hadoop的内存heap大小的配置参数

1、tasktracker的heapsize的大小设置

  mapred.child.java.opts
  -Xmx200m
  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/@[email protected]
 
  The configuration variable mapred.child.ulimit can be used to control the
  maximum virtual memory of the child processes.
 

2、namenode、datanode和jobtracker的heapsize的设置：
hadoop-env.sh中的HADOOP_HEAPSIZE的变量来制定