In my application, I use log4net, with all types creating their own logger based on their type - e.g. :
private static readonly ILog Log = LogManager.GetLogger(typeof(Program));
As I am developing, I leave the root logger on DEBUG so as to catch all log output from my code.
However, a third party component also uses this same approach, but is generating 100s of log messages a second, none of which I am interested in.
Is it possible to use some sort of wildcarding in the logger configuration, to force all their loggers to only log at WARN, e.g. :
<logger name="com.thirdparty.*">
<level value="WARN"/>
</logger>
[The exact example above, using a * doesn't work]
You can just specify part of a namespace so it will apply to all messages within that namespace (including nested).
Here is the example I often use:
<root>
<level value="FATAL" />
<appender-ref ref="RollingFile" />
</root>
<logger name="MyCompany.Web" >
<level value="WARN" />
<appender-ref ref="WebErrors" />
</logger>
<!-- Will log all FATALs from NHibernate, including NHibernate.SQL and all the nested -->
<logger name="NHibernate" >
<level value="FATAL" />
</logger>
Additionally I would recommend to read the manual. It provides a lot of explanation. For example you can read about Logger Hierarchy. Here is the quote from there:
A logger is said to be an ancestor of
another logger if its name followed by
a dot is a prefix of the descendant
logger name. A logger is said to be a
parent of a child logger if there are
no ancestors between itself and the
descendant logger. The hierarchy works
very much in the same way as the
namespace and class hierarchy in .NET.
and also:
Level Inheritance:
The inherited level for a given logger X, is equal to the first
non-null level in the logger
hierarchy, starting at X and
proceeding upwards in the hierarchy
towards the root logger.
Can't you do the opposite of what you're asking. What I mean is just set the default log level to warn and then set the specific loggers you have defined to DEBUG.
Also, you could set the threshold of your appender to DEBUG and have the other appender set the WARN.
For example:
<appender name="EventLogAppender" type="log4net.Appender.EventLogAppender">
<applicationName value="Application" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
</layout>
<threshold value="WARN" />
</appender>
<appender name="SmtpAppender" type="log4net.Appender.SmtpAppender,log4net">
<to value="asdf#example.com" />
<from value="group#example.com" />
<subject value="Notification" />
<smtpHost value="server01" />
<bufferSize value="1" />
<lossy value="false" />
<layout type="log4net.Layout.PatternLayout,log4net">
<conversionPattern value="%property{log4net:HostName} :: %level :: %message %newlineLogger: %logger%newlineThread: %thread%newlineDate: %date%newlineNDC: %property{NDC}%newline%newline" />
</layout>
<threshold value="DEBUG" />
</appender>
Related
I am trying to make log4net create it's log files in a folder structure, but so far I'm not successful.
What I'd like to accomplish is that log4net creates log files like this:
..\log\2017\10\30-10-2017_eva360Recorder.log
..\log\2017\10\31-10-2017_eva360Recorder.log
..\log\2017\11\01-11-2017_eva360Recorder.log
..\log\2017\11\02-11-2017_eva360Recorder.log
In my app.config I now have the following:
<!-- Log4net Logging Setup -->
<log4net>
<root>
<level value="ALL" />
<appender-ref ref="LogFileAppender" />
</root>
<appender name="LogFileAppender" type="log4net.Appender.RollingFileAppender, log4net">
<file type="log4net.Util.PatternString" value="log\\%date{yyyy}\\%date{MM}\\%date{dd-MM-yyyy}_eva360Recorder.log" />
<appendToFile value="true" />
<rollingStyle value="Date" />
<maxDateRollBackups value="60" />
<datePattern value="dd-MM-yyyy" />
<preserveLogFileNameExtension value="true"/>
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date [%thread] %-5level %logger %M - %message%newline" />
</layout>
</appender>
</log4net>
This, however, results in the following:
d:\Eva360\Recorder\log\2017\10\31-10-2017_eva360Recorder.log
d:\Eva360\Recorder\log\2017\10\31-10-2017_eva360Recorder31-10-2017.log
As you can see, this is not what I wanted. It did not create a month folder (..\2017\11..) and also did not change the name of the log file, but added a date within the file name.
Is what I want even possible?
If so, how should I do that?
And also importantly, where is this to be found in the documentation of log4net?
I realise that this conjecture, rather than a definitive answer, but this could probably be achieved through the use of a custom log4net appender. See IAppender in the log4net SDK.
Google is chock full of articles about creating custom log4net appenders, so no need to repeat anything here.
My main application either starts in a console environment or as a Windows Service, based on certain indicators (launch flags, #if directive,...). As long as the application runs in 'production mode', e.g. without a user context as a startup service, I want to log both in a file (info, warnings) as well as into the Windows event log. However when I'm debugging, I want log messages only been carried out to the console window.
Is there any way to achieve this using log4net that doesn't include touching the application configuration during runtime?
