Azure website keeps throwing the error "An attempt was made to access a socket in a way forbidden by its access permissions"

Question

I have a website running as a web app on a dedicated Azure plan. It connects to a Redis, SQL Azure and a MongoDB backend. The website has been running fine for weeks now and then without any new code I am now getting lots of socket exceptions starting like the one below.

An attempt was made to access a socket in a way forbidden by its access permissions.

The website intermittently gets the error when connecting to Redis, SQL Azure and MongoDB which makes no sense. I changed the Pricing Tier for the site which would move the website from one VM to another behind the scenes and the errors went away for a couple days and have returned again.

I just now changed the site from an S3 to an S2 (making it smaller) and they have gone away but I don't know for how long. How do I fix this? Does Azure limit the number of sockets for a site? Is there some setting on a site in Azure that could cause this?

Answer 1

Indeed, it does limit the amount of sockets. As far as I know, this isn't documented anywhere official. I do, however, have a blog post on this here: http://www.freekpaans.nl/2015/08/starving-outgoing-connections-on-windows-azure-web-sites/

Answer 2

I had the same problem and there was a very trivial reason for it: My ApiUrl connectionString replacement wasn't being completed successfully. That meant that my Webapp was trying to link with a localhost app, which would be forbidden.

In essence: troubleshoot your Configuration variables before making any conclusions.

Answer 3

I was getting the same error in the last few weeks. To fix that i deleted my website from azure and i redeployed using a different name. I know it is weird but when i deleted from azure and redeployed using the same name i got the same error again.