Install Apache Cassandra on CentOS

Install Apache Cassandra on CentOS:

1. Download cassandra:

# cd /opt

#wget ftp://apache.sunsite.ualberta.ca/pub/apache/cassandra/1.1.5/apache-cassandra-1.1.5-bin.tar.gz 

2.Create dirctories for the following keywords in cassandra.yaml file :

data_file_directories

commitlog_directory

saved_caches_directory

# sudo mkdir -p /var/lib/cassandra/data

# sudo mkdir -p /var/log/cassandra

# sudo mkdir -p /var/lib/cassandra/saved_caches

It is better to use separate disks for commitlog and data

# sudo mkdir -p /dev/shm/cassandra/commitlog

modify configuration file(cassandra.yaml), make sure the directories you just created match with the path in the configuration file.
Edit the log4j-server.properties, make sure the path is correct as created from above commands.
log4j.appender.R.File=/var/log/cassandra/system.log

3. Create softlink

# ln -s apache-cassandra-1.1.5 /opt/cassandra

4. Make cassandra as a service,

# sudo vim /etc/init.d/cassandra

and copy&paste the following script into /etc/init.d/cassandra

-------------------------------------------------------

#!/bin/bash

# init script for Cassandra.

# chkconfig: 2345 90 10

# description: Cassandra

# script slightly modified from

# http://blog.milford.io/2010/06/installing-apache-cassandra-on-centos/

. /etc/rc.d/init.d/functions

CASS_HOME=/opt/cassandra

CASS_BIN=$CASS_HOME/bin/cassandra

CASS_LOG=/var/log/cassandra/system.log

CASS_USER="root"

CASS_PID=/var/run/cassandra.pid

if [ ! -f $CASS_BIN ]; then

  echo "File not found: $CASS_BIN"

  exit 1

fi

RETVAL=0

start() {

  if [ -f $CASS_PID ] && checkpid `cat $CASS_PID`; then

    echo "Cassandra is already running."

    exit 0

  fi

  echo -n $"Starting $prog: "

  daemon --user $CASS_USER $CASS_BIN -p $CASS_PID >> $CASS_LOG 2>&1

  usleep 500000

  RETVAL=$?

  if [ "$RETVAL" = "0" ]; then

    echo_success

  else

    echo_failure

  fi

  echo

  return $RETVAL

}

stop() {

  # check if the process is already stopped by seeing if the pid file exists.

  if [ ! -f $CASS_PID ]; then

    echo "Cassandra is already stopped."

    exit 0

  fi

  echo -n $"Stopping $prog: "

  if kill `cat $CASS_PID`; then

    RETVAL=0

    echo_success

  else

    RETVAL=1

    echo_failure

  fi

  echo

  [ $RETVAL = 0 ]

}

status_fn() {

  if [ -f $CASS_PID ] && checkpid `cat $CASS_PID`; then

    echo "Cassandra is running."

    exit 0

  else

    echo "Cassandra is stopped."

    exit 1

  fi

}

case "$1" in

  start)

    start

    ;;

  stop)

    stop

    ;;

  status)

    status_fn

    ;;

  restart)

    stop

 usleep 500000

    start

    ;;

  *)

    echo $"Usage: $prog {start|stop|restart|status}"

    RETVAL=3

esac

exit $RETVAL

------------------------------------------------------

//end of service script

start or stop cassandra service

# sudo chmod +x /etc/init.d/cassandra

# sudo service cassandra start

# sudo service cassandra stop

bring cassandra alive when reboot:

# sudo chmod +x /etc/init.d/cassandra

# sudo chkconfig --add cassandra

# sudo chkconfig cassandra on

REFERENCE:

http://www.geilthings.com/wiki/Cassandra