Frankly the code approach doesn't sound like a very good idea to me, since it hides some behavior to the person that will manage the system in the end. Since you probably have two build configurations (release and debug?) why not use them instead to change the configuration file depending on the build you're doing.
If you really don't want to do this, then here is how to do it: you can set a custom property in the global context of your log4net library
// declare this code as soon as you've determined what context you're in
log4net.GlobalContext.Properties["ApplicationMode"] = "Service";
// or 'Console", with an #IF directive
Then in your log4net configuration, you can filter out the messages that will be caught by your appenders by using the PropertyFilter of log4net
The console appender for your dev:
<appender name="ConsoleAppender" type="log4net.Appender.ConsoleAppender,log4net">
<filter type="log4net.Filter.PropertyFilter">
<key value="ApplicationMode" />
<stringToMatch value="Console" />
<acceptOnMatch value="true" />
</filter>
<filter type="log4net.Filter.DenyAllFilter" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date %-5level %-25.25logger{1} - %message%newline" />
</layout>
</appender>
and the file appender for your production
<appender name="FileAppender" type="log4net.Appender.FileAppender,log4net">
<filter type="log4net.Filter.PropertyFilter">
<key value="ApplicationMode" />
<stringToMatch value="Service" />
<acceptOnMatch value="true" />
</filter>
<filter type="log4net.Filter.DenyAllFilter" />
<file value="mylogfile.txt" />
<appendToFile value="true" />
<lockingModel type="log4net.Appender.FileAppender+MinimalLock" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date %-5level %-25.25logger{1} - %message%newline" />
</layout>
</appender>
Then declare all appenders for your logs:
<root>
<level value="DEBUG"/>
<appender-ref ref="FileAppender"/>
<appender-ref ref="ConsoleAppender"/>
</root>
This will dispatch your message to the correct appender depending on the value that is in the global property. The DenyAllFilter is important; log4net works by letting all messages go through by default, and you only want the messages matching your PropertyFilter
All the appenders can be created, modified, or removed programatically. Why not just remove the appenders you want to avoid? This allows you to use the same code for detecting you are debugging and/or running in console.
To programatically disable the appender:
log4net.Appender.IAppender[] appenders = log4net.LogManager.GetRepository().GetAppenders();
for (int i = 0; i < appenders.Length; ++i)
{
Log4net.Appender.FileAppender appender = appenders[i] as log4net.Appender.FileAppender;
if (appender != null && appender.Name == "RollingFile")
appender.Threshold = log4net.Core.Level.Off;
}
I am using log4net for logging, I have two appenders one file and other eventlog appender. I have register application in registry editor, problem is now both logger are writing in event viewer. I need fileAppender to write in file and eventLogAppender to be shown in event viewer.
<log4net>
<appender name="LogFileAppender" type="log4net.Appender.FileAppender">
<file value="file.log"/>
<appendToFile value="false"/>
<layout type="log4net.Layout.PatternLayout">
<header value="Logging Start
"/>
<footer value="Logging End
"/>
<conversionPattern value="%date [%thread] %-5level %logger: %message%newline"/>
</layout>
</appender>
<appender name="EventLogAppender" type="log4net.Appender.EventLogAppender">
<param name="ApplicationName" value="eventlog" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date [%thread] %-5level %logger - %message%newline" />
</layout>
</appender>
<root>
<level value="DEBUG"/>
<appender-ref ref="LogFileAppender"/>
<appender-ref ref="EventLogAppender" />
</root>
</log4net>
and then in code
private static readonly ILog log = LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
// private static readonly ILog log = LogManager.GetLogger("LogFileAppender");
private static readonly ILog logEvents = LogManager.GetLogger("EventLogAppender");
I have tried different things but no one is working, any solution?
Thanks!
In order to use multiple ILog instances with log4net and to log different information to each, you must configure at least two Logger elements in the log4net section of your config file.
In your case, you have two targets that you want - file and event log. I'll call them FileLogger and EventLogger.
Here is an example of the additional configuration you need in the log4net section:
<logger name="FileLogger">
<level value="ALL" />
<appender-ref ref="LogFileAppender" />
</logger>
<logger name="EventLogger">
<level value="ALL" />
<appender-ref ref="EventLogAppender" />
</logger>
Then, to use each one in code, instantiate them like so:
private static readonly ILog fileLogger = LogManager.GetLogger("FileLogger");
private static readonly ILog eventLogger = LogManager.GetLogger("EventLogger");
Note that the ref attribute of the appender elements matches the name attribute of the appenders you have already configured and that the name passed to GetLogger matches the name attribute of the logger elements.
I built an application and want to use logging in my application before giving it out to a user to know the actions the user did in case before any error. I haven't used logging before, so I did a bit of study to find out good methods for the same and perhaps Trace class in .NET looks like what might help in this scenario.
Using a text file seems to be a better idea here for the logging setting a TextWriterTraceListener in the App.Config file of my project, and using in the code Trace.Writeline("Error info", "Field");
1) Even after reading good amount of content, I am not sure about good approaches for logging? Should there be different error logger and information logging files? How does logging work for specifying different types of error (such as warning, critical, error etc.?)
