Hadoop 2.5.0 Failure to Write File Remotely

Question

I'm having an issue when using the Hadoop Java API remotely to put a file to a HDFS 2.5.0 Single Node Hadoop Docker Container. When running on the Hadoop system I'm able to copy a local file to hdfs with no issue. However I'm having a problem remotely when attempting to put data to a file. I get the following exception:

Exception in thread "main" org.apache.hadoop.ipc.RemoteException(java.io.IOException): File /user/root/books/beowulf.txt could only be replicated to 0 nodes instead of minReplication (=1). There are 1 datanode(s) running and 1 node(s) are excluded in this operation.
    at org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.chooseTarget(BlockManager.java:1471)
    at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getAdditionalBlock(FSNamesystem.java:2791)
    at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.addBlock(NameNodeRpcServer.java:606)
    at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.addBlock(ClientNamenodeProtocolServerSideTranslatorPB.java:455)
    at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java)
    at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:585)
    at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:928)
    at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2013)
    at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2009)
    at java.security.AccessController.doPrivileged(Native Method)
    at javax.security.auth.Subject.doAs(Subject.java:415)
    at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1614)
    at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2007)

    at org.apache.hadoop.ipc.Client.call(Client.java:1411)
    at org.apache.hadoop.ipc.Client.call(Client.java:1364)
    at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:206)
    at com.sun.proxy.$Proxy14.addBlock(Unknown Source)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:187)
    at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:102)
    at com.sun.proxy.$Proxy14.addBlock(Unknown Source)
    at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.addBlock(ClientNamenodeProtocolTranslatorPB.java:368)
    at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.locateFollowingBlock(DFSOutputStream.java:1449)
    at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.nextBlockOutputStream(DFSOutputStream.java:1270)
    at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.run(DFSOutputStream.java:526)

I don't see any errors in the datanode logs, but I see the corresponding error message in the namenode logs:

2014-11-04 14:19:26,111 INFO org.apache.hadoop.hdfs.server.namenode.FSEditLog: Number of transactions: 3 Total time for transactions(ms): 13 Number of transactions batched in Syncs: 0 Number of syncs: 2 SyncTimes(ms): 10 
2014-11-04 14:19:26,801 INFO org.apache.hadoop.hdfs.server.blockmanagement.CacheReplicationMonitor: Rescanning after 30000 milliseconds
2014-11-04 14:19:26,802 INFO org.apache.hadoop.hdfs.server.blockmanagement.CacheReplicationMonitor: Scanned 0 directive(s) and 0 block(s) in 1 millisecond(s).
2014-11-04 14:19:27,136 INFO org.apache.hadoop.hdfs.StateChange: BLOCK* allocateBlock: /user/root/books/beowulf.txt. BP-342727372-10.0.0.17-1414068411758 blk_1073741852_1028{blockUCState=UNDER_CONSTRUCTION, primaryNodeIndex=-1, replicas=[ReplicaUnderConstruction[[DISK]DS-511723cb-ff72-4585-bb81-90a2e1f154a3:NORMAL|RBW]]}
2014-11-04 14:19:50,859 WARN org.apache.hadoop.hdfs.server.blockmanagement.BlockPlacementPolicy: Failed to place enough replicas, still in need of 1 to reach 1. For more information, please enable DEBUG log level on org.apache.hadoop.hdfs.server.blockmanagement.BlockPlacementPolicy
2014-11-04 14:19:50,860 INFO org.apache.hadoop.ipc.Server: IPC Server handler 3 on 9000, call org.apache.hadoop.hdfs.protocol.ClientProtocol.addBlock from 192.168.56.1:3805 Call#4 Retry#0
java.io.IOException: File /user/root/books/beowulf.txt could only be replicated to 0 nodes instead of minReplication (=1).  There are 1 datanode(s) running and 1 node(s) are excluded in this operation.
    at org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.chooseTarget(BlockManager.java:1471)
    at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getAdditionalBlock(FSNamesystem.java:2791)
    at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.addBlock(NameNodeRpcServer.java:606)
    at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.addBlock(ClientNamenodeProtocolServerSideTranslatorPB.java:455)
    at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java)
    at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:585)
    at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:928)
    at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2013)
    at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2009)
    at java.security.AccessController.doPrivileged(Native Method)
    at javax.security.auth.Subject.doAs(Subject.java:415)
    at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1614)
    at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2007)

As far as I can tell the Exception is coming only after I close the FSDataOutputStream.

Here is the code that I'm using which produces this issue:

import com.spectralogic.ds3.hadoop.HadoopConstants;
import org.apache.commons.io.IOUtils;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.security.UserGroupInformation;

import java.io.IOException;
import java.io.InputStream;
import java.security.PrivilegedExceptionAction;

public class HdfsPutFile {
    public static void main(final String[] args) throws IOException, InterruptedException {

        final Configuration conf = new Configuration();
        final UserGroupInformation usgi = UserGroupInformation.createRemoteUser("root");

        usgi.doAs(new PrivilegedExceptionAction<Object>() {
            @Override
            public Object run() throws Exception {
                conf.set(HadoopConstants.FS_DEFAULT_NAME, "hdfs://192.168.56.102:9000");
                conf.set(HadoopConstants.HADOOP_JOB_UGI, "root");

                try (final FileSystem hdfs = FileSystem.get(conf)) {

                    System.out.printf("Total Used Hdfs Storage: %d\n", hdfs.getStatus().getUsed());

                    final String resourceName = "books/beowulf.txt";

                    final Path path = new Path("/user/root", resourceName);

                    try (final InputStream inputStream = HdfsPutFile.class.getClassLoader().getResourceAsStream(resourceName);
                         final FSDataOutputStream outputStream = hdfs.create(path, true)) {

                        IOUtils.copy(inputStream, outputStream);
                    }
                }
                return null;
            }
        });
    }
}

Answer 1

Hadoop's ports

So when Hadoop is in docker and you want play with it remotely , you needed use -p to publish some Hadoop's ports to the host .

And in order to tell Hadoop that you would like to use the host names instead of the IP addresses you have to add the following block to your hdfs-site.xml on the client side.

set the dfs.client.use.datanode.hostname is true.

Answer 2

Turns out that the reason this was failing was because my code could not reach the datanode due to it being inside of a Docker container and it's IP address being the internal Docker container's IP address. If I'm inside of the container and run the code, then I'm able to put the file successfully.