.net - MemoryFailPoint无条件抛出InsufficientMemoryException

我有一个很奇怪的问题；在我们的REST应用程序中，我们引入了一个用于上传WebPackage的选项。由于解压缩时这些空间可能很大，因此我们希望确保通过MemoryFailPoint获得成功的内存检查体验。

在我的本地IIS 7.5上，它可以完美工作-甚至可以达到最大。预期值为2GB。
在带有IIS 7.5的虚拟Windows Server 2008R2 x64上，此操作无条件失败-即使仅尝试1MB。

虚拟服务器托管在VMWare ESXi 4.1.0、348481上。

这是在虚拟机上失败的示例代码:

using (MemoryFailPoint failPoint = new MemoryFailPoint(1))
{
   ... // deliberately excluded webpackage code
}

和异常(exception)(在XML中):

<InsufficientMemoryException>
    <Message>Insufficient memory to meet the expected demands of an operation, and this system is likely to never satisfy this request.  If this is a 32 bit system, consider booting in 3 GB mode.</Message>
    <StackTrace>
        <Line>at System.Runtime.MemoryFailPoint..ctor(Int32 sizeInMegabytes)</Line>
        <Line>at System.ServiceModel.Dispatcher.SyncMethodInvoker.Invoke(Object instance, Object[] inputs, Object[]&amp; outputs)</Line>
        <Line>at System.ServiceModel.Dispatcher.DispatchOperationRuntime.InvokeBegin(MessageRpc&amp; rpc)</Line>
        <Line>at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage5(MessageRpc&amp; rpc)</Line>
        <Line>at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage31(MessageRpc&amp; rpc)</Line>
        <Line>at System.ServiceModel.Dispatcher.MessageRpc.Process(Boolean isOperationContextSet)</Line>
    </StackTrace>
    <UserDefinedInformation>
        <failpointSizeInMegaBytes>1.00</failpointSizeInMegaBytes>
        <gcTotalMemoryBeforeInMegaBytes>153.34</gcTotalMemoryBeforeInMegaBytes>
    </UserDefinedInformation>
</InsufficientMemoryException>

和我机器上的类似异常-请注意，在我可能触发异常之前，我需要分配 64GB :

<InsufficientMemoryException>
    <Message>Insufficient available memory to meet the expected demands of an operation at this time.  Please try again later.</Message>
    <StackTrace>
        <Line>at System.Runtime.MemoryFailPoint..ctor(Int32 sizeInMegabytes)</Line>
        <Line>at System.ServiceModel.Dispatcher.SyncMethodInvoker.Invoke(Object instance, Object[] inputs, Object[]&amp; outputs)</Line>
        <Line>at System.ServiceModel.Dispatcher.DispatchOperationRuntime.InvokeBegin(MessageRpc&amp; rpc)</Line>
        <Line>at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage5(MessageRpc&amp; rpc)</Line>
        <Line>at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage31(MessageRpc&amp; rpc)</Line>
        <Line>at System.ServiceModel.Dispatcher.MessageRpc.Process(Boolean isOperationContextSet)</Line>
    </StackTrace>
    <UserDefinedInformation>
        <failpointSizeInMegaBytes>65536.00</failpointSizeInMegaBytes>
        <gcTotalMemoryBeforeInMegaBytes>150.63</gcTotalMemoryBeforeInMegaBytes>
    </UserDefinedInformation>
</InsufficientMemoryException>

这真让我发疯..真的。.但是，嘿!注意两个(非常)不同的异常(exception):

服务器:内存不足，无法满足操作的预期需求，并且该系统很可能永远无法满足此请求。如果这是32位系统，请考虑以3 GB模式启动。

使用Jetbrains的dotPeek和这个网站http://reflector.webtropy.com/default.aspx/4@0/4@0/untmp/DEVDIV_TFS/Dev10/Releases/RTMRel/ndp/clr/src/BCL/System/Runtime/MemoryFailPoint@cs/1305376/MemoryFailPoint@cs，我们可以看到问题所在(尽管我仍然很头疼):

        // Check to see that we both have enough memory on the system
        // and that we have enough room within the user section of the
        // process's address space.  Also, we need to use the GC segment
        // size, not the amount of memory the user wants to allocate.
        // Consider correcting this to reflect free memory within the GC
        // heap, and to check both the normal & large object heaps.
        ulong num1 = (ulong) sizeInMegabytes << 20;
        this._reservedMemory = num1;
        ulong size = (ulong)(Math.Ceiling((double)num1 / (double)MemoryFailPoint.GCSegmentSize) * (double)MemoryFailPoint.GCSegmentSize);
        if (size >= MemoryFailPoint.TopOfMemory)
            throw new InsufficientMemoryException(Environment.GetResourceString("InsufficientMemory_MemFailPoint_TooBig"));

本地:可用内存不足，无法满足当前操作的预期需求。请稍后再试。

编辑

Hans和我讨论了VM Size，但是由于我现在得出的结论是，它在开发服务器和我的机器上或多或少是平等的，因此我暂时将这一部分排除在外。任何提示，建议等都非常受欢迎。

