After dedicating countless hours, dollars and other resources into developing your Web site, the last thing you want is for your customers not to be able to access it. Downtime and inaccessibility can occur for a number of reasons, but the results are almost always the same: frustrated, sometimes even lost customers and missed opportunities to boost revenue.
Here are five of the most common Web errors we see, and that you'll likely want to avoid.
1. HTTP 503 Service Unavailable. This error is seen when larger Web sites have capacity or maintenance issues. It indicates the Web server is up, but just minimally, and it can't fulfill the request. You might be familiar with the "Fail Whale" on Twitter. This is an example of an HTTP 503 error.
2. DNS (domain name services) error. This means the Internet's directory system doesn't know how to find the site you're looking for. It usually indicates a mistake with DNS entry for that Web site has occurred.
3. No response to Web page request. This error indicates the Web server hardware is down or the HTTP services are not running. The HTTP services could also be overloaded from, say, a denial-of-service (DoS) attack like Twitter experienced last August.
4. HTTP 500 Internal Server Error. This usually indicates a problem with the Web application, as opposed to the Web server. Hardware and Web services are functioning, but there is some sort of problem trying to execute the logic required to produce the page you are requesting.
5. Down for maintenance. This means exactly what it says: The Web site is over capacity or down for maintenance. Web site operators are getting better at protecting users from ugly errors, such as some of the ones described above. Instead, they have a friendly message appear to let them know what's going on. Twitter's come up with some pretty unique ones for this error as well.