Azure Cloud Service 503 error outside of instance

Question

I have three mvc 3 web applications in a single web role on Azure Cloud Services. All of a sudden this morning both the single instance in production and in staging give "HTTP Error 503. The service is unavailable." when navigated to in a browser.

I rebooted the production instance but nothing changed. Then I deployed a remote desktop enabled version to the staging instance and logged in. However, strangely when I navigate to the web applications in a browser inside the remoted staging instance everything works.

Looking at IIS server logs it seems there are some issues starting the roles (warning level about the appPoolId being incorrect) but obviously the roles are starting as they are accessible from inside the staging server.

The World Wide Web Publishing service is also running and even after restarting this service the web application is not accessible externally.

Does anyone have an explaination for why the sites are accessible locally but not remotely that would help me debug this issue?

Answer 1

I found out where the issue came from, the bindings that were configured in IIS7 did not include bindings for the actual [abc].cloudapp.net host headers.

I assume that for some reason since some time last night or this weekend the requests seem to come with those headers instead of the original headers for the website. This is really strange but adding these bindings fixed both the staging and production instances and they were available again after this change.