Apache with various PHP versions, using SCL

RHSCL 1.1 Beta is available and provides Apache httpd 2.4, PHP 5.4 and PHP 5.5.

The most common configuration for Apache and PHP uses mod_php, but this only allows a single PHP version. Apache httpd 2.4 introduces mod_proxy_fgci which can simply redirect requests to a php-fpm backend.

This article shows a simple way to use a single Apache server and simultaneously run 3 versions of PHP (5.3, 5.4 and 5.5). The same site will be served through 3 sub-URL.

Continue reading “Apache with various PHP versions, using SCL”


DevNation Speakers: An Interview with Catherine Robson on UX

Here’s what Red Hat’s Catherine Robson, UX designer, had to say about DevNation.

What session are you giving at DevNation?

I’m presenting User Experience Bootcamp on Tuesday at 1:20pm.   Here’s the abstract:

“Do you have to design websites or applications for your company? Do you feel like they just don’t compare to apps and websites you regularly use?

Learn how to apply user-centric design principles and visual design basics to bring your applications from bland to beautiful. From mobile to web to applications, these practices will bring your design skills to the next level. We’ll cover some guerrilla usability tactics that anyone can do, visual design principles that make any design look cleaner, and how to focus your application around user tasks over system design.”

Continue reading “DevNation Speakers: An Interview with Catherine Robson on UX”


Which tasks are periodically taking processor time?

When running a latency-sensitive application one might notice that on a regular basis (for example every 5 minutes) there is a delay. The SystemTap periodic.stp script can provide some possible causes of that regular delay. The SystemTap periodic.stp script generates a list of the number of times that various scheduled functions run and the time between each scheduled execution. In the case of delay every five minutes one would run the periodic script for tens of minutes and then look through the output list for a function that has a period of approximately 300,000,00 microseconds (5 minutes*60 seconds*1,000,000 microseconds/second).

Continue reading “Which tasks are periodically taking processor time?”


Repost – The Application Apartment Complex: Red Hat Enterprise Linux & Linux Containers

With April showers, comes talk about containers.  (Well, not exactly, but there’s a lot of container discussion going on these days.)  Bhavna has produced this excellent article to summarize Red Hat’s efforts on them.  Here’s an excerpt:

“Let’s dive into world of containers. Red Hat customers often desire for their applications to run in a secure environment and have been seeking, whether they actually know it or not, a fully supported light weight application isolation solution.  At the other end of the spectrum, ISVs want to develop software applications that are easy to deploy, update, and scale.  They may also want to more precisely control certain runtime elements so as to reduce the risk of application failure, and desire a separation of host OS and runtime images.  And let’s not forget that developers stand to benefit from a world where they can build and package their applications into a small, portable runtime image; just think of the possibilities!

Continue reading “Repost – The Application Apartment Complex: Red Hat Enterprise Linux & Linux Containers”


DevNation Speakers – an interview with Oved Ourfali, RHEV guru

Oved Ourfali (@ovedou), Senior Software Engineer at Red Hat, and oVirt community member, will be speaking at DevNation.  Here is what he had to say about the DevNation developer conference.

What session are you giving at DevNation?

Advanced Integration with the oVirt engine“, a talk that aims to teach how one can extend and customize oVirt to fit its needs, by using oVirt plugin mechanisms: UI, Scheduling and Host plugins (VDSM hooks).

Continue reading “DevNation Speakers – an interview with Oved Ourfali, RHEV guru”


Which task is getting all the CPU processor cycles?

If an important task is processor limited, one would like to make sure that the task is getting as much processor time as possible and other tasks are not delaying the execution of the important task. The SystemTap example script, cycle_thief.stp, lists what interrupts and other tasks run on the same processor as the important task. The cycle_thief.stp script provides the following pieces of information: