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