Custom logger on AS 6

[nickarls]

Hi,

  I've played around with a custom log4j-logger but so far, no go. What I've done:

I've packed my logger in a jar in <JBOSS_HOME>/server/default/lib, the logger looks something like

public class DummyLogger extends AppenderSkeleton

{

          @Override

          public void close()

          {

          }

          @Override

          public boolean requiresLayout()

          {

                    return true;

          }

          @Override

          protected void append(LoggingEvent event)

          {

                    System.out.println("Logging " + event.getMessage() );

          }

}

and included in jboss-logging.xml like

<log4j-appender name="DUMMY" class="concept.DummyLogger">

                    <error-manager>

                              <only-once/>

                    </error-manager>

                    <level name="DEBUG"/>

                    <formatter>

                              <pattern-formatter pattern="%d %-5p [%c] (%t) %m%n"/>

                    </formatter>

</log4j-appender>

and

   <root-logger>

      <level name="${jboss.server.log.threshold:DEBUG}"/>

      <handlers>

         <handler-ref name="CONSOLE"/>

         <handler-ref name="FILE"/>

         <handler-ref name="DUMMY"/>

      </handlers>

   </root-logger>

Am I missing something trivial?

[nickarls]

If I make a typo in the class name the AS reacts so I guess the class is picked up. It's not just getting any action. And the documentation on loggers on AS 6 was a bit...thin that last time I checked...

[jaikiran]

Just to check whether it's the logging level which is preventing the call to your append method, try adding this method to that appender:

@Override
public void doAppend(LoggingEvent event) {

  System.out.println("Custom appender invoked");
  super.doAppend(event);
}  

[nickarls]

I don't get any output, I've tried fiddling with most thresholds I could find...

[nickarls]

Does anyone have an example of a custom logger + jboss-logging.xml that shows how the log levels are set up (and info on if you use jboss logging, slf4j or what for application logging)?

[nickarls]

I tried uncommenting the SMTP logger, add the handler ref to the root logger and set it's threshold to INFO for a boot. I didn't get any warnings about wrong mail server etc (kept the default values).

[nickarls]

log4j appender? working? anyone?

[jaikiran]

Let me give it a try this week, if no else gets there by then. If you have something ready that I can easily test/reuse, please attach it here.

[nickarls]

I have a dummy logger (attached) that basically just does

public class DummyLogger extends AppenderSkeleton

{

   public void close()

   {

   }

   public boolean requiresLayout()

   {

      return true;

   }

   @Override

   protected void append(LoggingEvent event)

   {

      System.out.println("Custom appender invoked");

      super.doAppend(event);

   }

}

I add it to the root logger (copied from SMTP definition) and logging shows up for console and file but nothing from here. FQCN is jboss.logtest.DummyLogger

[jaikiran]

There is more than one issue in here.

1) jboss-logmanager doesn't report a error which makes it look like the appender is just not picked up. org.jboss.logmanager.LoggerNode has this:

void publish(final ExtLogRecord record) {
        for (Handler handler : handlers) try {
            handler.publish(record);
        } catch (VirtualMachineError e) {
            throw e;
        } catch (Throwable t) {
            // todo - error handler
        }
        if (useParentHandlers) {
            final LoggerNode parent = this.parent;
            if (parent != null) parent.publish(record);
        }
    }

Notice the Throwable catch block. That's where it's ending up currently.

2) The real issue is that the jboss-logmanager-log4j project is incompatible with the version of log4j (1.2.14) that's shipped in JBoss AS. The jboss-logmanager-log4j requires 1.2.15 http://anonsvn.jboss.org/repos/common/jboss-logmanager-log4j/trunk/pom.xml and runs into a:

16:17:24,763 ERROR [STDERR] java.lang.NoSuchMethodError: org.apache.log4j.spi.LoggingEvent.<init>(Ljava/lang/String;Lorg/apache/log4j/Category;JLorg/apache/log4j/Level;Ljava/lang/Object;Ljava/lang/String;Lorg/apache/log4j/spi/ThrowableInformation;Ljava/lang/String;Lorg/apache/log4j/spi/LocationInfo;Ljava/util/Map;)V

in the org.jboss.logmanager.log4j.ConvertedLoggingEvent constructor:

public final class ConvertedLoggingEvent extends LoggingEvent {
...
public ConvertedLoggingEvent(final ExtLogRecord rec) {
        super(rec.getLoggerClassName(),
                new DummyCategory(rec.getLoggerName()),
                rec.getMillis(),
                LevelMapping.getPriorityFor(rec.getLevel()),
                rec.getMessage(),
                rec.getThreadName(),
                rec.getThrown() == null ? null : new ThrowableInformation(rec.getThrown()),
                rec.getNdc(),
                new LocationInfo(new Throwable(), rec.getLoggerClassName()),
                null);
    }

As a workaround, replace the log4j.jar in JBOSS_HOME/common/lib with 1.2.15 version of log4j.jar and see if it works.

Ah, all these logging frameworks and abstractions - so much fun!

[nickarls]

*facepalm* Well, good thing is not just me ;-)

Empty catch blocks are always nice. e.printStackTrace() is so hard to type...

We need some abstraction for logger abstraction-abstractions. I'll try the log4j replacement trick and let you know. Was there some JIRA born from this?

[jaikiran]

Nicklas Karlsson wrote:

Was there some JIRA born from this?

Haven't yet created one (been busy with a different task). So if you have some time, do create one. Else, I'll do it later tonight.

[nickarls]

Upgrading log4j didn't work. Well, I should really try on a clean server to make sure I haven't broken something else while trying to fix this...

[nickarls]

Correction, now I get hits on the logger!

[jaikiran]

Nicklas Karlsson wrote:

Correction, now I get hits on the logger!

Thanks for verifying that. So I guess, the easiest way to fix this is to upgrade to 1.2.15 of log4j in JBoss AS6. I'll file a JIRA for that.