sqoop导入MySQL数据出现Call From hadoop/172.16.59.90 to hadoop:10020 failed on connecti

利用sqoop导入MySQL数据的时候出现

ERROR tool.ImportTool: Encountered IOException running import job: java.io.IOException: java.net.ConnectException: Call From hadoop/172.16.59.90 to hadoop:10020 failed on connection exception: java.net.ConnectException: Connection refused; For more details see:  https://wiki.apache.org/hadoop/ConnectionRefused
	at org.apache.hadoop.mapred.ClientServiceDelegate.invoke(ClientServiceDelegate.java:337)
	at org.apache.hadoop.mapred.ClientServiceDelegate.getJobStatus(ClientServiceDelegate.java:422)
	at org.apache.hadoop.mapred.YARNRunner.getJobStatus(YARNRunner.java:575)
	at org.apache.hadoop.mapreduce.Job$1.run(Job.java:325)
	at org.apache.hadoop.mapreduce.Job$1.run(Job.java:322)
	at java.security.AccessController.doPrivileged(Native Method)
	at javax.security.auth.Subject.doAs(Subject.java:421)
	at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1628)
	at org.apache.hadoop.mapreduce.Job.updateStatus(Job.java:322)
	at org.apache.hadoop.mapreduce.Job.isSuccessful(Job.java:622)
	at org.apache.hadoop.mapreduce.Job.waitForCompletion(Job.java:1329)
	at org.apache.sqoop.mapreduce.ImportJobBase.doSubmitJob(ImportJobBase.java:196)
	at org.apache.sqoop.mapreduce.ImportJobBase.runJob(ImportJobBase.java:169)
	at org.apache.sqoop.mapreduce.ImportJobBase.runImport(ImportJobBase.java:266)
	at org.apache.sqoop.manager.SqlManager.importTable(SqlManager.java:673)
	at org.apache.sqoop.manager.MySQLManager.importTable(MySQLManager.java:118)
	at org.apache.sqoop.tool.ImportTool.importTable(ImportTool.java:497)
	at org.apache.sqoop.tool.ImportTool.run(ImportTool.java:605)
	at org.apache.sqoop.Sqoop.run(Sqoop.java:143)
	at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
	at org.apache.sqoop.Sqoop.runSqoop(Sqoop.java:179)
	at org.apache.sqoop.Sqoop.runTool(Sqoop.java:218)
	at org.apache.sqoop.Sqoop.runTool(Sqoop.java:227)
	at org.apache.sqoop.Sqoop.main(Sqoop.java:236)
Caused by: java.net.ConnectException: Call From hadoop/172.16.59.90 to hadoop:10020 failed on connection exception: java.net.ConnectException: Connection refused; For more details see:  https://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:791)
	at org.apache.hadoop.net.NetUtils.wrapException(NetUtils.java:731)
	at org.apache.hadoop.ipc.Client.call(Client.java:1472)
	at org.apache.hadoop.ipc.Client.call(Client.java:1399)
	at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:232)
	at com.sun.proxy.$Proxy14.getJobReport(Unknown Source)
	at org.apache.hadoop.mapreduce.v2.api.impl.pb.client.MRClientProtocolPBClientImpl.getJobReport(MRClientProtocolPBClientImpl.java:133)
	at sun.reflect.GeneratedMethodAccessor9.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at org.apache.hadoop.mapred.ClientServiceDelegate.invoke(ClientServiceDelegate.java:323)
	... 23 more
Caused by: java.net.ConnectException: Connection refused
	at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
	at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:744)
	at org.apache.hadoop.net.SocketIOWithTimeout.connect(SocketIOWithTimeout.java:206)
	at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:530)
	at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:494)
	at org.apache.hadoop.ipc.Client$Connection.setupConnection(Client.java:607)
	at org.apache.hadoop.ipc.Client$Connection.setupIOstreams(Client.java:705)
	at org.apache.hadoop.ipc.Client$Connection.access$2800(Client.java:368)
	at org.apache.hadoop.ipc.Client.getConnection(Client.java:1521)
	at org.apache.hadoop.ipc.Client.call(Client.java:1438)
	... 31 more

错误说明DataNode 需要访问 MapReduce JobHistory Server，而我已经配置了

{hadoop_home}/etc/hadoop/mapred-site.xml

配置如下

    mapreduce.jobhistory.address
    
    {namenode}:10020

配置完成之后要启动

{hadoop_dir}/sbin/mr-jobhistory-daemon.sh start historyserver

而我没有启动JobHistory 服务。

所以发生了此错误，如果启动JobHistory服务后还发生如下错误；

ERROR org.apache.hadoop.mapreduce.v2.hs.HistoryFileManager: Error while trying to scan the directory hdfs://namenode:9000/tmp/had
oop-yarn/staging/history/done_intermediate/hadoop

那么修改${HADOOP_DIR}/etc/hadoop/mapred-env.sh这个配置文件的heap大小

export HADOOP_JOB_HISTORYSERVER_HEAPSIZE=2000

然后在重新启动JobHistory服务，问题解决！