import com.google.common.base.Stopwatch;
import org.apache.log4j.Level;
import org.apache.log4j.Logger;

import java.util.Random;
import java.util.concurrent.TimeUnit;


public class Log4jRecordGenerator {
    public static void main(String[] args) {

        Logger logger = Logger.getLogger("Log4jRecordGenerator");
        MessageGenerator generator = new MessageGenerator();

        int count = 100000;
        int recordSize = 2; //kb

        Stopwatch stopwatch = Stopwatch.createStarted();

        for (int i = 0; i < count; i++) {
            String msg = generator.buildMessage(i, recordSize * 1024);
            logger.log(Level.toLevel(i % 5 * 10000), msg);
        }

        logger.debug("-----------------  DONE HERE -----------------------");

        long time = stopwatch.elapsed(TimeUnit.MILLISECONDS);
        System.out.println("Time to generate "
                + count
                + " records: "
                + time
                + " milli sec with rate: "
                + Math.round(count / time));
    }

    static public class MessageGenerator {

        Random random = new Random();

        public String buildMessage(long sequence, int length) {
            StringBuilder builder = new StringBuilder(length);
            builder.append('<').append(sequence).append(">\u001F");
            for (int i = 0; i < length; i++) {
                builder.append((char) (random.nextInt(86) + 40));
            }
            return builder.toString();
        }
    }
}


# Simple configuration
#log4j.rootLogger = DEBUG, toFile1
#log4j.appender.toFile1=org.apache.log4j.RollingFileAppender
#log4j.appender.toFile1.File=logs/example.log
#log4j.appender.toFile1.MaxFileSize=1Gb
#log4j.appender.toFile1.MaxBackupIndex=10
#log4j.appender.toFile1.Append=false
#log4j.appender.toFile1.layout=org.apache.log4j.PatternLayout
#log4j.appender.toFile1.layout.ConversionPattern=%d{yyyy-MM-dd'T'HH:mm:ss.SSSXXX}\u001F%p\u001F%m%n