asp.netiisiis-7iis-7.5w3wp.exe
Recently I encounter an issue which is related to http error 503 , service is unavailable. when I opened IIS I got that my application pool has stopped then I see windows logs and I see this message:
a process serving application pool suffered a fatal communication error 5011.
The .NET Framework version being used is v4.0.
My site was worked correctly until yesterday but I don't know how fix this issue, thanks if anyone can help me.
That looks like the IIS worker process is crashing. If you have multiple sites/applications running on the same AppPool, I'd start by isolating them one at a time into separate AppPools. You'll probably find which one is causing the problem that way, which should give you a place to start looking.
Aside from this, I'd guess I'd take a look at using adplus to get a crash dump of the AppPool process and then run through it in WinDBG to see what comes up. There are some good resources for this out there. Two that should help you get started are this and this. They are a bit outdated but the basic mechanics should still be mostly the same.
Make sure that each Application Pool in IIS, under Advanced Settings has Enable 32 bit Applications set to True
Best Answer
You are running into a classic application pool crash issue.
Please follow my MSDN blog here to identify the culprit. Let me know if you need any help with this.