#log4net

もともとlog4netの内部には以下のレベルがあるみたい。

EMERGENCY

FATAL

ALERT

CRITICAL

SEVERE

ERROR

WARN

NOTICE

INFO

DEBUG

FINE

TRACE

FINER

VERBOSE

Xamarin Studio나 MonoDevelop에서 Project Root에 App.config 안에 때려넣으면 알아서 로딩해주신다. App.config는 Build Action, Quick Property 설정 안해줘도 됨.

Configure log4Net for VB.net or C#.net

Download log4Net from apache http://logging.apache.org/log4net/

Add log4Net.dll to your project reference

Add following code to web.config under tab

<!--Root Logger is for all logger--> <!-- --> Check all the level

把log4net拷贝到类库项目A根文件夹，然后在类库项目A中引用log4net.dll。然后将以下黑体配置信息添加到正式项目B（引用类库的项目A的项目）中。

现在还有两个问题，一个是配置文件中同时写入log文件和SQLServer数据库，但是实际中不稳定，数据库不写入。第二个问题是没有学会把log4net的所有配置独立放在一个log4net.config文件中给app.config瘦身。

类库项目A中的日志类

using System; using System.Collections.Generic; using System.Linq; using System.Text;

[assembly: log4net.Config.XmlConfigurator(Watch = true)] namespace TestLog4Net {    public class LogHelper    {        /// <summary>        /// 输出日志到Log4Net        /// </summary>        /// <param name="t"></param>        /// <param name="ex"></param>        #region static void WriteLog(Type t, Exception ex)

       public static void WriteLog(Type t, Exception ex)        {            log4net.ILog log = log4net.LogManager.GetLogger(t);            log.Error("Error", ex);        }

       #endregion

       /// <summary>        /// 输出日志到Log4Net        /// </summary>        /// <param name="t"></param>        /// <param name="msg"></param>        #region static void WriteLog(Type t, string msg)

       public static void WriteLog(Type t, string msg)        {            log4net.ILog log = log4net.LogManager.GetLogger(t);            log.Error(msg);        }

       #endregion

   } }

web.config

<?xml version="1.0" encoding="utf-8"?> <!--  有关如何配置 ASP.NET 应用程序的详细信息，请访问  http://go.microsoft.com/fwlink/?LinkId=152368  --> <configuration>

 <configSections>    <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net"/>  </configSections>  <log4net>    <!--定义输出到文件中-->    <appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender">      <!--定义文件存放位置-->      <file value="log\\"/>      <appendToFile value="true"/>      <rollingStyle value="Date"/>      <datePattern value="yyyy\\yyyyMM\\yyyyMMdd'.log'"/>      <staticLogFileName value="false"/>      <param name="MaxSizeRollBackups" value="100"/>      <layout type="log4net.Layout.PatternLayout">        <!--每条日志末尾的文字说明-->        <!--输出格式-->        <!--样例：2008-03-26 13:42:32,111 [10] INFO  Log4NetDemo.MainClass [(null)] - info-->        <conversionPattern value="%newline %n记录时间：%date %n线程ID:[%thread] %n日志级别：  %-5level %n出错类：%logger property: [%property{NDC}] - %n错误描述：%message%newline %n"/>      </layout>    </appender>    <appender name="ADONetAppender" type="log4net.Appender.ADONetAppender">      <bufferSize value="10" />      <connectionType value="System.Data.SqlClient.SqlConnection, System.Data, Version=1.0.3300.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />      <connectionString value="server=localhost;database=CYTDWebChat;uid=sa;pwd=sasa;timeout=300;" />      <commandText value="INSERT INTO log ([dtDate],[sThread],[sLevel],[sLogger],[sMessage],[sException]) VALUES (@log_date, @thread, @log_level, @logger, @message, @exception)" />      <parameter>        <parameterName value="@log_date" />        <dbType value="DateTime" />        <layout type="log4net.Layout.RawTimeStampLayout" />      </parameter>      <parameter>        <parameterName value="@thread" />        <dbType value="String" />        <size value="50" />        <layout type="log4net.Layout.PatternLayout">          <conversionPattern value="%t" />        </layout>      </parameter>      <parameter>        <parameterName value="@log_level" />        <dbType value="String" />        <size value="200" />        <layout type="log4net.Layout.PatternLayout">          <conversionPattern value="%p" />        </layout>      </parameter>      <parameter>        <parameterName value="@logger" />        <dbType value="String" />        <size value="200" />        <layout type="log4net.Layout.PatternLayout">          <conversionPattern value="%logger" />        </layout>      </parameter>      <parameter>        <parameterName value="@message" />        <dbType value="String" />        <size value="2000" />        <layout type="log4net.Layout.PatternLayout">          <conversionPattern value="%m" />        </layout>      </parameter>      <parameter>        <parameterName value="@exception" />        <dbType value="String" />        <size value="2000" />        <layout type="log4net.Layout.ExceptionLayout" />      </parameter>    </appender>    <root>      <level value="ERROR"/>      <level value="WARN"/>      <level value="INFO"/>      <level value="DEBUG"/>      <level value="FINE"/>      <!--文件形式记录日志-->      <appender-ref ref="ADONetAppender" />      <appender-ref ref="RollingLogFileAppender"/>    </root>  </log4net>

