Mapreduce作业失败，并显示“ MAX_FAILED_UNIQUE_FETCHES;救助”

Question

Map-reduce作业失败，并且在reducer上出现以下错误

Error: org.apache.hadoop.mapreduce.task.reduce.Shuffle$ShuffleError: error in shuffle in fetcher#5 at org.apache.hadoop.mapreduce.task.reduce.Shuffle.run(Shuffle.java:134) at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:376) at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:170) 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:1869) at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:164) Caused by: java.io.IOException: Exceeded MAX_FAILED_UNIQUE_FETCHES; bailing-out. at org.apache.hadoop.mapreduce.task.reduce.ShuffleSchedulerImpl.checkReducerHealth(ShuffleSchedulerImpl.java:366) at org.apache.hadoop.mapreduce.task.reduce.ShuffleSchedulerImpl.copyFailed(ShuffleSchedulerImpl.java:288) at org.apache.hadoop.mapreduce.task.reduce.Fetcher.copyFromHost(Fetcher.java:354) at org.apache.hadoop.mapreduce.task.reduce.Fetcher.run(Fetcher.java:193) ```

Answer 1

您可以编辑yarn-site.xml文件

添加

    <property>
        <name>yarn.nodemanager.local-dirs</name>
        # please replace ${hadoop.tmp.dir} for your actual path
        # example: /home/hadoop/app/tmp
        # then, this value for `/home/hadoop/app/tmp/nm-local-dir`
        <value>${hadoop.tmp.dir}/nm-local-dir</value>
    </property>

重新启动Hadoop和纱线