Voldemort is a NoSQL database, a distributed key-value storage system… a kind of hashmap (for java guys…).

URL resources:
– http://project-voldemort.com/
– https://github.com/voldemort/voldemort/downloads
– https://github.com/voldemort/voldemort/wiki

Your base server can be for instance a CentOS 6 Net install installation in “Basic server” mode.

Let’s update everything:

yum update -y

We need a Java Virtual Machine:

yum install -y java-1.6.0-openjdk

And then let’s download the Voldemort project:

cd /usr/local/
wget -c https://github.com/downloads/voldemort/voldemort/voldemort-0.90.tar.gz
tar zxvf voldemort-0.90.tar.gz
rm -f voldemort-0.90.tar.gz
ln -s voldemort-0.90 voldemort

Just prepare some configuration file:

cp /usr/local/voldemort/config/single_node_cluster/config/* /usr/local/voldemort/config/

And we affects rights:

groupadd voldemort
useradd -g voldemort voldemort
chown -R voldemort:voldemort /usr/local/voldemort
chown -R voldemort:voldemort /usr/local/voldemort-0.90

We need a little startup script:

cat > /etc/init.d/voldemort << "EOF"
#!/bin/bash
# chkconfig: 3 21 91
#
# Voldemort
#
# description: Start up the Voldemort NoSQL DB.

# Source function library.
. /etc/init.d/functions

RETVAL=$?
VOLDEMORT_HOME=/usr/local/voldemort
VOLDEMORT_USER=voldemort

case "$1" in
  start)
    if &#91; -f $VOLDEMORT_HOME/bin/voldemort-server.sh &#93;;
      then
      echo $"Starting Voldemort"
      /bin/su - $VOLDEMORT_USER -c $VOLDEMORT_HOME/bin/voldemort-server.sh > $VOLDEMORT_HOME/voldemort.log 2>&1 &
    fi
  ;;

  stop)
    if [ -f $VOLDEMORT_HOME/bin/voldemort-stop.sh ];
      then
      echo $"Stopping Voldemort"
      /bin/su - $VOLDEMORT_USER -c $VOLDEMORT_HOME/bin/voldemort-stop.sh
    fi
  ;;

  *)
    echo $"Usage: $0 {start|stop}"
    exit 1
  ;;
esac

exit $RETVAL
EOF

Let’s make it executable:

chmod a+x /etc/init.d/voldemort

And we add a VOLDEMORT_HOME in the /etc/bashrc file:

cat >> /etc/bashrc << EOF export VOLDEMORT_HOME=/usr/local/voldemort EOF [/shell] We export this line in our current terminal in order to use it now: [shell]export VOLDEMORT_HOME=/usr/local/voldemort[/shell] And we launch voldemort: [shell]/etc/init.d/voldemort start[/shell] If you want your server to execute it at boot time (and kill it before shutdown): [shell] /sbin/chkconfig --level 3 voldemort on /sbin/chkconfig --level 06 voldemort off [/shell] If you need to add rules to the firewall: [shell] iptables -A INPUT -p tcp --dport 6666 -j ACCEPT iptables -A INPUT -p tcp --dport 6667 -j ACCEPT iptables -A INPUT -p tcp --dport 8081 -j ACCEPT /sbin/service iptables save [/shell] And that's it.. your Voldemort server is up and running (quite easy actually). Configuration

Everything is nicely described here: http://project-voldemort.com/configuration.php (beware, some XML tags are not closed correctly in their samples).

For my tests I’m using virtualized servers inside VirtuaBox, network cards are cofigured with “Host only networking”, so it’s easy to make them talk together… (my IP adresses are 192.168.56.101 and 192.168.56.102)

Here is the /usr/local/voldemort/config/cluster.xml file I use:

<cluster>
    <name>VBOX_JU_CLUSTER</name>
    <zone>
      <zone-id>0</zone-id>
      <proximity-list>1</proximity-list>
    </zone>
    <zone>
      <zone-id>1</zone-id>
      <proximity-list>0</proximity-list>
    </zone>
    <server>
      <id>0</id>
      <host>192.168.56.101</host>
      <http-port>8081</http-port>
      <socket-port>6666</socket-port>
      <admin-port>6667</admin-port>
      <partitions>0,1,2,3</partitions>
      <zone-id>0</zone-id>
    </server>
    <server>
      <id>1</id>
      <host>192.168.56.102</host>
      <http-port>8081</http-port>
      <socket-port>6666</socket-port>
      <admin-port>6667</admin-port>
      <partitions>4,5,6,7</partitions>
      <zone-id>1</zone-id>
    </server>
</cluster>

You copy this file on your 2 servers, they must be identical on every server. Then we have to configure our specific /usr/local/voldemort/config/server.properties for each server, you must adapt node.id and max.thread. node.id is sequential, unique, and starts with 0:

– Serveur 01

– Serveur 02

For now we will work only with one data store, and you configure it inside /usr/local/voldemort/config/stores.xml file:

test
2

Let’s check where the data are currently saved :

This means your data is saved on both server ! Why ? Just look inside your /usr/local/voldemort/config/stores.xml file, we have :
– replication-factor = 2
– preferred-reads = 2
– required-reads = 1
– preferred-writes = 2
– required-writes = 1
Pretty clear no !

See you…