 <appSettings>    <add key="ClientValidationEnabled" value="true"/>    <add key="UnobtrusiveJavaScriptEnabled" value="true"/>    <add key="test" value="testvalue"/>  </appSettings>

 <system.web>    <compilation debug="true" targetFramework="4.0">      <assemblies>        <add assembly="System.Web.Abstractions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />        <add assembly="System.Web.Helpers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />        <add assembly="System.Web.Routing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />        <add assembly="System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />        <add assembly="System.Web.WebPages, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />      </assemblies>    </compilation>

   <authentication mode="Forms">      <forms loginUrl="~/Account/LogOn" timeout="2880" />    </authentication>

   <pages>      <namespaces>        <add namespace="System.Web.Helpers" />        <add namespace="System.Web.Mvc" />        <add namespace="System.Web.Mvc.Ajax" />        <add namespace="System.Web.Mvc.Html" />        <add namespace="System.Web.Routing" />        <add namespace="System.Web.WebPages"/>      </namespaces>    </pages>  </system.web>

 <system.webServer>    <validation validateIntegratedModeConfiguration="false"/>    <modules runAllManagedModulesForAllRequests="true"/>  </system.webServer>

Is there a way to redirect Log4Net output to the ASP.NET Trace listener

I have a significant amount of logging code throughout our codebase which uses log4net. Generally this is logged to an external output file. In this case I would like to know if there is a log4Net configuration change I could make to get this log information to show up in the ASP.NET pages trace output.

I’m just looking to redirect the output, not implement a different type of logging.

Be…

How to configure NHibernate logging with log4net in code, not in xml file?

Relying on this doc http://nhforge.org/wikis/howtonh/configure-log4net-for-use-with-nhibernate.aspx it is quite easy to configure NHibernate logging through log4net by using XML config files.

But i need to do the same in C# code.

Best Answer

This answer is based on How to configure log4net programmatically from scratch (no config). However, since that answer only provides a solution for the…

If you are a Java developer and for some reason have to develop a .Net application you probably heard about Log4net. Rotating log files is awesome and the framework is pretty much easier to be consumed by your application.

Recently I started a project based on ELK stack (Elasticsearch + Logstash + Kibana). Our java projects are able to send the log messaging to a logstash forwarder (or shipper) through log4j2 SocketAppender easily, having all processed messages “persisted” into an elasticsearch instance with all metrics computed and all the data ready in a “queriable” state. Goal has been achieved.

Not so far… after that, we had to support some .Net applications. The adventure starts here.

The project architecture basically follows the “standard” logstash architecture where:

there is a logstash instance acting as a forwarder.

all logging messages are stored into a redis queue.

a logstash indexer instance process all messages, ignoring debug messages and applies metrics filters over all TRACE messages.

If you pay attention about the third bullet you may notice there is an IMPORTANT project convention: “all TRACE messages are considered something to be measured”. The problem is log4net does not provide TRACE method capabilities!

The good part is this can be “workarounded” if you build a extension. Just need to implement a static class called ILogExtensions and trace method will be available for all your applications Something like…

using System; namespace log4net {     namespace Ext {         public static class ILogExtentions          {             //private static readonly log4net.ILog log = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);             public static void Trace(this ILog log, string message, Exception exception)             {                 log.Logger.Log(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType,log4net.Core.Level.Trace, message, exception);             }             public static void Trace(this ILog log, string message)             {                 log.Trace(message, null);             }         }     } }

This strategy may be useful if you decide to implement other log categories like Critical, Fine, Alert… Just don’t forget to add have your extension namespace added in the classes will use your custom methods. Otherwise, they won’t will be available.

Once this little problem was solved, the second one was found: log4net does not has SocketAppender. Apparently, UdpAppender would be enough. Some testes were made, no issue found. But we can’t forget the concepts: you can’t trust on UDP because it was not supposed to be this way. Wen I decided to test sending about 2 millions of messages about 10% of the logging events didn’t reach the forwarder, even when running all on same server (127.0.0.1).

