I would like to have a company wide log4net configuration file but allow individuals to add additional appenders to their on application. How can I setup Log4Net to incorporate all appenders (from the system wide and the application specific).
I have considered reading in both xml documents and dynamically writing out a combined one but this seems error-prone.
Ideas??
The solution is to build a class that merges all the log4net sections in an in-memory XmlDocument and pass this to log4net.
The implementation of this class and its usage can be found on:
http://www.kopf.com.br/kaplof/using-multiple-configuration-files-with-log4net
Related
How do I attach logback to smartfox server?
smartfox uses log4j by default. How can I shift logging of my extensions/all of smartfox to logback?
I've tried this but this is failing with this error cause it has already boud to log4j I guess.
SmartFoxServer 2x uses Simple Logging Facade for Java (SLF4J) for logging. The very purpose of SLF4J is to provide a facade over the logging framework so the user can replace one logging framework with another. In your case log4J with Logback. I'll first explain how SLF4J works and how you can change one logging framework with another and briefly discuss some caveats. Then I'll cover some SmartFoxServer specifics.
Simple Logging Facade for Java Architecture
SLF4J provides API which serves as facade (abstraction layer) over the actual logging framework. This allows the user to easily switch between frameworks on deployment time without the need to change the code. But it also means that SLF4J on its own is not enough - the default implementation is no-op. In order to actually log anything you need actual logging framework (such as log4j or logback) and so called "binder" which servers as a bridge or adapter between SLF4J and the logging framework.
Swapping Logging Frameworks
The SLF4J User Manual provides detailed explanation on how you can swap one framework with another during deployment time. In short you just need to delete the old binder and logging framework and add the new binder and the new logging framework. To swap log4 with logback you need to delete slf4j-log4j12 and log4j jars and add logback-classic and logback-core.
Caveats
You should make sure that there is only one binder implementation in the classpath. Having more than one causes waring, not error. SLF4J would just pick one of the implementations. But I would not rule out the possibility for this to cause issues with more complex application (such as SmartFoxServer) that uses multiple class loaders. But more importantly you should make sure the SLF4J API, the binder and the logging framework versions are compatible. For example if you use old version of SLF4J with newer version of logback that may cause ClassNotFoundException. I suspect that this could be reason why you get the error you see.
Swapping lof4j with Logback as logging framework for SmartFoxServer 2x
SmartFoxServer 2x version 2.17.3 uses SLF4J API version 1.7.5. To swap log4j you need to first delete lib/slf4j-log4j12-1.7.5.jar and then add compatible version of logback-classic and logback-core jars. For example logback-classic 1.1.0 and logback-core 1.1.0.
You can delete lib/log4j-1.2.15.jar but I would rather keep it. The binder(lib/slf4j-log4j12-1.7.5.jar) is not meant to be used directly so it should be safe to be deleted. On other hand there are libraries that use log4j directly. I don't know if SmartFoxServer 2x uses any such library but it is safer to keep it just in case. Swapping the binder is enough for SLF4J to use Logback and ignore log4j.
Logger Output
SmartFoxServer 2x parses the logger output to provide some functionality such as the Admin Log Viewer. If you change the log output this may cause this functionality to stop working and maybe even cause other issues (on theory it should not, but you never know). There is configuration file (config/logParser.properties) that would allow you to configure the log parser, but I didn't found any documentation about it. You may try to ask on the SmartFoxServer forum. The developers are actually pretty active there so they may help.
Swapping loggers only for your extension
The instruction I gave swaps the logger for all extensions and SmartFoxServer. If you want you may try to swap them only for your extensions. But I'm not quite sure if and how that would work. Each class extension uses its own class loader but this provides isolation between extensions and SmartFoxServer and extensions, but not between extension and SmartFoxServer. What does this mean is that if you add lib.jar to Extension A classpath it would not be visible to Extension B or to SmartFoxServer code. But if you add lib.jar to the SmartFoxServer classpath it would be visible to both Extension A and Extension B. As SmartFoxServer already contains SLF4J API on its classpath you should not add it to your extension classpath. You can try to add logback-classic and logback-core to you extension classpath. But in this case you'll have two binder implementations in you extension classpath (logback and log4j from the SmartFoxServer classpath). As already discussed, I'm not quite sure how and if this would work.
