多个appender log4net配置

Question

对于log4net newb问题，很抱歉，这看起来像一个常见的设置，但是我找不到一个例子。

我正在尝试使用我的log4net配置获得以下设置:

两个输出源:

• File_Appender -> log4net.Appender.RollingFileAppender
• Smtp_Appender -> log4net.Appender.SmtpAppender
  (评估器阈值设置为ERROR)

许多伐木工

:

• 所有日志(根)-> INFO,WARN,ERROR -> File_Appender
• 所有日志记录器(根)-> ERROR -> Smtp_Appender
• 特定记录器-> DEBUG -> File_Appender
• 特定记录器-> INFO -> Smtp_Appender

我不确定如何配置"根"记录器以将不同级别的日志记录到不同的appender(我不想显式地配置每个记录器以将错误记录到Smtp_Appender)。

Answer 1

我最终使用了自己的appender过滤器，它允许为显式指定的记录器设置较低的匹配级别:

public class MultipleLevelFilter : LevelMatchFilter
{
    public MultipleLevelFilter()
    {
        LevelToMatchForSpecificLoggers = Level.Fatal;
        _specificLoggers = new string[0];
    }
    /// <summary>
    /// Gets or sets the level to match for loggers
    /// specified in the <see cref="SpecificLoggers"/> property.
    /// </summary>
    /// <value>The level to match for specific loggers.</value>
    public Level LevelToMatchForSpecificLoggers { get; set; }
    private string[] _specificLoggers;
    /// <summary>
    /// Gets or sets a comma separated list of "specific" loggers.
    /// For these loggers, <see cref="LevelToMatchForSpecificLoggers"/>
    /// property is checked to see whether they should be logged.
    /// </summary>
    /// <value>The specific loggers.</value>
    public string SpecificLoggers 
    {
        get { return string.Join(",", _specificLoggers); }
        set
        { 
            _specificLoggers = value.Split(',').Select(s=>s.Trim()).ToArray();
        }
    }
    /// <summary>
    /// Tests if filter matches the specified logging event.
    /// </summary>
    /// <param name="loggingEvent">the event to filter</param>
    public override FilterDecision Decide(LoggingEvent loggingEvent)
    {
        // if base.LevelToMatch is matched, always match
        if (loggingEvent.Level >= LevelToMatch)
           return AcceptOnMatch ? FilterDecision.Accept : FilterDecision.Deny; 
        // if specific level is matched, check if logger name matches
        if (loggingEvent.Level >= LevelToMatchForSpecificLoggers)
        {
            string name = loggingEvent.LoggerName;
            for (int i = 0; i < _specificLoggers.Length; i++)
                if (name == _specificLoggers[i])
                    return AcceptOnMatch ?
                        FilterDecision.Accept : FilterDecision.Deny;
        }
        // continue with next filter
        return FilterDecision.Neutral;
    }
}

用法:

<appender name="Smtp_Appender" 
     type="Ster.Log4Net.DelayedSendSmtpAppender">
  <!-- ... common properties (from, to, etc) -->
  <!-- our custom filter -->      
  <filter type="MyNamespace.MultipleLevelFilter">
    <!-- this level is ALWAYS matched -->
    <levelToMatch value="ERROR" />
    <!-- this level is matched only for specific loggers -->
    <levelToMatchForSpecificLoggers value="INFO" />
    <!-- these are the "specific" loggers (comma separated) -->
    <specificLoggers value="SomeLogger, SomeOtherLogger" />
  </filter>
  <!-- always end the filter chain with DenyAll -->
  <filter type="log4net.Filter.DenyAllFilter" />
</appender>
<root>
  <priority value="INFO" />
  <appender-ref ref="File_Appender" />
  <appender-ref ref="Smtp_Appender" />
</root>