In my last post, I discussed the performance gains on a multicore system when switching from MRI Ruby to Jruby.

However, in that post I used RVM to install Jruby and that in some cases may not be the best choice.

Here's how I installed Jruby in CentOS 6.x and created an RPM package out of it to make installation faster in the future.

1. First install OpenJDK 1.8.0.

yum -y install java-1.8.0-openjdk

2. Then download the latest Jruby source code - at the time of writing, that's 9.1.6.0.

cd /tmp/
curl -LO https://s3.amazonaws.com/jruby.org/downloads/9.1.6.0/jruby-bin-9.1.6.0.tar.gz
tar -xzf jruby-bin-*.tar.gz -C /

3. To create an RPM package we'll use FPM. To use FPM, we need Ruby :) So I'm installing my personal RPM repository to install Ruby quickly:

yum -y install http://rpm.chaidas.com/rpm.chaidas.com-0.1-1.x86_64.rpm
yum -y install ruby rpm-build libffi-devel make gcc

4. Cool, now install the FPM gem:

gem install fpm --no-ri --no-rdoc

5. Nice - now go to the Jruby directory and delete the samples (we don't need them):

cd /jruby-*
# delete unnecessary dirs
rm -r -f -v samples/ tool/

6. Create the RPM package:

fpm --verbose -v 9.1.6.0 -n jruby -d java-1.8.0-openjdk -s dir -t rpm .=/usr

7. Now remove the MRI Ruby and install Jruby:

yum -y remove ruby\*
yum -y install jruby-9.1.6.0-1.x86_64.rpm

8. Check the version of Jruby using the jruby -v command:

[root@jruby helpy-1.0]# jruby -v
jruby 9.1.6.0 (2.3.1) 2016-11-09 0150a76 OpenJDK 64-Bit Server VM 25.111-b15 on 1.8.0_111-b15 +jit [linux-x86_64]

And we're done!