Intermittent 503 Error caused by SQL Server & web.config file?_问答_开发者

Good morning, I've been fighting with this issue over the weekend, and have gotten several different stories from my hosting provider. The reason I'm asking here now is because they're now blaming me and my code for the issue. The issue is that all of the .com and .co domains on our hosting account are not accessible due to a 503 service unavailable error, and this appears to be intermittent, and varies across ISP's. Checking out the websites at www.isitdownforeveryoneorjustme.com when the site first goes down confirms that this isn't just my ISP. The domains in question are www.mhn.co, hub.mhn.co, www.mrbarbershop.co, and www.adecor.co, along with a handful of others.

www.mhn.co and hub.mhn.co are both Asp.Net MVC2 Applications that I worked on, the other two sites are static html (as far as i know, they are not my projects). Where it begins to get weird is while I am getting the 503 Service Unavailable message from my ISP when accessing www.adecor.co, my boss is getting the yellow screen of death saying an exception has occurred and the stack trace points to the application running at hub.mhn.co, saying the column name "ImageUrl" is invalid. He hasn't been able to reproduce the message since, but took a screenshot when it first happened.

At this point in time, I can access开发者_Python百科 all of the websites from my iPhone through my cell network without issues. I have reset the application pool manually and still cannot access any of the sites above from my home ISP.

Calling domainhut over the weekend has had various results. The first time we called and they said it was something on their end and they tinkered around and somehow got everything working again. The problem came back and persisted over the weekend, and when I called them this morning, they claimed to have no idea. When my boss called, they told him its due to a handler in my web.config file (I haven't changed anything in there for over 2 months) and that I should check my SQL Server for any issues. I'm stumped, am I being given the runaround, or is it really my fault?

edit

So, after looking into it a little more - www.adecor.co was pointing to the hosting root, where there was a duplicate views folder from hub.mhn.co and a default.aspx, probably from an upload mistake, but removing that clears the yellow screen. Could this have been the cause of the 503? Or is it only because of this error we've noticed the misplaced files in the root. It's been sitting there for a while (since august) and the 503 error has only been happening since Friday.

I get a:

Server Error in '/' Application.
Invalid column name 'ImageUrl'.

And a stack trace.

Have you tried checking to make sure the imageURL field exists in the database? Have you ran the code through the remote debugger? This doesn't' look like an intermittent error to me it looks like a bona fide bug.

You might not be seeing it on other devices because of caching issues.

Is there possibly an older version of your code running on another server, with an out-of-date DNS record somewhere that's directing certain requests to the older server code?

Failing that - is there an error in your Application_Start handler or something, that will only appear immediately following an application restart so it'll look like an intermittent bug?

If one person's seeing a running site and another person's seeing a Yellow Screen of Death, they're either seeing different servers, different code, or the same code in a different state. Start with the servers because that's easy to resolve, and work forwards from there.

This turned out to indeed be a DDOS attack on the shared host. We moved to a new hosting and everything has been working fine since. We left a splash page on the original hosting - and it went down, with the intermittent downtime we had been seeing that week. Thanks for everyone's suggestions (even the guys in chat who helped me out, you deserve some rep).