流程信息

Process Name: w3wp
PID: 5716
User Name: NT AUTHORITY\NETWORK SERVICE
Working Set: 376.456 K
Peak Working Set: 432.400 K
Private Working Set: 320.684 K
Commit Size: 538.552 K
Handles: 919
Threads: 39

操作系统(WMI)

BootDevice: \Device\HarddiskVolume1
BuildNumber: 7601
BuildType: Multiprocessor Free
Caption: Microsoft Windows Server 2008 R2 Standard
CodeSet: 1252
CountryCode: 45
CreationClassName: Win32_OperatingSystem
CSCreationClassName: Win32_ComputerSystem
CSDVersion: Service Pack 1
CSName: SOME_NAME [MODIFIED]
CurrentTimeZone: 120
DataExecutionPrevention_32BitApplications: True
DataExecutionPrevention_Available: True
DataExecutionPrevention_Drivers: True
DataExecutionPrevention_SupportPolicy: 3
Debug: False
Description: Development Server
Distributed: False
EncryptionLevel: 256
ForegroundApplicationBoost: 2
FreePhysicalMemory: 5.366.516 K
FreeSpaceInPagingFiles: 8.368.456 K
FreeVirtualMemory: 12.985.412 K
InstallDate: 17-01-2011 15:01:55
LargeSystemCache: null
LastBootUpTime: 11-09-2012 14:44:33
LocalDateTime: 03-10-2012 14:13:47
Locale: 0406
Manufacturer: Microsoft Corporation
MaxNumberOfProcesses: 4294967295
MaxProcessMemorySize: 8.589.934.464 K
MUILanguages: System.Object[]
Name: Microsoft Windows Server 2008 R2 Standard |C:\Windows|\Device\Harddisk0\Partition2
NumberOfLicensedUsers: null
NumberOfProcesses: 70
NumberOfUsers: 7
OperatingSystemSKU: 7
Organization:
OSArchitecture: 64-bit
OSLanguage: 1033
OSProductSuite: 272
OSType: 18
OtherTypeDescription: null
PAEEnabled: null
PlusProductID: null
PlusVersionNumber: null
Primary: True
ProductType: 3
RegisteredUser: Windows User
SerialNumber: 11111-111-1111111-11111 [MODIFIED]
ServicePackMajorVersion: 1
ServicePackMinorVersion: 0
SizeStoredInPagingFiles: 8.388.152 K
Status: OK
SuiteMask: 272
SystemDevice: \Device\HarddiskVolume2
SystemDirectory: C:\Windows\system32
SystemDrive: C:
TotalSwapSpaceSize: null
TotalVirtualMemorySize: 16.774.452 K
TotalVisibleMemorySize: 8.388.152 K
Version: 6.1.7601
WindowsDirectory: C:\Windows

VMMap开发服务器上的屏幕快照

出于对虚拟大小的好奇，我从Sysinternals下载了VMMap:http://technet.microsoft.com/en-us/sysinternals/dd535533

我的本地计算机上的VMMap屏幕快照(其中MemoryFailPoint可以按预期工作)

对我来说，仍然不清楚为什么MemoryFailPoint会失败-并且重要的是(尤其是在使用Windows Azure或其他云提供商的情况下)确保有足够的内存用于操作。举个例子，由于资源非常有限，ExtraSmall实例将在进程中的某个地方失败(甚至是x64架构)-MemoryFailPoint可以防止这种情况，从而确保数据的有效状态。

任何帮助，我们将不胜感激。

最佳答案

.net 4.5和IIS中有一个错误(或功能)。

MemoryFailPoint类取决于内部与GC相关的变量，但在x64下，此变量可以为0，除以零可以生成正无穷大( double )，并且某些操作(甚至与零相乘)具有此极值可以生成大的double值(取决于实际的FPU设置)。

您可以非常轻松地检查此错误。
创建一个简单的Web应用程序并添加一个页面，然后粘贴以下代码:

<%
    var memoryFailPointType = typeof(System.Runtime.MemoryFailPoint);
    var staticPrivateFieldFlags =
        System.Reflection.BindingFlags.NonPublic |
        System.Reflection.BindingFlags.Static;
    var gCSegmentSizeField = memoryFailPointType
        .GetField("GCSegmentSize", staticPrivateFieldFlags);
    var gCSegmentSize = (uint)gCSegmentSizeField.GetValue(null);
    string allocationResult;
    try
    {
        using (var mfp = new System.Runtime.MemoryFailPoint(1))
        {
            allocationResult = "Ok";
        }
    }
    catch (Exception exception)
    {
        allocationResult = exception.Message;
    }
%>
<%= gCSegmentSize %><br /> <!-- it can be 0 -->
<%= allocationResult %><br /> <!-- Insufficient memory to meet the expected demands of an operation, and this system is likely to never satisfy this request. If this is a 32 bit system, consider booting in 3 GB mode. -->

因此，如果gCSegmentSize为零，并且(ulong)(double.PositiveInfinite *(uint)0)不等于0，则不应使用MemoryFailPoint类。

在控制台应用程序中，FPU控制字是0x09001F，但是在IIS下，FPU控制字是0x08001F。