2) I want to use the same logfile in one of my other projects in the solution. So, do I add the same Trace Listener section in the App.Config of my project?
With a logging library (such as log4net), you can do all the things you are asking about easily. You can set up your logging in a config file to go to event log, file, console, etc (or any combination) and set the logging levels independently.
That is, you can say the file will have informationals, warnings, errors, and fatals, but the event log will log only the errors and fatals.
In general, nearly all of the logging libraries have these features. The examples below are just in terms of log4net but the same concepts apply to most logging libraries...
To get the logger in any class in your solution, you just need to ask for a logger in your class:
public MyClass
{
private static readonly ILog _log = log4net.LogManager.GetLogger(typeof(MyClass));
public void SomeMethod()
{
_log.Debug("This is a debug message.");
_log.Info("This is an informational message.");
_log.Warn("This is a warning message.");
_log.Error("This is an error message.");
_log.Fatal("This is a fatal message.");
}
}
In addition, you can filter based on the loggers, that is, you could suppress log messages from paraticular classes or only display logging messages for a subset of classes, etc.
A sample config settings block would look like this. This creates a rolling file appender (keeps several days worth of logs) and Console appender
<log4net>
<appender name="RollingFileAppender" type="log4net.Appender.RollingFileAppender">
<file value="c:\logs\AgentLog"/>
<appendToFile value="true"/>
<datePattern value=".yyyy-MM-dd"/>
<rollingStyle value="Date"/>
<MaxSizeRollBackups value="14"/>
<param name="StaticLogFileName" value="false"/>
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%d{HH:mm:ss.fff} [%thread] %-5level %logger{1} - %m%n"/>
</layout>
</appender>
<appender name="ColoredConsoleAppender" type="log4net.Appender.ColoredConsoleAppender">
<mapping>
<level value="FATAL"/>
<foreColor value="Yellow"/>
<backColor value="Red, HighIntensity"/>
</mapping>
<mapping>
<level value="ERROR"/>
<foreColor value="Red, HighIntensity"/>
</mapping>
<mapping>
<level value="WARN"/>
<foreColor value="Yellow, HighIntensity"/>
</mapping>
<mapping>
<level value="INFO"/>
<foreColor value="Green, HighIntensity"/>
</mapping>
<mapping>
<level value="DEBUG"/>
<foreColor value="White"/>
</mapping>
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%d{HH:mm:ss.fff} [%thread] %-5level %logger{1} - %m%n"/>
</layout>
</appender>
<root>
<level value="INFO"/>
<appender-ref ref="RollingFileAppender"/>
<appender-ref ref="ColoredConsoleAppender"/>
</root>
</log4net>
When you have 2 appenders, say one for debug errors and one for product errors, in your code, do you explicitly create 2 log classes or is an appender basically going to write any log messages that meet a certain criteria?
So in your code, you use a single log method, and depending on how your appenders are setup, it will log the message if it e.g. is logged from a specific namespace, or is a certain log level.
So its possible a single log entry is written to 2 log files?
Yes, you can have single log statements post to multiple appenders. As long as it meets the criteria for each, it will use each appender.
For example, take this config section, it logs all messages to file, and also logs warnings and errors to event viewer.:
<log4net>
<appender name="RollingFileAppender" type="log4net.Appender.RollingFileAppender">
<file value="c:\logs\MySite"/>
<appendToFile value="true"/>
<datePattern value=".yyyy-MM-dd.\l\o\g"/>
<rollingStyle value="Date"/>
<MaxSizeRollBackups value="14"/>
<param name="StaticLogFileName" value="false"/>
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%d{HH:mm:ss.fff} [%thread] %-5level %logger{1} - %m%n"/>
</layout>
</appender>
<appender name="EventLogAppender" type="log4net.Appender.EventLogAppender">
<applicationName value="Trading.Web"/>
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%d{HH:mm:ss.fff} [%thread] %-5level %logger{1} - %m%n"/>
</layout>
<filter type="log4net.Filter.LevelRangeFilter">
<param name="LevelMin" value="WARN"/>
<param name="LevelMax" value="ERROR"/>
</filter>
</appender>
<root>
<level value="DEBUG"/>
<appender-ref ref="RollingFileAppender"/>
<appender-ref ref="EventLogAppender" />
</root>
</log4net>
So this:
_log.Debug("This is a debug message");
Will only appear in the log file (because it doesn't meet the event log appender's filter criteria).
But this:
_log.Error("This is an error message.");
Will log to both the log file and the event viewer.
UPDATE: On your filtering question, if you had:
<root>
<level value="DEBUG"/>
<appender-ref ref="RollingFileAppender"/>
</root>
<!-- Print only messages of level WARN or above in the namespace Com.Foo -->
<logger name="Com.Foo">
<level value="WARN" />
</logger>
Then all things under Com.Foo will log if WARN or higher, but everything else would log at DEBUG or higher....