Conclusion
SLF4J provides an easy way to swap logging frameworks, but there some caveats. And SmartFoxServer adds some caveats on its own. Unless SmartFoxServer team supports swapping of the underlaying logging framework (which judging by some anwers in their forum, they don't), I would be quite careful and do such swap only if there are some benefits and it is not just a matter of personal preference.
I have a C# custom appender library which needs to be used by several applications in different solutions which run in the same server. I have an addon installer solution that creates all the folders and stuffs which includes the custom appender library, which the other projects needs to use. Instead of adding this library into all the application's directory, I just want to let the each application's App.Config to point to this single custom appender library.
I have built a custom appender call MyCustomAppender in a library call MyCustomLibrary.dll.
Here is the xml code of one of the App.Configs:
<appender name="MyCustomAppender" type="MyCustomerLibrary.MyCustomAppender, C:\Users\Admin\Libraries\MyCustomLibrary">
It is not possible for me to put the path of the library because Log4net doesn't work this way. Is there a walk around for each application to point to C:\Users\Admin\Libraries\MyCustomLibrary.dll? to use the MyCustomAppender? The other applications needs to have 0 code changes, only their App.Config can be modified due the the reason this process needs to have minimal changes.
You can add the dll to the GAC on the machine your application is runnen. This will allow all programs to find the dll. BTW, coping the dll into the bin directory of the application will not change the code of the application.
Can I have multiple log4net configurations for the same program? Functionality similar to Spring's <import> element would be optimal. The idea here would to have multiple programs that have their own log4net configuration, as well as sharing a central log4net configuration file containing a shared error log (so that definition isn't repeated). Alternatively is this functionality possible with .NET Common Logging?
Related: log4net - configure using multiple configuration files
you can achieve this by using named repositories i think
log4net.LogManager.CreateRepository(repositoryName)
log4net.Config.XmlConfigurator.Configure(repositoryName, configFile)
then by using
LogManager.GetLogger(repositoryName,loggerName)
you can get the corresponding logger.
Not out-of-the-box. You must implement yourself the merging of different config files into a single XmlNode and pass this to log4net XmlConfiguratot.
An example is to be found here: http://www.kopf.com.br/kaplof/using-multiple-configuration-files-with-log4net
I am learning log4j. I have seen the <category> tag in the xml configuration file but could find nothing information about it's subelements(children) and attributes.
Could anyone, please, tell me, how to use this tag and what do it's parameters do?
Maybe there are some usefull link?
The answer is:
One of the common requirement in Java projects, that are using Log4j logging, is to have different log files for each module (or layer) in the project. For example, if you have a web application, you may want to log the debug/info messages from the service layer to a service.log file and the log messages from the presentation layer to the web-app.log file and so on. This is very simple to achieve in Log4j.
Log4j has a concept called Category using which you can classify a package as a category and assign a appender to that category alone.
I have linqpad referencing one of my own assemblies which uses log4net. When linqpad calls my assembly method I am setting my log4net logging levels to ERROR yet I see debug level messages from my assembly showing up in the linqpad results area.
Anybody know what causes this? Does Linqpad use log4net itself or have any special behavior with log4net?
LINQPad uses SharpDevelop which has a dependency on log4net, but this is kept pretty well isolated to the UI domain and shouldn't have any effect on your queries.
How are you configuring log4net? Is it programmatically or via an application config file? If it's the latter, the application config file should be named linqpad.config in order to be picked up by your queries.
I was having trouble with my configuration not being picked up. Creating a separate Linqpad.config (not editing LINQPad's own!) is the key bit of info I was missing - thanks Joe. Fantastic app by the way!