1. Abnormal phenomena

After changing the configuration files of Hadoop: core-site.xml and mapred-site.xml, restart Hadoop and HBase, and find the following exception in HBase log:

2018-03-22 15:56:09,948 WARN  [ResponseProcessor for block BP-792111345-192.168.1.102-1521639243869:blk_1073741858_1034] hdfs.DFSClient: DFSOutputStream ResponseProcessor exception  for block BP-792111345-192.168.1.102-1521639243869:blk_1073741858_1034
java.io.EOFException: Premature EOF: no length prefix available
    at org.apache.hadoop.hdfs.protocolPB.PBHelper.vintPrefixed(PBHelper.java:2294)
    at org.apache.hadoop.hdfs.protocol.datatransfer.PipelineAck.readFields(PipelineAck.java:244)
    at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer$ResponseProcessor.run(DFSOutputStream.java:847)
2018-03-22 15:56:09,951 WARN  [ResponseProcessor for block BP-792111345-192.168.1.102-1521639243869:blk_1073741857_1033] hdfs.DFSClient: DFSOutputStream ResponseProcessor exception  for block BP-792111345-192.168.1.102-1521639243869:blk_1073741857_1033
java.io.EOFException: Premature EOF: no length prefix available
    at org.apache.hadoop.hdfs.protocolPB.PBHelper.vintPrefixed(PBHelper.java:2294)
    at org.apache.hadoop.hdfs.protocol.datatransfer.PipelineAck.readFields(PipelineAck.java:244)
    at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer$ResponseProcessor.run(DFSOutputStream.java:847)
2018-03-22 15:56:22,866 INFO  [regionserver/rayner/192.168.1.102:0.logRoller] wal.FSHLog: 
java.io.IOException: All datanodes DatanodeInfoWithStorage[127.0.0.1:50010,DS-44043b27-9b72-419d-9b17-372546490c57,DISK] are bad. Aborting...
    at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.setupPipelineForAppendOrRecovery(DFSOutputStream.java:1224)
    at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.processDatanodeError(DFSOutputStream.java:990)
    at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.run(DFSOutputStream.java:507)
2018-03-22 15:56:23,381 INFO  [RS_OPEN_META-rayner:48626-0-MetaLogRoller] wal.FSHLog: 
java.io.IOException: All datanodes DatanodeInfoWithStorage[127.0.0.1:50010,DS-44043b27-9b72-419d-9b17-372546490c57,DISK] are bad. Aborting...
    at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.setupPipelineForAppendOrRecovery(DFSOutputStream.java:1224)
    at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.processDatanodeError(DFSOutputStream.java:990)
    at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.run(DFSOutputStream.java:507)
2018-03-22 15:56:25,296 WARN  [LeaseRenewer:ray@localhost:9000] hdfs.LeaseRenewer: Failed to renew lease for [DFSClient_NONMAPREDUCE_-1494745515_1] for 30 seconds.  Will retry shortly ...
java.net.ConnectException: Call From rayner/192.168.1.102 to localhost:9000 failed on connection exception: java.net.ConnectException: Connection refused; For more details see:  http://wiki.apache.org/hadoop/ConnectionRefused
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
    at org.apache.hadoop.net.NetUtils.wrapWithMessage(NetUtils.java:792)
    at org.apache.hadoop.net.NetUtils.wrapException(NetUtils.java:732)
    at org.apache.hadoop.ipc.Client.call(Client.java:1480)
    at org.apache.hadoop.ipc.Client.call(Client.java:1413)
    at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:229)
    at com.sun.proxy.$Proxy15.renewLease(Unknown Source)
    at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.renewLease(ClientNamenodeProtocolTranslatorPB.java:595)
    at sun.reflect.GeneratedMethodAccessor22.invoke(Unknown Source)
    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:191)
    at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:102)
    at com.sun.proxy.$Proxy16.renewLease(Unknown Source)
    at sun.reflect.GeneratedMethodAccessor22.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.hadoop.hbase.fs.HFileSystem$1.invoke(HFileSystem.java:307)
    at com.sun.proxy.$Proxy17.renewLease(Unknown Source)
    at sun.reflect.GeneratedMethodAccessor22.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.hadoop.hbase.fs.HFileSystem$1.invoke(HFileSystem.java:307)
    at com.sun.proxy.$Proxy17.renewLease(Unknown Source)
    at org.apache.hadoop.hdfs.DFSClient.renewLease(DFSClient.java:892)
    at org.apache.hadoop.hdfs.LeaseRenewer.renew(LeaseRenewer.java:423)
    at org.apache.hadoop.hdfs.LeaseRenewer.run(LeaseRenewer.java:448)
    at org.apache.hadoop.hdfs.LeaseRenewer.access$700(LeaseRenewer.java:71)
    at org.apache.hadoop.hdfs.LeaseRenewer$1.run(LeaseRenewer.java:304)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.net.ConnectException: Connection refused
    at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
    at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:744)
    at org.apache.hadoop.net.SocketIOWithTimeout.connect(SocketIOWithTimeout.java:206)
    at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:531)
    at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:495)
    at org.apache.hadoop.ipc.Client$Connection.setupConnection(Client.java:615)
    at org.apache.hadoop.ipc.Client$Connection.setupIOstreams(Client.java:713)
    at org.apache.hadoop.ipc.Client$Connection.access$2900(Client.java:376)
    at org.apache.hadoop.ipc.Client.getConnection(Client.java:1529)
    at org.apache.hadoop.ipc.Client.call(Client.java:1452)
    ... 26 more

Solution:

Find find their namenode and datanode folder /home/hduser/dfs in each node do the same operation, delete the folders and files in the dfs folder.

Then pass . /bin/hdfs namenode -format to format the namenode, and finally. /sbin/start-dfs.sh and . /sbin/start-yarn.sh to start the cluster, in the test will be successful.