Kestrel Queue – Installation in Ubuntu

Introduction

Kestrel is a cool, light-weight persistent message queue server written in Scala that speaks the memcached protocol.
It was originally developed by Robey Pointer (robey) from Twitter.
It was originally a port of its predecessor Starling, which is written in Ruby.

Installation

It’s pretty straight forward to install Kestrel but requires a number steps

# install scala

sudo apt-get install -y scala

# install sbt launcher - create download and build directory

mkdir -p ~/bin/

cd ~/bin/

# download sbt launch

wget http://typesafe.artifactoryonline.com/typesafe/ivy-releases/org.scala-tools.sbt/sbt-launch/0.11.2/sbt-launch.jar

echo 'java -Xms512M -Xmx1536M -Xss1M -XX:+CMSClassUnloadingEnabled -XX:MaxPermSize=384M -jar `dirname $0`/sbt-launch.jar "$@"' > ./sbt

chmod +x ./sbt

# ensure git is installed

sudo apt-get install -y git

# ensure java jdk is installed

#sudo apt-get install openjdk-7-jdk-y

# create download and build directory

mkdir -p ~/build/kestrel

cd ~/build/kestrel

# download kestrel

git clone git://github.com/robey/kestrel.git

cd kestrel

# build kestrel - automatically downloads required libraries - can take AGES. In my case, it was ~30 mins

~/bin/sbt clean update package-dist

# install kestrel

cd dist/kestrel/

# link the kestrel version to current

ln -s $(ls *SNAPSHOT.jar) kestrel.jar

# create the installation directory

sudo mkdir -p /usr/local/lib/kestrel/

sudo cp -R * /usr/local/lib/kestrel/

# create data directory

sudo mkdir -p /var/spool/kestrel

# create log file directory

sudo mkdir -p /var/log/kestrel

# create pid directory

sudo mkdir -p /var/run/kestrel

Create init.d Script

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cat <<- "_EOF_" | sudo tee /etc/init.d/kestrel

#!/bin/bash

APPNAME="kestrel"

ADMIN_PORT=2223

JAR=$(ls /usr/local/lib/kestrel/*SNAPSHOT.jar)

START_CMD="java -jar ${JAR}"

STOP_CMD="wget -qO- http://localhost:${ADMIN_PORT}/shutdown.txt"

INFOLOG="/var/log/${APPNAME}/output.log"

ERRLOG="/var/log/${APPNAME}/error.log"

PIDFILE="/tmp/${APPNAME}.pid"

mkdir -p /var/log/${APPNAME}/ /tmp/

function getpid(){

sudo ps aux| grep -e "$START_CMD"|grep -v grep|awk "{print \$2}";

}

function start() {

PID=`getpid`

if [ -n "$PID" ]; then

echo "$APPNAME is already running with PID $PID."

return 0

#echo "$START_CMD > $INFOLOG 2> $ERRLOG & echo \$! > $PIDFILE&"

eval "$START_CMD > $INFOLOG 2> $ERRLOG &"

PID=`getpid`

if [ -n "$PID" ]; then

echo "$APPNAME sucessfully started. PID: $PID."

else

echo "Failed to Start $APPNAME."

eval "cat $ERRLOG"

}

function stop() {

PID=`getpid`

if [ ! -n "$PID" ]; then

echo "$APPNAME is not running."

return 0

echo "Stopping $APPNAME..."

if [ -n "$STOP_CMD" ]; then

eval "$STOP_CMD"

sleep 1

PID=`getpid`

if [ ! -n "$PID" ]; then

echo "done."

return 0

kill -3 $PID

if kill -9 $PID ; then

sleep 1

else

pkill -f "$START_CMD"

PID=`getpid`

if [ ! -n "$PID" ]; then

echo "done."

else

pkill -KILL -f "$START_CMD"

PID=`getpid`

if [ ! -n "$PID" ]; then

echo "done."

else

echo "Failed to stop $APPNAME."

}

function status(){

PID=`getpid`

if [ -n "$PID" ]; then

echo "$APPNAME is running with PID $PID."

return 0

else

echo "$APPNAME is not running."

return 1

}

case "${1:-''}" in

'start')

start

;;

'stop')

stop

;;

'restart')

stop

start

;;

'status')

status

;;

*) # no parameter specified

exit 1

;;

esac

_EOF_

# set permissions of init.d script

sudo chmod +x /etc/init.d/kestrel

Start and Stop Kestrel Server

# start kestrel

sudo /etc/init.d/kestrel start

# kestrel sucessfully started. PID: 15881.

# check if server is running :)

sudo /etc/init.d/kestrel status

#kestrel is running with PID 15881.

References

1. Home: https://github.com/robey/kestrel
2. Service Start and Stop Scripts: http://www.cyberciti.biz/tips/linux-write-sys-v-init-script-to-start-stop-service.html

About Gugulethu Ncube

IT enthusiast getting things done.