[slf4j-user] Per-web-app logging with jars on the server's classpath

[Ceki Gülcü]

Hi Mark,

I have not looked at the code closely, but in any case you need to tell 
log4j that it should use your context selector class which is can be done 
by specifying a system property. Are you doing that?

At 12:15 PM 3/13/2007, Mark Stralka wrote:
>Jacob Kjome <hoju <at> visi.com> writes:
>
> >
> >
> > It doesn't much matter what the config file looks like, but what your
> > custom repository selector is doing.  Clearly it isn't working,
> > otherwise you'd have separate logger repositories and no cross-talk
> > between application-specific logger repositories.  So, what does your
> > implementation look like?  How it the repository selector
> > installed?.  How are you configuring each repository?  Where are your
> > config files?  Where's Log4j?
> >
> > Jake
> >
> > At 06:59 PM 3/12/2007, you wrote:
> >  >We have a custom web framework packaged into a jar file
> > (myframework.jar) that
> >  >is used by 50 web applications deployed as WAR files on Weblogic 8.1 SP4.
> >  >myframework.jar uses the Spring framework internally (which uses commons
> >  >logging API), so we must continue to use SLF4J's 
> jcl104-over-slf4j-1.3.0.jar
> >  >for the foreseeable future.  None of these web apps use EJBs and I 
> want to
> >  >avoid them.
> >  >
> >  >myframework.jar, log4j.jar, slf4j*.jar spring.jar, and dozens of 
> other 3rd
> >  >party dependencies are loaded on Weblogic's server classpath.
> >  >myframework.jar is under continual development by my team and we can't
> >  >redeploy every WAR file with the new version of libraries in 
> WEB-INF/lib -
> >  >so we have to load myframework and other JARs on weblogic's classpath.
> >  >Each web app has very few Java classes of its own - most are 
> Spring-injected
> >  >from myframework.jar.
> >  >
> >  >This has proven to be an interesting puzzle because we want each web 
> app to
> >  >write to its own log file (appA.log, appB.log, etc), but be able to 
> record
> >  >log entries from classes inside myframework.jar, spring.jar, etc for
> >  >debugging purposes.
> >  >
> >  >I bought the Log4J book, read Chapter 8, and followed the JBoss 
> instructions
> >  >here http://wiki.jboss.org/wiki/Wiki.jsp?page=Log4jRepositorySelector
> >  >to create a custom RepositorySelector (which loads
> > /WEB-INF/log4j.properties),
> >  >and modified myframework's StartupListener to initialize this
> >  >RepositorySelector in each web app's web.xml.
> >  >
> >  >The problem is that when I start weblogic with several webapps (appA.war,
> >  >appB.war, appC.war, etc), all log entries are written to appA.log, even
> >  >though each application has its own WEB-INF/log4j.properties (albeit they
> >  >are currently all the same, except for the "log4j.appender.file.File" 
> value).
> >  >
> >  >Am I doing something wrong to keep JAR files at the server level but let
> >  >each web app write to its own log file?  Thank you
> >  >
> >  >Here is appA's log4j.properties file:
> >  >log4j.rootLogger=warn, file
> >  >
> >  >### direct messages to file <app name>.log ###
> >  >log4j.appender.file=org.apache.log4j.DailyRollingFileAppender
> >  >log4j.appender.file.DatePattern='.'yyyy-MM-dd
> >  >#Each app should go to its own log file but they are not
> >  >log4j.appender.file.File=c:/logs/appA.log
> >  >log4j.appender.file.layout=org.apache.log4j.PatternLayout
> >  >log4j.appender.file.layout.ConversionPattern=%d{dd MMM yyyy HH:mm:ss,SSS}
> >  >%5p %C{1} - %m%n
> >  >
> >  >log4j.logger.org.apache.struts=error
> >  >log4j.logger.org.apache.commons=error
> >  >log4j.logger.org.apache.jcs=error
> >  >log4j.logger.org.springframework=error
> >  >log4j.logger.org.hibernate=error
> >  >log4j.logger.org.acegisecurity=error
> >  >
> >  >#Make sure you turn logging off before deploying to staging or 
> production.
> >  >log4j.logger.com.myframework.core=debug
> >  >
> >  >_______________________________________________
> >  >user mailing list
> >  >user <at> slf4j.org
> >  >http://www.slf4j.org/mailman/listinfo/user
> >
>
>
>public class JbossAppRepositorySelector implements RepositorySelector {
>         private static boolean initialized = false;
>         private static Object guard = LogManager.getRootLogger();
>         private static Map repositories = new HashMap();
>         private static LoggerRepository defaultRepository;
>
>         public static synchronized void init(ServletConfig servletConfig)
>         throws ServletException {
>                 init(servletConfig.getServletContext());
>         }
>
>         public static synchronized void init(ServletContext servletContext)
>         throws ServletException {
>                 if (!initialized) // set the global RepositorySelector
>                 {
>                         defaultRepository = LogManager.getLoggerRepository();
>                         RepositorySelector theSelector = new 
> JbossAppRepositorySelector();
>                         LogManager.setRepositorySelector(theSelector, guard);
>                         initialized = true;
>                 }
>
>                 Hierarchy hierarchy = new Hierarchy(new 
> RootCategory(Level.DEBUG));
>                 loadLog4JConfig(servletContext, hierarchy);
>                 ClassLoader loader = 
> Thread.currentThread().getContextClassLoader();
>                 repositories.put(loader, hierarchy);
>         }
>
>         public static synchronized void removeFromRepository() {
> 
>repositories.remove(Thread.currentThread().getContextClassLoader());
>         }
>
>         // load log4j.xml from WEB-INF
>         private static void loadLog4JConfig(ServletContext servletContext,
>                 Hierarchy hierarchy) throws ServletException {
>                 String log4jFile = null;
>                 InputStream log4JConfig = null;
>                 Properties properties = new Properties();
>                 PropertyConfigurator conf = new PropertyConfigurator();
>                 try {
>                         log4jFile = "/WEB-INF/log4j_webapp.properties";
>                         log4JConfig = 
> servletContext.getResourceAsStream(log4jFile);
>                         properties.load(log4JConfig);
>                         conf.doConfigure(properties, hierarchy);
>                 } catch (Exception e) {
>                         throw new ServletException(e);
>                 }
>         }
>
>         private JbossAppRepositorySelector() {
>         }
>
>         public LoggerRepository getLoggerRepository() {
>                 ClassLoader loader = 
> Thread.currentThread().getContextClassLoader();
>                 LoggerRepository repository = (LoggerRepository) 
> repositories.get(loader);
>                 if (repository == null) {
>                         return defaultRepository;
>                 } else {
>                         return repository;
>                 }
>         }
>}
>
>
>com.myframework.web.StartupListener:
>public void contextInitialized(ServletContextEvent event) {
>         ...
>         JbossAppRepositorySelector.init(event.getServletContext());
>         ...
>}
>
>_______________________________________________
>user mailing list
>user at slf4j.org
>http://www.slf4j.org/mailman/listinfo/user

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Ceki Gülcü
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