#! /bin/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,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# This file is used to run multiple instances of certain HBase daemons using init scripts.
# It replaces the local-regionserver.sh and local-master.sh scripts for Bigtop packages.
# By default, this script runs a single daemon normally. If offsets are provided, additional
# daemons are run, identified by the offset in log and pid files, and listening on the default
# port + the offset. Offsets can be provided as arguments when invoking init scripts directly:
#
#     /etc/init.d/hbase-regionserver start 1 2 3 4
#
# or you can list the offsets to run in /etc/init.d/regionserver_offsets:
#
#    echo "regionserver_OFFSETS='1 2 3 4' >> /etc/default/hbase"
#    sudo service hbase-$HBASE_DAEMON@ start
#
# Offsets specified on the command-line always override the offsets file. If no offsets are
# specified on the command-line when stopping or restarting daemons, all running instances of the
# daemon are stopped (regardless of the contents of the offsets file).

# chkconfig: 345 87 13
# description: Summary: HBase is the Hadoop database. Use it when you need random, realtime read/write access to your Big Data. This project's goal is the hosting of very large tables -- billions of rows X millions of columns -- atop clusters of commodity hardware.
# processname: HBase
#
### BEGIN INIT INFO
# Provides:          hbase-regionserver
# Required-Start:    $network $local_fs $remote_fs
# Required-Stop:     $remote_fs
# Should-Start:      $named
# Should-Stop:
# Default-Start:     3 4 5
# Default-Stop:      0 1 2 6
# Short-Description: Hadoop HBase regionserver daemon
### END INIT INFO

NAME='HBase Region Server'
USER='{{options.user.name}}'
GROUP='{{options.group.name}}'
CONF_DIR='{{options.conf_dir}}'
RUN_DIR='{{options.pid_dir}}'
PID_FILE="${RUN_DIR}/hbase-hbase-regionserver.pid"
CMD="su - $USER -c \"/usr/hdp/current/hbase-regionserver/bin/hbase-daemon.sh --config $CONF_DIR start regionserver\""
KILL_FORCE=0
KILL_SLEEP=10

function start {
  if [ -f $PID_FILE ]; then
    pid=`cat $PID_FILE`
    if kill -0 $pid >/dev/null 2>&1 $pid; then
       echo "$NAME already running [$pid]"
       exit 0
    else
      rm -rf $PID_FILE
    fi
  fi
  eval $CMD
  echo "$NAME running [`cat $PID_FILE`]"
}

function stop {
  if [ ! -f $PID_FILE ]; then
    echo "$NAME already stopped"
    return
  fi
  pid=$(<$PID_FILE)
  kill $pid 2>/dev/null
  i=0
  while kill -0 $pid 2>/dev/null && [ $i -lt $KILL_SLEEP ]; do
    (( i++ ))
    sleep 1
  done
  if ! kill -0 $pid 2>/dev/null; then
    rm  $PID_FILE 2>/dev/null || true
    echo "$NAME stopped"
    return
  fi
  force_stop
}

function force_stop {
  pid=$(<$PID_FILE)
  kill -9 $pid 2>/dev/null
  sleep 1
  if kill -0 $pid; then
    echo "$NAME failed to stop"
    exit 1
  fi
  rm $PID_FILE
  echo "$NAME forced stopped after ${KILL_SLEEP}s"
}

function status {
  if [ -f $PID_FILE ]; then
    pid=`cat $PID_FILE`
    if kill -0 >/dev/null 2>&1 $pid; then
       echo "$NAME started [$pid]"
       exit 0
    fi
  fi
  echo "$NAME stopped"
  exit 3
}

if [[ $1 == "start" ]]; then
  start "$@"
elif [[ $1 == "stop" ]]; then
  stop "$@"
elif [[ $1 == "restart" ]]; then
  stop "$@"
  sleep 1
  start "$@"
elif [[ $1 == "status" ]]; then
  status "$@"
else
  N=/etc/init.d/$NAME
  echo "Usage: $N {start|stop|restart|status}" >&2
fi