【发布时间】：2018-06-02 19:09:31
【问题描述】：
我使用 HDFS 作为一些 spark 作业的检查点目录，但有时它们只是开始无法写入 HDFS。
Spark 中的错误信息是
Caused by: org.apache.hadoop.ipc.RemoteException(java.io.IOException): File /streaming/example-query/state/0/0/temp--1233934526312931692 could only be replicated to 0 nodes instead of minReplication (=1). There are 3 datanode(s) running and no node(s) are excluded in this operation.
at org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.chooseTarget4NewBlock(BlockManager.java:1547)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getNewBlockTargets(FSNamesystem.java:3107)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getAdditionalBlock(FSNamesystem.java:3031)
at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.addBlock(NameNodeRpcServer.java:724)
at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.addBlock(ClientNamenodeProtocolServerSideTranslatorPB.java:492)
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:2043)
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.addBlock(Unknown Source)
at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.addBlock(ClientNamenodeProtocolTranslatorPB.java:418)
at sun.reflect.GeneratedMethodAccessor17.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.$Proxy16.addBlock(Unknown Source)
at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.locateFollowingBlock(DFSOutputStream.java:1455)
at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.nextBlockOutputStream(DFSOutputStream.java:1251)
at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.run(DFSOutputStream.java:448)
namenode 打印以下错误消息：
17/12/20 08:49:52 WARN blockmanagement.BlockPlacementPolicy: Failed to place enough replicas, still in need of 1 to reach 3 (unavailableStorages=[], storagePolicy=BlockStoragePolicy{HOT:7, storageTypes=[DISK], creationFallbacks=[], replicationFallbacks=[ARCHIVE]}, newBlock=true) For more information, please enable DEBUG log level on org.apache.hadoop.hdfs.server.blockmanagement.BlockPlacementPolicy
17/12/20 08:49:52 WARN protocol.BlockStoragePolicy: Failed to place enough replicas: expected size is 1 but only 0 storage types can be selected (replication=3, selected=[], unavailable=[DISK], removed=[DISK], policy=BlockStoragePolicy{HOT:7, storageTypes=[DISK], creationFallbacks=[], replicationFallbacks=[ARCHIVE]})
17/12/20 08:49:52 WARN blockmanagement.BlockPlacementPolicy: Failed to place enough replicas, still in need of 1 to reach 3 (unavailableStorages=[DISK], storagePolicy=BlockStoragePolicy{HOT:7, storageTypes=[DISK], creationFallbacks=[], replicationFallbacks=[ARCHIVE]}, newBlock=true) All required storage types are unavailable: unavailableStorages=[DISK], storagePolicy=BlockStoragePolicy{HOT:7, storageTypes=[DISK], creationFallbacks=[], replicationFallbacks=[ARCHIVE]}
17/12/20 08:49:52 INFO hdfs.StateChange: BLOCK* allocate blk_1345727054_271990505{UCState=UNDER_CONSTRUCTION, truncateBlock=null, primaryNodeIndex=-1, replicas=[ReplicaUC[[DISK]DS-33af5c05-f2fd-4f9d-9e13-96f9fa64fbeb:NORMAL:172.20.95.127:50010|RBW], ReplicaUC[[DISK]DS-57ecb9a7-a853-42d9-a213-01389658305d:NORMAL:172.20.69.2:50010|RBW]]} for /streaming/example-query/state/0/199/550.snapshot.temp--5780088563343554929
17/12/20 08:49:52 WARN blockmanagement.BlockPlacementPolicy: Failed to place enough replicas, still in need of 2 to reach 3 (unavailableStorages=[], storagePolicy=BlockStoragePolicy{HOT:7, storageTypes=[DISK], creationFallbacks=[], replicationFallbacks=[ARCHIVE]}, newBlock=true) For more information, please enable DEBUG log level on org.apache.hadoop.hdfs.server.blockmanagement.BlockPlacementPolicy
17/12/20 08:49:52 WARN protocol.BlockStoragePolicy: Failed to place enough replicas: expected size is 2 but only 0 storage types can be selected (replication=3, selected=[], unavailable=[DISK], removed=[DISK, DISK], policy=BlockStoragePolicy{HOT:7, storageTypes=[DISK], creationFallbacks=[], replicationFallbacks=[ARCHIVE]})
在某个时候，它又开始冷却并平稳运行。
我在这里遇到一些资源短缺吗？我检查了磁盘空间、inode cpu 和内存，它们似乎都很好。
【问题讨论】：
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你有想过这个吗？
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是的，实际上，datanodes 很多时候不同步。主要是删除操作，但数以百万计。我通过对 HDFS 集群进行分片并为我的结构化流作业使用间隔解决了这个问题。
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如果您可以添加更多详细信息的答案，那就太好了。我自己被困在这个问题上。
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对不起@aaandis，我只记得真正的问题是什么。我把它写下来作为答案。要查看这是否是您的问题，请尝试记录 iotop 和 htop 输出并检查
du进程。
标签： hadoop apache-spark hdfs