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Installing Tomcat and Solr on RedHat Enterprise Linux 5
posted: 07-Aug-2007
updated: Updating in-progress
I needed to install
Solr
on a new RHEL5 box that had not run Tomcat or Solr before.
Finding, installing, and debugging Java,
Tomcat, and Solr on this system turned out to be a fairly
confusing process, so I thought I'd write up my expereicnes
in hopes that I may help someone in the future
(perhaps even myself when I need to do this again).
I spent about a day and a half trying to get Solr installed
and working using RHEL5 packages (default packages plus
a few additional packages installed from RedHat using yum).
Ultimately, I never got it working using this approach.
Instead, what worked for me was to do a fresh install
of Tomcat from an Apache mirror.
After I gave up on using the RHEL/yum Tomcat installation
and installed a new Tomcat myself, I had Solr working in
about 20 minutes.
The Problem
Install Solr with Tomcat on a RHEL5 machine, using
as much of the RHEL 5 default infrastructure as possible.
The Solution
Summary
- Download and install a recent Sun Java JDK RPM.
- Don't try to use Tomcat as installed by yum for RHEL5.
Instead, download and install a Tomcat on your own.
I found the instructions for a
"Simple Example Install" at the
Apache SolrTomcat wiki
especially useful.
I first tried to use the installation of Tomcat that RHEL5
supports (see False Starts below). I was never able to get
the RHEL5 Tomcat working with Solr. Instead, I had success
downloading and installing a fresh version of Tomcat from
an Apache mirror site. On the plus side, using this approach
I got Solr working in about 20 minutes. On the minus side,
I now have a non-RHEL-standard piece of software to administer
on my system. This means writing and maintaining startup
and shutdown scripts for it and doing any updates manually
instead of through yum update.
Step 1: Download and install a recent Sun Java JDK RPM
RHEL5 comes with the GNU Compiler for Java (GCJ),
which supports Java 1.4.2. Tomcat is okay with 1.4.2, but
Solr needs Java 1.5.
You can check what Java you are running by typing:
java -version
To get Java 1.5 support, I recommend getting a recent
version of the Sun JDK in an RPM. I followed the instructions
for "Install the Sun JDK" at
Switching to a Sun JVM in RHEL.
These instructions walk you through downloading the Sun JDK RPM,
installing it, and then installing JPackage. JPackage is a nice
tool that allows you to easily switch between multiple versions
of Java on a RHEL system.
The instructions below are largely based on the steps
detailed at
Switching to a Sun JVM in RHEL
are:
- Download the latest Sun JDK RPM.
- Go to java.sun.com and navigate to the downloads page.
As of this writing it is
http://java.sun.com/javase/downloads/index.jsp
- If you are on a text console, you may want
to use the "links" text browser rather than
wget or curl. The Sun site requires you to
accept a license agreement before it will
allow you to access the download.
- Navigate to the downloads for a recent version
of the JDK (e.g. JDK 6 update 2).
- On the downloads page, download the
"Linux RPM in self-extracting file"
This will have a name such as
jdk-6u2-linux-i586-rpm.bin
- Save the file in a convient location (/tmp would work).
- Extract and install the RPM
- In the directory that you saved the rpm.bin file,
type:
./jdk-6u2-linux-i586-rpm.bin
- The JDK should extract and install.
There is a licence agreement.
- Download and install JPackage, a tool to help
manage multiple installation of Java on the same
machine.
- Go to
ftp://jpackage.hmdc.harvard.edu/JPackage/1.7/generic/RPMS.non-free/
- Download the rpm that corresponds to the version
of the Sun Java JDK that you just installed.
This can be a bit confusing... you need to get the
version and build correct (i.e 1.6.0.02).
For my installation of JDK 6u2, I downloaded
java-1.6.0-sun-compat-1.6.0.02-1jpp.i586.rpm
- Install the RPM by typing:
rpm -ivh java-1.6.0-sun-compat-1.6.0.02-1jpp.i586.rpm
- Use the jpackage tools to configure which java to use
- Enter the following commands and when prompted
by each command, select
the Sun JDK version that you just installed.
/usr/sbin/alternatives --config java
/usr/sbin/alternatives --config javac
- Verify which java is in use:
java -version
Step 2: (optional) Remove existing tomcat installation
If you don't need it (be sure of this!), you can remove the existing
tomcat installation that may have come with RHEL5. It is possible
to have two different tomcat installations on the same server, so
if you are not sure, it is okay to leave the existing one.
I choose to remove the default RHEL5 tomcat since I didn't
need it and so that I would not get confused about which
version of tomcat was in use.
Here are the steps I used (as root):
- Use yum to remove the tomcat5 RHEL5 package:
yum remove tomcat5*
- Remove the tomcat user and directory:
/usr/sbin/userdel -r tomcat
/bin/rm -fr /usr/share/tomcat5
Step 3: Download and install Tomcat from an Apache mirror
- First, download Tomcat from Apache or a mirror site
and unpack it.
For example:
cd /opt
wget http://mirrors.ibiblio.org/pub/mirrors/apache/tomcat/tomcat-5/v5.5.23/bin/apache-tomcat-5.5.23.tar.gz
tar xvzf apache-tomcat-5.5.23.tar.gz
- Next you need to decide where to put Tomcat.
