#!/usr/bin/env bash

# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
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# Start hadoop dfs daemons.
# Optinally upgrade or rollback dfs state.
# Run this on master node.

usage="Usage: start-dfs.sh [-upgrade|-rollback]"

bin=`dirname "$0"`
bin=`cd "$bin"; pwd`

. "$bin"/hdfs-config.sh

# get arguments
if [ $# -ge 1 ]; then
	nameStartOpt=$1
	shift
	case $nameStartOpt in
	  (-upgrade)
	  	;;
	  (-rollback) 
	  	dataStartOpt=$nameStartOpt
	  	;;
	  (*)
		  echo $usage
		  exit 1
	    ;;
	esac
fi

# start dfs daemons
# start namenode after datanodes, to minimize time namenode is up w/o data
# note: datanodes will log connection errors until namenode starts
"$HADOOP_CORE_HOME"/bin/hadoop-daemon.sh --config $HADOOP_CONF_DIR --script "$bin"/hdfs start namenode $nameStartOpt
"$HADOOP_CORE_HOME"/bin/hadoop-daemons.sh --config $HADOOP_CONF_DIR --script "$bin"/hdfs start datanode $dataStartOpt
"$HADOOP_CORE_HOME"/bin/hadoop-daemons.sh --config $HADOOP_CONF_DIR --hosts masters --script "$bin"/hdfs start secondarynamenode