c #windows-services - 如何处理日志记录异常？

Question

我正在创建一个Windows服务.当发生异常时,我会适当地处理它并创建一个日志.我正在使用装饰器模式,因为人们会看到这些日志的方式有很多种.我有一个电子邮件记录器,一个文件记录器和一个Windows事件记录器,它们都是从LoggingDecorator继承的,它实现了ILogger.因此,没有记录器知道任何其他记录器.

我的问题是:我应该如何处理日志记录异常？

如果写入文件失败,或发送电子邮件失败,我该怎么办？我想用其他记录器记录初始日志内容,但是如何处理日志记录异常呢？它不依赖于构造函数中记录器的顺序吗？

现在,我只是使用空catch(Exception)语句来包装try/catch块,这只会感觉很脏并且让FxCop对我大喊大叫.然而,这是"依赖"的时刻吗？

[Flags]
public enum LoggingCategories
{
    None = 0,
    ServiceEvents = 1, 
    ProcessingInformation = 2,
    ProcessingErrors = 4,
    UnexpectedErrors = 8
}

public interface ILogger
{
    void LogMessage(LoggingCategories category, string message);
}

public abstract class LoggerDecorator : ILogger
{
    private ILogger _decoratedLogger;
    private LoggingCategories _categories;

    protected LoggerDecorator(ILogger logger, LoggingCategories categories)
    {
        this._decoratedLogger = logger;
        this._categories = categories;
    }

    protected bool ShouldLogCategory(LoggingCategories category)
    {
        return ((this._categories & category) == category);
    }

    public virtual void LogMessage(LoggingCategories category, string message)
    {
        _decoratedLogger.LogMessage(category, message);
    }

}

public class ControlLogger : ILogger
{
    public ControlLogger()
    {
    }

    public void LogMessage(LoggingCategories category, string message)
    {
        Console.WriteLine(LoggingHelper.ConstructLog(category, message));
    }
}

(WindowsEventLogger中有问题的代码)

try
{
    this._eventLog.WriteEntry(log, type);
}
catch (Exception)
{
    //Even if this logging fails, we do not want to halt any further logging/processing.
}

(服务构造函数中的代码)

ILogger controlLogger = new ControlLogger();
ILogger windowsEventLogger = new WindowsEventLogger(controlLogger, windowsEventLogCategories, windowsEventLogSource);
ILogger emailLogger = new EmailLogger(windowsEventLogger, emailCategories, emailSubject, emailAddresses);
ILogger fileLogger = new FileLogger(emailLogger, fileCategories, logDirectory, logFileNamePrefix, logFileExtension);

this._logger = fileLogger;

Answer 1

如果记录器失败,为什么不将它放在实际的Windows事件日志中？