You will need a directory for your Tomcat installation
and also a place to store your Tomcat applications.
This can be the same directory, but does not have to be.
The method that I will illustrate here uses /opt/mytomcat
for both directories.
Note that Tomcat as installed by RHEL5 packages
has a 'tomcat' user with a home directory of
/usr/share/tomcat5. To allow for two installations
of Tomcat and to avoid confusion with the RHEL5
'tomcat' user, I like to distinguish this
custom installation by naming it 'mytomcat':
Often you may need to refer to the directory
in which Tomcat is installed. This is stored
in the environment variable $CATALINA_HOME
(Catalina is Tomcat's servlet container).
Thus, by installing Tomcat into /opt/mytomcat,
we can consider /opt/mytomcat to be $CATALINA_HOME.
ln -s /opt/apache-tomcat-5.5.23 /opt/mytomcat
- Next, you need to decide how you will run Tomcat.
Tomcat can be run as root or as a regular user.
For security reasons, many people prefer to create
a special user account to run Tomcat and to own
Tomcat files. In this example, I will show how
to set up a 'mytomcat' user.
You'll need to do most of the installation
and setup as root and can then chown files
to be owned by the mytomcat user.
/usr/sbin/groupadd mytomcat
/usr/sbin/useradd -g mytomcat -d /opt/mytomcat mytomcat
- Change the directory to be owned by the mytomcat user
(and also group mytomcat):
chown mytomcat.mytomcat mytomcat
chown mytomcat.mytomcat apache-tomcat-5.5.23
- In order for Tomcat to find the installation
of Java, you need to set the JAVA_HOME environment
variable. One way to do this is to create a
file $CATALINA_HOME/bin/setenv.sh that contains
the following line:
JAVA_HOME="/usr/java/latest"
- At this point, we should be able to try starting
Tomcat. Since you are probably root, but we want
to run Tomcat as user 'mytomcat', use 'su -c'
to run the startup.sh script:
su mytomcat -c $CATALINA_HOME/bin/startup.sh
If everything worked, you should be able to navigate
to http://localhost:8080 and see the Tomcat welcome
page.
To stop the server, use:
su mytomcat -c $CATALINA_HOME/bin/shutdown.sh
Step 4: Download and install SOLR
- Download SOLR from Apache or a mirror,
unpack it, and set up a link to it from /opt/solr.
cd /opt
wget ftp://www.ibiblio.org/pub/mirrors/apache/lucene/solr/1.2/apache-solr-1.2.0.tgz
tar xvzf apache-solr-1.2.0.tgz
ln -s apache-solr-1.2.0.tgz /opt/solr
- Change the ownership and group to be mytomcat:
chown mytomcat.mytomcat solr
chown mytomcat.mytomcat apache-solr-1.2.0
- Make a copy of a SOLR webapp.
SOLR instances run as web applications in the webapps directory
of Tomcat. There is a default application in /opt/solr/dist
that is packaged as a .war file. To use this, just copy it
over to /opt/mytomcat/webapps and give it a descriptive name:
cp /opt/solr/dist/apache-solr-1.2.0.war /opt/mytomcat/webapps/mytestapp.war
chown mytomcat.mytomcat /opt/mytomcat/webapps/mytestapp.war
- SOLR stores its indicies for each instance in
a "solr/home" directory. For SOLR webapps that
you run, you will need to create a solr/home
directory. I put all mine in /opt/solr_home,
so that I have directories like /opt/solr_home/app1,
/opt/solr_home/app2,...
There is a sample directory that you should copy
that contains the starting files and directories
that SOLR expects for the solr/home:
mkdir /opt/solr_home
cp -R /opt/solr/example/solr /opt/solr_home/mytestapp
chown -R mytomcat.mytomcat /opt/solr_home
False Starts
RHEL5 Tomcat
First, I needed to make sure that Tomcat was installed
and working. This seemed easy enough:
yum install tomcat5
Yum installed the tomcat5 package, and by doing:
yum list installed | grep tomcat5
I could see that I was running Tomcat 5.5.23.
So far, so good. Pointing a browser to
http://localhost:8080
gave a timeout error -- understandable since I
had not started Tomcat yet.
The RHEL5 Tomcat package installed a startup
script that I used to start Tomcat:
/etc/init.d/tomcat5 start
Again I pointed a browser to
http://localhost:8080
this time expecting to see the familiar Tomcat
logo and start page. Instead, I got a blank browser
window. No timeout error, but no Tomcat start page.
Turns out there are additional packages that need
to be installed if you want the Tomcat admin webapp
and the sample webapps:
yum install tomcat5-webapps
yum install tomcat5-admin-webapps
After installing these, Tomcat needed to be restarted:
/etc/init.d/tomcat5 restart
Finally, when I pointed my browser to
when I pointed my browser to
http://localhost:8080
I got the familiar Tomcat logo and startup page.
I tried a few of the sample applications and all
seemed to be working well.
Links/References
-
SolrTomcat
-
Switching to a Sun JVM in RHEL
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