c# - Log4Net 新事件日志不工作

Question

我已设置 log4net 为我的应用程序使用单独的事件日志。事件日志存在并且可见(记录到该日志曾经甚至可以工作!)

名称是 "sbsysrst" isUat 是 true。

预期的 LogName 是 SB3-UAT 但是它坚持记录到 Applicaiton 日志，尽管下面有 log4net 调试消息。

返回 ILog 对象的方法。

public static ILog GetLogger(string name, bool isUat = false)
{
    var eventLogAppender = new EventLogAppender
    {
        ApplicationName = name,
        Layout = new PatternLayout
        {
            ConversionPattern = "%message%newline%exception" 
        },
        LogName = "SB3" + (isUat ? "-" + UatSuffix : string.Empty),
        Threshold = Level.Info
    };

    BasicConfigurator.Configure(eventLogAppender, FileAppenders[isUat]);
    eventLogAppender.ActivateOptions();
    return LogManager.GetLogger(name);
}

从 log4net 调试输出

log4net: Searched for existing files in [C:\Windows\...]
log4net: curSizeRollBackups starts at [0]
log4net: Opening file for writing [C:\Windows\...\SB3.log] append [True]
log4net: Searched for existing files in [C:\Windows\...]
log4net: curSizeRollBackups starts at [0]
log4net: Opening file for writing [C:\Windows\...\SB3.log] append [True]
log4net: Searched for existing files in [C:\Windows\...UAT]
log4net: curSizeRollBackups starts at [0]
log4net: Opening file for writing [C:\Windows\...UAT\SB3.log] append [True]
log4net: Searched for existing files in [C:\Windows\...UAT]
log4net: curSizeRollBackups starts at [0]
log4net: Opening file for writing [C:\Windows\...UAT\SB3.log] append [True]
log4net: Converter [message] Option [] Format [min=-1,max=2147483647,leftAlign=False]
log4net: Converter [newline] Option [] Format [min=-1,max=2147483647,leftAlign=False]
log4net: Converter [message] Option [] Format [min=-1,max=2147483647,leftAlign=False]
log4net: Converter [newline] Option [] Format [min=-1,max=2147483647,leftAlign=False]
log4net: log4net assembly [log4net, Version=1.2.11.0, Culture=neutral, PublicKeyToken=669e0ddf0bb1aa2a]. Loaded from [...]. (.NET Runtime [2.0.50727.5448] on Microsoft Windows NT 6.1.7601 Service Pack 1)
log4net: defaultRepositoryType [log4net.Repository.Hierarchy.Hierarchy]
log4net: Creating repository for assembly [..., Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]
log4net: Assembly [..., Version=1.0.0.0, Culture=neutral, PublicKeyToken=null] Loaded From [...]
log4net: Assembly [..., Version=1.0.0.0, Culture=neutral, PublicKeyToken=null] does not have a RepositoryAttribute specified.
log4net: Assembly [..., Version=1.0.0.0, Culture=neutral, PublicKeyToken=null] using repository [log4net-default-repository] and repository type [log4net.Repository.Hierarchy.Hierarchy]
log4net: log4net assembly [log4net, Version=1.2.11.0, Culture=neutral, PublicKeyToken=669e0ddf0bb1aa2a]. Loaded from [...]. (.NET Runtime [2.0.50727.5448] on Microsoft Windows NT 6.1.7601 Service Pack 1)
log4net: defaultRepositoryType [log4net.Repository.Hierarchy.Hierarchy]
log4net: Creating repository for assembly [..., Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]
log4net: Assembly [..., Version=1.0.0.0, Culture=neutral, PublicKeyToken=null] Loaded From [...]
log4net: Assembly [..., Version=1.0.0.0, Culture=neutral, PublicKeyToken=null] does not have a RepositoryAttribute specified.
log4net: Assembly [..., Version=1.0.0.0, Culture=neutral, PublicKeyToken=null] using repository [log4net-default-repository] and repository type [log4net.Repository.Hierarchy.Hierarchy]
log4nlog4net: Creating repository [log4net-default-repository] using type [log4net.Repository.Hierarchy.Hierarchy]
et: Creating repository [log4net-default-repository] using type [log4net.Repository.Hierarchy.Hierarchy]
log4net: Changing event source [sbsysrst] from log [SB3] to log [SB3-UAT]
log4net: Source [sbsysrst] is registered to log [SB3-UAT]
log4net: Changing event source [sbsysrst] from log [SB3] to log [SB3-UAT]
log4net: Source [sbsysrst] is registered to log [SB3-UAT]

