今天跑了个mr，执行命令bin/yarn logs -applicationId application_1450176501510_0001看log时，出现以下错误：
15/12/15 14:03:34 INFO client.RMProxy: Connecting to ResourceManager at hd1/10.172.153.46:8032
/tmp/logs/root/logs/application_1450176501510_0001does not exist.
Log aggregation has not completed or is not enabled.
查找原因后，发现yarn-site.xml 配置文件中少配置了一项
<property>
<description>Whether to enable log aggregation</description>
<name>yarn.log-aggregation-enable</name>
<value>true</value>
</property>