Besides that, I was not in the mood to:

implement my own logging lib.

configure logstash to monitor the log4net rotating file.

configure a different input on logstash because few .Net applications.

As an alternative, I decided to implement a SocketAppender for log4net. The best part is log4net allows you to do such kind of thing by your own. The “receipt” basically is:

create your own appender user log4net AppenderSkeleton as your base class.

override ActivateOptions method if your appender needs to “reserve”/prepare some resources or configure when log4net starts.

override Append method to determine the logic of “appending”. Don’t forget logging is about appending something to somewhere.

override onClose method to release resources. This is VERY IMPORTANT to avoid having the TCP port stuck and not having your stuff being disposed properly.

using System; using System.Text; using System.Net;  using System.Net.Sockets;  using log4net.Core; using log4net.Appender; namespace log4net {     namespace Appender {         public class SocketAppender : AppenderSkeleton         {             // properties set by log4net xml config file             public string remoteAddress { get; set;}             public int    remotePort { get; set;}             public bool   debugMode { get; set;}             // this is the socket (you don’t say!)             private Socket sender = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);             // connect to a remote device             public override void ActivateOptions() {                 // Establish the remote endpoint for the socket.                 try {                     sender.Connect (remoteAddress, remotePort);                 } catch (ArgumentNullException ane) {                     Console.WriteLine(“ArgumentNullException : {0}”,ane.ToString());                 } catch (SocketException se) {                     Console.WriteLine(“SocketException : {0}”,se.ToString());                 } catch (Exception e) {                     Console.WriteLine(“Unexpected exception : {0}”, e.ToString());                 }             }             protected override void Append(LoggingEvent loggingEvent) {                 string rendered = ”“;                 // check connectivity before send                 if (sender.Connected) {                     // Renderizing event                     rendered = RenderLoggingEvent (loggingEvent);                     // Encode the data string into a byte array.                     byte[] msg = Encoding.UTF8.GetBytes(rendered);                     // Send the data through the socket.                     int bytesSent = sender.Send(msg);                     if (debugMode) {                         Console.WriteLine (“- Bytes sent: ” + bytesSent.ToString());                     }                 } else {                     // accumulate?!                     Console.WriteLine (“[SKIPPED]:: ” + rendered);                 }             }             protected override void OnClose() {                 sender.Shutdown (SocketShutdown.Both);                 sender.Close ();             }         }     } }

Things will happen “magically” and your appender will be available to be configured in your log4net.config file with no issues.

<?xml version=”1.0” encoding=”utf-8” ?> <configuration>   <configSections>     <section name=”log4net” type=”log4net.Config.Log4NetConfigurationSectionHandler,log4net”/>   </configSections>   <log4net>     <appender name=”ConsoleAppender” type=”log4net.Appender.ConsoleAppender”>         <layout type=”log4net.Layout.PatternLayout”>             <conversionPattern value=”[%property{log4net:HostName}][%-5level] %date{ISO8601} [%thread]::%logger - %message%newline” />         </layout>         <filter type=”log4net.Filter.LevelRangeFilter”>             <levelMin value=”INFO”/>         </filter>     </appender>     <appender name=”SocketAppender” type=”log4net.Appender.SocketAppender”>         <remoteAddress value=”localhost” />         <remotePort value=”9500” />         <layout type=”log4net.Layout.PatternLayout, log4net”>             <conversionPattern value=”%property{log4net:HostName} %level %date{ISO8601} %thread %logger - %message%newline” />         </layout>     </appender>     <root>         <level value=”Trace” />         <appender-ref ref=”ConsoleAppender” />         <appender-ref ref=”SocketAppender” />     </root>   </log4net> </configuration>

THE TRICKY PART: how to read additional attributes from xml file nad make them available to be used by my appender? As you can see, remoteAddress and remotePort are configurable and we need to set them to have our appender working properly.

Don’t worry. Your job is create properties inside your appender class with same name! Log4net will do the job and then, you can avoid logging events loss through a TCP, reusing same input configured in logstash for log4j or log4j2.

The full code of this example can be found on github (CLICK HERE). Log4net-extensions project provides TRACE method and SocketAppender. I hope it helps someone who faced the same issues I did.

Fixed log4net vs. Nlog #dev #it #asnwer

log4net vs. Nlog

Anyone have experience for both? How do they stack up against each other?

We are planning on using one of them for logging in an enterprise application.

References:

log4net

nlog

EDIT: We have no existing dependencies to either nlog or log4net.

Answer: log4net vs. Nlog

I think the general consensus is that nlog is a bit easier to configure and use. Both are quite capable, though.