更新 1

查看 log4net 源代码，代码主要归结为以下内容，

// Inside ActivateOptions()
using (SecurityContext.Impersonate(this))
{
    sourceAlreadyExists = EventLog.SourceExists(m_applicationName);
    if (sourceAlreadyExists)
    {
        currentLogName = EventLog.LogNameFromSourceName(m_applicationName, m_machineName);
    }
}

using (SecurityContext.Impersonate(this))
{
    if (sourceAlreadyExists && currentLogName != m_logName)
    {
        //
        // Re-register this to the current application if the user has changed
        // the application / logfile association
        //
        EventLog.DeleteEventSource(m_applicationName, m_machineName);
        CreateEventSource(m_applicationName, m_logName, m_machineName);

        registeredLogName = EventLog.LogNameFromSourceName(m_applicationName, m_machineName);
    }
    else if (!sourceAlreadyExists)
    {
        CreateEventSource(m_applicationName, m_logName, m_machineName);

        registeredLogName = EventLog.LogNameFromSourceName(m_applicationName, m_machineName);
    }
}

// Inside Append(LoggingEvent loggingEvent)
using(SecurityContext.Impersonate(this))
{
    EventLog.WriteEntry(m_applicationName, eventTxt, entryType, eventID, category);
}

关键部分是 EventLog.LogNameFromSourceName(m_applicationName, m_machineName); 确实按预期返回 SB3-UAT。

更新 2

我已经编写了自己的 EventLogAppender，它通过使用设置为日志和源名称的实例 Eventlog 对象来覆盖 log4net 功能。

令我非常惊讶的是，这也不起作用，所以我越来越倾向于机器问题，或者与 log4net 中的 SecurityContext.Impersonate() 代码有关>.

更新 3

所以这不是 log4net 问题，甚至也不是 dotnet 问题。下面是直接使用 Windows API 的代码，它仍然失败。源名称曾在应用程序日志中注册这一事实使事情变得复杂。

我正在查看适当的 WinAPI 以查看是否可以消除这种混淆。当然，查看注册表项这不会是个问题。

const string SourceName = "sbsysrst";
const string TextMessage = "Test";
const string MachineName = ".";

// This code is essentially the watered down version behind `EventLog`
// in dotnet.  There are two main WinAPI calls and just boiler code around
// passing parameters to them as expected.

var message = new[] { TextMessage };
SafeHandle eventLogHandle = null;
var numArray = new IntPtr[message.Length];
var gcHandleArray = new GCHandle[mesage.Length];
GCHandle gcHandle = GCHandle.Alloc(numArray, GCHandleType.Pinned);
try
{
    eventLogHandle = SafeEventLogWriteHandle
        .RegisterEventSource(MachineName, SourceName);
    for (int index = 0; index < message.Length; index++)
    {
        gcHandleArray[index] = GCHandle
            .Alloc(message[index], GCHandleType.Pinned);
        numArray[index] = gcHandleArray[index]
            .AddrOfPinnedObject();
    }

    if (!ReportEvent(
        eventLogHandle,
        0x0004,           // Information type
        0,                // Category
        0,                // EventID
        null,             // user id
        message.Length,   // size of text array
        0,                // size of raw data array
        new HandleRef(this, gcHandle.AddrOfPinnedObject()),
        new byte[0]))     // raw data (none)
    {
        throw new Win32Exception(Marshal.GetLastWin32Error());
    }

}
finally
{
    for (int index = 0; index < message.Length; ++index)
    {
        if (gcHandleArray[index].IsAllocated)
        {
            gcHandleArray[index].Free();
        }
    }

    gcHandle.Free();
    if (eventLogHandle != null)
    {
        eventLogHandle.Dispose();
    }
}

// RegisterEventSource cannot return an abstract object.
internal sealed class SafeEventLogWriteHandle :
    SafeHandleZeroOrMinusOneIsInvalid
{
    internal SafeEventLogWriteHandle() : base(true)
    {
    }

    [DllImport("advapi32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
    internal static extern SafeEventLogWriteHandle RegisterEventSource(
        string uncServerName, string sourceName);

    [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
    [DllImport("advapi32.dll", SetLastError = true)]
    private static extern bool DeregisterEventSource(IntPtr hEventLog);

    protected override bool ReleaseHandle()
    {
        return DeregisterEventSource(this.handle);
    }
}

Answer 1

问题在于源名称过去曾在不同的 EventLog 下注册过。虽然源注册已更改(在注册表中)，但事件日志服务似乎缓存了注册。在重新启动机器并尝试再次记录时(您无法重新启动事件日志服务)，事件条目进入了正确的事件日志。