hdfs directory item limit

18/11/05 22:21:44 WARN scheduler.TaskSetManager: Lost task 186792.0 in stage 0.0 (TID 1046119, emr-worker-343.cluster-40699, executor 324): org.apache.hadoop.ipc.RemoteException(org.apache.hadoop.hdfs.protocol.FSLimitException$MaxDirectoryItemsExceededException): The directory item limit of /public/sample/big_scale_fm/test_data_50_billion_sorted/_temporary/0/ is exceeded: limit=1048576 items=1048576
    at org.apache.hadoop.hdfs.server.namenode.FSDirectory.verifyMaxDirItems(FSDirectory.java:932)
    at org.apache.hadoop.hdfs.server.namenode.FSDirRenameOp.verifyFsLimitsForRename(FSDirRenameOp.java:117)
    at org.apache.hadoop.hdfs.server.namenode.FSDirRenameOp.unprotectedRenameTo(FSDirRenameOp.java:189)
    at org.apache.hadoop.hdfs.server.namenode.FSDirRenameOp.renameTo(FSDirRenameOp.java:474)
    at org.apache.hadoop.hdfs.server.namenode.FSDirRenameOp.renameToInt(FSDirRenameOp.java:73)
    at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.renameTo(FSNamesystem.java:3650)
    at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.rename(NameNodeRpcServer.java:867)
    at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.rename(ClientNamenodeProtocolServerSideTranslatorPB.java:575)
    at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java)
    at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:616)
    at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:969)
    at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2049)
    at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2045)
    at java.security.AccessController.doPrivileged(Native Method)
    at javax.security.auth.Subject.doAs(Subject.java:422)
    at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1657)
    at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2045)

    at org.apache.hadoop.ipc.Client.call(Client.java:1475)
    at org.apache.hadoop.ipc.Client.call(Client.java:1412)
    at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:229)
    at com.sun.proxy.$Proxy15.rename(Unknown Source)
    at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.rename(ClientNamenodeProtocolTranslatorPB.java:487)
    at sun.reflect.GeneratedMethodAccessor43.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:191)
    at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:102)
    at com.sun.proxy.$Proxy16.rename(Unknown Source)
    at org.apache.hadoop.hdfs.DFSClient.rename(DFSClient.java:1951)
    at org.apache.hadoop.hdfs.DistributedFileSystem.rename(DistributedFileSystem.java:626)
    at org.apache.hadoop.mapreduce.lib.output.FileOutputCommitter.commitTask(FileOutputCommitter.java:531)
    at org.apache.hadoop.mapred.FileOutputCommitter.commitTask(FileOutputCommitter.java:172)
    at org.apache.hadoop.mapred.OutputCommitter.commitTask(OutputCommitter.java:343)
    at org.apache.spark.mapred.SparkHadoopMapRedUtil$.performCommit$1(SparkHadoopMapRedUtil.scala:50)
    at org.apache.spark.mapred.SparkHadoopMapRedUtil$.commitTask(SparkHadoopMapRedUtil.scala:76)
    at org.apache.spark.SparkHadoopWriter.commit(SparkHadoopWriter.scala:106)
    at org.apache.spark.rdd.PairRDDFunctions$$anonfun$saveAsHadoopDataset$1$$anonfun$13.apply(PairRDDFunctions.scala:1219)
    at org.apache.spark.rdd.PairRDDFunctions$$anonfun$saveAsHadoopDataset$1$$anonfun$13.apply(PairRDDFunctions.scala:1197)
    at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:87)
    at org.apache.spark.scheduler.Task.run(Task.scala:99)
    at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:282)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

