What is an HTTP Error 503? The Result of a DDoS Attack

Many major websites Wednesday were hit by a DDoS attack which effectively took them down and rendered them unavailable to access by internet users. If you tried visiting several major sites, including Reddit, Kickstarter and the New York Times, you probably came across this phrase: “HTTP Error 503.”*

An Error 503 is essentially a sign that the website’s server has been comprised by a temporary overload (or sometimes purposeful maintenance). A DDoS attack (short for Distributed Denial of Service) is when a malicious party flood the bandwidth or resources of a specific system. In the case of Wednesday, a DDoS attack overwhelmed a series of servers which were critical for several websites.

When this occurs, there’s really nothing that users themselves can do the remedy the situation — it’s all incumbent on server operators to fix the issue by waiting it out or fighting back to repel the DDoS attack. The simplicity of a DDoS attack belies how disruptive they can be to the normal operations and functionality of a single website.

Fortunately, when most major websites produce an Error 503, they usually have a fairly quick solution in mind for how to fix the issue and get the sites back online. Nearly every site supported by a compromised server Wednesday morning is now back online.

This is a developing story.