denial of service attack

In a new post to his blog Nikita Popov talks about a little trick with inserting values into arrays that can make it take a lot longer than it should (because of how PHP stores its array values in hashtables).

In an announcement today, the UK’s Information Commissioner’s Office (ICO) has revealed that Andrew Crossley, the former boss of ACS:Law, has been handed a penalty for his failure to ensure the security of sensitive data held on their computer systems.

As readers will be aware, last year the company succeeding in spilling the details of around 6,000 Internet subscribers onto an unprotected web page following a Denial of Service attack carried out by Anonymous.

After recovering from the largest Distributed Denial of Service attack in the service's history (

You’re indubitably familiar with various php scripts that accept an image, and bounding box as parameters, it then resizes the image to fit within the bounding box, returning the output. phpThumb seems to be a popular option.

The problem with Apache's approach to dealing with multiple clients, is that there's only ever a limited amount of Client processes available.

This is usually is around a few hundred on common webservers.

Because of this, it becomes necessary to handle HTTP requests as quickly as possible.

As soon as a request is handled, it can go on serving the next. If a client happens to have a slow connection, this can have a direct effect on the scalability of your frontend server.