Articles

Rsync is a remote file sync protocol written by the same people who brought us the Samba project.

Rsync copies files from one location to another keeping both copies in sync. This means that files changed on location A will be copied to B and vice versa.

Rsync is also used by ibackup.com is a commerical service for online backup and online storage.

Some sites need extra customization to make pages look a certain way. This is often done via theme customization.

One area that often advanced clients ask for is the user profile page. Drupal core offers pages based on profile categories, which each category listing the fields that belong to it.

The following methods require some additional programming.

Since 2bits moved into using VPS (Virtual Private Servers) when Xen became available we did not have to directly use other technologies, such as Virtuozzo, OpenVZ (free version of Virtuozzo), or the older User Mode Linux.

However, two recent cases proved what we have suspected for a long time: that indeed Xen is superior to competing technologies when it comes to performance.

One of the powerful features in Drupal is the node_access system. This is an API within Drupal which allows modules to do fine grained access access contol to individual nodes.

If you are using Drupal core, this system does nothing. You need to either enable one of the many node access modules, or write your own module to do that.

Writing a simple specialized node access module is what this article covers.

Roadsend's PHP Compiler is now open source!

It moves PHP into directions never possible before, by compiling PHP into native executables on Linux, FreeBSD and Windows. It does not depend on Zend's PHP engine at all.

It has some drawbacks though: it requires Scheme to compile it (more work), does not support PHP 5 (stuck with PHP4), and has no 64-bit version yet (my test server is AMD64 native 64bit).

After compiling your PHP application, you can run it using the built in microserver, or as a FastCGI process.

In the past, we were able to reduce the size of an Apache 2 process to 10-12M (resident set size), by using eAccelerator, and disabling all unnecessary modules.

Last week we ran a Drupal caching benchmark on Ubuntu Feisty (7.04) and noticed that we cannot run as many concurrent processes as we used to under Ubuntu Edgy (6.10). After running the following command against Drupal 5.1:

Testing environment

We used a simple setup, with memcached on the same server that is running Drupal. In a real production environment, memcached would be distributed over several servers, and Drupal would be running on one or more web servers, and a database server.

The hardware consists of the following:

• AMD64 3000+
• 1GB RAM
• WD 160GB SATA

The software is as follows:

• Ubuntu Feisty 7.04, AMD 64bit kernel
• PHP 5.2.1
• MySQL 5.0.38
• eAccelerator 0.9.5.1
• Drupal 5.1

The tests were simple too, they consisted of 500 requests to the home page anonymously, with a concurrency of 5.

The command used is ab -n500 -c5 http://example.com/

In a previous article on op-code cache benchmarking, we briefly mentioned instructions on installing eAccelerator from source.

We now expand these instructions a bit to update that for installing on Ubuntu Feisty 7.04.

Download eAccelerator

First, download eAccelerator 0.9.5.1 from the project's web site. Note that 0.9.5.1 has a patch for PHP 5.2.x which Ubuntu Feisty installs by default.

A recent request for a site that uses the image module was to have easier navigation for their collection. The requirements was to have the thumbnail of the previous and next image below the image that is being displayed as a visual cue for the user so they click on the ones that interest them.

Of course, with a bit of magic, this is perfectly possible.

Two pieces of code are needed. The first go into the template.php of the theme you are using.

In this file, add the following function:

These are the slides from the presentation on building communities using the Userpoints module and API, given at Drupal Camp Toronto 2007, held at the University of Toronto Bahen Centre on 11 and 12 May 2007.

Slides in PDF and Open Office formats are attached.