yarn 报错 requested virtual cores < 0, or requested virtual cores > max configured, requestedVirtualCores=6, maxVirtualCores=4 原因

INFO  ApplicationMaster:54 - Final app status: FAILED, exitCode: 13, (reason: Uncaught exception: org.apache.hadoop.yarn.exceptions.InvalidResourceRequestException: Invalid resource request, requested virtual cores < 0, or requested virtual cores > max configured, requestedVirtualCores=6, maxVirtualCores=4

原因是 任务请求 6vcores 但是最大只有4vcores ，申请不到可用的6vcores 所以报错了。

我们是hadoop-2.6.0 升级hadoop-2.8.4 之后报了此问题
yarn-site.xml

<!-- 2.8.4 最大default 4 -->
<property>
    <name>yarn.scheduler.maximum-allocation-vcores</name>
    <value>4</value>
</property>

<!-- 2.6.0 最大default 32 -->
<property>
    <name>yarn.scheduler.maximum-allocation-vcores</name>
    <value>32</value>
</property>

把2.8.4 yarn-site.xml 修改到32，重启yarn就行了