修改hive内存限制

错误：

GB physical memory used; 4.7 GB of 2.1 GB virtual memory used. Killing container.
Dump of the process-tree for container_1454126356092_0026_01_000373

<property>        <name >mapred.child.java.opts</name>        <value>-Xmx3024m </value>    </property>    <property>        <name>mapreduce.reduce.memory.mb</name>        <value>4096</value>    </property>    <property>        <name>mapreduce.map.memory.mb</name>        <value>4096</value>    </property>