Sometimes a web server and a database is fair enough to meet our project requirements. But if the project scales we probably need to think in a clustered solution. This post is an attempt at being an unsorted list of ideas working with clustered PHP applications. Maybe more than a list of ideas is a list of problems that you will face when swapping from a standalone server to a clustered server.

He touches on a few different topics you might need to consider:

• consistency in source code
• writing to the file systems
• deployment problems
• authentication/authorization issues
• handling sessions/logs/cache files

You need php session-clustering and you need it done yesterday. The project is at risk. The suits are breathing down your neck and monitoring your every tweet. Memcache to the rescue.

He show how to get it started up (you'll need to already have it installed) and where to grab the PHP extension you'll need to connect the two. Finally he gets to the actual clustering, changing the session.save_handler setting to "memcache" and several of the memcache-specific php.ini settings for his example setup. A snippet of code is also included so you can see how it all works together.

As maps get busier, marker clustering is likely to be needed. Marker clustering is a technique by which several points of interest can be represented by a single icon when they're close to one another.

The tool, created by Mike Tuupola, lets you break up the map into cells and place points inside them. When there's more than one point in a general area, an extra icon is created to reference those points together (cleaning up the map and preventing you from having lot of little Google Maps markers cluttering up your map. Mike also has a blog post about the library showing it in a bit more detail.

Articles in this issue include:

• Anant Narayanan's look at development in PHP-GTK 2 (cover story)
• Eric Angel's tutorial on using random images in form validation
• Stefan Priebsch's thoughts on code structure and refactoring
• and, of course, the Security Corner (with Chris Shiflett) and Test Pattern (with Jeff Moore) columns

You can either order a single issue or get a year's subscription of this great publication. The issue costs about $4.20 USD and the full year only comes in at $35.40 USD.