How To Install Apache Solr on CentOS 6

In this tutorial, we will show you how to install and configuration of Apache Solr on CentOS 6.  For those of you who didn’t know, Apache Solr is an open-source search platform written on Java. It is based on Apache Lucene and is written in Java. Just like Elasticsearch, it supports database queries through REST APIs. Solr aims at providing distributed indexing, replication, and load-balanced querying with automated failover and recovery.

This article assumes you have at least basic knowledge of Linux, know how to use the shell, and most importantly, you host your site on your own VPS. The installation is quite simple. I will show you the step-by-step installation of Apache Solr on CentOS 6.

Prerequisites

• A server running one of the following operating systems: CentOS 6.
• It’s recommended that you use a fresh OS install to prevent any potential issues.
• SSH access to the server (or just open Terminal if you’re on a desktop).
• A non-root sudo user or access to the root user. We recommend acting as a non-root sudo user, however, as you can harm your system if you’re not careful when acting as the root.

Install Apache Solr on CentOS 6

Step 1. Install Java.

Download the latest Java SE Development Kit 8 release from its official download page or use the following commands to download from the shell:

### CentOS 64-Bit ###
cd /opt/
wget --no-cookies --no-check-certificate --header "Cookie: gpw_e24=http%3A%2F%2Fwww.oracle.com%2F; oraclelicense=accept-securebackup-cookie" "http://download.oracle.com/otn-pub/java/jdk/8u40-b25/jdk-8u40-linux-x64.tar.gz"
tar xzf jdk-8u40-linux-x64.tar.gz

### CentOS 32-Bit ###
cd /opt/
wget --no-cookies --no-check-certificate --header "Cookie: gpw_e24=http%3A%2F%2Fwww.oracle.com%2F; oraclelicense=accept-securebackup-cookie" "http://download.oracle.com/otn-pub/java/jdk/8u40-b25/jdk-8u40-linux-i586.tar.gz"
tar xzf jdk-8u40-linux-i586.tar.g

Verify Installed Java version:

# java -version
java version "1.8.0_40"
Java(TM) SE Runtime Environment (build 1.8.0_40-b25)
Java HotSpot(TM) 64-Bit Server VM (build 25.40-b25, mixed mode)

Step 2. Install Solr.

Now we download the latest version of Solr and extract it (5.0.0 is the latest at the time of writing):

cd /opt
http://www.us.apache.org/dist/lucene/solr/5.0.0/solr-5.0.0.tgz
tar -xvf solr-5.0.0.tgz
mv /opt/solr-5.0.0 /opt/solr
mv /opt/solr/example /opt/solr/core

Step 3. Create a script for handling the Solr server service.

Create a systemd service for Solr or if you are used to the old init scripts, you can keep using them. Create an init script for the Solr service:

nano /etc/init.d/solr

#!/bin/bash
#
# chkconfig: 2345 20 20
# short-description: Solr
# description: Startup script for Apache Solr Server

SOLR_DIR="/opt/solr/core"
LOG_FILE="/var/log/solr.log"
JAVA="/usr/bin/java -DSTOP.PORT=8079 -DSTOP.KEY=stopkey -jar start.jar"

start() {
echo -n "Starting Solr... "
cd $SOLR_DIR
$JAVA > $LOG_FILE 2>&1 &
sleep 2
RETVAL=$?

    if [ $RETVAL = 0 ]
    then
        echo "done."
    else
        echo "failed. See error code for more information."
    fi
    return $RETVAL
}

stop() {
echo -n "Stopping Solr... "
pkill -f start.jar > /dev/null
RETVAL=$?

    if [ $RETVAL = 0 ]
    then
        echo "done."
    else
        echo "failed. See error code for more information."
    fi
    return $RETVAL
}

case "$1" in
start)
start
;;
stop)
stop
;;
restart)
stop
start
;;
*)
echo $"Usage: solr {start|stop|restart}"
exit 3
esac
exit $RETVAL

Save the file and make it executable:

chmod +x /etc/init.d/solr
chkconfig --add solr

Start Solr using the following command:

/etc/init.d/solr start

Step 4. Configure Iptables or Firewall.

If you use Iptables add a rule to allow access to Solr’s admin section and query Solr data:

iptables -A INPUT -p tcp -m tcp --dport 8983 -j ACCEPT
service iptables save

Step 5. Accessing Apache Solr.

Apache Solr will be available on HTTP port 8983 by default. Open your favorite browser and navigate to http://yourdomain.com:8983/solr/  or http://your-server-ip:8983/solr/.

Congratulations! You have successfully installed Apache Solr. Thanks for using this tutorial for installing Apache Solr on your CentOS 6 system. For additional help or useful information, we recommend you check the official Apache Solr website.