.collection.Iterator$$anon$11.hasNext(Iterator.scala:408)
at scala.collection.Iterator$$anon$11.hasNext(Iterator.scala:408)
at scala.collection.Iterator$$anon$11.hasNext(Iterator.scala:408)
at org.apache.spark.sql.catalyst.expressions.GeneratedClass$GeneratedIteratorForCodegenStage1.processNext(Unknown Source)
at org.apache.spark.sql.execution.BufferedRowIterator.hasNext(BufferedRowIterator.java:43)
at org.apache.spark.sql.execution.WholeStageCodegenExec$$anonfun$10$$anon$1.hasNext(WholeStageCodegenExec.scala:614)
at org.apache.spark.sql.execution.SparkPlan$$anonfun$2.apply(SparkPlan.scala:253)
at org.apache.spark.sql.execution.SparkPlan$$anonfun$2.apply(SparkPlan.scala:247)
at org.apache.spark.rdd.RDD$$anonfun$mapPartitionsInternal$1$$anonfun$apply$25.apply(RDD.scala:830)
at org.apache.spark.rdd.RDD$$anonfun$mapPartitionsInternal$1$$anonfun$apply$25.apply(RDD.scala:830)
at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:38)
at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:324)
at org.apache.spark.rdd.RDD.iterator(RDD.scala:288)
at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:38)
at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:324)
at org.apache.spark.rdd.RDD.iterator(RDD.scala:288)
at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:87)
at org.apache.spark.scheduler.Task.run(Task.scala:109)
at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:345)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
19/08/21 12:14:05 WARN DFSClient: Failed to connect to /10.0.0.10:9866 for block, add to deadNodes and continue. org.apache.hadoop.net.ConnectTimeoutException: 60000 millis timeout while waiting for channel to be ready for connect. ch : java.nio.channels.SocketChannel[connection-pending remote=/10.0.0.10:9866]
org.apache.hadoop.net.ConnectTimeoutException: 60000 millis timeout while waiting for channel to be ready for connect. ch : java.nio.channels.SocketChannel[connection-pending remote=/10.0.0.10:9866]
at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:533)
at org.apache.hadoop.hdfs.DFSClient.newConnectedPeer(DFSClient.java:3101)
at org.apache.hadoop.hdfs.BlockReaderFactory.nextTcpPeer(BlockReaderFactory.java:755)
at org.apache.hadoop.hdfs.BlockReaderFactory.getRemoteBlockReaderFromTcp(BlockReaderFactory.java:670)
at org.apache.hadoop.hdfs.BlockReaderFactory.build(BlockReaderFactory.java:337)
at org.apache.hadoop.hdfs.DFSInputStream.blockSeekTo(DFSInputStream.java:576)
at org.apache.hadoop.hdfs.DFSInputStream.readWithStrategy(DFSInputStream.java:800)
at org.apache.hadoop.hdfs.DFSInputStream.read(DFSInputStream.java:847)
at java.io.DataInputStream.read(DataInputStream.java:100)
解決方案是在ide中resource的hdfs-site.xml 配置如下：意思是使用hostname連接datanode
<property>
<name>dfs.client.use.datanode.hostname</name>
<value>true</value>
<description>only cofig in clients</description>
</property>
問題解決