我正在与一个时髦的问题作斗争。经过几天运行Asp.Net 4.5网站变得不负责任。我的配置：Windows 7，IIS 7.5,64位，16Gb。应用程序的内存消耗很小，不应该是一个问题（w3wp.exe在其生命周期内需要大约500Mb的内存）。
我已经检查了应用程序池，它处于运行状态。所以我的第一个猜测是垃圾收集过程中应该存在死锁。应用程序中的所有线程都被GC挂起，并且不允许为新请求分配新线程，因此所有请求都会挂起。
所以我收集了进程转储并将其交给DebugDiag进行分析。记忆分析证实了我的猜测。它向我发出警告：
该进程目前处于垃圾收集的中间
然后我切换到crush-hang分析来查看线程。 GC挂起的原因通常是禁用抢占式模式的线程。通过我的应用程序中的所有线程看起来很好：
Debugger Thread ID Managed Thread ID OS Thread ID Thread Object GC Mode Domain Lock Count Apt Exception
7 1 3552 14601f0 Preemptive 1456e80 0 Unknown
15 2 3476 c5b31e0 Preemptive 1456e80 0 MTA (Finalizer)
17 3 4696 c608ee0 Preemptive 1456e80 0 MTA (Threadpool Worker)
18 4 3756 c60cb10 Preemptive 1456e80 0 Unknown
19 6 4672 d6e51d0 Preemptive 1456e80 0 Unknown (Threadpool Worker)
20 7 4652 c6caf90 Preemptive c61f8f0 0 MTA
9 9 4684 d749120 Preemptive 1456e80 0 MTA (Threadpool Completion Port)
21 10 3220 d738fa0 Preemptive c61f8f0 0 MTA
22 11 3084 d74af40 Preemptive c61f8f0 0 MTA
23 12 4280 d740450 Preemptive c61f8f0 0 MTA
24 13 1212 d740bf0 Preemptive c61f8f0 0 MTA
25 14 1012 d741390 Preemptive c61f8f0 0 MTA
26 17 3548 d802660 Preemptive 1456e80 0 Unknown (GC Thread)
27 18 1800 d802e30 Preemptive 1456e80 0 Unknown (GC Thread)
28 19 4088 d803600 Preemptive 1456e80 0 Unknown (GC Thread)
29 20 2880 d803dd0 Preemptive 1456e80 0 Unknown (GC Thread)
3 8 3872 d805d10 Preemptive 1456e80 0 Unknown
54 eac7280 Preemptive 1456e80 0
100 eae16b0 Preemptive 1456e80 0
94 da67c80 Preemptive 1456e80 0
107 d6daf30 Preemptive 1456e80 0
76 d6db700 Preemptive 1456e80 0
56 eaecf40 Preemptive 1456e80 0
86 146b210 Preemptive 1456e80 0
65 d82c930 Preemptive 1456e80 0
102 da43750 Preemptive 1456e80 0
101 d90e220 Preemptive 1456e80 0
25 eb18770 Preemptive 1456e80 0
85 da64570 Preemptive 1456e80 0
88 d898820 Preemptive 1456e80 0
89 eb17fa0 Preemptive 1456e80 0
93 da5fdd0 Preemptive 1456e80 0
64 d82d8d0 Preemptive 1456e80 0
81 d8d4260 Preemptive 1456e80 0
31 92 3340 eaf17d0 Preemptive 1456e80 0 MTA (Threadpool Worker)
32 79 4012 eaf1fa0 Preemptive 1456e80 0 MTA (Threadpool Worker)
55 eaebfa0 Preemptive 1456e80 0
80 eaf2770 Preemptive 1456e80 0
108 d82c160 Preemptive 1456e80 0
50 d90da50 Preemptive 1456e80 0
49 d8d4a30 Preemptive 1456e80 0
48 eaf2f40 Preemptive 1456e80 0
33 84 3556 eb16770 Preemptive 1456e80 0 MTA (Threadpool Worker)
35 103 740 d808bf0 Preemptive 1456e80 0 MTA (Threadpool Worker)
34 68 4160 d82d100 Preemptive 1456e80 0 MTA (Threadpool Worker)
66 eaeb7d0 Preemptive 1456e80 0
98 eae1e80 Preemptive 1456e80 0
36 91 5048 eaec770 Preemptive 1456e80 0 Unknown
37 63 4768 da61540 Preemptive 1456e80 0 MTA (Threadpool Worker)
38 75 2300 da64d40 Preemptive 1456e80 0 MTA (Threadpool Worker)
39 99 3980 d90f1c0 Preemptive 1456e80 0 MTA (Threadpool Worker)
40 52 2512 eb15fa0 Preemptive 1456e80 0 MTA (Threadpool Worker)
41 90 3560 d8d3a90 Preemptive 1456e80 0 MTA (Threadpool Worker)
42 67 3624 d90e9f0 Preemptive 1456e80 0 MTA (Threadpool Worker)
44 53 1404 eae2e20 Preemptive 1456e80 0 MTA (Threadpool Worker)
43 74 4860 da60d70 Preemptive 1456e80 0 MTA (Threadpool Worker)
45 83 4424 da63da0 Preemptive 1456e80 0 MTA (Threadpool Worker)
46 106 1408 d8d5200 Preemptive 1456e80 0 MTA (Threadpool Worker)
47 61 3100 da605a0 Preemptive 1456e80 0 Unknown
48 58 2228 eac5b10 Preemptive 1456e80 0 MTA (Threadpool Worker)
49 43 1448 d807c50 Preemptive 1456e80 0 Unknown
此外，通过调用堆栈，我无法找到一些表明GC进程真正被触发的调用。我正在寻找像GarbageCollectGeneration或(GC) (Threadpool Worker)这样的东西，但没有找到。
所以我是不确定的国王：我真的有GC运行吗？如果我做了那么哪个线程触发了它？为什么没有完成？
转储中另一个有趣的观察是“Previous .NET Exceptions”部分。它说：
Exception Type Count Message Stack Trace
System.Exception 1 <none>
System.OutOfMemoryException 1 <none>
System.StackOverflowException 1 <none>
System.ExecutionEngineException 1 <none>
System.Threading.ThreadAbortException 2 <none>
System.Web.HttpException 2 The remote host closed the connection. The error code is 0x800704CD.
我知道拥有OutOfMemoryException，StackOverflowException或ExecutionEngineException之类的内容并不好。但这可能是该网站耗尽服务的原因吗？如果堆栈不可用，如何跟踪这些异常？