Oct 252012

This is an article of mine first published on Wazi

The mod_jk connector serves as the glue between the Apache HTTP server and a Java application server such as Tomcat or JBoss. While most adminstrators concentrate on optimizing Apache or the Java server, setting up mod_jk optimally can also improve your users’ experience.

To be precise, mod_jk connects the Apache web server to the AJP port of a Java server. Apache Jserv Protocol is a binary version of HTTP that is optimized for communication over TCP between the Apache HTTP server and Apache Tomcat or other software.

Continue reading »

flattr this!

Apr 302012

Varnish is an open source “web accelerator” which you can use to speed up your website.

It can cache certain static elements, such as images or javascript but you can also use it for other purposes such as Load balancing or some additional security, in general most of the people want to try it and test their website to see if it’s really so amazing (IMO yes, but test it yourself).

The traditional guides will tell you to move your webserver to another port, perhaps 81,8080 or just bind to localhost, configure Varnish to listen to port 80 and use the web server as backend, the server where Varnish will forward requests not found in his cache.

This is the “normal” configuration and it works fine, but sometimes you just want to make a quick Test or perhaps you are using a Control Panel, such as Cpanel, Kloxo or ISPConfig and in my experience change the standard listening ports of Apache is not a decision to be taken lightly with these tools.

So in a VPS (with Kloxo) I’ve used a different approach: iptables.
Continue reading »

flattr this!

Nov 072010

Lvslogo2In the previous article we looked at what’s the use LVS, to have a system of load balancing built into the Linux kernel. As mentioned, however, LVS was born to be good in one thing: the load balance, but does not provide additional options, such as monitoring the progress of the machines on which we are balancing service and in case of trouble in one machine remove it from the active machines.

To accomplish this goal and many more wel” take a look at ldirectord

Continue reading »

flattr this!

Introduction to LVS

Linux Virtual Server, LVS is an advanced load balancing solution for Linux systems. It is an open source project started by Wensong Zhang in May 1998. The mission of the project is to build a high-performance and highly available server for Linux using clustering technology, which provides good scalability, reliability and serviceability. The major work [...]