18/11/05 22:21:44 INFO scheduler.TaskSetManager: Starting task 186792.1 in stage 0.0 (TID 1050576, emr-worker-801.cluster-40699, executor 158, partition 186792, RACK_LOCAL, 6062 bytes)
18/11/05 22:21:44 INFO scheduler.TaskSetManager: Lost task 197623.0 in stage 0.0 (TID 1048044) on emr-worker-801.cluster-40699, executor 158: org.apache.hadoop.ipc.RemoteException (The directory item limit of /public/sample/big_scale_fm/test_data_50_billion_sorted/_temporary/0/ is exceeded: limit=1048576 items=1048576
    at org.apache.hadoop.hdfs.server.namenode.FSDirectory.verifyMaxDirItems(FSDirectory.java:932)
    at org.apache.hadoop.hdfs.server.namenode.FSDirRenameOp.verifyFsLimitsForRename(FSDirRenameOp.java:117)
    at org.apache.hadoop.hdfs.server.namenode.FSDirRenameOp.unprotectedRenameTo(FSDirRenameOp.java:189)
    at org.apache.hadoop.hdfs.server.namenode.FSDirRenameOp.renameTo(FSDirRenameOp.java:474)
    at org.apache.hadoop.hdfs.server.namenode.FSDirRenameOp.renameToInt(FSDirRenameOp.java:73)
    at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.renameTo(FSNamesystem.java:3650)
    at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.rename(NameNodeRpcServer.java:867)
    at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.rename(ClientNamenodeProtocolServerSideTranslatorPB.java:575)
    at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java)
    at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:616)
    at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:969)
    at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2049)
    at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2045)
    at java.security.AccessController.doPrivileged(Native Method)
    at javax.security.auth.Subject.doAs(Subject.java:422)
    at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1657)
    at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2045)
) [duplicate 1]
18/11/05 22:21:44 INFO scheduler.TaskSetManager: Starting task 197623.1 in stage 0.0 (TID 1050577, emr-worker-176.cluster-40699, executor 201, partition 197623, RACK_LOCAL, 6063 bytes)
18/11/05 22:21:44 INFO scheduler.TaskSetManager: Lost task 198559.0 in stage 0.0 (TID 1048304) on emr-worker-176.cluster-40699, executor 201: org.apache.hadoop.ipc.RemoteException (The directory item limit of /public/sample/big_scale_fm/test_data_50_billion_sorted/_temporary/0/ is exceeded: limit=1048576 items=1048576
    at org.apache.hadoop.hdfs.server.namenode.FSDirectory.verifyMaxDirItems(FSDirectory.java:932)
    at org.apache.hadoop.hdfs.server.namenode.FSDirRenameOp.verifyFsLimitsForRename(FSDirRenameOp.java:117)
    at org.apache.hadoop.hdfs.server.namenode.FSDirRenameOp.unprotectedRenameTo(FSDirRenameOp.java:189)
    at org.apache.hadoop.hdfs.server.namenode.FSDirRenameOp.renameTo(FSDirRenameOp.java:474)
    at org.apache.hadoop.hdfs.server.namenode.FSDirRenameOp.renameToInt(FSDirRenameOp.java:73)
    at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.renameTo(FSNamesystem.java:3650)
    at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.rename(NameNodeRpcServer.java:867)
    at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.rename(ClientNamenodeProtocolServerSideTranslatorPB.java:575)
    at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java)
    at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:616)
    at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:969)
    at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2049)
    at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2045)
    at java.security.AccessController.doPrivileged(Native Method)
    at javax.security.auth.Subject.doAs(Subject.java:422)
    at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1657)
    at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2045)
) [duplicate 2]

18/11/05 22:22:15 INFO scheduler.TaskSetManager: Lost task 203616.0 in stage 0.0 (TID 1049710) on emr-worker-412.cluster-40699, executor 228: org.apache.hadoop.ipc.RemoteException (The directory item limit of /public/sample/big_scale_fm/test_data_50_billion_sorted/_temporary/0/ is exceeded: limit=1048576 items=1048576
    at org.apache.hadoop.hdfs.server.namenode.FSDirectory.verifyMaxDirItems(FSDirectory.java:932)
    at org.apache.hadoop.hdfs.server.namenode.FSDirRenameOp.verifyFsLimitsForRename(FSDirRenameOp.java:117)
    at org.apache.hadoop.hdfs.server.namenode.FSDirRenameOp.unprotectedRenameTo(FSDirRenameOp.java:189)
    at org.apache.hadoop.hdfs.server.namenode.FSDirRenameOp.renameTo(FSDirRenameOp.java:474)
    at org.apache.hadoop.hdfs.server.namenode.FSDirRenameOp.renameToInt(FSDirRenameOp.java:73)
    at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.renameTo(FSNamesystem.java:3650)
    at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.rename(NameNodeRpcServer.java:867)
    at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.rename(ClientNamenodeProtocolServerSideTranslatorPB.java:575)
    at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java)
    at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:616)
    at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:969)
    at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2049)
    at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2045)
    at java.security.AccessController.doPrivileged(Native Method)
    at javax.security.auth.Subject.doAs(Subject.java:422)
    at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1657)
    at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2045)
) [duplicate 23]

错误原因： 一个目录下的子目录数量达到限制，默认的上限是 1048576。 每次执行hive语句时，都会在 hive.exec.scratchdir 配置的目录下生成一个临时目录，执行结束后会自动删除，如果异常中断则有可能会保留目录。

提供两种解决办法：

提高目录的限制上限，通过 dfs.namenode.fs-limits.max-directory-items 参数限制，最高不能超过 6400000

<property>
  <name>dfs.namenode.fs-limits.max-directory-items</name>
  <value>1048576</value>
  <description>Defines the maximum number of items that a directory may contain. Cannot set the property to a value less than 1 or more than 6400000.</description>
</property>

比较靠谱的方法还是在作业中，适当做一下控制。