hadoop启动和关闭脚本分析

1.启动hadoop

start-all.sh 包含两个部分

"$bin"/start-dfs.sh (start dfs daemons)

"$bin"/start-mapred.sh (start mapred daemons)

2.查看start-dfs.sh

."$bin"/hadoop-config.sh

"$bin/hadoop-daemon.sh --config $HADOOP_CONF_DIR start namenode $nameStartOpt

"$bin/hadoop-daemons.sh --config $HADOOP_CONF_DIR start datanode $dataStartOpt

"$bin/hadoop-daemons.sh --config $HADOOP_CONF_DIR --hosts masters start secondarynamenode

3.查看start-mapred.sh

"$bin/hadoop-daemon.sh --config $HADOOP_CONF_DIR start jobtracker

"$bin/hadoop-daemons.sh --config $HADOOP_CONF_DIR start tasktracker

4查看hadoop-daemons.sh

"$bin/slaves.sh" and "$bin/hadoop-daemon-sh"

5查看"$bin/slaves.sh" and "$bin/hadoop-daemon-sh"

这个就是真正的启动命令了。就是常见的java程序启动了,入口方法为java中的main 函数