问题处理记录

1、问题描述：java.lang.IncompatibleClassChangeError: Found interface org.apache.hadoop.mapreduce.JobContext, but class was expected
at org.apache.hive.hcatalog.mapreduce.HCatBaseInputFormat.getSplits(HCatBaseInputFormat.java:102)
at org.apache.hadoop.mapreduce.JobSubmitter.writeNewSplits(JobSubmitter.java:303)
at org.apache.hadoop.mapreduce.JobSubmitter.writeSplits(JobSubmitter.java:320)
at org.apache.hadoop.mapreduce.JobSubmitter.submitJobInternal(JobSubmitter.java:198)
at org.apache.hadoop.mapreduce.Job$11.run(Job.java:1341)
at org.apache.hadoop.mapreduce.Job$11.run(Job.java:1338)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:415)
at org.apache.hadoop.security.UserGroupinformation.doAs(UserGroupinformation.java:1844)
at org.apache.hadoop.mapreduce.Job.submit(Job.java:1338)
at org.apache.kylin.engine.mr.common.AbstractHadoopJob.waitForCompletion(AbstractHadoopJob.java:180)
at org.apache.kylin.engine.mr.steps.FactdistinctColumnsJob.run(FactdistinctColumnsJob.java:111)
at org.apache.kylin.engine.mr.common.MapReduceExecutable.doWork(MapReduceExecutable.java:131)
at org.apache.kylin.job.execution.AbstractExecutable.execute(AbstractExecutable.java:162)
at org.apache.kylin.job.execution.DefaultChainedExecutable.doWork(DefaultChainedExecutable.java:69)
at org.apache.kylin.job.execution.AbstractExecutable.execute(AbstractExecutable.java:162)
at org.apache.kylin.job.impl.threadpool.DefaultScheduler$JobRunner.run(DefaultScheduler.java:307)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)

处理方法：

hive版本问题（老的是1.1.0，更换成2.3.2就好了）

2、问题描述：Failed: Execution Error, return code -101 from org.apache.hadoop.hive.ql.exec.mr.MapRedTask. PermGen space

处理方法：

在hive/conf/hive-env.sh文件中，加入下面的内容，问题得以解决：
export HADOOP_OPTS="$HADOOP_OPTS -XX:PermSize=512M -XX:MaxPermSize=1024M"

参考https://blog.csdn.net/u014454538/article/details/83792344

3、问题描述
Exception: java.net.ConnectException: Call From clzx4/134.64.14.139 to clzx4:10020 Failed on connection exception: java.net.ConnectException: Connection refused; For more details see: http://wiki.apache.org/hadoop/ConnectionRefused
java.net.ConnectException: Call From clzx4/134.64.14.139 to clzx4:10020 Failed on connection exception: java.net.ConnectException: Connection refused; For more details see: http://wiki.apache.org/hadoop/ConnectionRefused

处理方法：

检测端口是否开启netstat -aln|grep 10020
启动historyserver，解决
$HADOOP_HOME/sbin/mr-jobhistory-daemon.sh start historyserver