404 Not Found is the most common error for many production web apps. So, many operations folks just start ignoring them after a while.
Turns out this can actually be very bad, as 404 errors often signal real production problems that CAN and SHOULD be fixed.
Problems like:
- Broken links to your site that are causing you to lose potential sales.
- Botched deployment / code changes that prevent your users from using your site correctly.
- Hacking activity that is wasting significant processing resources on your server.
Read on to learn about the 4 common classes of 404 Not Found errors that you should find and fix.
Good read, definitely guilty of ignoring 404s in our apps. What do you recommend for tracking these on a regular basis?
@JC, we hear this all the time. Its one of those obvious things everyone ignores.
You can use LogParser for IIS log analysis, and detailed errors/Failed Request Tracing for more troubleshooting. [shameless plug] Of course LeanSentry will do it for you automatically.
Best,
Mike
Do you really have to make promotion for LeanSentry in every of your posts? Is it selling that badly?
I added the official IIS-Blog to my feeds for some good Information, but it feels like every second post is filled with promotion for that LeanSentry. It’s just annoying, srsly.
Hey Nerved,
I blog about ways to help people scale and troubleshoot their web apps. I’ve been doing it for years, and we built LeanSentry largely to help everyone else have access to the same troubleshooting and diagnostic techniques.
The post is about recognizing important 404 errors and how to approach fixing them. You don’t need LeanSentry for this, but I have to mention that LeanSentry helps do it with a lot less work.
Did you feel the article did not have merit? If so, this is certainly feedback I can take for future posts.
Best,
Mike
The point about hacking activity causing application pools to start + ASP.NET apps loading was spot on! We have tens of inactive sites per server and this can create significant ram/cpu load.
Very informative as usual, thanks!
Oh, the irony. Your ‘read on’ link gives a 404.
Definitely! Thanks for pointing it out – still working through broken links on the site after moving blogs to WPENGINE. Too bad they do not run LeanSentry 🙂 Both links fixed.