1、tasktracker的heapsize的大小设置 <property> <name>mapred.child.java.opts</name> <value>-Xmx200m</value> <description>Java opts for the task tracker child processes. The following symbol, if present, will be interpolated: @taskid@ is replaced by current TaskID. Any other occurrences of '@' will go unchanged. For example, to enable verbose gc logging to a file named for the taskid in /tmp and to set the heap maximum to be a gigabyte, pass a 'value' of: -Xmx1024m -verbose:gc -Xloggc:/tmp/@taskid@.gc The configuration variable mapred.child.ulimit can be used to control the maximum virtual memory of the child processes. </description> </property> 2、namenode、datanode和jobtracker的heapsize的设置： hadoop-env.sh中的HADOOP_HEAPSIZE的变量来制定