Manage Parallel Connections in IIS7

Question

I have a problem with my hosting provider (winhost.com). My application is built on ASP.NET 4 MVC 3. Until a few days ago everything worked fine. Suddenly, I started getting 503 errors when trying to access my site (wikipediamaze.com). This does not always happen, just in most cases.

When someone starts playing the game, a request is made to wikipedia.org to get the page content for the current puzzle step. I basically creak the wikipedia.org screen, typing in some html, and then showing the results. All my web requests are closed immediately after receiving the data.

What winhost tells me is that the connections remain open and cause additional requests to the site to receive the 503 Service Unavailable error message. What I see for my part is that only one request is allowed only for wikipediamaze.com at a time. If you continue to refresh the page, you end up with HTML, but all subsequent requests (css, images, js) get a 503 error. Even pages that never access wikipedia.org.

If this was a problem with throttling the connection in IIS, then both inbound and outbound (requests made inside) fall into the same bucket? If I’m sure that all my connections are closed (and I have never had this problem before), what else can cause this?

This is a hosted environment, so my hands are tied, and I know that all this is incomprehensible, but if someone had any understanding, it would be very useful.

Answer 1

My first suggestion is to make sure you close your connections (preferably using usage statements) when you are done with them, because then you can reuse them. I know you said that you were already closing them, but sometimes they have to dispose of them.

In addition to this, you can change the number of connections your server will make to other servers by placing the following in the web.config file.

<system.net>
    <connectionManagement>
        <add address="*" maxconnection="48" />
    </connectionManagement>
</system.net>