Need a working example of configuring log4j RollingFileAppender via properties

Question

I am using log4j for logging, and a property file for configuration. Currently, my log files are too big (3.5 GB is too large for a log file). So think I need to use RollingFileAppender - but when I do so the log file continues to grow overly large. I believe I have just misconfigured it; does anyone have a working example of configuring RollingFileAppender?

For the record, my current configuration looks like this:

log4j.appender.MAIN_LOG.File=${catalina.base}/logs/webtop.log
log4j.appender.MAIN_LOG=org.apache.log4j.RollingFileAppender
log4j.appender.MAIN_LOG.layout=com.mycompany.util.log.Log4JSimpleLayout
log4j.appender.MAIN_LOG.DatePattern='.'yyyy-MM-dd
log4j.appender.MAIN_LOG.MaxFileSize=10MB
log4j.appender.MAIN_LOG.MaxBackupIndex=99
log4j.appender.MAIN_LOG.append=true
log4j.rootCategory=ALL, MAIN_LOG

An alternative to RollingFileAppender would also be a fine solution.

Answer 1

This seems to work fine for me @mcherm. See below.

Are you sure that you are using the log4j.properties that you think you are? Try changing the .File to another path to see if log output goes to the new file. What version of log4j are you using? I'm running 1.2.15.

Hope this helps.

---

I created the following test program:

package com.j256.ormlite;
import org.apache.log4j.Logger;
public class Foo {
    private static Logger logger = Logger.getLogger(Foo.class);
    public static void main(String[] args) {
        for (int x = 0; x < 10000000; x++) {
            logger.error("goodness this shouldn't be happening to us right here!!!!");
        }
    }
}

My log4j.properties file holds:

log4j.appender.MAIN_LOG=org.apache.log4j.RollingFileAppender
log4j.appender.MAIN_LOG.File=${catalina.base}/logs/webtop.log
log4j.appender.MAIN_LOG.layout=com.j256.ormlite.Log4JSimpleLayout
log4j.appender.MAIN_LOG.MaxFileSize=10MB
log4j.appender.MAIN_LOG.MaxBackupIndex=5
log4j.appender.MAIN_LOG.append=true
log4j.rootCategory=ALL, MAIN_LOG

Notice that I removed the DateFormat which wasn't valid for my RollingFileAppender. My layout is:

package com.j256.ormlite;
import org.apache.log4j.spi.LoggingEvent;
public class Log4JSimpleLayout extends org.apache.log4j.Layout {
    @Override
    public String format(LoggingEvent event) {
        return "log message = " + event.getMessage().toString() + "\n";
    }
    @Override
    public boolean ignoresThrowable() {
        return true;
    }
    public void activateOptions() {
    }
}

Running with -Dcatalina.base=/tmp/ I get files in /tmp/logs/ which go up to index #5 and are 10mb in size. If I tune the MaxFileSize of the MaxBackupIndex, it adjusts appropriately.