大数据集群运维（31）Spark提交任务时报beyond virtual memory limits错误

以Spark-Client模式运行，Spark-Submit时出现了下面的错误：

User:  hadoop  
Name:  Spark Pi  
Application Type:  SPARK  
Application Tags:   
YarnApplicationState:  FAILED  
FinalStatus Reported by AM:  FAILED  
Started:  16-五月-2017 10:03:02  
Elapsed:  14sec  
Tracking URL:  History  
Diagnostics:  Application application_1494900155967_0001 failed 2 times due to AM Container for appattempt_1494900155967_0001_000002 exited with exitCode: -103 
For more detailed output, check application tracking page:http://master:8088/proxy/application_1494900155967_0001/Then, click on links to logs of each attempt. 
Diagnostics: Container [pid=6263,containerID=container_1494900155967_0001_02_000001] is running beyond virtual memory limits. Current usage: 107.3 MB of 1 GB physical memory used; 2.2 GB of 2.1 GB virtual memory used. Killing container.

我的SPARK-EXECUTOR-MEMORY设置的是1G，即物理内存是1G，Yarn默认的虚拟内存和物理内存比例是2.1，也就是说虚拟内存是2.1G，小于了需要的内存2.2G。解决的办法是把拟内存和物理内存比例增大，在yarn-site.xml中增加一个设置：

<property>
        <name>yarn.nodemanager.vmem-pmem-ratio</name>
        <value>2.5</value>
</property>

再重启Yarn，这样一来就能有2.5G的虚拟内存，运行时就不会出错了。